Membrane and electrode structure for implantable sensor
First Claim
1. A measuring device for determining concentration of a first material in an environment in contact with the device, which first material reacts within said device in presence of a catalyst with a second material to form a third material;
- and which device comprises;
a membrane comprising a body, a surface in contact with said environment, and at least one discrete hydrophilic region in communication with said body, wherein said hydrophilic region is permeable to said first and second materials, and said body is otherwise permeable to said second material and essentially impermeable to said first material, wherein both said first and second materials diffuse into said device from said environment through said surface;
a catalyst within said hydrophilic region wherein reaction of said first and second materials occurs;
at least one critical zone within said hydrophilic region containing said catalyst;
at least one sensor, having a surface communicating with at least one said hydrophilic region and sensitive to either said second material or said third material and producing a signal indicative of the concentration of said second or third material in said region; and
a control responsive to said signal for comparing said signal to a reference to determine the concentration of said first material in said environment;
wherein further an average vector direction of diffusion of said first material in said critical zone is substantially parallel to an average vector direction of diffusion of said first material in said hydrophilic region.
2 Assignments
0 Petitions
Accused Products
Abstract
The invention is the design of a biological measuring device for the determination of the concentration of biomolecules (e.g. glucose) in an environment which is designed for implantation into an individual or for use in the context of an external apparatus. The device contains a composite membrane that is essentially entirely permeable to oxygen and permeable to larger biomolecules only in discrete hydrophilic regions. The membrane diffusionally limits the access of biomolecules to an enzyme, present in the hydrophilic region that catalyzes the oxidation of the biomolecule to produce hydrogen peroxide. A sensor in communication with the hydrophilic region is used to determine the amount of product produced or the amount of excess oxygen present allowing for the concentration of the biomolecule to be determined.
-
Citations
27 Claims
-
1. A measuring device for determining concentration of a first material in an environment in contact with the device, which first material reacts within said device in presence of a catalyst with a second material to form a third material;
- and which device comprises;
a membrane comprising a body, a surface in contact with said environment, and at least one discrete hydrophilic region in communication with said body, wherein said hydrophilic region is permeable to said first and second materials, and said body is otherwise permeable to said second material and essentially impermeable to said first material, wherein both said first and second materials diffuse into said device from said environment through said surface; a catalyst within said hydrophilic region wherein reaction of said first and second materials occurs;
at least one critical zone within said hydrophilic region containing said catalyst;at least one sensor, having a surface communicating with at least one said hydrophilic region and sensitive to either said second material or said third material and producing a signal indicative of the concentration of said second or third material in said region; and a control responsive to said signal for comparing said signal to a reference to determine the concentration of said first material in said environment; wherein further an average vector direction of diffusion of said first material in said critical zone is substantially parallel to an average vector direction of diffusion of said first material in said hydrophilic region. - View Dependent Claims (4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
- and which device comprises;
-
2. A measuring device for determining concentration of a first material in an environment in contact with the device, which first material reacts within said device in presence of a catalyst with a second material to form a third material;
- and which device comprises;
a membrane comprising a body, a surface in contact with said environment, and at least one discrete hydrophilic region in communication with said body, wherein said hydrophilic region is permeable to said first and second materials, and said body is otherwise permeable to said second material and essentially impermeable to said first material, wherein both said first and second materials diffuse into said device from said environment through said surface; a catalyst within said hydrophilic region wherein reaction of said first and second materials occurs;
at least one critical zone within said hydrophilic region containing said catalyst, wherein the critical zone has a length and an average equivalent radius less than said length of said critical zone, wherein further said equivalent radius is obtained by dividing the cross-sectional area of said critical zone by pi and then taking a square root of the resulting quantity;at least one sensor, having a surface communicating with at least one said hydrophilic region and sensitive to either said second material or said third material and producing a signal indicative of the concentration of said second or third material in said region; and a control responsive to said signal for comparing said signal to a reference to determine the concentration of said first material in said environment.
- and which device comprises;
-
3. A measuring device for determining concentration of a first material in an environment in contact with the device, which first material reacts within said device in presence of a catalyst with a second material to form a third material;
- and which device comprises;
a membrane comprising a body, a surface in contact with said environment, and at least one discrete hydrophilic region in communication with said body, wherein said hydrophilic region is permeable to said first and second materials, and said body is otherwise permeable to said second material and essentially impermeable to said first material, wherein both said first and second materials diffuse into said device from said environment through said surface; a catalyst within said hydrophilic region wherein reaction of said first and second materials occurs;
at least one critical zone within said hydrophilic region containing said catalyst, said critical zone having an average equivalent radius and a length, wherein the average equivalent radius of said critical zone is less than said length of said critical zone, and wherein further the average vector direction of diffusion of said first material in said critical zone is substantially parallel to an average vector direction of diffusion of said first material in said hydrophilic region;at least one sensor, having a surface communicating with at least one said hydrophilic region and sensitive to either said second material or said third material and producing a signal indicative of the concentration of said second or third material in said region; and a control responsive to said signal for comparing said signal to a reference to determine the concentration of said first material in said environment.
- and which device comprises;
Specification