1. Field of the Invention
The present invention relates generally to the medical field; and more particularly to a device for removal of gasses from fluids delivered to a patient during a medical procedure.
2. Description of Related Art
It is often desirable to introduce one or more fluids to an internal site of a patient during a medical procedure. The fluid introduced can be, for example, a drug, an anesthetic, blood, saline, flush solution, a marker dye, intravenous nutrients, or other bioactive fluids or soluble medications. Fluid delivery may be necessary or desirable in medical procedures including conventional angiography, interventional angiography, neurointerventional angiography, cardiac catheterization, arterial pressure monitoring, Swanz-Ganz catheterization, indwelling catheters, and intravenous or interarterial delivery procedures.
In order to prevent or minimize the risk of injury to the patient from air embolism, it is generally necessary to eliminate air or other gasses from the fluid delivered. Typically, fluid delivery lines are manually cleared of visible air bubbles by flushing prior to use. Existing drip chamber devices used with some fluid delivery systems to reduce the likelihood of air embolism must be maintained in an upright position to prevent the formation of air bubbles in a fluid delivery line. Thus, inadvertent tilting of the device can endanger the patient. The risk of air bubble formation increases with increasing drip rate. Dissolved gasses within the delivered fluid can form bubbles out of solution due to pressure changes, temperature changes, flow irregularities, or other factors. Thus it can be seen that a need yet exists for a gas elimination device for removing gas bubbles and/or dissolved gas from fluids delivered to an internal site of a patient during a medical procedure. A further need exists for such a device that is not required to be maintained in an upright configuration, and that permits use with standard fluid delivery equipment. A need also exists for such a device that can be located at a point in the fluid delivery line near the patient, to minimize the potential for bubble formation between the device and the patient.
It is frequently desirable to access the internal site of delivery of the fluid, as by a surgical tool, and/or monitoring equipment. previously known devices typically do not make provision for access therethrough. Thus, it can be seen that a need exists for a gas elimination device that permits access to the fluid delivery site by a surgical tool or monitoring device.
It is to the provision of a gas elimination device meeting these and other needs that the present invention is primarily directed.
Briefly described, in preferred form, one aspect of the invention is a device for removing gas bubbles and dissolved gases from fluids introduced to a patient during medical procedures. The device can be used for intravenous or intraarterial applications, including without limitation: conventional angiography, interventional angiography, neurointerventional angiography, cardiac catheterization, arterial pressure monitoring, Swanz-Ganz catheters, syringes or intravenous lines for injection of drugs or solutes or nutrients, arterial lines, venous lines, and indwelling catheters, or during operative procedures. The device preferably includes a housing having a first end comprising an inlet port, a second end comprising an outlet port, an interior surface extending between the inlet port and the outlet port, and a vent port between the inlet port and the outlet port. The device preferably further includes at least one hollow fiber membrane within the housing, each having a first end adjacent the inlet port and a second end adjacent the outlet port. A first fluid tight seal is provided between the first end of the at least one hollow fiber membrane and the interior surface of the housing. A second fluid tight seal is provided between the second end of the at least one hollow fiber membrane and the interior surface of the housing.
In another aspect, the present invention comprises a device for removal of gas from a liquid, the device comprising a housing having a fluid inlet, a fluid outlet and a gas vent; a sealed chamber within the housing between the fluid inlet and the fluid outlet, and in communication with the gas vent; and a plurality of hollow fiber membranes extending through the sealed chamber, each having a first end in communication with the fluid inlet and a second end in communication with the fluid outlet.
In another aspect, the present invention comprises a device for removal of gas from a liquid infused to an internal delivery site, and for allowing passage of a medical implement to the internal delivery site. The medical implement may be, for example, a catheter, a catheter guide wire, a probe, a laparoscope, or another surgical or monitoring instrument. The device preferably includes a housing comprising a fluid inlet, a fluid outlet and a gas vent. A sealed chamber is preferably provided within the housing between the fluid inlet and the fluid outlet. The sealed chamber is in communication with the gas vent. A plurality of hollow fiber membranes extend through the sealed chamber, each having a first end in communication with the fluid inlet and a second end in communication with the fluid outlet. A passage is provided through the sealed chamber for allowing passage of the medical implement through the device to the delivery site. The passage comprises a first end in communication with the fluid inlet, a second end in communication with the fluid outlet, and a sleeve extending between the first and second ends.
Another aspect of the present invention is a method of removing gas from a liquid infused to an internal delivery site of an organism, and accessing the internal delivery site with a medical implement. The method preferably includes passing the liquid through at least one hollow fiber membrane within a housing; degassing the liquid by removing gasses through pores in the at least one hollow fiber membrane; infusing the liquid to the internal delivery site; and accessing the internal delivery site by passing the medical implement through a passage extending through the housing.
Another aspect of the present invention is a method of fabricating a device for removal of a gas from a liquid. The method preferably comprises providing a housing having an inlet port, an outlet port and a vent port; installing a plurality of hollow fiber membranes within the housing, extending generally from adjacent the inlet port to adjacent the outlet port; installing an annulus within the housing, extending generally from adjacent the inlet port to adjacent the outlet port; and applying first and second sealing means at the ends of the plurality of hollow fiber membranes and the ends of the annulus, to form a fluid tight seal between the plurality of hollow fiber membranes, the annulus, and the housing.
These and other features and advantages of preferred forms of the present invention are described more fully herein with reference to the accompanying drawing figures.