2016-10-11 Assigned to ENDOTRONIX, INC. reassignment ENDOTRONIX, INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: VITAL SENSORS HOLDING COMPANY INC.
An anchored implantable pressure monitor.
This application is a continuation of U.S. application Ser. No. 11/515,915, filed Sep. 6, 2006, hereby incorporated herein by reference, which incorporates by reference U.S. provisional application Ser. No. 60/738,980, filed Nov. 23, 2005, and U.S. provisional application Ser. No. 60/773,344, filed Feb. 15, 2006. This application also hereby incorporates herein by reference U.S. application Ser. No. 11/452,920, filed Jun. 15, 2006.
The invention is directed generally to a method and apparatus and for sensing a characteristic of a patient, such as blood pressure and/or temperature, and more particularly to methods and devices particularly adapted for telemetric measurement of blood pressure by a device implanted via a catheter within the cardiovascular system and particularly within the heart.
The National Institute of Health (NIH) has concluded that heart failure constitutes "a new epidemic" in the USA. Heart failure, a chronic, progressive and incurable disease, affects over 20 million people worldwide. In the US alone, some 5 million people have been diagnosed with heart failure. Heart failure is estimated to cost the US economy today more than $40 billion annually.
Various sensors and devices have been used or proposed for the measurement and analysis of the blood pressure and/or temperature of a patient with mixed success. The currently contemplated sensors have certain disadvantages. For example, the telemetric sensor described in U.S. Pat. No. 6,855,115 can be implanted in the heart by a catheter. Moreover, the sensor, which is rolled up during the implantation procedure, must be made of a flexible material of a specific configuration so that any change of the blood pressure inside the heart effectuates a change in the distance of the sensor height, i.e., the distance between the two capacitor plates used in the sensor. This flexible sensor is folded for delivery via a catheter and then unfolded at the place of implantation. However, a disadvantage of such a configuration is its required flexibility as constant and precise acquisition of measurement data may not be possible when the sensor is placed on or close to the cardiac muscle, and therefore is exposed to the cardiac motions, which may influence correct pressure readings. In addition, the flexible material of a sensor made in accordance with U.S. Pat. No. 6,855,115 may deform due to exposure to constantly streaming liquids, especially a turbulent blood stream likely encountered inside the heart. As a consequence, the capacitance of the capacitor may be changed and measurement values may deteriorate and/or deviate from the true value. Another disadvantage of this type of sensor is due to its use of a pressure-dependent LC-oscillator. The resonant frequency of this oscillator can be analyzed telemetrically. In principle, this kind of device can be applied to measure the pressure that affects the measurement capacitor. Thus, any damage to the material can affect the pressure measurements obtained. Further, as the sensor is influenced by the surrounding media of the sensor, a corruption of measurement values may occur. In addition, there is no circuitry in this type of sensor to digitize the pressure measurement values acquired. Using analog signals may result in external interference during the acquisition and transmission of data, which causes inaccuracies in readings.
Another exemplary implantable device, described in U.S. Pat. No. 6,409,674, uses a catheter filled with a pressure transmitting fluid or gel-like material. The catheter transmits pressure to a pressure transducer within a housing. The sensed pressure is then telemetrically transmitted to an external reader. However, such a device requires a housing for the electronic signal processing circuitry, which results in a larger and heavier sensor structure that can cause strain on the heart when implanted into a heart wall. Moreover, the catheter and housing configuration creates a more complicated, mechanical structure that may be at increased risk for mechanical failure, and therefore is not suitable for long term implantation.
Another device, described in U.S. Pat. No. 6,970,742, has a pressure sensor placed within the heart. A signal from the pressure sensor is transmitted to a housing outside the heart which contains the electronic processing circuits. The signal is processed by the electronic processing circuits, such as converting the signals from analog to digital, and then telemetrically transmitted to an external reader. However, housing the electronic processing circuitry requires additional components and a relatively larger implanted device. Moreover, because digitization of the signal does not occur until outside of the heart, there is a risk of interference in the wire connecting the sensor and the electronic processing circuitry, as analog interference may result from external sources.
Small pressure sensor chips including the electronic processing circuits have been used in other applications. For example, integrated chips having pressure sensors have been used for pressure measurement in optical and cranial applications. These sensors are compact and have fewer mechanical components. Examples of such pressure sensor chips are described in EP 1 312 302 A2 and German Pat. application DE 10 2004 055 220.7, of which the inventors of the present invention were involved. However, these integrated chips are used in a relatively stable environment, with little movement in the fluids of the eye or brain. Nor are these pressure sensors subject to the cyclical, dynamic movements found in the heart. Such movement may harm connections, such as connections between wires and the pressure sensing chip. Thus, the use of such pressure sensor chips is not suited for the environment of the heart, where there is cyclical and dynamic movement, and where there is continuous and turbulent fluid movement around the pressure sensor.
Thus, there is a need for intra-cardiac pressure sensors that are more reliable and accurate, and which cause less irritation when implanted in the heart and are more compatible with the dynamic conditions encountered in a moving heart. Also, a need exists for such a sensor to be used at other locations within the cardiovascular system with little or no modifications.
The invention meets the above needs and avoids the disadvantages and drawbacks of the prior art by providing a substantially rigid, chip-based telemetric sensor and system in which an extremely small and lightweight chip, including at least one pressure sensor and all necessary electrical circuitry, may be placed in the heart or other portion of the cardiovascular system via a catheter or other minimally-invasive procedure, to monitor blood pressure and/or temperature.
To protect the ASIC and particularly the membrane sensor elements from damage during the implantation procedure, such as strain and stress due to bending of the tip of the catheter during insertion and/or unfolding of the antenna, or from damage due to handling, e.g., as a consequence of contact with a surgical instrument during implantation and/or during use, the sensor design may have a unique geometry. For example, the ASIC may be connected to a substantially rigid substrate in a spaced apart relationship from the ASIC such that the substrate is opposite the pressure sensing elements of the sensor chip, with an aperture in the substrate providing access to the pressure elements to expose them to fluid pressure to be sensed. A silicone or other similar flexible material may be disposed between the ASIC and the substrate. Moreover, a pressure transmitting material may be placed within the gap between the ASIC and the rigid substrate so that pressure from the blood can be transmitted to the pressure elements via the material.
The invention may be implemented in a number of ways. According to one aspect of the invention, an intra-cardiac pressure measuring system for measuring blood pressure inside the cardiovascular system of a patient includes an antenna and an integrated chip including a first substantially rigid substrate, at least one pressure sensor disposed within the substrate to generate signals indicative of a sensed pressure, and electronic signal processing components to process the signals generated by the at least one pressure sensor. The electronic signal processing components are operatively connected to the antenna, and the integrated chip is powered by a signal received at the antenna. An anchor structure mounts the integrated chip to a wall in the cardiovascular system such that the at least one pressure sensor is exposed to blood. A remote receiver is provided such that the integrated chip is operative to send digital signals indicative of the pressure sensed in the heart telemetrically via the antenna to the remote receiver. The antenna, the integrated chip and the anchor structure are sized to fit within a delivery catheter for implantation in the cardiovascular system.
According to another aspect of the invention a method of sensing blood pressure within the cardiovascular system of a subject includes the steps of: implanting within the subject a substantially rigid, integrated chip minimally-invasively using at least one catheter, the integrated chip including a substantially rigid substrate and at least one capacitive-based pressure sensor disposed within the substrate in a position to sense blood pressure within the cardiovascular system; powering on the integrated chip telemetrically by activating a power source located outside the subject; obtaining one or more analog signals from the at least one pressure sensor indicative of the pressure at the position in the cardiovascular system; and converting the analog signals to digital signals at or directly adjacent to the position in the cardiovascular system where the sensing occurs.
FIG. 4 illustrates a greatly enlarged, plan view of a substantially rigid ASIC constructed according to principles of the invention for sensing intra-cardiac pressure and temperature including active and passive, capacitive membrane sensing elements and on-chip electronics for digital signal processing and telemetrical power supply.
FIG. 35 is a block diagram of the major electronic components of an external reader constructed according to the principles of the invention for telemetrically receiving data from an implanted sensor chip.
FIG. 1 schematically illustrates an embodiment of an implantable telemetric measuring device and reader constructed according to principles of the invention providing for continuous or regular intra-cardiac pressure monitoring. A coil or antenna 14 connected with an external reader 12 generates a radio frequency (RF) field in a manner known in the art. The coil 14 and external reader 12 may be fixed to individual belts that wrap around the patient and connect to each other via a standard cable. The RF field induces a current in a coil 18 connected to a substantially rigid sensor chip 20, such as described herein, implanted within the heart 16 of the patient 10, such as the septum or the wall of the left atrium, to sense pressure in the left atrium. The sensor chip 20 may consist of an application specific integrated circuit (ASIC) such as described herein, having power conditioning circuitry that detects when adequate power is being delivered and switches on sensing, analog-to-digital, and data processing circuits. The data processing circuitry sends the sensor data to the ASIC transmitter, which uses the coil 18 as an antenna. The coil 18 telemetrically transmits, via signal 22, the data to the antenna 14 of the external reader 12. The external reader 12 may provide secure reception and storage of pressure and temperature values, compare the pressure reading of the implanted device 20 to ambient pressure via an internal sensor in the reader, and deliver the intracardiac data to other devices, such as computers, personal digital assistants (PDAs), cell phones, etc., via standard protocols.
FIG. 2 schematically illustrates another embodiment of an implantable telemetric measuring device and reader, which may operate similarly to the FIG. 1 embodiment but provides for on demand intra-cardiac pressure monitoring according to principles of the invention. In this embodiment, a coil 28 in a hand-held reader 26 generates an RF field that induces a current in the coil 18 of the substantially rigid sensor chip 20 implanted within the heart 16 of the patient 10, as in the FIG. 1 embodiment. As described above, sensor chip 20 may include an ASIC that operates similarly to the FIG. 1 embodiment. Thus, power conditioning circuitry in the sensor chip 20 detects when adequate power is being delivered, and turns on the sensing, analog-to-digital, and data processing circuits. The data processing circuitry sends the sensor data to the ASIC transmitter, which uses the coil 18 as an antenna. The coil 18 transmits, via signal 24, the data to the antenna 28 of the hand-held reader 26. The hand-held reader 26 may be extendable to expose the antenna 28 and provides reception and storage of pressure and temperature values, and compares the implant's pressure reading to ambient pressure via an internal sensor in the readout device. The hand-held device 26 may deliver the intracardiac data to other devices, such as computers, PDAs, cell phones, etc., via standard protocols.
