Continuous cardiac output derived from the arterial pressure waveform using pattern recognition

Patent 5390679 Issued on February 21, 1995. Estimated Expiration Date:

June 3, 2013. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

Relay circuit for cardiac pacemaker implant
Patent #: 4423733
Issued on: 01/03/1984
Inventor: Grassi , et al.

Noninvasive continuous cardiac output monitor
Patent #: 4450527
Issued on: 05/22/1984
Inventor: Sramek

Method and system for non-invasive ultrasound Doppler cardiac output measurement
Patent #: 4509526
Issued on: 04/09/1985
Inventor: Barnes , et al.

Apparatus and method for measuring cardiac output
Patent #: 4542748
Issued on: 09/24/1985
Inventor: Roy

Method and apparatus for measuring cardiac output
Patent #: 4572206
Issued on: 02/25/1986
Inventor: Geddes , et al.

Method for measuring cardiac output
Patent #: 4671295
Issued on: 06/09/1987
Inventor: Abrams , et al.

Method and apparatus for measuring ventricular volume
Patent #: 4674518
Issued on: 06/23/1987
Inventor: Salo

Cardiac output measurement system and method
Patent #: 4685470
Issued on: 08/11/1987
Inventor: Sekii , et al.

Apparatus for measuring cardiac output
Patent #: 4722347
Issued on: 02/02/1988
Inventor: Abrams , et al.

Blood flow measurement catheter
Patent #: 4733669
Issued on: 03/29/1988
Inventor: Segal

More ...

Inventor

Martin, James F.

Assignee

Eli Lilly and Company

Application

No. 072038 filed on 06/03/1993

US Classes:

600/486, Testing means inserted in body600/481, Cardiovascular600/526Blood output per beat or time interval

Examiners

Primary: Sykes, Angela D.

Attorney, Agent or Firm

Fulwider, Patton, Lee & Utecht

International Class

A61B 005/021.5

Abstract

A system and method of determining cardiac output from a cardiac pressure waveform. The pressure waveform is continuously sensed and converted into a digital data stream. When a complete beat frame of data is sensed, the processor extracts a plurality of features from the sensed waveform which characterize the waveform. These features are compared to stored representative pressure waveforms (RPW's) which have a known cardiac output. The RPW's are obtained by applying a pattern recognition methodology to pressure waveforms of known cardiac output. In one embodiment the typical shapes function is used. The pattern recognition methodology results in classes and associated cardiac outputs which are stored as the RPW's. The features extracted from waveforms representative of unknown cardiac output are thus classified by the comparison to the RPW's. When a match is made between the extracted features and an RPW, the cardiac output of the selected RPW is output as the cardiac output of the patient.

Other References

Kevin C. Ehlers et al., Ann.Biomed. Eng. 1986, pp. 219-239 "Cardiac Output Measurements. A Review of Current Techniques and Research"
Leonid B. Volfson, University of California, San Diego, pp. 1-172 "Pattern Recognition and Classification and Its Applications to Pre-Processing Arterial Pressure Waveform Signals and Image Processing Problems"
N. T. Kouchoukos, et al.; "Estimation of Stroke Volume in the Dog by a Pulse Contour Method"; May 1970; pp. 611-623 [Circulation Research, vol. XXVI