US3877463A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermal method and device for the differential diagnosis of human tumors and circulatory disorders
Assignee: Massachusetts Institute of Technology
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Filing: 1973-07-02
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Granted: 1975-04-15
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Expires: 1993-07-02
Abstract
Abstract The thermal analysis method includes controlled cooling of the surface of skin tissue and measurement of the surface temperature difference between cooled cancerous and similarly cooled healthy tissue. The device which utilizes the effect of local skin cooling to diagnose the presence of tumors includes a heat sink, a thermal resistance which maximizes the skin temperature difference between cancerous and healthy tissue, and a heat collecting disk containing a temperature sensing device. During diagnostic examinations, the heat collecting disk is placed upon an area of skin where a tumor is suspected and upon a contra-lateral area of normal skin. The skin temperature difference observed by use of the device indicates blood perfusion changes between the two areas, which for the identical cooling conditions used, reflects morphological changes in the tissue. Perfusion rate differences between cancerous and healthy tissue are indicated by skin temperature differences of up to 10*C under conditions of strong cooling. For small superficial tumors of 1 cm3 volume, temperature differences of a few degrees centrigrade will be observed with strong cooling. The method and device can also be used for the detection of various circulatory disorders.
Inventors
- 👤 John D Cary
- 👤 Borivoje B Mikic
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:16
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/01
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
194 words
A device for determining the perfusion rate of superficial skin tissue by measuring the temperature of skin after the superficial tissue has been cooled below its normal temperature comprising: a flat heat collecting surface having a defined area which can be placed in thermal communication with the skin and enable heat transfer from the skin to said heat collecting surface; a heat sink means for cooling said heat collecting surface to enable the superficial tissue to be cooled below its normal temperature when said heat collecting surface is placed in thermal communication with the skin; a thermal resistance connected between said heat collecting surface and said heat sink means including spacer means for defining the height of said thermal resistance, said heat sink means cooling said heat collecting surface through said thermal resistance to a temperature above the value of the heat sink means at steady state; and, means for measuring the temperature of skin when cooled by said surface, the device being designed so that the value of the thermal resistance, the heat sink means temperature, and the area of the heat collecting surface maximize the skin temperature difference for different perfusion rates.
Claim 2
Independent Claim
194 words
A device for determining the perfusion rate of superficial skin tissue by measuring the temperature of skin after the superficial tissue has been cooled below its normal temperature comprising: a flat heat collecting surface having a defined area which can be placed in thermal communication with the skin and enable heat transfer from the skin to said heat collecting surface; a heat sink means for cooling said heat collecting surface to enable the superficial tissue to be cooled below its normal temperature when said heat collecting surface is placed in thermal communication with the skin; a thermal resistance connected between said heat collecting surface and said heat sink means including spacer means for defining the height of said thermal resistance, said heat sink means cooling said heat collecting surface through said thermal resistance to a temperature above the value of the heat sink means at steady state; and, means for measuring the temperature of skin when cooled by said surface, the device being designed so that the value of the thermal resistance, the heat sink means temperature, and the area of the heat collecting surface maximize the skin temperature difference for different perfusion rates.
Claim 3
Dependent Claim
44 words
The device as set forth in claim 1 wherein said means for measuring the temperature of skin tissue is a temperature sensing device within the said heat collecting disc having means for connecting said temperature sensing device to a means for displaying the temperature.
Claim 4
Dependent Claim
16 words
The device as set forth in claim 2 wherein said temperature sensing device is a thermocouple.
Claim 5
Dependent Claim
16 words
The device as set forth in claim 2 wherein said temperature sensing device is a thermistor.