FIG. 3 illustrates a cross-sectional view of the heart area of a patient where the implanted device may be employed, including the left and right atrium and the crossing of veins at the posterior septum. The heart 30 has a right atrium 32 and a left atrium 34, which are divided by the septum 36. As described in more detail herein, it may be advantageous to locate and/or anchor the implantable sensor chip 20 at the septum 36 separating the right atrium 32 and the left atrium 34, such that a portion of the sensor 20 extends into the chamber to be sensed, e.g., the left atrium 34. The implantable device may work as a short-term implant as well as a long-term implant. Furthermore, an embodiment of the invention may be implanted at the "Waterston's groove" near the access of the pulmonary vein or any other locations of the heart or in larger vessels near the heart chosen by the doctor. The implantable sensor chip 20 also may be designed to facilitate ready removal of the device if medically necessary.
FIG. 4 illustrates a substantially rigid sensor ASIC constructed according to principles of the invention for sensing intra-cardiac pressure and temperature in any of the embodiments of the invention. The ASIC 400 contains pressure sensing elements 402, such as eight passive sensors 404 and eight active sensors 406, temperature sensor 408, an analog-to-digital (A/D) converter 410, data transmission circuitry 412, power conditioning circuitry including components such as smoothing and resonance capacitors (not shown), a digital state control 414 including a code redundancy check for secure data transmission and memory 416, such as Electrically Erasable Read-Only Memory (EEPROM) cells, for unit identification, which are components known in the cart. An example of the suitable ASIC structure is described in U.S. Pat. Nos. 5,321,989 and 5,431,057, the contents of which are expressly incorporated by reference in their entirety.
According to the principles of the invention, the ASIC 400 should be an extremely small and lightweight chip to avoid placing undue stress on the heart and/or producing turbulent flow in the heart chamber(s). For example, an ASIC particularly adapted for use in the embodiments described herein as being implanted during open catheter procedure should weigh less than fractions of a gram, have a surface area of less than or equal to about 10 mm2 per side, and a thickness of about ¼ mm to about 1 mm. In one advantageous embodiment, the ASIC may be about 2 mm wide by 5 mm to 8 mm long by about 250 to 800 microns thick. According to an embodiment of the invention, it may be advantageous to have the ASIC 400 be no more than about 2 mm wide to facilitate delivery of a sensor system including the ASIC 400 via a catheter. Moreover, it may be desirable to break the chip into two or more parts, as described subsequently. Other dimensions may also be used depending upon the particular application or location in the cardiovasculature where the sensing will occur and depending upon the delivery method. In general, the dimensions of the ASIC 400 may range from about 1.5 mm to about 8 mm long, about 0.6 mm to about 2.5 mm wide, and about 0.2 mm to about 1.3 mm high. Other dimensions, such as an ASIC that is substantially square, may also be used.
In the embodiment of the invention shown in FIG. 4, the ASIC 400 includes sixteen capacitive pressure sensors cells 402, eight of which are active pressure sensors 406 and provide pressure data, and eight of which are passive pressure sensors 404 and act as an internal reference. The pressure sensor cells 402 may include minute, flexible membranes that are housed within the substantially rigid ASIC structure as shown schematically in FIG. 5. Specifically, the active pressure sensors 406 have flexible membranes 424 and passive pressure sensors 404 have flexible membranes 426. The membranes 424 of the active pressure sensors 406 are distortable based on the level of cardiac blood pressure. The distortion may be mainly in a direction generally perpendicular to the planar top surface of the ASIC 400. The distortion may be determined based on capacitive measurements or by use of distension measuring tapes. By way of one specific exemplary embodiment, the sixteen capacitive pressure sensing elements 402 of the ASIC 400 may each be about 96 microns in diameter.
Thus, the blood pressure measuring process may be a capacitive pressure measurement process via measuring membranes 424, 426 that are integrated into the ASIC 400, such as the planar top surface of the chip as shown in FIG. 5. The ASIC 400 may have a substantially inflexible, substrate made of silicon that cannot be folded or rolled up. The thin, but mechanically inflexible substrate creates a mechanically stable device providing a substantially rigid structure to house the measuring membranes 424, 426 as shown in FIG. 5. Changes in the geometry of the ASIC 400, such as twisting due to blood turbulences, may be avoided due to this substantially rigid, chip-based configuration, even when the ASIC 400 is exposed to turbulent, blood flow. Thus, the implanted ASIC 400 provides a durable device capable of withstanding the internal environment of the heart and other locations in the cardiovasculature without producing dangerous stresses within the heart.
Numerous small membranes 424, 426 having relatively small dimensions (e.g., a diameter of less than 0.2 mm) may be used as capacitive pressure sensors. Such small dimensions may result in membranes 424 that are less vulnerable to mechanical forces, such as the force of blood flow within the heart, and therefore more reliable.
In accordance with drift compensation principles of the invention, a plurality of active sensors 406 and a plurality of passive sensors 404 are provided, such as eight of each. According to an embodiment of the invention, the structure of the active sensors 406 and the structure of the passive sensors 404 are identical. However, as illustrated in FIG. 5, the membranes 424 of the active sensors 406 are open to the sensing environment (e.g., a heart chamber) for sensing pressure, while the membranes 426 of the passive sensors 404 are isolated from the environment, e.g., by placing a glass layer 428 or other suitable material over the surface of the membrane 426 so that pressure in heart will not affect the passive sensors 404. Both the active sensors 406 and passive sensors 404 are affected substantially the same by age, usage and sagging and any other effects of the environment. Using the passive sensors 404, the ASIC 400 may determine how much of the change in position of the pressure sensor membrane 426 is effected by the age and sagging. The change in capacitance based on the change in position of the passive pressure sensor membrane 426 is determined. This amount is then used to offset the change in capacitance measured in the active pressure sensor membrane 424. This system allows the change in capacitance due the pressure within the heart to be more accurately determined. Compensating for drift may allow a doctor or patient to better determine short term (e.g., days, weeks) trends in pressure within the patient, such as the heart.
FIG. 6 is a cross-sectional view of the ASIC 402 of the invention with a gel or fluid between a sheathing and the active pressure sensors 406. As described above, a glass substrate 428 or other suitable material isolates the passive pressure sensors 404. A liquid or gelatinous pressure transmitting medium 432 is used between sheathing 430 and the active pressure sensors 406. As will be described below, this liquid or gelatinous medium 432 may improve the measurement or reception of blood pressure values within the chamber to be sensed, e.g., within the left atrium. Even though fibrous tissue or plaque may grow in the area of the implant over time (e.g., months or years after the implantation), encapsulating the pressure sensors within a separate gel-filled membrane may allow reliable measurement values to still be obtained.
Thus, as illustrated in FIG. 6, the surface of the active pressure sensors 406 are coated with a gel or fluid 432 and encapsulated in the membrane 430. In this manner, endothelia growth or plaque on the membrane 430 directly over the surface of one of the active pressure sensors 406 will have a reduced or negligible effect on the pressure sensor measurement, as the pressure is transmitted via the endothelia growth and the membrane 430 through the gel/fluid 432 to the active pressure sensors 406. Further, plaque growth and/or endothelialization on the entire surface would still allow pressure sensing measurements to be obtained, as the pressure exerted on the endothelia is transmitted via the gel/fluid 432 to the active pressure sensors 406. In particular, the gel/fluid filled membrane 430 may function to integrate the change in pressure over a larger area than the individual active pressure sensors 406 themselves. This minimizes the effects of endothelialization and/or plaque adherence to the sheathing 430. Although sheathing 430 is shown as only covering the gel/fluid 432, it is understood that the sheathing 430 or other sheathings could cover part or all of sensor chip 400, as described below.
In addition, the fully digitized data can be handled for more easily by data transmission systems, making the external readers compatible with computer, Internet and telemedicine interfaces. For example, highly accurate pressure sensors and a 9-bit analog-to-digital converter may impart high resolution to the sensing systems, where an accuracy of about +/−2 mm Hg or less may be achieved.
The operation of the ASIC 400 is based on the interaction between a connected antenna and an external reader according to well-known principles of transponder technology. Therefore, no internal power source is required. The ASIC 400 and the external reader may be tuned so that continuous measurements, e.g. up to 120 single measurements per second, may be processed and transmitted. As described above in FIG. 1, the total system may be programmed so that measurements are taken and stored in given intervals or at defined time periods. Retrieval, monitoring, and recording of data may be possible at any time.
The ASIC 400 may be formed from a single complementary metal oxide semiconductor ("CMOS") chip to produce a smaller implantable device then with other methods, and help minimize power use and maximize measurement accuracy reliability. Since the consumption of power produces heat, minimization of power may be desirable in implantation applications. In a one-chip solution, the ASIC 400 may be highly resistant to mechanical or electrical interference from the outside, as there is no interaction between multiple chips.
An integrated temperature sensor 408 may be provided in the ASIC 400 to allow for temperature sensing as shown in FIG. 4. The temperature sensor 408 may use the circuit in the ASIC 400 and base the temperature measurement on current characteristics within the circuit, thereby determining the temperature in the heart based on the temperature based current characteristics within the ASIC 400. Each ASIC 400 may be individually calibrated to determine its current characteristics (magnitude, frequency, etc.) at a given temperature (e.g., body temperature). As the temperature changes, the current characteristics within the ASIC 400 change. Using the information on the current characteristics and the specific calibration determination for the ASIC 400, the temperature at a particular time can be determined based on current characteristics at that time. The raw pressure data must be corrected for temperature and other external and/or internal influences, and calibration information, such as a calibration curve of the embedded chip, may be established for each ASIC 400 or system that implements an ASIC 400. Each ASIC may have a unique identification number to facilitate calibration and use of data as discussed below.
The ASIC 400 includes a data memory 416, such as the EEPROM cells, in which the unique identification number may be stored. This identification number is transmitted telemetrically together with the measurement values. The identification number may be used to determine the appropriate calibration information for an ASIC 400. Also, a single external reader may then be used to interrogate multiple implanted ASICs, as described below.
The ASIC 400 also includes a bi-directional power circuitry 424 for working with the reader to evaluate the strength of the signals sent between the reader and the ASIC 400. The components in the bi-directional power circuitry 424 interact with a reader to ensure that appropriate signal strength and data transmission is achieved. The interaction between the bi-directional power evaluation module 424 and the reader is described in greater detail below with respect to FIG. 35.
Although the ASIC 400 of FIG. 4 has been described in a one chip solution, it is understood that multiple chips may be used to implement the functionality of the invention. By way of example, a first ASIC may include the pressure sensing membranes and digitization circuitry, while the telemetric and transmission circuitry may be located on a second ASIC. Moreover, the multiple chips may be located in different portions of the heart to provide information about the absolute pressure at different locations within the heart, as well the differential pressure between different locations. By way of example, the first ASIC may be located in the left atrium and the second ASIC may be located in the right atrium. Such a chip configuration may be similar to that found in FIG. 34. Other configurations may also be used.
