Patent Application
20070156035
This invention relates generally to blood testing performed on patients, and more specifically to, an intravenous (IV) catheter configured to monitor patients blood serum lab values without requiring additional venapuncture, taking of blood samples, and transportation of the blood samples to a lab for testing and reporting.
Currently, nearly every patient admitted to a hospital, having outpatient surgery, or an invasive cardiology procedure requires both insertion of an IV catheter for fluid delivery and withdrawal of blood samples for blood serum lab testing. Examples of blood serum lab testing includes, but is not limited to, determining a level of electrolytes, a hemoglobin count, and a measure of hematocrit. Current procedures typically require that the patient be punctured multiple times. At least once for delivery of IV fluids and at least once more for the blood withdrawal.
Alternatively, the blood is withdrawn upon initial insertion of the IV catheter, placed in a container and sent to a lab for analysis, and once the blood samples have been withdrawn, the IV fluid delivery is initiated. However, if additional blood testing is needed, secondary venapuncture is required.
Both of these current procedures have drawbacks. One drawback is the requirement that the skin of the patient be punctured several times, once for IV fluid delivery and at least one more secondary venapuncture for blood draw. Other drawbacks include blood loss, increased likelihood of error, and the increased exposure of the healthcare provider to HIV and other blood borne pathogens with every puncture and when collecting the blood samples.
Other medical testing procedures performed at clinics, hospitals, and the like have similar drawbacks. For example, biopsies are performed, and the samples are transferred to a laboratory so that testing can be performed. Such procedures, though due care has been taken, can still result in the swapping of test results between patients.
In one aspect, an intravenous catheter is provided that comprises a catheter assembly, a valve, and an electro-chemical sampling device. The catheter assembly comprises an end portion configured for insertion into the bloodstream of a patient to deliver intravenous liquids. The valve, which in alternative embodiments may be a stop cock or flush valve, is configured to temporarily interrupt a flow of intravenous fluid into the blood stream, and the electro-chemical sampling device is located near the end portion of the catheter assembly.
In another aspect, a catheter is provided that comprises a hollow tube and an electro-chemical sampling device. The hollow tube comprises an end portion that is configured for insertion into the bloodstream of a patient. The electro-chemical sampling device is attached to the hollow tube approximate the end portion.
In still another aspect, a method for preparing an intravenous catheter for performing blood tests on a patient is provided. The method comprises configuring the catheter with an electrochemical sensing device configured for blood testing, providing a valve having an ability to interrupt any fluid infusion into the bloodstream of the patient through the catheter, and adapting the sensing device to provide data relating to blood testing to an external device.
Described herein is a catheter that is utilized to provide, in an intravenous (IV) embodiment, IV fluid to a patient. The catheter is also configured to monitor, for example, the patient's blood serum laboratory values without requiring additional, or secondary, venapuncture. Such a catheter also eliminates the need for the taking of blood samples from the patient and also removes the need to transport the blood samples to a laboratory for testing. Such a catheter is also thought to eliminate the possibility of reporting errors as laboratory test results ate transferred from the laboratory back to the healthcare provider.
While described herein as an IV catheter, it is to be understood the embodiments may be equally applied within other medical testing applications. For example, the embodiments may be applied for urinary tract testing, angioplasty and other testing that might occur within arteries and veins, as well as a replacements for biopsies.
As shown in
Catheter 10 is operable for the delivery of intravenous fluids. In addition, electro-chemical sampling device 20, through simple contact with a patients blood stream is operable to initiate lab testing sequences that can produce, for example, the patient's serum electrolyte levels, as well as hemoglobin and hematocrit testing. To provide such test results, in one embodiment, sampling device 20 is coated with one or more of glucose oxidase, dehydrogenase, and hexokinase which combine with glucose present in a bloodstream. In alternative embodiments, electro-chemical sampling device 20 may be utilized for diabetes testing as well as in applications where an electro-chemical sampling device is placed in contact with substances other than a patient's blood, for example, a urinary tract, an esophagus or stomach, and into masses that would be currently subject to biopsy. Other testing that may be performed utilizing various embodiments of sampling device 20 includes, but are not limited to, sodium level, potassium level, carbon dioxide level, venous oxygen level, calcium level, magnesium level, glucose level, BUN, platelet levels, leukocyte levels, monocyte levels, bleeding time, clotting time, and erythrocytes.
Various embodiments of sampling device 20 are reduced scale versions of sampling devices utilized in other applications. For example, similar to the test strips found in various blood glucose monitors, one embodiment of sampling device 20 is configured to perform testing based on an amount of electricity that passes through a blood sample adjacent sampling device 20. In this embodiment, the amount of electricity passing through the blood stream at sampling device 20 causes a signal to be passed through conductive strip 22 which is analyzed at the above described external equipment.
In an alternative embodiment not illustrated, catheter 10 further includes a light sourcing mechanism such that the blood sample passes between the light source and the sampling device 20. In this embodiment, the amount of light reflecting from sampling device 20 causes a signal to be passed through conductive strip 22 which is analyzed at the above described external equipment. In one embodiment, the interaction between the blood and sampling device 20 causes a color of sampling device 20 to change, which affects an amount of light that reflects from, or is absorbed by, sampling device 20.
While described herein in terms of a blood glucose monitor and a blood sample, it is to be understood that such a description should not be construed as limiting. The described embodiments of catheter 10 and sampling device 20 are applicable for performing tests outside of the intravenous application herein described, including, but not limited to, urinary tract testing, digestive tract testing, and any other application where a catheter may be utilized and for which laboratory tests are desired.
Referring once again to the IV catheter embodiment,
In order to produce usable test results, IV catheter 10 (and the other contemplated embodiments) include electro-chemical sampling device 20 which is configured for the particular tests to be performed.
In one embodiment, to provide undiluted blood to sampling device 20, catheter 10 is configured with a valve assembly 50.
Currently, at least some blood glucose testing for diabetics is done using a micro liter of separately drawn blood, a metering device, and an electro-chemical test strip. However, this method still requires an active puncture and a free flow of blood. Incorporating an electrochemical sampling device 20 into catheter 10 provides real time test results, eliminates blood loss, reduces error risks, and helps to eliminate the risk to the healthcare provider of exposure to HIV and other blood borne pathogens. Utilization of such a sampling device, as described above and configured for specific testing methods, also reduces the possibility of processing errors as the test results are provided at the patient, rather than from a remote lab.
While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.