Claim 6
Independent Claim
209 words
A device for diagnosing tumors and circulatory disorders by determining the perfusion rate of superficial skin tissue by measuring the temperature of skin after the superficial tissue has been cooled below its normal temperature comprising: a flat heat collecting surface having a defined area which can be placed in thermal communication with the skin and enable heat transfer from the skin to said heat collecting surface; a vessel for containing a coolant which functions as a heat sink for cooling said heat collecting surface to enable the superficial tissue to be cooled below its normal temperature when said heat collecting surface is placed in thermal communication with the skin; a coolant in said vessel; a thermal resistance in the heat flow path between said heat collecting surface and said coolant including spacer means for defining the height of said thermal resistance, said coolant cooling said heat collecting surface through said thermal resistance to a steady state temperature above the temperature of the coolant; and, means for measuring the temperature of skin when cooled by said surface, the device being designed so that the value of the thermal resistance, the heat sink temperature, and the area of the heat collecting surface maximize the skin temperature difference for different perfusion rates.
Claim 7
Independent Claim
209 words
A device for diagnosing tumors and circulatory disorders by determining the perfusion rate of superficial skin tissue by measuring the temperature of skin after the superficial tissue has been cooled below its normal temperature comprising: a flat heat collecting surface having a defined area which can be placed in thermal communication with the skin and enable heat transfer from the skin to said heat collecting surface; a vessel for containing a coolant which functions as a heat sink for cooling said heat collecting surface to enable the superficial tissue to be cooled below its normal temperature when said heat collecting surface is placed in thermal communication with the skin; a coolant in said vessel; a thermal resistance in the heat flow path between said heat collecting surface and said coolant including spacer means for defining the height of said thermal resistance, said coolant cooling said heat collecting surface through said thermal resistance to a steady state temperature above the temperature of the coolant; and, means for measuring the temperature of skin when cooled by said surface, the device being designed so that the value of the thermal resistance, the heat sink temperature, and the area of the heat collecting surface maximize the skin temperature difference for different perfusion rates.
Claim 8
Dependent Claim
44 words
The device as set forth in claim 5 wherein said means for measuring the temperature of skin tissue is a temperature sensing device within the said heat collecting disc having means for connecting said temperature sensing device to a means for displaying the temperature.
Claim 9
Dependent Claim
16 words
The device as set forth in claim 6 wherein said temperature sensing device is a thermocouple.
Claim 10
Dependent Claim
16 words
The device as set forth in claim 6 wherein said temperature sensing device is a thermistor.
Claim 11
Dependent Claim
22 words
The device as set forth in claim 6 also including a heat distributor in thermal communication with said resistance and said coolant.
Claim 12
Dependent Claim
15 words
The device as set forth in claim 9 wherein said heat collecting disc contains copper.
Claim 13
Dependent Claim
70 words
The device as set forth in claim 6 wherein said heat collecting disc is inclusive of a heat conducting inner disc, an outer ring of a heat conducting material and an insulating ring between said outer ring and said inner disc, With the temperature sensing device being positioned within said inner disc to maximize the penetration depth of said heat collecting surface while maximizing the device''s sensitivity to small tumors.
Claim 14
Independent Claim
246 words
A device for diagnosing tumors and circulatory disorders by dEtermining the perfusion rate of superficial skin tissues by measuring the temperature of skin after the superficial tissue has been cooled below its normal temperature comprising: a heat collecting disc having a flat heat collecting surface having a defined area which can be placed in thermal communication with the skin and enable heat transfer from the skin to said heat colleting surface; a vessel for containing a coolant which functions as a heat sink for cooling said heat collecting surface to enable the superficial tissue to be cooled below its normal temperature when said heat collecting surface is placed in thermal communication with the skin; a coolant in said vessel; a heat distributor in thermal communication with said coolant; a spacer ring between said heat distributor and said heat collecting disc, said spacer ring defining the height of a column of liquid between said heat distributor and said heat collecting disc to provide a thermal resistance in the heat flow path between said heat collecting surface and said coolant, said coolant cooling said heat collecting surface through said thermal resistance to a steady state temperature above the temperature of the coolant; and, means for measuring the temperature of skin when cooled by said surface, the device being designed so that the value of the thermal resistance, the heat sink temperature, and the area of the heat collecting surface maximize the skin temperature difference for different perfusion rates.