FIGS. 7 and 8 schematically illustrate an embodiment of an implantable sensor chip 700 of the invention including a substantially rigid sensor chip connected at two ends to a substantially rigid substrate 708 having a cut out. A sensor chip 702, such as ASIC 400, includes pressure sensing membranes 704 and four spaced chip bond pads 706. A substantially rigid substrate 708 having an aperture 710 and bond tracks 712 connected to bond pads 706 are also provided. The substrate 708 is configured in a spaced apart relationship to the sensor chip 702. More particularly, the aperture 710 of the substrate 708 is located substantially opposite of the capacitive pressure membranes 704 of the sensor chip 702 so pressure from the blood surrounding the device may be transmitted readily to the pressure membranes 704. A pressure transferring material (not shown) may be located at the aperture 710 to ensure that pressure from the blood is transferred to the pressure membranes 704.
The sensor chip 702 and the substrate 708 may be configured in a fixed relationship, so that the distance, or offset, between the sensor chip 702 and the substrate 708 does not change. The chip bond pads 706 may be connected to the substrate bond pads 712 to fix the distance between the sensor chip 702 and the substrate 708. As shown in the embodiment of FIGS. 7 and 8, the sensor chip 702 and the substrate 708 both have four bond pads. However, it is understood that other amounts of bond pads may also be used.
FIGS. 9 and 10 schematically illustrate another embodiment of an implantable sensor chip including a substantially rigid sensor chip connected at one end to a substantially rigid substrate having a cut out. The device 900 of FIGS. 9 and 10 has similar components and operation to the device 700 illustrated in FIGS. 7 and 8. However, device 900 has chip bond pads 906 located in generally close proximity to each other at one end of the sensor chip 902. In addition, the substrate bond pads 912 are generally located in close proximity to each other on the substrate 908. When the chip bond pads 906 and the substrate bond pads 912 are connected, the sensor chip 902 and the substrate 908 are fixed at one end, with the other free end being supported in a cantilevered manner. This arrangement of chip bond pads 906 and substrate bond pads 912 may reduce stress on the sensor chip 902, as changes in the size of the substantially rigid substrate 908, such as due to thermal expansion, may have less of an effect on the sensor chip 902 due to the location of the chip bond pads 906 on the sensor chip 902.
FIG. 11 is a perspective illustration of an implantable sensor chip such as the FIGS. 7 and 8 or FIGS. 9 and 10 embodiments showing the electrical wire and core filament connection to the ASIC and antenna. The device 1100 includes a substantially rigid sensor chip 1102 having pressure membranes 1104, and a substantially rigid substrate 1108 with an aperture 1110 exposing the pressure membranes 1104. A pressure transmitting material 1112, such as a liquid or gelatinous material, is located within the aperture 1110 to transmit pressure from the blood to the pressure membranes 1104. The entire device 1100 is enclosed by a biocompatible sheathing 1106, such as silicone. In addition, the sheathing 1106 can also be used as the pressure transmitting material 1112 within the aperture 1110.
Substrate 1108 may further include connector holes 1120 for facilitating attachment of an antenna connector 1114 to the substrate 1108 and the sensor chip 1102. The connector 1114 includes electrical wires 1116 and a filament core 1118, such as nylon. Electrical wires 1116, which may be formed of gold cable, or other appropriate material, provide an electrical connection between the sensor chip 1102 and an antenna (not shown). Electrical power from the antenna may be conducted via the electrical wires 1116 to the sensor chip 1102 for powering the sensor chip 1102 to obtain measurements. Signals, such as pressure measurements and identification indicia, may be transmitted over the electrical wires 1116 from the sensor chip 1102 to the antenna for transmission to a reader. The filament core 1118 provides strength to the connector 1114 to reduce or eliminate strain on the connection between the substrate bond pad (not shown) and the electrical wires 1116. By way of example, this type of strain relief may be implemented in a connection between two implanted chips or between the chip and the coil. The filament core may be made of nylon or other similar, synthetic flexible material that does not conduct electricity and has a low coefficient of thermal expansion. This connection will now be described in greater detail below with reference to the examples of FIGS. 12-14.
FIGS. 12 and 13 illustrate an implantable sensor chip 1200 with a cut out located at an edge of the substantially rigid substrate, including a cable and core filament connection. The implantable device 1200 includes a substantially rigid sensor chip 1202 having pressure membranes 1204. In this embodiment, the capacitive pressure membranes 1204 are located near the edge of one side of the sensor chip 1202. The device 1200 further includes a substantially rigid substrate 1208 having connector holes 1220 and a cut out 1210 opposite of the pressure membranes 1204. A pressure transmitting material 1212 is located within the cut out 1210 to transmit pressure from the blood to the pressure membranes 1204. The device 1200 is surrounded by a biocompatible sheathing 1206, such as silicone. According to a preferred embodiment of the invention, the pressure transmitting material 1212 may be the same as the sheathing material 1206.
The device 1200 further includes a connector 1214 which includes electrical wires 1216 and a filament core 1218. The electrical wires 1216, which may be formed of gold, or any other suitable similar material, connect to substrate bond pads 1222, and the substrate bond pads 1222 are connected to chip bond pads 1224. This results in an electrical connection between the electrical wires 1216 and the sensor chip 1202. The filament core 1218 may be attached directly to the substrate 1208, such as by an adhesive. As shown in FIG. 13, the filament core 1218 is threaded through the connector hole 1220 for attachment to the substrate 1208 such that the electrical wires 1216 have extra slack when the filament core 1218 is pulled straight. This configuration may reduce or eliminate the strain on the connection between the electrical wires 1216 and the substrate bond pad 1222 when there is movement of either the connector 1214 or the substrate 1208. Moreover, such methods for providing strain relief may be used in embodiments employing two or more chips such as relief to a wire connecting two chips. Any other method providing for strain relief known in the art of electrical wires 1216 may also be used.
FIGS. 14 and 15 schematically illustrate an implantable sensor chip with a cut out located at an edge of the substrate and a protective barrier wall located at one end of the substrate. The device 1400 has a substantially rigid sensor chip 1402 having capacitive pressure membranes 1404 (shown in FIG. 15). The device 1400 further includes a substantially rigid substrate 1408 having a cut out 1410 located substantially opposite the pressure membranes 1404. A chip bond pad 1418 on the sensor chip 1402 is connected to a substrate bond pad 1420 of the substrate 1408 in a conventional manner. The device 1400 is encapsulated in a biocompatible sheathing 1406.
FIG. 16 schematically illustrates a cross sectional view of a further embodiment of a barrier wall formed as an end cap at one end of the sensor chip. The device 1600 has a sensor chip 1602 having capacitive pressure membranes 1604. The device 1600 further includes a substrate 1608 having a cut out 1610 located substantially opposite the pressure membranes 1604. A chip bond pad 1618 on the sensor chip 1602 is connected to a substrate bond pad 1620 of the substrate 1608 in a conventional manner. The device 1600 may also be encapsulated in a biocompatible sheathing (not shown in FIG. 16).
The substrate 1608 may include a barrier wall 1614 that is substantially perpendicular to the plane of the substrate 1608, as in the prior embodiment. The height of the barrier wall 1614 may be such that the top of the barrier wall 1614 is at or above the top of the sensor chip 1602 when it is attached to the substrate 1608. In addition, the barrier wall includes a top cover 1616 extending inwardly from the top of the barrier wall 1614 substantially parallel to the substrate 1608 over the sensor chip 1602 to provide protection to the top of the sensor chip 1602. Although shown in FIG. 16 as extending over only a small area of the sensor chip 1602, it is understood that the barrier top cover 1616 could extend further, including along the entire length of the sensor chip or beyond. The barrier wall 1614 and the barrier top cover 1616 may provide additional protection to the chip sensor 1602 and the sheathing as discussed above. More specifically, the barrier top cover 1616 may inhibit damage to the sheathing 1606 that could occur by rubbing of sharp edges of the chip sensor 1602 against the sheathing material 1606. In addition, a front portion 1612 of the substrate 1608 is located beyond the barrier wall 1614 and may be tapered to reduce turbulence, as well as aid in the implantation of the device 1600 within the heart, also as discussed above.
FIG. 17 schematically illustrates a sensor chip of the invention encased in a biocompatible sheathing. A sensor chip 1700 includes an ASIC 1704 positioned on a substantially rigid substrate 1702 and encapsulated in a biocompatible sheathing 1706. The sensor system, i.e., the ASIC 1704, substrate 1702, cable (not shown) and antenna (not shown) may be encapsulated in a biocompatible sheathing such as, silicone, polyurethane or other suitable material. The encapsulation of the system preferably is seamless, i.e., has no break or seam. This reduces or eliminates the risk of contamination or damage to the sensor system structure by fluids within the body. By way of example, the thickness of the encapsulation may be in the range of about 0.01 mm to about 0.8 mm. A seamless sheathing may be obtained by seamless molding or by dipping the entire sensor chip 1700 (sensor ASIC, cable and antenna) into the biocompatible material.
The implanted device may be positioned in heart to minimize turbulence of the blood flow within the heart chamber and reactionary forces. As illustrated in FIG. 18, the sensor chip 1700 may be orientated such that its shortest side, such as side 1712, may be positioned to be in the most upstream position in the blood flow path 1716. This presents the minimum area in the blood flow and reduces and/or minimizes currents and reactionary forces caused by the implanted device 1700. This positioning may be done regardless of location of the pressure sensors 1708 on the chip. As illustrated, the longer sides 1710 of the sensor chip 1700 containing the top surfaces of the capacitive pressure membranes 1708 may be parallel to the blood flow 1716.
As illustrated in FIG. 18, the shape of the sheathing surface 1714 also may be curved or shaped, e.g., similar to the football shape shown in FIG. 18, to further reduce the turbulence caused by blood flow 1716 around the sensor chip. The biocompatible sheathing 1708 may be applied to the implanted device 1700 to form the curved surface 1714. Such curves or other shapes may be designed to minimize hydrodynamic forces.
The encapsulation in a fully biocompatible material, such as silicone may result in very little change in the sensitivity of the pressure sensor. Further, a small offset due to the influence of the encapsulation material may be compensated for during calibration. This may allow, for example, measurements of about +/−2 mm Hg or less.
FIG. 19 is a side view of a dual substrate sensor embodiment of the invention illustrating how the shape of the sheathing may be configured to minimize turbulence and reactionary fluid forces in the heart. The implantable device 1900 includes a substantially rigid ASIC 1902 having capacitive pressure membranes 1904 and a substrate 1908 with an aperture 1910 substantially opposite the pressure membranes 1904. As illustrated, the device 1900 is encapsulated in a sheathing 1906. The sheathing 1906 may be made of a biocompatible material, such as silicone, that is flexible so that the pressure from the blood may be transmitted to the pressure membranes 1904. A pressure transmitting material (not shown) may be placed in the aperture 1910 to aid in transmitting the pressure. The sheathing 1906 may be shaped, such as an oval or football configuration, to reduce or eliminate hydrodynamic forces from the blood flow 1912. Again, the smallest sides of the device are orientated into the upstream portion of 1912 of the blood flow.
