The present invention relates to fluid drug delivery devices and, in particular, it concerns a portable insulin delivery device.
There are known portable insulin delivery devices, commonly referred to as insulin pumps, that generally consist of a pump mechanism, an insulin container, a processor, and a power source for the processor and pump mechanism. The pump mechanisms of prior art generally use motor driven push rods to push a piston into the insulin containment region of the insulin container, thus forcing the insulin into a delivery tube and therefore into the patient. The inventions of prior art have gone to great lengths to devise variations of the motor driven push rod and piston assembly that is accurate, reliable, and space efficient. Disclosures representative of this case of devices will be found in U.S. Pat. Nos. 6,248,093, 5,637,095, 5,097,122, and 5,505,709. Devices based on this configuration suffer from two inherent problems, the motor and the push rod and piston assembly, as discussed in the following paragraphs.
The amount of insulin delivered to the patient is therefore controlled by the speed at which the motor turns (RPM""s) and the amount of time the motor is turning. The accuracy of insulin delivery is, then, dependent on the reliability and accuracy of the motor. Variations on RPM""s will cause variations in the amount of insulin delivered to the patient. Due to a limited power supply the motor is turned on and off at preset intervals. Even when the system is operating properly, the medication is delivered in xe2x80x9cspurtsxe2x80x9d and the delivery rate is determined as an average over time.
As the motor turns, it moves a push rod, which in turn moves a piston that forces the insulin out of the container. The seal between the piston and the side of the container must be very tight in order to prevent leakage of insulin. A side effect of this tightness is the tendency of the piston to move forward at an uneven rate. That is to say, that the piston may stick and then jump forward. This uneven movement of the piston causes uneven delivery of the insulin to the patient.
The prior art has developed elaborate devices to detect and respond to occlusion and other flow rate or system malfunctions as is demonstrated in U.S. Pat. Nos. 5,097,122, 5,462,525, 4,619,653, and 5,647,853. In cases of occlusion, most commonly these devices allow the motor to continue to push against the blockage. Due the limitation of the motor, and since this happens only in cases of full occlusion, this is not a very satisfactory solution. Further, if the blockage is opened, the pressure built up in the container and delivery tube is released through the tube, thereby forcing a possibility dangerously larger than prescribed dose of insulin into the patient. One proactive approach to occlusion includes the use of xe2x80x9cinertxe2x80x9d cleaning fluid being pumped through the device and into the patient.
There is therefore a need for a portable insulin delivery device that is able to deliver the insulin at a substantially consistent dosage rate, quickly detect flow rate malfunction, overcome blockage with substantially no affect on the prescribed dosage or the use of non-medicative cleaning fluids, and has very low energy requirements. It would be preferable if the device had low power requirements, and was more compact and economical than devices currently in use.
The present invention is a fluid drug delivery device.
According to the teachings of the present invention there is provided, a fluid drug delivery device comprising: a) a fluid supply assembly having a chamber, a piston, and a spring element, the piston deployed within the chamber so as to define a fluid containment volume within the chamber, the spring element deployed so as to bias the piston toward the fluid containment volume so as to pressurize an amount of the fluid drug supplied within the fluid containment volume, the containment volume having a supply outlet; b) a pressure regulator having a fluid inlet in fluid communication with the fluid supply assembly, the pressure regulator also having a fluid outlet; and c) a flow control assembly in fluid communication with the pressure regulator fluid outlet.
According to a further teaching of the present invention, the flow control assembly includes: a) a flow control valve interconnected with the fluid outlet; b) a flow actuator deployed so as to regulate the flow control valve thereby varying amounts of fluid flowing through the flow control valve; c) a positioning component deployed so as to properly position the flow control valve actuator in relationship to the flow control valve; and d) a processing unit electronically interconnected with a pressure sensor and the flow actuator, the processing unit configured so as to use data from the pressure sensor to determine activation of the flow actuator.
According to a further teaching of the present invention, the pressure regulator includes an elongated pressure reduction passageway configured so as to reduce the pressure in the fluid thereby creating a pressure differential between the fluid inlet and the fluid outlet.
According to a further teaching of the present invention, at least one pressure sensor is interconnected with at least a first and a second pressure sensing points, the pressure sensing points being located at intervals along the flow reduction passage.
According to a further teaching of the present invention, the flow actuator includes a piezoelectric actuator.
According to a further teaching of the present invention, the positioning component includes a rotatable adjustment shaft manually rotated by a thumb-wheel, the shaft and the thumb-wheel being connected by way of an over-running clutch mechanism configured to allow the thumb-wheel to continue turning while discontinuing rotation of the shaft when the flow actuator is properly positioned in relationship to the flow control valve.
According to a further teaching of the present invention, the processing unit is further interconnected to an alarm unit, the processing unit using data from the pressure sensor to determine activation of the alarm unit.
According to a further teaching of the present invention, the flow actuator, the manual positioning component, the pressure sensor, and the processing unit are housed in a base unit further including a processing unit display, a processing unit input keypad, and a power supply.
According to a further teaching of the present invention, the fluid supply assembly, the flow reduction passage, and the flow control valve, are housed in a removable cartridge unit.
