Method for carrying out blood flow measurements and a probe therefor

Claim 1

A probe for regional blood flow measurement, comprising: a housing of low thermal conduction and heat capacity, at least one face of which is adapted to make contact with a tissue region investigated, said face being provided with a recessed portion; a single relatively thin plate made of a material of high thermal conductivity, located in said recessed portion and being substantially flush with said tissue-contacting face of said housing; a temperature-sensing means in thermal contact with said plate and adapted to transfer temperature-related information to the outside of said housing, wherein the respective configurations of said plate and said housing are such as to minimize the area of contact between them relative to the area of contact between said plate and said tissue region, in order to minimize heat flow between said plate and said housing.

Claim 11

A method for carrying our regional blood flow measurements, comprising the steps of: providing a minimal-heat-leak probe having a single heat-sensitive face capable of producing signals indicative of the temperature of said face; attaching said probe to a tissue region to be investigated, so that signals produced by said heat-sensitive face will be indicative of the temperature of said tissue region; exposing said probe to the heat emanating from said tissue region for at least two equal periods of time, a first period P 1 starting at a time t 1 and ending at a time t 2 , and a second period P 2 starting at a time t 3 and ending at a time t 4 , thereby obtaining a temperature T 1 at time t 1 , a temperature T 2 at time t 2 , a temperature T 3 at time t 3 , and a temperature T 4 at time t 4 ; using the values thus obtained to determine a temperature-vs.-time curve, and applying the expression ##EQU2## to calculate the regional blood flow, where I 12 and I 34 are the areas under said curve that represent the integrals of the temperature over said periods P 1 and P 2 , respectively, and wherein the highest temperature to be attained by said heat-sensitive face of said probe is lower than local arterial temperature.

Claim 12

A method for carrying our regional blood flow measurements, comprising the steps of: providing a minimal-heat-leak probe having a single heat-sensitive face capable of producing signals indicative of the temperature of said face; attaching said probe to a tissue region to be investigated, so that signals produced by said heat-sensitive face will be indicative of the temperature of said tissue region; exposing said probe to the heat emanating from said tissue region for at least two equal periods of time, a first period P 1 starting at a time t 1 and ending at a time t 2 , and a second period P 2 starting at a time t 3 and ending at a time t 4 , thereby obtaining a temperature T 1 at time t 1 , a temperature T 2 at time t 2 , a temperature T 3 at time t 3 , and a temperature T 4 at time t 4 ; using the values thus obtained to determine a temperature-vs.-time curve, and applying the expression ##EQU2## to calculate the regional blood flow, where I 12 and I 34 are the areas under said curve that represent the integrals of the temperature over said periods P 1 and P 2 , respectively, and wherein the highest temperature to be attained by said heat-sensitive face of said probe is lower than local arterial temperature.