FIG. 20 is a side view of another embodiment of the invention illustrating how the shape of the sheathing may be configured to minimize turbulence and reactionary fluid forces in the heart. The device 2000 has the same components as the FIG. 19 embodiment and is like-numbered. However, in this embodiment, the sheathing 2006 may be shaped, such as in a rounded triangle configuration, to reduce or eliminate hydrodynamic forces from the blood flow 1912.
FIG. 21 illustrates an embodiment of an implantable telemetric measuring device constructed according to principles of the invention, which is particularly adapted for implantation via catheterization in which the sensor chip and the antenna are located on opposite sides of the septum. For purposes of illustration, the implantable device 2100 is implanted into the cardiac septum 36 in a position to sense pressure in the left atrium of the heart, but may be implanted in a position to sense pressure in any heart chamber or other location in the cardiovasculature such as the pulmonary artery or any of the other great vessels. The implantable device 2100 includes a substantially rigid sensor chip 2102, an antenna structure 2106, and a resilient, anchorage structure 2108. The sensor chip 2102 may be an ASIC 2118; similar to any of the ASICs described above, with pressure sensors 2126. The anchorage structure 2108 is used to affix the implantable device 2100 to the heart, such as to the septum 36. The anchorage structure 2108 includes a connection piece 2104, an anchor 2110, and an anchor clip 2112 and a fixing attachment 2130. In the course of the implantation process, the connection piece 2104 is passed through foramen 40 in the cardiac septum 36 and connects the ASIC 2118 and coil 2106 to the heart wall. The connection piece 2104 may be an oblong element made of polyamide plastic. Other materials known in the art may also be used. As shown, the connection between anchor structure 2108 and connection piece 2104 may be done via anchor clip 2112. Other fasteners which provide a mechanical and/or electrical connection between the anchor structure 2108 with anchor 2110 and the connection piece 2104. The connection piece 2104 and sensor chip 2102 may be connected by fixing attachment 2130. The connection piece 2104 may be embedded into a hermetically sealed, biocompatible sheathing, and may fit snugly into the foramen 40 in the cardiac septum 36. While the connection piece shown FIGS. 21 and 22 passes through the ASIC, it is understood that other structure methods for connecting the sensor and antenna to the heart may also be used, including connections that do not pass through the ASIC, such as a flexible wire or the cables between the antenna and the chip.
As shown in the embodiment of FIG. 21, the anchor 2110 and the anchor clip 2112 are connected to one end of the connection piece 2104. The anchor 2110 resiliently engages the antenna structure 2106 and forces the antenna structure 2106 against the septum 36. FIG. 21 illustrates a minimum distance "d" between the anchor structure 2108 and the sensor chip 2102. The minimum distance "d" may correspond to or be slightly less than the thickness of the cardiac septum 36. When an antenna structure 2106 is placed between anchor structure 2108 and sensor chip 2102, the distance "d" may be enlarged based on the width dimensions of the antenna structure 2106.
As described above, all energy which is required for the acquisition of measurement data may be provided telemetrically by antenna structure 2106. The coil 2114 may be designed as a passive coil. Examples of suitable coils are illustrated in German patents DE 199 45 879 A1 or DE 101 56 469 A1.
As shown in FIGS. 21-22, the sensor chip and the antenna, designed as a passive transponder coil, are arranged separately. In this way, the shape and size of the transponder coil may be independent from the dimensions of the sensor chip. Due to this configuration, the whole implantable device, including the substantially rigid, sensor chip, flexible, transponder coil and electroconductive connection, may be rolled up to a structure with a significantly small diameter. Therefore, the entire telemetric measuring device is suitable for implantation using typical cardiac catheters having narrow lumens, as described subsequently.
FIG. 22 illustrates another embodiment of an implantable telemetric measuring device similar to be FIG. 21 embodiment. FIG. 22 differs from FIG. 21 in that the antenna structure 2106 is placed between the sensor chip 2102 and cardiac septum 36. Therefore, for ease of reference and description, the same reference numerals have been used for the same or similar parts. In FIG. 22, the sensor chip 2102 and antenna structure 2106 are implanted into the left atrium 34, while the anchor structure 2108 is disposed in the right atrium 32.
The anchor structure 2108 and the sensor chip 2102 are connected with a connection piece 2104, which is extends through the foramen 40 in the cardiac septum 36. As in the FIG. 21 embodiment, the mechanical tension that arises from the tension between the sensor chip 2102 and connection piece 2104 produces adhesion used to firmly affix the device to the septum. In FIG. 22, the contact surface 2120 of the sheathing 2124 on the antenna structure 2106 serves as a counter bearing for anchor structure 2108.
FIG. 23 illustrates another embodiment of a pressure sensor that may be used in the devices of FIGS. 21 and 22 according to principles of the invention. FIG. 23 illustrates a second transponder coil 2128 for internal data transmission, which is mechanically and electrically fixed to the sensor chip 2102, such as by metallizations or thin wires. The second transponder coil may obviate the need for connection wire 2132 between coil 2114 and the sensor chip 2102 as shown in FIGS. 21 and 22, because data is transmitted telemetrically from the internal data transponder coil 2128 to the external data transponder coil 2114 and then on to the external reader. Alternatively, the data may be transmitted telemetrically from the internal data transponder coil 2128 to another chip (not shown) and then on to the external reader.
FIGS. 24, 25, and 26 schematically illustrate catheterization apparatus and three general principles—puncturing, inserting and implanting—that may be employed in a minimally invasive implantation method for implanting a telemetric measuring device according to principles of the invention. FIG. 24 illustrates puncturing the implantation site, such as the septum 36 of the heart. A conventional cardiac catheter 2400 may be used to deliver and position an implantable device 2402 of the invention within the cardiovascular system, such as the heart, of a patient. The implantable device 2402 includes a substantially rigid sensor chip 2404, a connection piece 2406 and an anchor structure 2408 of the invention, all shown in highly schematic fashion. The sensor chip 2404 includes an antenna (not shown). According to an embodiment of the invention, both the sensor chip 2404 and the anchor structure 2408 may be connected to the connection piece 2406 for selective longitudinal and pivotal or transverse movement, i.e. the sensor chip, anchor structure and connection piece may be longitudinally moved as a unit by or through the catheter, and the sensor chip and anchor structure may be selectively moved transversely or pivoted relative to the connection piece, as described below.
As illustrated in FIG. 25, the catheter is inserted through the septum 36 at the foramen 40 with the distal end of catheter 2400 initially located within the right atrium. The sensor chip 2404 may be configured to pierce the septum 36, e.g. may have a conical tip, such that moving the sensor chip 2404 distally punctures the septum 36 at the foramen 40.
As illustrated in FIG. 26, after the sensor chip 2404 pierces the septum 36 and passes into the left atrium, the connection piece 2406 is located within the foramen 40 of the septum 36. The anchor structure 2408 remains in the right atrium. The sensor chip 2404 may be moved or pivoted about its connection to the connection piece 2406 in any manner know in the art to occupy an expanded position against the interior surface of the septum 36 to secure the sensor chip 2404. Specifically, the sensor chip 2404 is then retracted in a proximal direction toward the doctor so that its surface contacts the interior of the septum 36. A portion of the connection piece 2406 fits within the foramen 40 of the septum 36. The anchor structure 2408 is simultaneously or subsequently moved or pivoted about its connection to the connection piece 2406 in any manner know in the art such that it is transverse to the longitudinal axis of the connection piece. The anchor structure 2408 is then positioned against the septum 36 and affixed to the connection piece 2406. The anchor structure 2408 and connection piece 2406 interact to attach the sensor chip 2402 to the septum 36 as disclosed above in FIGS. 21-22, for example.
FIGS. 27, 28, 29, 30, and 31 illustrate another embodiment of catheterization apparatus and more specific operational steps and structure that may be employed in another minimally invasive method for implanting telemetric measuring devices according to principles of the invention. According to an embodiment of the invention, the telemetric measuring device of the invention includes a collapsible anchor structure 2712, which may be formed from resilient arms that spring into an expanded position after release from the open, distal end 2718 of the catheter. By use of this anchor structure 2712, a sensor chip 2708 may be an ASIC as described herein or made of other, substantially rigid material that is not readily flexible, foldable or rolled. The anchor structure 2712 may be used to fix the sensor chip 2708 to a location at or near the cardiac septum 36. A portion of the anchor structure 2712 is placed within the foramen 40, as well as on both sides of the cardiac septum 36. Resilient arms 2714 of the anchor structure 2712, which may be formed from wire, will be disposed on both sides of the cardiac septum 36 after delivery (as shown in FIG. 32) to support the implanted sensor chip 2708. The apparatus and implantation steps will now be described in greater detail below.
With reference to FIG. 27, a telemetric measuring device is located within the lumen 2706 of a catheter 2700, which may be a conventional, cardiac catheter used to place medical devices within the cardiovasculature, including the heart. The sensor chip 2708 may be located within a conic end piece 2704 for piercing a heart wall such as septum 36. The sensor chip 2708 is located near the distal catheter opening 2718, while the anchor structure 2712 is folded into a collapsed position within the catheter lumen 2700, before it is delivered and implanted.
As discussed above, the anchor structure 2712 may be made of one or more looped, wired elements 2714 that normally occupy an expanded position, but are collapsible into a folded position fitting within lumen 2706. Anchor clips 2716 a, 2716 b, 2716 c, such as quilled clips, may be used to attach together portions of the wired elements 2714 of the anchor structure 2712. Clips 2716 a, 2716 b, and 2716 c are attached prior to delivery. The wired elements 2714 may be self-expanding support units made of synthetic material. For example, a metal with a shape memory, such as nitinol, may be used, so that the wired elements 2714 expand to their original shape upon deployment from the end of the catheter. The anchor structure 2712 is designed to be compressed within the catheter lumen 2706 during delivery.
As illustrated in FIGS. 27 and 28, after distal catheter end 2718 and the sensor chip 2708 are inserted through the septum 36, the anchor structure 2712 also is inserted through the septum 36 such that anchor clip 2716 a is located beyond the septum 36 and in the heart chamber, but clip 2716 b remains in the lumen 2706. The wire arms 2714 are now free and deploy towards their normally expanded positions.
As illustrated in FIGS. 29 and 30, the catheter lumen 2706 is then pulled back proximately through and out of the foramen 40. This also pulls the sensor 2708 and the wire arms 2714 proximally, which expand to their original shape and contact the inner surface of the septum 36. In the embodiment illustrated in FIGS. 29 and 30, an antenna 2710 is located on one of the three wire arms 2714 that contact the septum 36, i.e. the antenna 2710 is on the same side of the septum 36 as the sensor chip 2708.