There is also provided according to the teachings of the present invention, a fluid drug delivery device comprising: a) a fluid supply assembly; b) an elongated pressure reduction passageway having a fluid inlet in fluid communication with the fluid supply assembly, and a fluid outlet, the elongated passageway configured so as to reduce pressure in the fluid thereby creating a pressure differential between the fluid inlet and the fluid outlet; c) at least one pressure sensor interconnected with a first and a second pressure sensing points, the pressure sensing points located at intervals along the elongated passageway so as to discern a pressure differential between the first and second pressure sensing points; and d) a flow control assembly responsive to the pressure sensor and controlled in response to the pressure differential.
According to a further teaching of the present invention, the flow control assembly includes: a) a flow control valve interconnected with the fluid outlet; b) a flow actuator deployed so as to regulate the flow control valve thereby varying amounts of fluid flowing through the flow control valve; c) a positioning component deployed so as to properly position the flow control valve actuator in relationship to the flow control valve; and d) a processing unit electronically interconnected with a pressure sensor and the flow control valve actuator, the processing unit configured so as to use data from the pressure sensor to determine activation of the flow control valve actuator.
According to a further teaching of the present invention, the flow actuator includes a piezoelectric actuator.
According to a further teaching of the present invention, the positioning component includes a rotatable adjustment shaft manually rotated by a thumb-wheel, the shaft and the thumb-wheel being connected by way of an over-running clutch mechanism configured to allow the thumb-wheel to continue turning while discontinuing rotation of the shaft when the flow control valve actuator is properly positioned in relationship to the flow control valve.
According to a further teaching of the present invention, the processing unit is further interconnected to an alarm unit, the processing unit using data from the pressure sensor to determine activation of the alarm unit.
According to a further teaching of the present invention, the flow actuator, the manual positioning component, the pressure sensor, and the processing unit are housed in a base unit further including a processing unit display, processing unit input keypad, and a power supply.
According to a further teaching of the present invention, the fluid supply assembly, the flow reduction passage, and the flow control valve, are housed in a removable cartridge unit.
There is also provided according to the teachings of the present invention, a fluid drug delivery device comprising: a) a fluid supply assembly; b) a pressure reduction passage having a fluid inlet in fluid communication with the fluid supply assembly, the flow passage also having a fluid outlet; c) a flow control valve interconnected to the fluid outlet; and d) a piezoelectric actuator deployed so as to regulated the flow control valve thereby varying the amount of fluid flowing through the flow control valve.
According to a further teaching of the present invention, there is further included: a) a positioning component deployed so as to position the flow control valve actuator in a predefined spatial relationship to the flow control valve; and b) a processing unit electronically interconnected with a pressure sensor and the flow control valve actuator, the processing unit configured so as to use data from the pressure sensor to determine activation of the flow control valve actuator.
According to a further teaching of the present invention, the positioning component includes a rotatable adjustment shaft manually rotated by a thumb-wheel, the shaft and the thumb-wheel being connected by way of an over-running clutch mechanism configured to allow the thumb-wheel to continue turning while discontinuing rotation of the shaft when the flow control valve actuator is properly positioned in relationship to the flow control valve.
According to a further teaching of the present invention, the processing unit is further interconnected to an alarm unit, the processing unit using data from the pressure sensor to determine activation of the alarm unit.
According to a further teaching of the present invention, the, flow actuator, the manual positioning component, the pressure sensor, and the processing unit are housed in a base unit further including a processing unit display, processing unit input keypad, and a power supply.
According to a further teaching of the present invention, the fluid supply assembly, the flow reduction passage, and the flow control valve, are housed in a removable cartridge unit.
There is also provided according to the teachings of the present invention, a fluid drug delivery device comprising: a) a portable base unit including, a flow actuator, a manual positioning component, at least one pressure sensor, a processing unit, a display, keypad and a power source for the processing unit are housed in a base unit; and b) a cartridge unit that is removably interconnected to the base unit, the cartridge including a fluid supply assembly, a pressure reduction passage, and a flow control valve, the fluid supply assembly providing a pre-pressurized chamber containing a quantity of fluid drug.
According to a further teaching of the present invention, the flow actuator is a piezoelectric actuator deployed so as to regulate the flow control valve thereby varying the amount of fluid flowing through the flow control valve.
According to a further teaching of the present invention, the manual positioning component includes a rotatable adjustment shaft manually rotated by a thumb-wheel, the shaft and the thumb-wheel being connected by way of an over-running clutch mechanism configured to allow the thumb-wheel to continue turning while discontinuing rotation of the shaft when the flow control valve actuator is properly positioned in relationship to the flow control valve.
According to a further teaching of the present invention, the processing unit is electronically interconnected with the pressure sensor and the piezoelectric actuator, the processing unit configured so as to use data from the pressure sensor to determine activation of the piezoelectric actuator.
According to a further teaching of the present invention, the pre-pressurized chamber is accomplished by use of a piston deployed within the chamber so as to define a fluid containment volume within the chamber, a spring element deployed so as press the piston into the fluid containment volume so as to pressurize the quantity of fluid drug supplied within the fluid containment volume.
According to a further teaching of the present invention, the pressure reduction passage is an elongated passageway interconnected to the fluid supply assembly, the elongated passageway having a fluid inlet and a fluid outlet, the elongated passageway configured so as to reduce the pressure in the fluid thereby creating a pressure differential between the fluid inlet and the fluid outlet.