Abstract:
The present disclosure provides the use of vacuum to enhance the transdermal transport of fluids in sampling methods for the detection of analytes in a patient's blood.
Abstract:
Provided are methods of measuring analyte concentrations in interstitial fluid samples, methods of determining accuracy of subcutaneously implantable analyte sensors, methods of manufacturing and determining calibration factors for subcutaneously implantable analyte sensors, as well as subcutaneously implantable analyte sensors manufactured according to the described methods and having a high level of accuracy. Methods of determining the concentration of an analyte in a bodily sample, and methods of extracting interstitial fluid are also provided.
Abstract:
A biosensor for determining the concentration of an analyte, such as, for example, ALT, in a sample of biological fluid, such as, for example, whole blood, comprising: (a) a base layer; (b) a detecting layer comprising a reference electrode and a working electrode, the surface of the electrically conductive portion of the working electrode being sufficiently smooth so that determination of the concentration of an analyte present in a low concentration, e.g., less than 1 mM, can be made; (c) a layer overlying said electrodes, said layer comprising dried reagents; and (d) an anticoagulant disposed in such a location that it will prevent the sample from coagulating during the determination. The biosensor preferably further includes a fluid-transporting layer to aid in delivering the sample from a sample application zone to the electrodes. The biosensor preferably further includes a covering layer overlying the electrode area to reduce evaporation of the sample during the assay and to help define the fluid transport path and the volume of fluid over the detecting layer.
Abstract:
A device for obtaining a sample of interstitial fluid from a patient for use in monitoring the level of blood glucose in the patient. The device comprises a hollow tube having a wall surrounding a cavity, wherein the wall of the tube contains a multiplicity of pores.
Abstract:
Method and apparatus for obtaining a sample of blood from a patient for subsequent diagnostic tests, e.g., glucose monitoring. In one aspect of the invention, the method comprises the steps of:(a) placing a blood collection device over a region on the surface of the skin from which said sample is to be obtained,(b) forming a seal between said blood collection device and said surface of the skin,(c) creating a vacuum sufficient to result in said surface of the skin becoming stretched and engorged with blood,(d) triggering a lancing assembly and causing a lancet to penetrate said skin,(e) retracting said lancet,(f) withdrawing blood toward and onto a fluid collector, and(g) releasing the vacuum.In another aspect of the invention, an apparatus for carrying out the method described previously is provided. The apparatus comprises:(a) a housing having a sealable chamber located therein and a sealable opening in fluid communication with said sealable chamber,(b) a power source,(c) a vacuum pump operably connected to said power source, said vacuum pump in communication with said sealable chamber,(d) a lancing assembly positioned within said housing, said lancing assembly capable of moving a lancet towards said sealable opening, and(e) a fluid collector positioned in said sealable chamber, said fluid collector in fluid communication with said sealable opening.
Abstract:
A method for increasing the permeability of the stratum corneum by means of a source of light, preferably a laser, more preferably a pulsed laser. By increasing the permeability of the stratum corneum, access to the interstitial fluid is achieved, thereby enabling measurement of analytes in the interstitial fluid. In one aspect, the method comprises the steps of:(a) providing a source of light having a wavelength of from about 930 nm to about 1040 nm; and(b) exposing a region of the stratum corneum of the patient to said source of light for a period of time sufficient to form an opening in the stratum corneum.Preferably, exposure of the region of the stratum corneum to the source of light is ceased when an amount of interstitial fluid fills the opening in the stratum corneum, which amount is sufficient to cause the scatter intensity of the light reflected from the surface of the interstitial fluid occupying the opening in the stratum corneum to differ from the scatter intensity of the light reflected from a region of the stratum corneum that is substantially free of interstitial fluid. The invention also involves an apparatus for carrying out the foregoing method.
Abstract:
A sensor for measuring the concentration of an analyte in a solution is disclosed. The sensor may be adapted for use as either an amperometric or a potentiometric sensor. It includes a membrane having a biologically active protein immobilized within. The membrane is attached and reliably sealed to a housing by means of ultrasonic welding, either directly or indirectly. Further, the membrane may be compressed to a fraction of its original dimensions. Metallic parts of the device may, optionally, be physically isolated from the sample solution to reduce corrosion. These features operate synergistically so that the claimed device exhibits relatively fast response and recovery times, is reliably leak-proof, and may be constructed in relatively small sizes.
Abstract:
Method and apparatus for obtaining a sample of blood from a patient for subsequent diagnostic tests, e.g., glucose monitoring. In one aspect of the invention, the method comprises the steps of: (a) placing a blood collection device over a region on the surface of the skin from which said sample is to be obtained, (b) forming a seal between said blood collection device and said surface of the skin, (c) creating a vacuum sufficient to result in said surface of the skin becoming stretched and engorged with blood, (d) triggering a lancing assembly and causing a lancet to penetrate said skin, (e) retracting said lancet, (f) withdrawing blood toward and onto a fluid collector, and (g) releasing the vacuum. In another aspect of the invention, an apparatus for carrying out the method described previously is provided. The apparatus comprises: (a) a housing having a sealable chamber located therein and a sealable opening in fluid communication with said sealable chamber, (b) a power source, (c) a vacuum pump operably connected to said power source, said vacuum pump in communication with said sealable chamber, (d) a lancing assembly positioned within said housing, said lancing assembly capable of moving a lancet towards said sealable opening, and (e) a fluid collector positioned in said sealable chamber, said fluid collector in fluid communication with said sealable opening.
Abstract:
Method and apparatus for obtaining a sample of blood from a patient for subsequent diagnostic tests, e.g., glucose monitoring. In one aspect of the invention, the method comprises the steps of: (a) forming an unobstructed opening in the area of the skin from which the sample of blood is to be extracted; and (b) extracting the sample of blood from the unobstructed opening in the skin, with the aid of a vacuum and a stretching of the skin. In another aspect of the invention, an apparatus for carrying out the method described previously is provided. The apparatus comprises: (a) a device for forming an unobstructed opening in an area of skin from which said sample is to be extracted, preferably a lancing assembly; and (b) a vacuum pump. Preferably, the apparatus also includes a housing.
Abstract:
A method and apparatus for obtaining a sample of interstitial fluid from a patient for subsequent diagnostic tests, e.g., glucose monitoring. In one aspect of the invention, the method comprises the steps of (a) treating an area of the skin with vacuum or heat or both vacuum and heat to increase the availability of interstitial fluid at that area of the skin; (b) forming an opening in the treated area of the skin; and (c) extracting the sample of interstitial fluid from the opening in the skin, with the aid of vacuum and stretching of the skin. In another aspect of the invention, an apparatus for carrying out the method described previously is provided. Th apparatus comprises (a) a device for forming an unobstructed opening in the area of the skin from which the sample is to be extracted, preferably a lancing assembly; and (b) a vacuum pump. Preferably, the apparatus also includes a housing.