# US 6,537,243 B1 · Device and method for obtaining interstitial fluid from a patient for diagnostic tests > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,537,243 B1 - Document ID: US6537243B1 - Status: Granted - Kind: B1 - Application number: 09/689,527 - Filed: 2000-10-12 - Granted: 2003-03-25 - Earliest claimed: 2000-10-12 - Assignees: Abbott Laboratories - Inventors: Timothy P. Henning; Michael G. Lowery - Web page: https://patentgrep.com/patent/US6537243B1 ## CPC - A61B 5/14514: {using means for aiding extraction of interstitial fluid, e.g. microneedles or suction} - A61B 5/150022: {for capillary blood or interstitial fluid} - A61B 5/150061: {Means for enhancing collection} - A61B 5/150099: {by negative pressure, other than vacuum extraction into a syringe by pulling on the piston rod or into pre-evacuated tubes} - A61B 5/150389: {Hollow piercing elements, e.g. canulas, needles, for piercing the skin} - A61B 5/150442: {Blade-like piercing elements, e.g. blades, cutters, knives, for cutting the skin} - A61B 5/150503: {Single-ended needles (hollow piercing element tip design A61B5/150396)} - A61B 5/150946: {Means for varying, regulating, indicating or limiting the speed or time of blood collection} - A61B 5/150969: {Low-profile devices which resemble patches or plasters, e.g. also allowing collection of blood samples for testing} - A61B 5/15142: {Devices intended for single use, i.e. disposable} - A61B 2010/008: {Interstitial fluid} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## 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. ## Claims ### Claim 1 An assembly for obtaining fluid from an opening formed in the skin of a patient comprising: (a) a device suitable for use in withdrawing fluid from an opening formed in the skin of a patient, said device comprising a hollow tube comprising a wall surrounding a cavity, said hollow tube having a first end and a second end, said wall running from said first end to said second end, said wall having a multiplicity of pores formed therein; (b) an elongated element capable of forming said opening in said skin, said elongated element capable of being inserted in said first end of said hollow tube and projecting beyond said second end of said tube. ### Claim 2 (depends on 1) The assembly of claim 1, wherein said wall of said tube comprises a polymeric material. ### Claim 3 (depends on 1) The assembly of claim 1, wherein said tube has a length ranging from about 2 mm to about 10 mm. ### Claim 4 (depends on 1) The assembly of claim 1, wherein said tube has a length ranging from about 5 mm to about 10 mm. ### Claim 5 (depends on 1) The assembly of claim 1, wherein said tube is cylindrical in shape. ### Claim 6 (depends on 5) The assembly of claim 5, wherein the inside diameter of said tube is at least about 0.25 mm but the inside diameter of said tube does not exceed about 1.25 mm. ### Claim 7 (depends on 5) The assembly of claim 5, wherein said tube has an outside diameter ranging from a minimum outside diameter of about 0.45 mm to a maximum outside diameter of about 2.25 mm. ### Claim 8 (depends on 5) The assembly of claim 5, wherein a maximum pore size is less than the inside diameter of the tube. ### Claim 9 (depends on 1) The assembly of claim 1, wherein said tube is in the shape of a parallelepiped. ### Claim 10 (depends on 1) The assembly of claim 1, wherein said wall of said tube has a porosity of from about 1% to about 10%. ### Claim 11 (depends on 1) The assembly of claim 1, wherein the number of pores per mm of tube length ranges from about 10 to about 10,000. ### Claim 12 (depends on 1) The assembly of claim 1, wherein a maximum pore diameter does not exceed 1 mm and a lower limit of pore diameter is not less than 5 micrometers. ### Claim 13 (depends on 1) The assembly of claim 1, further including a patch bearing a layer of adhesive on one major surface thereof for adhering said assembly to said skin. ### Claim 14 (depends on 1) The assembly of claim 1, further including a holder for said elongated element. ### Claim 15 (depends on 1) The assembly of claim 1, further including guides for aligning a detector holder. ### Claim 16 (depends on 1) A method for obtaining interstitial fluid from the body of a patient, said method comprising the steps of: (a) providing the assembly of claim 1, said tube surrounding said elongated element; (b) inserting said elongated element and said tube surrounding said elongated element into said body of said patient; (c) removing said elongated element from said cavity of said tube; and (d) collecting interstitial fluid from said body of said patient, said interstitial fluid exiting from said first end of said tube. ### Claim 17 (depends on 16) The method of claim 16, further including the step of determining the blood glucose level from said collected interstitial fluid. ### Claim 18 (depends on 16) The method of claim 16, wherein said interstitial fluid is collected with the aid of vacuum.