Further, the implantable clip 2716 b, which also engages the wire elements 2714, is pulled into the foramen 40. Proximal portions of the three wire arms 2714 between clips 2716 b and 2716 c also are deployed out of the catheter lumen 2706 as the catheter is further retracted, although clip 2716 c and the remaining portions of the wire elements 2714 may remain within the catheter lumen 2706 at this time. The wire elements 2714 on the proximal, outer side of the septum 36 opposite the sensor chip 2708 are now deployed and begin to regain their original, expended shape as shown in FIGS. 29 and 30.
FIG. 31 illustrates the telemetric measuring device implanted in position and attached to the septum 36, after the catheter has been removed from the device, by any means known in the art. The wire arms 2714 on both sides of the septum 36 have regained their expanded shape and contact the walls of the septum 36, with the intermediate portion of the wire elements 2714 located within the foramen 40 in a collapsed position held by clip 2716 b. A sensor fastener 2702 such as a bend or elbow supports the sensor chip 2708 within the left atrium 34 and away from the heart itself, and particularly the septum 36. Thus, the design of the anchor structure 2712 allows the implantation of the sensor chip 2708 into the left atrium. The antenna structure 2710 may be located on the surface of the wired elements 2714 of the anchor structure 2712. Blood pressure can act directly on the pressure sensors (not shown) of the sensor chip 2708. Thus, the sensor fastener 2702 of the anchor structure 2712 attaches the sensor chip 2708 to the anchor structure 2712 and places the sensor chip 2708 away from the septum 36. The cardiac motion, especially the motion of the cardiac septum, will have reduced or no significant, deteriorating effect on the sensor chip 2708 and, therefore has less or no significant influence on the quality of measurement results. This may also be due to the design of the substantially rigid sensor, such as an ASIC as described above, in which the pressure sensors are housed. This enables only the actual blood pressure values to be measured and obtained by the sensor chip 2708. Mismeasurements or negative reports which may occur with conventional, flexible pressure measuring devices can be avoided.
FIGS. 32 and 33 illustrate another embodiment of an implantable telemetric measuring device of the invention for use in the method described in FIGS. 27, 28, 29, 30, and 31. More specifically, the embodiment of FIGS. 32 and 33 illustrates the implantable device affixed to the septum 36, but with the antenna 2710 located on the side of the septum 36 opposite the sensor chip 2708. According to an embodiment of the invention, electrical conductive wires (not shown) may be located in the foramen 40 and connect the antenna device 2710 with the sensor chip 2708. Alternatively, the sensor chip 2708 may have an internal coil that telemetrically communicates with antenna 2710. Other configurations may also be used as the skilled artisan will recognize.
According to another embodiment of the invention, the implantable sensor chip of the invention may sense conditions in more than one chamber of the heart. FIG. 34 illustrates the placement of a multiple, heart chamber sensing device 3400 of the invention. Sensor chip 3400 is implanted in the septum 36 of the heart 30 surgically or via catheterization, e.g. using the technique described herein. The sensor chip 3400, such as an ASIC, has a first pressure sensing portion 3402, having pressure sensors, located in the right atrium 34 and a second pressure sensing portion 3404, having pressure sensors located in the right atrium 32. Alternatively, two or more chips may be connected via a wire and positioned to achieve sensing in two or more chambers. The data could then be transmitted to an external reader using appropriate protocols, in accordance with the invention.
FIG. 35 is a block diagram of the major electronic components of an external reader 3500 of the invention for telemetrically receiving data from an implanted sensor chip. An antenna 3502 may be integrated with the external reader 3500, as shown schematically in FIGS. 1-2. Also, as illustrated in FIG. 1, the external reader 12 may be attached to the patient, or alternatively, as illustrated in FIG. 2, the external reader 26 may be incorporated inside a handheld device. In other cases, the antenna 3502 may be attached to the patient's body or connected to the external reader 3500 by cable connections. Another method attaches the external reader to the patient's bed or seat. Numerous such arrangements may be employed to adapt to the particular application, as the skilled artisan will recognize.
The calibration memory 3522, the data memory 3524 and the parameter memory 3526 may be separate memory storage devices within the external reader, or each may be a portion of a single memory storage device. The reader may use a signal at 13.56 MHz, or other known frequencies. One example of a suitable reader is disclosed in published patent application No. PCT/EP2004/012670.
Bi-directional power evaluation module 3528 assists in evaluating the strength of signals received from the implanted device to ensure that a minimum signal strength is received. The signal received from the implanted devices via antenna 3502 is evaluated by the bi-directional power evaluation module 3528. The evaluation may be implemented via various methodologies. According to an embodiment of the invention, the reader may increase the power of the signal sent via the antenna 3502 to the implanted device over small increasing increments. At each increment, the bi-directional power evaluation module 3528 evaluates the signal received back from the implanted device to determine the quality and strength of the signal. This process is repeated until a successful signal is received from the implanted device. The reader than uses the minimum power necessary to achieve an acceptable signal and begins performing the reading of data, such as pressure and temperature measurements, from the device. This may be performed by taking a predetermined number of readings (e.g., five readings) in a row. All the readings may be taken after the minimum power level has been determined. Alternatively, the bi-directional power evaluation module 3528 may determine the minimum power level after each of the predetermined readings.
By way of another embodiment of the invention, the reader can increase the power level supplied by the antenna 3502 by larger increments, such as by quarter Fourier steps (FS steps), until a valid signal is received from the implanted device. Once a valid signal is obtained, the power is decreased by one step, such as ¼ FS, then increased in smaller steps, such as ⅛ FS steps) until a valid signal is received. This process is repeated using progressively smaller steps ( 1/16 FS, 1/32 FS) until a minimum power level is determined. The reader then uses the resulting minimum power level to compute the required power setting and obtains a predetermined number of readings.
Use of power conditioning may result is various beneficial characteristics and features for the voltage controller/stabilizer supply voltage (VDDA) used in the ASIC. When using power conditioning, there is generally a high common mode rejection ratio (CMRR) for VDDA, as well as good radio frequency (RF) suppression for VDDA. In addition, a fast power on reset (POR) signal is used if VDDA falls below tolerance, which would happen if supply power is not sufficient. Because there is no measurement or signal transmission if POR not "1," determining a proper power supply using the power conditioning may prevent this drawback.
While the invention has been described in terms of exemplary embodiments, those skilled in the art will recognize that the invention can be practiced with modifications in the spirit and scope of the appended claims. For example, while the embodiments described above have been directed to implantation of the telemetric sensing device of the invention within the heart, one or more such devices may be implanted within other positions in the cardiovascular system of a patient, such as the aorta, pulmonary artery, or any of the other great vessels. These examples given above are merely illustrative and are not meant to be an exhaustive list of all possible designs, embodiments, applications or modifications of the invention.
a sensor fastener holding the sensor assembly away from the anchor structure.
2. The implantable pressure monitor of claim 1, wherein the sensor fastener comprises a bend or an elbow shape.
3. The implantable pressure monitor of claim 1, wherein the sheath has a curved shape to reduce or eliminate hydrodynamic forces.
4. The implantable pressure monitor of claim 1, wherein the substantially rigid substrate extends distally from the chip to a distal end which comprises a barrier wall protecting a distal end of the chip.
5. The implantable pressure monitor of claim 4, wherein the barrier wall forms an end cap at the distal end of the chip.
6. The implantable pressure monitor of claim 5, wherein the barrier wall extends in a direction substantially perpendicular to a plane of the substrate and to a height such that a top of the barrier wall is at or above a top of the chip.
7. The implantable pressure monitor of claim 4, wherein the substantially rigid substrate further extends distally from the barrier wall to a tapered front portion.
8. The implantable pressure monitor of claim 1, wherein the sheath comprises a one-piece, seamless silicone covering.
9. The implantable pressure monitor of claim 1, wherein the pressure-transferring medium comprises silicone.
10. The implantable pressure monitor of claim 1, wherein the anchor structure comprises resilient arms that spring into an expanded position after release from confinement.
11. The implantable pressure monitor of claim 10, wherein the resilient arms of the anchor structure are arranged as two looped wire elements separated by a distance corresponding to or slightly less than the thickness of a cardiac septum, and the sensor assembly is positioned outside the anchor structure.
12. The implantable pressure monitor of claim 1, wherein the substrate is sufficiently rigid such that it cannot be folded or rolled up.
13. The implantable pressure monitor of claim 1, wherein the substrate is sufficiently rigid to protect the pressure sensors from damage as a consequence of contact with a surgical instrument during implantation and from mechanical damage during use.
14. The implantable pressure monitor of claim 1, wherein the substantially rigid substrate is sufficiently rigid to protect the pressure sensors from damage due to stress and strain due to bending of the monitor during insertion.
15. The implantable pressure monitor of claim 1, wherein the substrate is sufficiently rigid to avoid twisting of the chip due to turbulent blood flow.
16. The implantable pressure monitor of claim 1, wherein the substrate is rigid.
17. The implantable pressure monitor of claim 1, wherein the substrate is mechanically inflexible.
18. The implantable pressure monitor of claim 1, wherein the flexible filler material comprises silicone.
19. The implantable pressure monitor of claim 1, wherein the flexible filler material holds the chip and the substrate together in a fixed relationship.
A. Ohlsson, D. Steinhaus, B. Kjellstrom, L. Ryden, T. Bennett, "Central Hemodynamic Responses During Serial Exercise Tests in Heart Failure Patients Using Implantable Hemodynamic Monitors," The European Journal of Heart Failure, vol. 5, 2003, pp. 253-259.
A. Ohlsson, S.H. Kubo, D. Steinhaus, D.T. Connelly, S. Adler, C. Bitkover, R. Nordlander, L. Ryden and T. Bennett, "Continuous Ambulatory Monitoring of Absolute Right Ventricular Pressure and Mixed Venous Oxygen Saturation in Patients with Heart Failure Using an Implantable Haemodynamic Monitor," European Heart Journal, vol. 22, Issue 11, Jun. 2001, pp. 942-954.
A. Ohlsson, T. Bennett, F. Ottenhoff, C. Bitkover, B. Kjellstrom, R. Nordlander, H. Astrom and L. Ryden, "Long-Term Recording of Cardiac Output Via an Implantable Haemodynamic Monitoring Device," European Heart Journal, vol. 17, Dec. 1996, pp. 1902-1910.
Andrew DeHennis and Kensall D. Wise, "A Double-Sided Single-Chip Wireless Pressure Sensor," Digest IEEE Conference on MicroElectroMechanical Systems, Las Vegas, pp. 252-255, Jan. 2002.
Andrew DeHennis and Kensall D. Wise, "A Passive-Telemetry-Based Pressure Sensing System," Proc. Solid State Sensors and Actuators Workshop, Hilton Head, SC 2002, pp. 165-168.
