EP0235811A2
Expired / Lapsed
EP
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Catheters for measurement of cardiac output and blood flow velocity
Assignee: Terumo Corp
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Filing: 1987-03-04
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Granted: —
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Expires: 2007-03-04
Abstract
Abstract A catheter introduced into the pulmonary artery for use in measuring cardiac output or blood flow velocity includes temperature sensing device including a temperature sensing element for sensing the temperature of blood in the pulmonary artery diluted by an indicator liquid infused for measurement of cardiac output based on a thermodilution method, and a self-heating thermistor for sensing a signal relating to blood flow velocity near the temperature sensing element, the signal being an equilibrium temperature sensed by the thermistor. The catheter is connected to a cardiac output measurement system adapted to measure cardiac output on the basis of the thermodilution method, measure the blood flow velocity which prevails when the cardiac output is measured, and obtain a parameter which links this blood flow velocity to the cardiac output measured in accordance with the thermodilution method. Once the parameter is found, merely measuring the blood flow velocity enables cardiac output to be determined from the flow velocity and the parameter.
Inventors
- 👤 Susumu Tanabe
- 👤 Shigekazu Sekii
- 👤 Kouji Tsuchida
- 👤 Yoshio Ishizu
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 19:09
CPC Classifications
G; G01; G01N; G01N25/00; A; A61; A61B; A61B5/00; A61B5/02; A61B5/026; A61B5/029; A61B5/0275; A61B5/028
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
74 words
A catheter for measuring cardiac output, which comprises: an aperture portion for discharging a liquid for measuring cardiac output based on a thermodilution method; temperature sensing means including a temperature sensing element arranged at a position a predeterimined distance from said aperture portion for sensing the temperature of blood diluted by said liquid; and blood flow velocity signal sensing means for sensing a signal relating to blood flow velocity near said temperature sensing element.
Claim 2
Dependent Claim
74 words
A catheter for measuring cardiac output, which comprises: an aperture portion for discharging a liquid for measuring cardiac output based on a thermodilution method; temperature sensing means including a temperature sensing element arranged at a position a predeterimined distance from said aperture portion for sensing the temperature of blood diluted by said liquid; and blood flow velocity signal sensing means for sensing a signal relating to blood flow velocity near said temperature sensing element.
Claim 3
Dependent Claim
35 words
The catheter according to claim 1, wherein said blood flow velocity signal sensing means includes a self-heating type thermistor, said signal relating to the blood flow velocity being an equilibrium temperature sensed by said thermistor.
Claim 4
Dependent Claim
54 words
The catheter according to claim 1, wherein said blood flow velocity signal sensing means includes a heating element for supplying heat to the blood, and a thermistor provided near said heating element and heated by said heating element, said signal relating to the blood flow velocity being an equilibrium temperature sensed by said thermistor.
Claim 5
Dependent Claim
19 words
The catheter according to claim 3, wherein said heating element has a calorific value of 0.01 - 50 J.
Claim 6
Dependent Claim
25 words
The catheter according to claim 2, wherein said thermistor is located at a distance of 5 - 25 mm from said temperature sensing element. 3
Claim 7
Dependent Claim
24 words
The catheter according to claim 3, wherein said thermistor is located at a distance of 5 - 25 mm from said temperature sensing element.
Claim 8
Dependent Claim
27 words
The catheter according to claim 1, wherein said temperature sensing element is provided on a side of said aperture portion toward a tip end of the catheter.
Claim 9
Dependent Claim
27 words
The catheter according to claim 1, wherein said temperature sensing element is provided on a side of said aperture portion toward a base end of the catheter.
Claim 10
Dependent Claim
26 words
The catheter according to claim 2, wherein said temperature sensing element is provided on a side of said thermistor toward a tip end of the catheter.
Claim 11
Dependent Claim
26 words
The catheter according to claim 3, wherein said temperature sensing element is provided on a side of said thermistor toward a base end of the catheter.
Claim 12
Dependent Claim
56 words
The catheter according to claim 2, wherein said catheter has an interior partitioned into at least two independent lumens, one of said lumens communicates with said aperture portion and the other of said lumens is closed at a tip portion of said catheter, lead wires of said temperature sensing element and said thermistor being passed therethrough.
Claim 13
Dependent Claim
56 words
The catheter according to claim 3, wherein said catheter has an interior partitioned into at least two independent lumens, one of said lumens communicates with said aperture portion and the other of said lumens is closed at a tip portion of said catheter, lead wires of said temperature sensing element and said thermistor being passed therethrough.
Claim 14
Dependent Claim
15 words
The catheter according to claim 1, further comprising a pressure port used for sensing pressure.
Claim 15
Dependent Claim
40 words
A catheter for measuring cardiac output, which comprises: an aperture portion for discharging a liquid for measuring cardiac output based on a thermodilution method; and blood flow velocity signal sensing means for sensing a signal relating to blood flow velocity.
Claim 16
Dependent Claim
40 words
A catheter for measuring cardiac output, which comprises: an aperture portion for discharging a liquid for measuring cardiac output based on a thermodilution method; and blood flow velocity signal sensing means for sensing a signal relating to blood flow velocity.
Claim 17
Dependent Claim
28 words
The catheter according to claim 14, wherein said dilution method is a dye dilution method, and said indicator liquid discharged from said discharge port includes a predetermined dye.
Claim 18
Dependent Claim
49 words
The catheter according to claim 14, wherein said dilution method is a resistance value dilution method, said indicator liquid discharged from said discharge port includes a predetermined electrolytic medium, and said catheter further comprises two electrodes downstream of said aperture portion for sensng a resistance value in the blood.
Claim 19
Dependent Claim
60 words
A catheter for measuring blood flow velocity, comprising: a temperature sensing element for sensing temperature in blood; and a heating element provided near said temperature sensing element for heating the same; said temperature sensing element sensing an equilibrium temperature resulting from a quantity of heat applied thereby by said heating element and a quantity of heat absorbed by the blood.
Claim 20
Dependent Claim
60 words
A catheter for measuring blood flow velocity, comprising: a temperature sensing element for sensing temperature in blood; and a heating element provided near said temperature sensing element for heating the same; said temperature sensing element sensing an equilibrium temperature resulting from a quantity of heat applied thereby by said heating element and a quantity of heat absorbed by the blood.
Claim 21
Dependent Claim
20 words
The catheter according to claim 17, wherein said temperature sensing element is a self-heating type thermistor containing said heating element.
Claim 22
Dependent Claim
19 words
The catheter according to claim 17, wherein said heating element has a calorific value of 0.01 - 50 J.
References Cited (Backward Citations)
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