US 4,685,463 AGranted

Device for continuous in vivo measurement of blood glucose concentrations

OwnerR. Bruce Williamsinventor

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Abstract

A device is disclosed for continuous in vivo measurement of blood glucose concentrations in arterial blood. A quantity of glucose oxidase enzyme is confined within at least one elongate double-lumened tube by means of a semi-permeable membrane tubule permeable to permit diffusion of glucose from blood passing through an inner lumen of the tube into an outer lumen in which the enzyme is confined. The enzyme catalyzes the oxidation of glucose to produce heat. The tube is insulated so that the heat produced by the glucose oxidation is transferred to the blood flowing through the inner lumen. Either micro-thermocouples or solid state temperature sensors are positioned to measure the increase in temperature of the blood to produce a signal that is a function of the glucose concentration in the blood.

Claims12

Dependent claims

A device for continuous in vivo measurement of blood glucose concentration, comprising:

at least one elongate, double passageway having a first passageway adapted to be in flow communication with one or more small arteries to receive and conduct a flow of blood and to deliver the flow of blood back to one or more veins, and having a second passageway adjacent said first passageway;
a semi-permeable membrane wall located within said double passageway to separate said first passageway from said second passageway, said membrane wall being permeable to permit diffusion therethrough of glucose;
a quantity of enzyme located within said second passageway for catalyzing the oxidation of glucose diffusing into said second passageway to generate heat;
means for insulating said double passageway to substantially eliminate radial heat transfer out of said double passageway;
and
means for measuring the increase in temperature of blood passing through said first passageway, whereby glucose within the blood flowing in said first passageway diffuses through said membrane wall into said second passageway and is oxidized, generating heat and causing an increase in the temperature of blood flowing in said first passageway, with the magnitude of the increase measured by said means for measuring being a function of the glucose concentration in the blood.

3 more elements

A device for continuous, in vivo measurement of glucose concentration, comprising:

a module having a plurality of elongate, double-lumened tubes with said tubes extending through said module from an entry end thereof to an exit end thereof, said tubes having outer lumens generally concentrically disposed of inner lumens that are defined by semi-permeable membrane tubules permeable to permit diffusion of glucose from said inner lumens to said outer lumens;
said inner lumens adapted to be in flow communication with one or more small arteries to receive and conduct a flow of blood through said double-lumened tubes, and to deliver the flow of blood back to one or more veins;
a quantity of enzyme located in said outer lumens for catalyzing the oxidation of glucose diffusing into said outer lumens to generate heat;
means for substantially eliminating radial heat transfer out of each of said tubes;
and
means for producing a signal having a magnitude proportionate to the magnitude of the temperature increase of blood flowing through said inner lumens, whereby glucose within the blood flowing in said inner lumens diffuses through said membrane tubules into said outer lumens and is oxidized, generating heat and causing an increase in the temperatue of blood flowing in said inner lumens, with the magnitude of said signal being a function of the glucose concentration in the blood.

3 more elements

Dependencies are inferred from the claim text.