Anthony Magalski, Philip Adamson, Frederick Gadler, Michael Boehm, David Steinhaus, Dwight Reynolds, Kathryn Vlach, RN, Cecilia Linde, Bodo Cremers, Brandon Sparks, Tom Bennett, "Continuous Ambulatory Right Heart Pressure Measurements With an Implantable Hemodynamic Monitor: A Multicenter, 12-Month Follow-up Study of Patients With Chronic Heart Failure," Journal of Cardiac Failure, vol. 8, No. 2, 2002, pp. 63-70.
Bjorn Sonesson, Nuno Dias, Martin Malina, Perake Olofsson, Dennis Griffin, Bengt Lindblad, and Krassi Ivancev, "Intra-Aneurysm Pressure Measurements in Successfully Excluded Abdominal Aortic Aneurysm After Endovascular Repair," Journal of Vascular Surgery, Apr. 2003, pp. 733-738.
C. Shawn Skillern, Scott L. Stevens, K. Todd Piercy, Robert L. Donnell, Michael B. Freeman, and Mitchell H. Goldman, "Endotension in an Experimental Aneurysm Model," Journal of Vascular Surgery, Oct. 2002, vol. 36, No. 4, pp. 814-817.
David M. Steinhaus, Robert Lemery, Dennis R. Bresnahan, Jr., Larry Handlin, Tom Bennett, Alan Moore, Debbie Cardinal, Laura Foley, Richard Levine, "Initial Experience With an Implantable Hemodynamic Monitor," American Heart Association Circulation, 1996, vol. 93, pp. 745-752.
David Steinhaus, Dwight W. Reynolds, Frederick Gadler, G. Neal Kay, Mike F. Hess, and Tom Bennett, "Implant Experience with an Implantable Hemodynamic Monitor for the Management of Symptomatic Heart Failure," PACE, vol. 28, Aug. 2005, pp. 747-753.
F. Braunschweig, C. Linde, M.J. Eriksson, C. Hofman-Bang and L. Ryden, "Continuous Haemodynamic Monitoring During Withdrawal of Diuretics in Patients with Congestive Heart Failure," European Heart Journal, vol. 23, Issue 1, Jan. 2002, pp. 59-69.
Frieder Braunschweig, Barbro Kjellstrom, Mats Soderhall, Naomi Clyne, Cecilia Linde, "Dynamic Changes in Right Ventricular Pressures During Haemodialysis Recorded with an Implantable Haemodynaamic Monitor," Nephrology Dialysis Transplantation, 2006, vol. 21, pp. 176-183.
G.W.H. Schurink, N.J.M. Aarts, J. Wilde, J.M. Van Baalen, T.A.M. Chuter, L.J. Schultze Kool, and J.H. Vanbockel, "Endoleakage After Stent-Graft Treatment of Abdominal Aneurysm: Implications on Pressure and Imaging-an In Vitro Study," Journal of Vascular Surgery, vol. 28, No. 2, pp. 234-241, Aug. 1998.
G.W.H. Schurink, N.J.M. Aarts, J. Wilde, J.M. Van Baalen, T.A.M. Chuter, L.J. Schultze Kool, and J.H. Vanbockel, "Endoleakage After Stent-Graft Treatment of Abdominal Aneurysm: Implications on Pressure and Imaging—an In Vitro Study," Journal of Vascular Surgery, vol. 28, No. 2, pp. 234-241, Aug. 1998.
G.W.H. Schurink, N.J.M. Aarts, J.M. Van Baalen, L.J. Schultze Kool and J.H. VanBockel, "Experimental Study of the Influence of Endoleak Size on Pressure in the Aneurysm Sac and the Consequences of Thrombosis," British Journal of Surgery 2000, pp. 87, 71-78.
Gareth D. Treharne, Ian M. Loftus, Matthew M. Thompson, Nicola Lennard, Julia Smith, Guy Fishwick, and Peter R.F. Bell, "Quality Control During Endovascular Aneurysm Repair: Monitoring Aneurysmal Sac Pressure and Superficial Femoral Artery Flow Velocity," Journal of Endovascular Surgery, 1999, vol. 6 pp. 239-245.
George Akingba, Adrienne Cheng, Angela Shum, Peter Yang, "An Implantable Pressure Sensor for Aneurysmal Disease", published no later than Sep. 30, 2003.
H.E. Haynes and A.L. Witchey, "Medical Electronics: The Pill That "Talks"," RCA Engineer, pp. 52-54, vol. 5, No. 5, Feb.-Mar. 1960.
International Search Report and Written Opinion for PCT/2006/060798.
International Search Report and Written Opinion for PCT/2006/060800.
Jiang Zhe, K.R. Farmer and Vijay Modi, "A MEMS Device for Measurement of Skin Friction with Capacitive Sensing," "Microelectromechanical Systems Conference, 2001", Berkeley, CA, pp. 4-7.
John P. Boehmer, "Device Therapy for Heart Failure," The American Journal of Cardiology, vol. 91(6A), Mar. 20, 2003, pp. 53D-59D.
John T. Farrar, Carl Berkley, Vladimmir K. Zworykin, "Telemetering of Intraenteric Pressure in Man by an Externally Energized Wireless Capsule," Science, New Series Issue 3416, Jun. 1960, p. 1814, vol. 131.
Juan Carlos Parodi, Ramon Berguer, Luis Mariano Ferreira, Ricardo La Mura, and Mark L. Shermerhorn, "Intra-aneurysmal Pressure After Incomplete Endovascular Exclusion," Journal of Vascular Surgery, Nov. 2001, vol. 34, No. 5, pp. 909-914.
Kenneth Ouriel, "Role of Intrasac Pressure Measurements After EVAR: Can They be Followed Noninvasively?," Combined Session: Vascular Surgery and Interventional Radiology, VII 4.1, published no later than Sep. 30, 2003.
Kenton R. Kaufman, Tom Wavering, Duane Morrow, Jennifer Davis, Richard L. Lieber, "Performance charactericsts of a Pressure Microsensor," Journal of Biomechanics, vol. 36, 2003, pp. 283-287.
Kirkwood F. Adams, Jr., "Guiding Heart Failure Car by Invasive Hemodynamic Measurements: Possible or Useful?," Journal of Cardiac Failure, vol. 8, No. 2, 2002, pp. 71-73.
M. Gaweenda, J. Heckenkamp, S. Winter, G. Jaschke, J. Brunkwall, "Pressure is Transmitted Through PTFE and Dacron Grafts Leading to Aneurysm Sac Pressure Following Endoluminal Grafting of AAA-An In Vitro Study," Vascular Centre, University of Cologne, Germany, , published no later than Sep. 30, 2003.
M. Gaweenda, J. Heckenkamp, S. Winter, G. Jaschke, J. Brunkwall, "Pressure is Transmitted Through PTFE and Dacron Grafts Leading to Aneurysm Sac Pressure Following Endoluminal Grafting of AAA—An In Vitro Study," Vascular Centre, University of Cologne, Germany, , published no later than Sep. 30, 2003.
M. Gawenda, J. Heckenkamp, M. Zaehringer and J. Brunkwall, "Intra-aneurysm Sac Pressure-The Holy Grail of Endoluminal Grafting of AAA," Eur J Vas Endovasc Surg 24, 139-145, 2002.
M. Gawenda, J. Heckenkamp, M. Zaehringer and J. Brunkwall, "Intra-aneurysm Sac Pressure—The Holy Grail of Endoluminal Grafting of AAA," Eur J Vas Endovasc Surg 24, 139-145, 2002.
Mark L. Manwaring, Veljko D. Malbasa, Kim L. Manwaring, "Remote Monitoring of Intracranial Pressure," Annals of the Academy of Studencia, Apr. 2001, pp. 77-80, 2001.
P.L. Harris and S. Dimitri, "Predicting Failure of Endovascular Aneurysm Repair," Eur J Vasc Endovasc Surg., vol. 17, pp. 1-2, 1999.
Philip B. Adamson, Andrew L. SmithWilliam T. Abrahamkaren J. Kleckner, Robert W. Stadler, Alex Shih, Melissa M. Rohodes, "Continuous Autonomic Assessment in Patients With Symptomatic Heart Failure," American Heart Association Journals, Circulation, Oct. 19, 2004, pp. 2389-2394.
Philip B. Adamson, Anthony Magalski, Frieder Braunschweig, Michael Bohm, Dwight Reynolds, David Steinhaus, Allyson Lyby, Ceilia Linde, Lars Ryden, Bodo Cremers, Teri Takle, Tom Bennett, "Ongoing Right Ventricular Hemodynamics in Heart Failure," Journal of the American College of Cardiology, vol. 41, No. 4, 2003, pp. 565-571.
Ralph Shabetai, "Monitoring Heart Failure Hemodynamics With an Implanted Device: Its Potential to Improve Outcome," Journal of the American College of Cardiology, vol. 41, No. 4, 2003, pp. 572-573.
Richard A. Baum, Jeffrey P. Carpenter, Constantin Cope, Michael A. Golden, Omaida C. Velazquez, David G. Neschis, Marc E. Mitchell, Clyde F. Barker, and Ronald M. Fairman, "Aneurysm Sac Pressure Measurements After Endovascular Repair of Abdominal Aortic Aneurysms," Journal of Vascular Surgery, Jan. 2001, vol. 33, No. 1, pp. 32-41.
S.R. Vallabhaneni, J. Brennan, G. Gilling-Smith, D. Gould, T. How, R. McWilliams, P.L. Harris, "Aortic Side Branch Perfusion Alone Does not Account for High Intra-Sac Pressure After Endovascular Repair (EVAR) in the Absense of Graft-Related Endoleak", European Journal of Vascular and Endovascular Surgery, vol. 25, Issue 4, Apr. 2003, pp. 354-359.
T. Chuter, K. Ivancev, M. Malina, T. Resch, J. Brunkwall, B. Lindblad and B. Risberg, Endovascular and Surgical Techniques, "Aneurysm Pressure following Endovascular Exclusion," Eur J Vasc Endovasc Surg., vol. 13, pp. 85-87, 1997.
Tayfun Akin, Babak Ziaie, and Khalil Najafi, "RF Telemetry Powering and Control of Hermetically Sealed Integrated Sensors and Actuators," Digest, Solid-State Sensors and Actuators Workshop, Hilton Head, SC Jun. 1990, pp. 145-148.
Thomas B. Fryer, Harold Sandler, William Freund, Ernest P. McCutcheon, and Edwin L. Carlson, "A Multichannel Implantable Telemetry System for Flow, Pressure, and ECG Measurements," Journal of Applied Physiology, vol. 39, No. 2, Aug. 1975, pp. 318-326.
Tom Bennett, Barbro Kjellstrom, Robert Taepke, and Lars Ryden, "Development of Implantable Devices for Continuous Ambulatory Monitoring of Central Hemodynamic Values in Heart Failure Patients," PACE, vol. 28, Jun. 2005, pp. 573-584.
