Transcutaneous pH measuring instrument
First Claim
Patent Images
1. A device for measuring the concentration of a substance in the blood, said device comprising:
- a housing;
optical radiation source means mounted within said housing for providing optical radiation having at least one predetermined frequency component;
detector means mounted within said housing for detecting radiation at said at least one predetermined frequency;
a measuring chamber positioned within said housing in an optical path between said source means and said detector means;
means in the housing for maintaining a volumetric region adjacent an area of skin surface of the body when the device is brought into intimate contact with said area, said means allowing said substance in the blood to pass freely between the skin surface and said volumetric region while preventing the passage of undesired substances therebetween;
a measuring fluid in said volumetric region, said fluid having radiation absorption characteristics as a function of wavelength which vary as a function of the concentration of said substance in the blood; and
means for drawing measuring fluid from said volumetric region into said measuring chamber and forcing measuring fluid from said measuring chamber into the volumetric region.
0 Assignments
0 Petitions
Accused Products
Abstract
A transcutaneous pH measuring device is provided in which a known volume of fluid is brought into equilibrium with body fluids through a membrane on a portion of skin whose surface layers have been stripped away. The fluid contains a pH sensitive dye. Optical measurements of the transmission characteristics of the fluid are obtained when the fluid is in the optical path. During portions of each operating cycle, the fluid is driven back into the vicinity of the skin to pH equilibrate with body fluids while standardization measurements are obtained using an optical plug of known transmission characteristics in the optical path.
-
Citations
7 Claims
-
1. A device for measuring the concentration of a substance in the blood, said device comprising:
-
a housing; optical radiation source means mounted within said housing for providing optical radiation having at least one predetermined frequency component; detector means mounted within said housing for detecting radiation at said at least one predetermined frequency; a measuring chamber positioned within said housing in an optical path between said source means and said detector means; means in the housing for maintaining a volumetric region adjacent an area of skin surface of the body when the device is brought into intimate contact with said area, said means allowing said substance in the blood to pass freely between the skin surface and said volumetric region while preventing the passage of undesired substances therebetween; a measuring fluid in said volumetric region, said fluid having radiation absorption characteristics as a function of wavelength which vary as a function of the concentration of said substance in the blood; and means for drawing measuring fluid from said volumetric region into said measuring chamber and forcing measuring fluid from said measuring chamber into the volumetric region. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
Specification