Surgery – Diagnostic testing – Cardiovascular
Patent
1995-06-07
1999-01-12
Nasser, Robert L.
Surgery
Diagnostic testing
Cardiovascular
600526, 600549, A61B 500
Patent
active
058579761
ABSTRACT:
A thermodilution catheter having a heating filament which is fabricated so as to be thin and flexible enough to avoid contact with the patient's blood. The heating filament is either inserted in a preformed catheter lumen, incorporated into a wall of the catheter body itself, or wrapped around the catheter body wall and surrounded by an external sheath. Generally, the covering of the heating filament is minimally thin so as to allow the heat from the heating filament to be transferred to the surrounding blood and to minimally increase the overall cross-sectional area. Since the heating filament does not directly touch the patient's blood, the outer surface may be made smooth so as to prevent inducement of blood clots. In addition, the heating filament may be maintained at a safe temperature by forming the heating element of a flexible material having a high temperature coefficient of resistance, low thermal capacitance and high thermal conductivity. Preferably, the temperature coefficient of resistance of the material forming the heater filament is greater than 0.001 .OMEGA./.OMEGA.-.degree. C. and the resistance of the heating filament is proportional or inversely proportional to its temperature. By monitoring this resistance, the application of power to the heating filament may be regulated to prevent overheating of the heating filament. Calibration techniques are also disclosed whereby a memory containing encoded calibration information is disposed within or connected to a connector of the catheter. This memory may also include a program segment used by a cardiac output computer having a cardiac output calculation program, whereby the portion of code stored in the memory must be input into the cardiac output computer before the determination of the cardiac output can be performed. As a result of these improvements, the invention enables the thermodilution cardiac output calculation to be performed quite safely and accurately in a clinical setting.
REFERENCES:
patent: 3075515 (1963-01-01), Richards
patent: 3359974 (1967-12-01), Khalil
patent: 3595079 (1971-07-01), Grahn
patent: 3634924 (1972-01-01), Blake et al.
patent: 3720199 (1973-03-01), Rishton et al.
patent: 3746003 (1973-07-01), Blake et al.
patent: 3790910 (1974-02-01), McCormack
patent: 3798967 (1974-03-01), Geiles et al.
patent: 3995623 (1976-12-01), Blake et al.
patent: 4073287 (1978-02-01), Bradley et al.
patent: 4089336 (1978-05-01), Cage et al.
patent: 4091813 (1978-05-01), Shaw et al.
patent: 4185632 (1980-01-01), Shaw
patent: 4198957 (1980-04-01), Cage et al.
patent: 4199816 (1980-04-01), Humphrey
patent: 4206759 (1980-06-01), Shaw
patent: 4207896 (1980-06-01), Shaw
patent: 4209017 (1980-06-01), Shaw
patent: 4236527 (1980-12-01), Newbower
patent: 4240441 (1980-12-01), Khalil
patent: 4303984 (1981-12-01), Houvig
patent: 4364390 (1982-12-01), Shaw
patent: 4407298 (1983-10-01), Lentz et al.
patent: 4418392 (1983-11-01), Hata
patent: 4446715 (1984-05-01), Bailey
patent: 4481804 (1984-11-01), Eberhard et al.
patent: 4499547 (1985-02-01), Inuiya et al.
patent: 4611304 (1986-09-01), Butenko et al.
patent: 4621643 (1986-11-01), New, Jr. et al.
patent: 4632125 (1986-12-01), Webler et al.
patent: 4669066 (1987-05-01), Kagawa et al.
patent: 4684245 (1987-08-01), Goldring
patent: 4685470 (1987-08-01), Sekii et al.
patent: 4708777 (1987-11-01), Kuraoka
patent: 4770179 (1988-09-01), New, Jr. et al.
patent: 4785823 (1988-11-01), Eggers et al.
patent: 4796640 (1989-01-01), Webler
patent: 4819655 (1989-04-01), Webler
patent: 4841981 (1989-06-01), Tanabe et al.
patent: 4856530 (1989-08-01), Vandervelden
patent: 4858615 (1989-08-01), Meinema
patent: 4868476 (1989-09-01), Respaut
patent: 4869263 (1989-09-01), Segal et al.
patent: 4901734 (1990-02-01), Griffin et al.
patent: 4942877 (1990-07-01), Sakai et al.
patent: 4947842 (1990-08-01), Marchosky et al.
patent: 4954318 (1990-09-01), Yafuso et al.
patent: 5007423 (1991-04-01), Branstetter et al.
patent: 5009234 (1991-04-01), Alt
patent: 5046505 (1991-09-01), Sekii et al.
patent: 5047025 (1991-09-01), Taylor et al.
patent: 5056526 (1991-10-01), Khalil
patent: 5080106 (1992-01-01), Sekii et al.
patent: 5092335 (1992-03-01), Geddes et al.
patent: 5121749 (1992-06-01), Nassi et al.
patent: 5373850 (1994-12-01), Kohno et al.
Delavnois, "Thermal Method for Continuous Blood-Velocity Measurements in Large Blood Vessels, and Cardiac-Output Determination," Medical and Biological Engineering, Mar. 1973 vol. 11, No. 2, pp. 201-205.
Barankay et al, "Cardiac Output Estimation by a Thermodilution Method Involving Intravascular Heating and Thermistor Heating." Acta Physiologica Academise Scientiarum Hungaricae, Tomus 38(2-3), pp. 167-173 (1970).
A Continuous Cardiac Output Computer Based on Thermodilution Principles, R.A. Normann et al, Annals of Biomedical Eng. vol. 17, pp. 61-73, 1989.
Investigation of a Continuous Heating/Cooling Technique for Cardiac Output Measurement, Kevin C. Ehlers et al., Annals of Biomedical Eng., vol. 15, pp. 551-565, 1987.
Determination of Cardiac Output in Man by a New Method Based on Thermodilution, H.H. Khalil et al., Preliminary Communications, Jun. 22, 1963, pp. 1352-1354.
Service Manual for Model COM-1 Thermodilution Cardiac Output Computer, American Edwards Laboratories, Jun. 1984, p. 6, Table 2.1.
Repeated or Continual Measurements of Cardiac Output in the Squirrel Monkey (Saimiri sciureus) by Thermodilution, H.H. Kahlil, Bureau of Med. and Surgery, MR011.01.4, Naval Aerospace Med. Inst., Mar. 8, 1968.
CRC Handbook of Chemistry and Physics, 60.sup.TH Ed., 1979-1980, pp. 3-85 Cole-Parmer Instrument Co., Niles, Il. (Catalog pp. 1259-1261).
Cardiac Output Estimation by a Thermodilution Method Involving Intravascular Heating & Thermistor Recording, T. Barankay et al., Acta Physiologica Academiae Scientiarium Hungaricae, Tomus 38(2-3), pp. 167-173, 1970.
Baxter Healthcare Corp., (Catalog pp. 1, 2, 5, and 6) Jun. 1992.
Quinn Michael D.
Yelderman Mark L.
Baxter International Inc.
Nasser Robert L.
LandOfFree
Thermodilution catheter having a safe, flexible heating element does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Thermodilution catheter having a safe, flexible heating element, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Thermodilution catheter having a safe, flexible heating element will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1509297