Claim 15
Independent Claim
246 words
A device for diagnosing tumors and circulatory disorders by dEtermining the perfusion rate of superficial skin tissues by measuring the temperature of skin after the superficial tissue has been cooled below its normal temperature comprising: a heat collecting disc having a flat heat collecting surface having a defined area which can be placed in thermal communication with the skin and enable heat transfer from the skin to said heat colleting surface; a vessel for containing a coolant which functions as a heat sink for cooling said heat collecting surface to enable the superficial tissue to be cooled below its normal temperature when said heat collecting surface is placed in thermal communication with the skin; a coolant in said vessel; a heat distributor in thermal communication with said coolant; a spacer ring between said heat distributor and said heat collecting disc, said spacer ring defining the height of a column of liquid between said heat distributor and said heat collecting disc to provide a thermal resistance in the heat flow path between said heat collecting surface and said coolant, said coolant cooling said heat collecting surface through said thermal resistance to a steady state temperature above the temperature of the coolant; and, means for measuring the temperature of skin when cooled by said surface, the device being designed so that the value of the thermal resistance, the heat sink temperature, and the area of the heat collecting surface maximize the skin temperature difference for different perfusion rates.
Claim 16
Dependent Claim
23 words
The device as set forth in claim 12 wherein the coolant is ice water and said spacer ring defines a column of water.
Claim 17
Dependent Claim
34 words
The device as set forth in claim 13 wherein said spacer ring is dimensioned to result in a resistance such that the equilibrium temperature of normal tissue cooled with said device is approximately 15*C.
Claim 18
Dependent Claim
57 words
The device as set forth in claim 14 wherein said heat collecting disc is inclusive of a heat conducting inner disc, an outer ring of a heat conducting material and an insulating ring between said outer ring and said inner disc, said inner disc, insulating ring and outer ring being in thermal communication with said thermal resistance.
Claim 19
Dependent Claim
28 words
The device as set forth in claim 15 wherein said means for measuring the temperature of skin tissue is a temperature sensing device located in said inner disc.
Claim 20
Dependent Claim
16 words
The device as set forth in claim 16 wherein said inner disc is formed of copper.
Claim 21
Dependent Claim
16 words
The device as set forth in claim 17 wherein said temperature sensing device is a thermistor.
Claim 22
Dependent Claim
16 words
The device as set forth in claim 18 wherein said outer ring is formed of copper.
Claim 23
Independent Claim
145 words
A method for diagnosing the presence of human tumors and circulatory disorders comprising the following steps: A. applying a flat cooling surface to the skin to be diagnosed and cooling the skin through a thermal resistance of a known value which is in thermal communication with a heat sink at a known constant temperature to a steady state temperature below normal skin temperature and above the temperature of the heat sink. B. measuring the temperature of the skin cooled in Step A after a temperature equilibrium is reached between the skin and the cooling surface; and C. comparing the temperature of the skin measured in Step B with a standard to determine the presence of tumors or circulatory disorders beneath the skin by comparing the perfusion rates which are deduced from the cooled skin temperature, the sink temperature and the value of the thermal resistance.
Claim 24
Independent Claim
145 words
A method for diagnosing the presence of human tumors and circulatory disorders comprising the following steps: A. applying a flat cooling surface to the skin to be diagnosed and cooling the skin through a thermal resistance of a known value which is in thermal communication with a heat sink at a known constant temperature to a steady state temperature below normal skin temperature and above the temperature of the heat sink. B. measuring the temperature of the skin cooled in Step A after a temperature equilibrium is reached between the skin and the cooling surface; and C. comparing the temperature of the skin measured in Step B with a standard to determine the presence of tumors or circulatory disorders beneath the skin by comparing the perfusion rates which are deduced from the cooled skin temperature, the sink temperature and the value of the thermal resistance.
Claim 25
Dependent Claim
27 words
The method as set forth in claim 1 wherein the temperature of the skin is measured in Step B by measuring the temperature of the cooling surface.
Claim 26
Dependent Claim
22 words
The method as set forth in claim 21 wherein in Step A the skin is cooled to a temperature of about 15*C.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-14 | 1978-10-14 | 1979-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-14 | 1982-10-14 | 1983-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-14 | 1986-10-14 | 1987-04-15 | $7700.00 | Window Closed / Lapsed |