Method and means for measuring cardiac pumping performance of left ventricle

• US 4,137,910 A
• Filed: 09/30/1976
• Issued: 02/06/1979
• Est. Priority Date: 09/30/1976
• Status: Expired due to Term

• Current Assignee: Donald H. Murphy
• Original Assignee: Donald H. Murphy
• Inventors: Murphy, Donald H.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US05/728,207
• Time in Patent Office: 859 Days
• Field of Search: 128/2.05 D, 128/2.05 E, 128/2.05 F, 128/2.05 P, 128/2.05 Q, 128/2.05 R, 128/2.05 V
• US Class Current: 600/513
• CPC Class Codes: A61B 5/02028 Determining haemodynamic parameters not otherwise provided for, e.g. cardiac contractility or left ventricular ejection fraction
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/7239 using differentiation including higher order derivatives

Abstract

A method and system for measuring and monitoring the dynamics of left ventricular contraction by analyzing the signals from an electrocardiogram and signals corresponding to either an invasive aortic pressure pulse (obtained during catherization) or a non-invasive carotid arterial pulse (measured with a piezoelectric crystal). The pressure pulses are differentiated and amplified to produce data indicative of systolic blood flow. This blood flow data is then integrated during the ejection period in synchronism with pulses derived from the electrocardiogram to produce data indicative of the ejected stroke volume. This per beat volumetric data is further integrated over a uniform one minute time interval to yield cardiac output information. The differentiated pressure pulses are further differentiated and amplified to obtain data indicative of the left ventricular forces inparted to the blood flow during systole.

Claims

1. A system for measuring and monitoring the pumping performance of left ventricular contraction during systole of a patient'"'"'s heart, comprising:

pressure responsive means for deriving aortic pressure signals from a patient'"'"'s body which are caused by the ejection of said left ventricle;

differentiator means in circuit with said pressure responsive means for differentiating said pressure pulse signals; and

amplifier means in circuit with said differentiator means for amplifying said differentiated pressure pulse signals to obtain data indicative of the blood flow from said patient'"'"'s left ventricle during systole; and

display means connected to said amplifier means for indicating said pumping performance of left ventricle contraction.

2. A system as defined in claim 1, further comprising:

electrocardiographic means for obtaining an electrocardiogram of the patient;

discriminator means in circuit with said electrocardiographic signal means for deriving synchronized pulses from said electrocardiogram; and

integrator means in circuit with said amplifier means and said discriminator means to obtain stroke volume data indicative of the volume of blood flow per stroke from said patient'"'"'s left ventricle during systole; and

said integrator means being connected to said display means for indicating said stroke volume data.

3. A system as defined in claim 2, further comprising:

time means for producing uniform one minute time pulses; and

other integrator means in circuit with said timer means and the first named integrator means to produce cardiac output data indicative of the total blood flow per minute from the left ventricle of the patient'"'"'s heart during each minute; and

said other integrator means coupled to said display means for indicating blood flow per minute.

4. A system as defined in claim 1, further comprising:

another differentiator means in circuit with the first named differentiator means to obtain data indicative of the second derivative of said pressure pulses; and

other amplifier means in circuit with said other differentiator means to provide signal data indicative of the force with which blood flows from the patient'"'"'s left ventricle during systole;

said other amplifier means connected to said display means to indicate the force with which blood flows from the patient'"'"'s left ventricle during systole.

5. A system as defined in claim 1, wherein said pressure responsive means comprises a piezoelectric device.

6. A system as defined in claim 1, wherein said pressure responsive means comprises a catheter pressure device.

7. A method for measuring and monitoring the pumping performance of left ventricular contraction during systole of a patient'"'"'s heart, comprising:

deriving aortic pressure pulse signals caused by contraction of the left ventricle;

differentiating said pressure pulses; and

amplifying the differentiated pressure pulses to obtain data indicative of the blood flow from the patient'"'"'s left ventricle during systole;

displaying the amplified pressure pulses to measure and monitor the pumping performance of left ventricle contraction.

8. A method as defined in claim 7, further comprising:

obtaining an electrocardiogram of the patient while deriving said pressure pulses;

discriminating the electrocardiogram for deriving synchronous pulses therefrom; and

integrating said flow data in synchronism with said synchronous pulses to obtain stroke volume data indicative of the volume of blood per stroke from the patient'"'"'s left ventricle during systole.

9. A method as defined in claim 8, further comprising:

creating uniformly timed pulses; and

integrating said stroke volume data in synchronism with said uniformly timed pulses to produce cardiac output data indicative of the total per minute flow of blood from the left ventricle of the patient'"'"'s heart during each time interval.

10. A method as defined in claim 8, further comprising:

differentiating the differentiated pressure pulses to obtain further pulses indicative of the second derivative of said pressure pulses; and

amplifying said further pulses to obtain signal data indicative of the force with which blood flows from the patient'"'"'s left ventricle during systole.

11. A method as defined in claim 7, further comprising:

differentiating the differentiated pressure pulses to obtain further pulses indicative of the second derivative of said pressure pulses; and

amplifying said further pulses to obtain signal data indicative of the force with which blood flows from the patient'"'"'s left ventricle during systole.