Method and apparatus for monitoring and diagnosing peripheral blood flow
First Claim
1. A method for monitoring blood flow comprising applying an object of a temperature below normal skin temperature to the surface of an area of skin to lower the temperature of the area of skin;
- terminating the application of the object at a temperature below normal skin temperature whereby internal blood flow around the area of skin raises the temperature of the area of skin; and
monitoring the temperature within the area of the skin as the temperature changes in response to the application of the object at a temperature below normal skin temperature and as it returns to its original temperature when the application of the object at a temperature below normal skin temperature is terminated.
1 Assignment
0 Petitions
Accused Products
Abstract
A heat exchanger changes the temperature of a predetermined area of the skin at a programmed rate preferably by cooling. The rate at which the area of skin changes in response to temperature change of the heat exchanger and the rate the skin temperature returns to normal are then measured and compared to standard rates over a number of cycles. Impaired peripheral blood flow is evident especially on subsequent cycles as vascular disease slows the rate of return to normal temperature of the skin. The heat exchanger has a cooling chamber with one side of the chamber being a cooling surface adjacent to the skin. An injector is connected to a source of fluid having a boiling point at ambient pressure less than the temperature to which the skin is to be cooled and greater than ambient temperature of the apparatus. The injector injects fluid into the chamber and onto the side of the cooling surface opposite the skin to boil the fluid on the surface to cool the surface and the skin.
193 Citations
36 Claims
-
1. A method for monitoring blood flow comprising applying an object of a temperature below normal skin temperature to the surface of an area of skin to lower the temperature of the area of skin;
-
terminating the application of the object at a temperature below normal skin temperature whereby internal blood flow around the area of skin raises the temperature of the area of skin; and monitoring the temperature within the area of the skin as the temperature changes in response to the application of the object at a temperature below normal skin temperature and as it returns to its original temperature when the application of the object at a temperature below normal skin temperature is terminated. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
-
-
13. A method for monitoring blood flow comprising:
-
artificially cooling an area of skin by applying an object to the skin, the object being at a temperature below normal skin temperature; monitoring the rate of change of the skin temperature as it changes in response to the application of the object; and comparing the rate of change of the skin temperature to a predetermined normal rate of change in skin temperature for the area of skin.
-
-
14. A method for monitoring blood flow comprising:
-
artificially changing the temperature of an area of skin by applying an object to the skin for a period of time, the object being at a temperature below normal skin temperature; and monitoring the skin temperature as it returns to the original temperature after the period of time; and comparing the rate of change for the skin temperature to a predetermined normal rate of change in skin temperature for the area of skin.
-
-
15. A heat exchanger apparatus for cooling an object comprising:
-
a cooling chamber, one side of the chamber being surface means having two faces, a first face being adjacent to the object for contacting the object; injecting means connected to a source of fluid, the fluid having a boiling point at ambient pressure less than the temperature to which the object is to be cooled, the injecting means injecting fluid into the chamber and onto the face of the surface means opposite first face and the object to boil the fluid on the surface means to cool the surface and the object. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32)
-
-
33. A system for monitoring blood flow comprising:
-
heat exchanger means for changing the temperature of an area of skin in a controlled manner, the heat exchanger means having a cooling surface, a source of fluid having liquid and vapor phases under pressure, the liquid having a boiling point less than skin temperature at atmospheric pressure, controlling means for controlling injection of the liquid into the heat exchanger means whereby the skin temperature heating the heat exchanger means boils the liquid to cool the heat exchanger means thereby cooling the skin, cuff means attached to the heat exchanger means for attaching the heat exchanger means to the skin; monitoring means attached to the cuff means and mounted adjacent to the skin for monitoring he skin temperature as it changes in response to changes in the temperature of the heat exchanger means. - View Dependent Claims (34)
-
-
35. A system for measuring the level of peripheral blood flow comprising:
-
temperature changing means adapted to be attached to the skin for changing the temperature of the skin, monitoring means adapted to be attached to the skin adjacent the temperature changing means for monitoring change in skin temperature caused by the temperature changing means, control means operatively associated with the temperature changing means for selectively operating the temperature changing means through at least two cycles, during each cycle, the temperature changing means changing the skin temperature to a predetermined temperature then permitting the skin temperature to approach normal.
-
-
36. A system for measuring the level of peripheral blood flow comprising:
-
temperature changing means adapted to be attached to the skin for changing the temperature of the skin, control means for selectively operating the temperature changing means through at least two cycles, during each cycle, the temperature changing means changing the skin temperature for a predetermined time then permitting the skin temperature to approach normal.
-
Specification