Torsten Eggers and Matthias Wenzel, "Implantable Telemetric Pressure Measurement," Med. Device Technol., May 2004, 15(4), pp. 25-27.
Transoma Medical, "LVP-1000 Left Ventricular Pressure Telemetry," , accessed Oct. 27, 2005.
Transoma Medical, "LVP-1000 Left Ventricular Pressure Telemetry," <http://www.datasci.com/research/lvp1000.html>, accessed Oct. 27, 2005.
V. Bodecker, C. Bodecker-Kuhnert, S. Meyer, "The Mesograph: A New Technological Solution for Continuous IOP Monitoring", Proceedings of the World Microtechnologies Congress MICRO.tec 2000, vol. 2, Hanover, Germany, S. 437-440, 2000.
VDI/VDE-IT 1994, Micro System Technology Implantable Telemetrically Endo Systems (ITES), 1995-1997 publication.


Shambles has lists of the international schools in the 17 countries in S.E.Asia but if you are looking for a comprehensive database that covers these and all international schools worldwide then this may well be the solution for you.
The International School Consultancy (ISC) is the leading source of market intelligence on the world of international English-speaking schools. It has been a specialist in the sector for more than 30 years. ISC is the only organisation that has continuously operated in the marketplace to collect international school data, resulting in a unique set of current and historical data and market intelligence.
ISC's headquarters is in Faringdon, Oxfordshire. We also have local presence in Bangkok, Dubai, Hong Kong, Kuala Lumpur and the Netherlands.
We make data and intelligence on the English-medium international schools market available to organisations by means of a number of well-defined services. Each service is designed to satisfy a different need – from on-going sales and marketing operations to school investment decisions.
Our research team maintains and develops the information database of nearly 9000 schools worldwide. ISC Market Analysts generate market intelligence reports designed to inform clients on the school landscape in specific countries. Our Data Analysts produce requirement-specific statistical information to inform clients' projects. ISC also supports Sales and Marketing needs through ISC Online, through which clients have continuous real-time access to the market information, newsfeeds and school contact information covering all schools. ISC Premier Service provides best-of-breed clients with direct introductions to many of the most prestigious international schools in the world.
With our long history of operation in this sector, ISC has developed a huge network of relationships with schools, school associations and other industry stakeholders. These relationships facilitate our data collection and research efforts.
We gather much information direct from schools, both via our schools information sharing service and by visiting over 500 of the world's premier schools in Asia, Europe and Latin America. These visits take place at least once a year enabling us to carry out in-depth research.
This high level data is continuously merged into the information database and is used to inform published market reports.
contact ISC Research by clicking on the logo on the right for further information and Free Trial Access.
"Developing and, more importantly, maintaining a comprehensive and up-to-date database of international schools is beyond the means of most organisations. It takes a huge amount of time and effort just to keep pace with myriad small changes to basic information, never mind researching the large number of new international schools that open each year. We have a dedicated team around the world who do just that."
and keep up with developments as they happen."
find and contact international school organisations.
The ISC database is much more comprehensive and accurate than anything else available. Whether you are a head of school, a parent, a supplier or a school organisation, having instant access to the latest information is critical.
then email ISC directly by clicking on the logo on the right.


2. Distributed Practice. The art of spreading out small revision sessions over time rather than trying to pack it all into a single session. For example, if you want to commit to memory the atomic weights of elements, then it would be more effective to go through the table once every day for 5 days, rather than revise it 5 times in a day.... It's hard to remember all what you have read and learned, however it is certainly possible. To maintain a strategic distance from such a circumstance, we convey you straightforward approaches to help you recollect things better.
Study, concentrate and remember. Tips and strategies to help you study effectively, concentrate and remember what you have learned. Our tutors also know what it means to be a student, here are their study tips: Techniques for active learning. Active learning is when you do activities, such as reading, writing, discussions or problem solving, which encourage you to analyse, synthesise and how to set up cable modem router to be rerouted It's hard to remember all what you have read and learned, however it is certainly possible. To maintain a strategic distance from such a circumstance, we convey you straightforward approaches to help you recollect things better.
Today, I will be revealing to you 10 tips to study for JAMB 2019 and remember everything in the examination hall. I will list out the 10 tips now. So, let�s get started. I will list out the 10 tips now. how to use an hand impact driver Remember Everything You Want and Manage the Rest is a practical guide for anyone who wishes to improve their memory and learning and master information in a knowledge intensive world.
The first thing you need to realize is that you can't possibly study everything in the course in one day. That's simply impossible and would require way more time than you have. That's simply impossible and would require way more time than you have.
Remember Everything You Want and Manage the Rest is a practical guide for anyone who wishes to improve their memory and learning and master information in a knowledge intensive world.


While the high education has became a hot issue all over the world, the vast number of Chinese students abroad have also became a target of all the countries. That is because the students abroad are not only mean to promote the essence of the high education, but also related to the economic of the students receiving countries, which including to supply the amount of students for the low enrollment because of the declining birthrate, to increase the domestic market by the consumption of the students abroad, and to recruit the outstanding ones for the employment to provide the labor. Those factors cause the beneficial sides of the students abroad policy, and they also make the countries put the market mechanism into the high education for creating more overseas students.
To choose China and South Korea as the main object of this study is because since the two countries have established diplomatic relations in 1992, not only the political and economical aspects have progressed, but also the great growth of the educational cooperation and exchanges. After viewing the data of the students abroad transferring intra-Asian, the nation which attract Chinese student the most is South Korea, and South Korea makes no different on this issue. As of year 2010, the number of South Korean students studying in China reached 64,232 people, about 40% of the number of the overseas students; Chinese students studying in South Korea went as high as 83,842 people, about 70% of the number of the overseas students, two countries are both of each other's first place. According to this result, the main purpose of this study would be analyzing the policies and the data changes between the two countries, and try to discuss the attractive reasons between the two countries, the future expansibility of the students abroad , and the impacts of the bilateral relations under the close cooperation by the analysis.


text:
Junior Player Spotlight: Agnia Vustsina, MatchPoint NYC
Each day, Agnia Vustsina takes a 20-minute walk towards the coast of Gravesend Bay in Brooklyn where she arrives at MatchPoint NYC Bensonhurst, a beautiful facility that sits in view of the Verrazano Bridge. The top-ranked rising eighth-grader in New York, according to TennisRecruiting.net, has...Read more
At The Net w/ Giuliana Olmos
This article first appeared in the September/October 2021 issue of New York Tennis Magazine. Click Here to read the full digital edition. Earlier this summer, Giuliana "Gugu" Olmos got the phone call that many athletes from all sports can only dream about getting. While driving with her husband,...Read more
NYTM's Literary Corner: Doubles Domination: The Best of the Best by Bob Allcorn
He spent 40 years perfecting the art and science of pre-trial commercial litigation tactics and strategy – and sharing his expertise through teaching at law schools and legal institutes, lecturing to attorneys, training attorneys at the Inns of Court Foundation, writing numerous articles in legal...Read more
Beyond the Baseline: Parsa Samii
Tennis is a sport that has an impact beyond the wins and losses on the court. It's a sport that demands dedication and instills a work ethic, helping young people develop character traits that can be utilized in all walks of life. Embodying this mantra is Parsa Samii, a former collegiate and...Read more
At The Net w/ Advantage Tennis Clubs
A year ago, the country was in the heart of the COVID-19 pandemic and no one knew what the future would hold. Perhaps no place was hit harder in terms of infection rates, but also economically, than New York City. There wasn't a single industry that was left unaffected by the lack of people...Read more
McEnroe Brothers, Tennis Legends Return for Annual JMTP Pro-Am
Last year, as the global pandemic continued to wreak havoc on our normal everyday lives, organizations were forced to rethink how they planned their events, including ones that had been well-established. For the Johnny Mac Tennis Project (JMTP) and its annual Pro-Am tennis tournament , this meant...Read more
Junior Player Spotlight: Caroline McGinley and Doug Yaffa, Dwight Global Online School
In this era of learning from home and virtual programming, the need to have an education that is right for you has never been more important. This is especially true for high-level junior tennis players who often have to balance their learning with a jam-packed training and tournament schedule,...Read more
The Mental Side of Tennis
Cary Leeds Center Launches CLC Academy
Since 2015, the Cary Leeds Center for Tennis & Learning has served as the flagship location of the New York Junior Tennis & Learning (NYJTL), and has used tennis and academics to help change the lives of many Bronx residents. "Cary Leeds Center impacts our kids in different ways," said...Read more
At The Net w/ Alex Kotzen
When college athletics shut down due to the COVID-19 pandemic last year, athletes all across the country were forced into an unfamiliar position, one in which they were unable to compete and practice like normal with their teams. One of those athletes is Alex Kotzen, last year's ITA Northeast...Read more

redpajama_set_name: RedPajamaCommonCrawl


We care about the way you look.
Dry cleaning and Laundry services in Cincinnati, OH. Now offering Pick up & Delivery.
At Robinson Cleaners you'll receive the best, friendly, service and quality dry cleaning and laundry in the Cincinnati area. We understand quality garment care, whether it is dry cleaning, laundry, wedding dress, prom dresses, drapes, bed spreads or other special fabrics. You can be confident that we will take extra care of your spot removals, cleaning, laundry, and smoke, fire and water damage restoration needs.
We operate two state-of-the-art cleaning facility and have been in business over 30 years in the Greater Cincinnati area. Unlike most cleaners, all garments are cleaned on premises and we stand behind every garment we clean.


Do the Fed Funds futures markets tell us what the Fed is going to do? The answer to that question is a resounding "no"! Fed Funds futures contracts are simply trading vehicles in which hedgers, but mostly speculators, buy and sell according to their market outlook. Although it can be argued that the Fed has been looking to the financial markets for policy guidance, in the end, they are the decision makers. Nevertheless, as the opinions of the market sway in regard to the Fed's next move, so do the prices of the Fed Funds futures contracts. Accordingly, there are some viable trading opportunities; particularly from the bearish side of the market given the relatively limited upside potential (assuming the Fed doesn't lower interest rates anytime soon). In the video below we discuss Fed Funds futures trading strategy, market characteristics, and ideas on low-risk ways to trade the prospects of higher interest rates.


Air Canada, WestJet and Delta have dropped the price of some of their flights in 2018 from Edmonton to San Diego, California down to $273 CAD roundtrip including taxes.
- Use the Google Flights links at the top of this blog post.
edmonton, yeg, flight deals, united states, air canada, delta, california, north america, san diego and san.


text:
Meet 'Optician Sans,' the Weird and Wonderful Font Inspired by Your Eye Exams
Catie Keck
Before last month, you'd be hard-pressed to find the curiously shaped letters you're asked to name from charts at your optometrist's office in font lists in Word or Docs. But if you're a typeface nerd who also appreciates mathematical precision, the newly minted "Optician Sans" is the font for you.
