Microsensor needle for pH measurement in tissue
First Claim
1. A sensor probe for in-situ measurement of pH in a human tissue environment comprising:
- a hollow needle having a tip and a back end, the tip being insertable through tissue into the human tissue environment;
an optic cable comprising a light conduit surrounded by a cladding, wherein a first end of the light conduit not covered by the cladding has an outer diameter substantially conforming to the inner diameter of the hollow needle, is inserted from the back end of the needle, and extends to within a predetermined distance of the tip to define a cavity within the tip, wherein the optic cable is fixed to the hollow needle with the cladding abutting the back end of the needle;
a porous dye layer within the cavity adjacent to the first end of the light conduit, wherein the dye layer has a response to excitation light delivered through the light conduit that varies according to the pH of the human tissue environment; and
an overcoat layer deposited on the dye layer, wherein the overcoat layer is ionically permeable and substantially opaque at a light wavelength corresponding to the variable response of the dye layer.
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Accused Products
Abstract
A sensor probe for in-situ measurement of pH in a human tissue (e.g., cardiovascular) environment comprises a hollow needle having a tip and a back end. The tip is insertable into the tissue. An optic cable comprises a light conduit surrounded by a cladding. A first end of the light conduit is inserted from the back end of the needle and extends to within a predetermined distance of the tip to define a cavity within the tip. A porous dye layer is contained within the cavity, wherein the dye layer has a response to excitation light delivered through the light conduit that varies according to the pH of the tissue environment. An overcoat layer is deposited on the dye layer, wherein the overcoat layer is ionically permeable and substantially opaque at a light wavelength corresponding to the variable response of the dye layer.
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Citations
18 Claims
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1. A sensor probe for in-situ measurement of pH in a human tissue environment comprising:
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a hollow needle having a tip and a back end, the tip being insertable through tissue into the human tissue environment; an optic cable comprising a light conduit surrounded by a cladding, wherein a first end of the light conduit not covered by the cladding has an outer diameter substantially conforming to the inner diameter of the hollow needle, is inserted from the back end of the needle, and extends to within a predetermined distance of the tip to define a cavity within the tip, wherein the optic cable is fixed to the hollow needle with the cladding abutting the back end of the needle; a porous dye layer within the cavity adjacent to the first end of the light conduit, wherein the dye layer has a response to excitation light delivered through the light conduit that varies according to the pH of the human tissue environment; and an overcoat layer deposited on the dye layer, wherein the overcoat layer is ionically permeable and substantially opaque at a light wavelength corresponding to the variable response of the dye layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of manufacturing a sensor probe for in-situ measurement of pH in a human tissue environment, comprising the steps of:
- preparing a hollow needle having a slanted tip and a back end, the slanted tip being insertable through tissue into the human tissue environment;
preparing a cladded optic cable by removing the cladding from a first end of a light conduit within the optic cable where the light conduit not covered by the cladding has an outer diameter substantially conforming to the inner diameter of the hollow needle;
attaching a spacing jig onto the slanted tip of the hollow needle wherein the spacing jig has a finger extending from a base, the spacing jig being attached to the needle so that the slanted tip contacts the based and the finger extends into the interior of the hollow needle to define a cavity;
inserting the first end of the light conduit through the back end of the hollow needle to abut the finger of the spacing jig;
fixing the optic cable to the hollow needle with the cladding abutting the back end of the needle;
removing the spacing jig from the hollow needle to expose the cavity;
applying a porous dye layer within the cavity adjacent to the first end of the light conduit, wherein the dye layer has a response to excitation light delivered through the light conduit that varies according to the pH of the human tissue environment; and
applying an overcoat layer on the dye layer, wherein the overcoat layer is ionically permeable and substantially opaque at a light wavelength corresponding to the variable response of the dye layer. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
- preparing a hollow needle having a slanted tip and a back end, the slanted tip being insertable through tissue into the human tissue environment;
Specification