What Is Carbon Capture? With Gizmodo's Molly Taft | Techmodo
Fast Company spoke with the design firm ANTI Hamar, the creator of the font, about the neat typeface made available for free last month. The project began as a rebranding commission from the Norwegian family eyecare business Optician-K. According to Fast Company, the design firm used the history of optometry as a springboard for inspiration, leading them to the pioneering letter designs developed by Dutch eye doctor Hermann Snellen in 1862 for his Snellen chart, which used mathematical precision to zero in on a patient's visual acuity. Snellen did this by applying a 5 x 5 grid as the foundation for a total of 10 letters used in his tests.
In 1959, those 10 letters were given a reboot by American ophthalmologist Louise Sloan. She overhauled the letters to exclude Snellen's serifs—those little protruding details like in the "E" shown above—giving them a much cleaner and contemporary feel. Those were later for developed for the standardized Logarithm of the Minimum Angle of Resolution (LogMAR) tests now used by eye care professionals across the globe.
ANTI Hamar aimed to revamp the Optician-K brand using Sloan's designs, according to Fast Company, but there were only 10 to pull from—and only a single vowel. So they designed a comprehensive alphabet, with characters and numbers to boot, inspired by Snellen's original 5 x 5 grid design.
"We took some liberties on some parts, and stayed very conservative on other parts," the firm's art director Simen Schikulski told Fast Company. "We saw that there was some inconsistencies in the original letters in terms of shapes and sizes–as we expected, since the letters were created for optometrists, not as a typeface."
Flippr - BOGO 50% Off
Not your average broom
The Flippr makes traditional sweeping obsolete, with its two-in-one brush and roll functions.
Buy at Flippr
Use the promo code BOGO50
As Fast Company noted, the original set of letters intentionally made it difficult to discern letters like "C" from "O" at the teeny, tiny sizes meant for people with superhuman vision. So in order to make some of these more legible in other applications, ANTI Hamar also designed a number of alternatives.
Fábio Duarte Martins, a Type Designer who teaches typography at IADE University in Lisbon, worked on the project with Schikulski and his team. One clarification he notes is that the full alphabet in Optician Sans wasn't intended to expand the character set of the letters used in LogMAR charts, but is rather inspired by them.
"We took the LogMAR optotypes and did what in type design we call 'optical corrections,' or small adjustments to make their form aesthetically pleasing," he told Gizmodo by email. "The optotypes are made to measure visual acuity; so, for example, the equal stroke widths are important to measure how good your eyesight is. We didn't want to measure anything with Optician Sans. We just wanted a visually pleasing display typeface."
Ultimately in making the font freely available, Martins said both he and Schikulski hope that people have as much fun with it as they did.
"We're actually working on expanding the character set to support more languages," he said, "so we're just sharing something we think is nice with the world."
[Fast Company]
TechDesign


text:
Tag Archives: The Amazing Spider-Man 2
2014 Movies: The Not-So-Fabulous Fifteen Bottom Feeders!
2014 might not have been the best in terms of box office grosses or bums in seats, but there were a lot of really great movies across every genre.
These are not them. These are the fifteen movies that had me wanted my ninety-to-a-hundred-and-forty minutes back. A few did big box office; a few got many terrific reviews; most appalled all who saw them. I doubt any careers were ended by any of them, though some probably should have been.
Without any further ado, follow the jump for my least favorite films of 2014. Enjoy (if that's the right word)…
Continue reading 2014 Movies: The Not-So-Fabulous Fifteen Bottom Feeders! →
2014 Bottom FeedersA Most Violent YearDracula UntoldExodus: Gods and KingsExpendables 3Horrible Bosses 2Let's Be CopsMoviesNon-StopOuijaPompeiiTeenage Mutant Ninja TurtlesThe Amazing Spider-Man 2The F Word/What IfThe Other WomanTranscendenceTransformers: Age of Extinction
Movie Reviews, Movies
The Amazing Spider-Man is a Soulless Corporate Blockbuster. Michelle's Review
May 2, 2014 Michelle Alexandria	4 Comments
In an evil Green Goblin Broadway voice, sing with me, Spider-Man, Spider-Man, radioactive Spider-Man. After receiving lukewarm reviews from most and a downright hateful one from yours truly, The Amazing Spider-Man didn't exactly set the world on fire. They have a lot to live up to in the bigger budget sequel and are clearly betting the whole friendly neighborhood on it being a smash. The entire cast from the first film returns for the sequel, but then that's not saying much as it wasn't a particularly big one to begin with.
Continue reading The Amazing Spider-Man is a Soulless Corporate Blockbuster. Michelle's Review →
Marvel MoviesMovie ReviewsMoviesSony PicturesThe Amazing Spider-Man 2
The Amazing Spider-Man 2 Makes Spider-Man 3 Look Good!
May 2, 2014 Sheldon Wiebe
For all its flaws, Sam Raimi's Spider-Man 3 was committed. By comparison, The Amazing Spider-Man 2 a paint-by-numbers version of the comic. If not for the chemistry between Andrew Garfield and Emma Stone, TASM2 would be a complete bust – their on-again/off-again romance is the only part of the movie that feels at all real.
Continue reading The Amazing Spider-Man 2 Makes Spider-Man 3 Look Good! →
Andrew GarfieldColumbia PicturesEmma StoneMoviesThe Amazing Spider-Man 2
May 2014 Preview with Rotten Tomatoes and Opening Box Office Predictions (Part 1)
April 24, 2014 GeekScholars
Summer Blockbuster season is upon us, and GeekScholars Movie News is ready to release their Rotten Tomatoes and Opening Box Office Predictions for the first half of May 2014. Hit the jump to learn more about the movies covered in this episode, or hit play above! Continue reading May 2014 Preview with Rotten Tomatoes and Opening Box Office Predictions (Part 1) →
GodzillaMillion Dollar ArmNeighborsThe Amazing Spider-Man 2Walk of Shame
CinemaCon 2014, Movies
The Amazing Spider-Man 2 Swings Into Cinemacon
March 30, 2014 Michelle Alexandria
The rumors were true. Sony confirmed that yes indeed The Amazing Spider-Man is now an official "universe." There will be two spin-off films – Venom and The Sinister Six. After this big announcement Sony pictures surprised the crowd at CinemaCon by giving the audience a 30-minute taste of The Amazing Spider-Man 2. The three clips showcased an arc in the film.
Continue reading The Amazing Spider-Man 2 Swings Into Cinemacon →
CinemaCon 2014Sony PicturesSummer MoviesThe Amazing Spider-Man 2
Movie Trailers, Movies
Final Trailer: The Amazing Spider-Man 2!
March 19, 2014 Sheldon Wiebe
Take a leap (follow the jump) to the new (and final) trailer for The Amazing Spider-Man. It's all in the wrist.
The Amazing Spider-Man 2 opens on May 2nd.
Continue reading Final Trailer: The Amazing Spider-Man 2! →
More The Amazing Spider-Man 2 Footage
February 26, 2014 Michelle Alexandria
I don't know, I just don't know. Sony is getting out of control with all the footage for The Amazing Spider-Man 2. I feel like I've practically seen this thing. It looks miles better than the first film, but the web swinging moments aren't quite doing it for me. I will say the slow motion shot of Spider-Man flying through the air looks gorgeous. Here's 3 more minutes from The Amazing Spider-Man 2. This time out we get lots of Electro. There's a MASSIVE spoiler in here – If you look closely and know anything about Spider-Man's history.
Continue reading More The Amazing Spider-Man 2 Footage →
MoviesThe Amazing Spider-Man 2
Earth Hour and Spider-Man Join Forces To Save The Planet!
February 13, 2014 Sheldon Wiebe
Earth Hour is best known for its annual energy conservation 'Lights Out' campaign but it does so much more than that – it's a global force involved in work to preserve nature worldwide. And now, Earth Hour has named Spider-Man its first superhero ambassador – with a message to 'inspire individuals to use their power to become superheroes for the planet.
The powers that be at Earth Hour and Sony Pictures Entertainment have partnered to create a program called Earth Hour Blue that will set up crowdfunding for projects like the one that provides efficient cookstoves to prevent deforestation in the habitat of the Giant Panda. Members of The Amazing Spider-Man 2's cast, and director Marc Webb, have selected projects for which they feel a personal connection, as well.
For more information on Earth Hour, Earth Hour Blue and some of these programs, as well as the link to the Earth Hour/Spider-Man page, follow the jump.
Continue reading Earth Hour and Spider-Man Join Forces To Save The Planet! →
Andrew GarfieldEarth HourJamie FoxxMoviesThe Amazing Spider-Man 2
Spider-Man 2 Trailer
February 3, 2014 Michelle Alexandria
I'm going to be honest here, I didn't like the first Spider-Man but I'm hoping to love Spidey 2, but I'm just not sure about this trailer and the idea of this being a trilogy. I'm fairly positive that I can guess what the ending will be, but we'll see. Here is the brand new spot that aired during the Super-Bowl.
Continue reading Spider-Man 2 Trailer →
Movie TrailersMoviesSony PicturesThe Amazing Spider-Man 2
X-Men: Apocalypse Film, Wonder Woman Cast in Batman vs. Superman, Preview Review of The Amazing Spider-Man 2, The Adjustment Bureau Reviewed
December 11, 2013 GeekScholars
This week's episode of GeekScholars Movie News focuses on some very exciting developments in the world of comic-book movies.
First, news broke that the sequel to X-Men: Days of Future will be X-Men: Apocalypse, insinuating that the famous Marvel villain will serve as the primary antagonist. The GeekScholars break down everything you need to know about Apocalypse, and his role in the X-Men universe. Continue reading X-Men: Apocalypse Film, Wonder Woman Cast in Batman vs. Superman, Preview Review of The Amazing Spider-Man 2, The Adjustment Bureau Reviewed →
Batman vs. Supermanthe adjustment bureauThe Amazing Spider-Man 2X-Men
The Amazing Spider-Man Named Official Superhero of Times Square 2014!
December 10, 2013 Sheldon Wiebe
The Amazing Spider-Man will take part in the 2014 Ball Drop celebration in Times Square after being named the official superhero of Times Square by Times Square Alliance and Countdown Entertainment,the co-organizers of Times Square New Year's Eve. Everyone's favorite web-spinning wall-crawler will also take part in events leading up to the New Year's Eve countdown.
The evening will feature an exclusive clip from The Amazing Spider-Man 2 – and Spider-Man fans in NYC or one of the following surrounding New York Counties (Nassau, Westchester, Suffolk, Rockland), Connecticut Counties (Fairfield and Litchfield), and New Jersey Counties (Bergen and Hudson) could win the opportunity to meet him. Details are included in the press release following the jump.
Continue reading The Amazing Spider-Man Named Official Superhero of Times Square 2014! →
Countdown EntertainmentMoviesThe Amazing Spider-Man 2Times Square Alliance