Method and apparatus for obtaining electronic oscillotory pressure signals from an inflatable blood pressure cuff

• US 20090012411A1
• Filed: 06/13/2008
• Published: 01/08/2009
• Est. Priority Date: 06/20/2007
• Status: Abandoned Application

• Current Assignee: Pulsecor Ltd. (Uscom Ltd.)
• Original Assignee: Pulsecor Ltd. (Uscom Ltd.)
• Inventors: Lowe, Andrew, Roldan, Daniel Norberto, Sharrock, Nigel E.
• Application Number:
  US12/157,854
• Publication Number:
  US 20090012411A1
• Time in Patent Office: Days
• US Class Current: 600/495
• CPC Class Codes: A61B 5/02225 using the oscillometric method
• CPC Class Codes: A61B 5/0225 the pressure being controlled by electric signals, e.g. derived from Korotkoff sounds

Abstract

A method and apparatus are disclosed for the non-invasive measurement, processing and utility of blood pressure cuff oscillation signals from a blood pressure cuff applied to a body part when the blood pressure cuff pressure is at supra-systolic pressures. Oscillometric cardiac pulse waveforms associated with the peripheral artery are monitored during a plurality of cardiac ejection cycles while at supra-systolic pressure, and are measured pneumatically and transduced by an oscillometric pressure sensor. The analog signal is amplified, processed and digitized to provide a recordable waveform that can be analyzed to obtain information relating to the patient'"'"'s cardiovascular status.

Claims

1. Method of obtaining electronic, oscillatory pressure pulse-related signals from an inflatable blood pressure cuff on a patient, said method comprising the steps of:

(a) determining systolic blood pressure of the patient;

(b) selecting a measurement pressure which is above the systolic pressure;

(c) sensing oscillatory pressure pulse-related signals at the measurement pressure to produce an electronic analog signal;

(d) converting the analog signal to a digital signal.

2. The method of claim 1, wherein the systolic pressure is determined using the blood pressure cuff.

3. The method of claim 1, further comprising the step of amplifying the analog signal prior to converting said analog signal to a digital signal.

4. The method of claim 2, wherein the brachial artery is occluded by the blood pressure cuff inflated to a supra-systolic pressure.

5. The method of claim 4, wherein the measurement pressure is a pressure in the range of substantially 25-30 mm Hg above the determined systolic pressure.

9. The apparatus of claim 5, wherein said oscillometric pulse wave sensor comprises a piezoresistive pressure sensor pneumatically connected to said blood pressure cuff.

10. The apparatus of claim 5, wherein said oscillometric pulse wave sensor comprises a strain sensor mechanically connected to said blood pressure cuff.

11. The apparatus of claim 5, wherein said analog electronic circuitry comprises a differential amplifier and a latching comparator.

12. The apparatus of claim 5, wherein said analog to digital converting means produces a digital signal with at least 12 bits.

13. The apparatus of claim 5, further comprising means for measuring the systolic pressure of a patient.

14. The apparatus of claim 5, further comprising digital signal processing means.

16. The apparatus of claim 14, wherein said analog to digital converting means comprises at least a 16 bit A/D converter.

6. An apparatus for measuring an oscillometric pulse wave from a blood pressure cuff and producing a digital supra-systolic signal, comprising;

a. a blood pressure cuff applied to a human body part,

b. a pressure generator pneumatically connected to said blood pressure cuff, for generating a pre-determined supra-systolic pressure;

c. an oscillometric pulse wave sensor pneumatically connected to said blood pressure cuff for measuring oscillometric pulses wave from said blood pressure cuff and generating an analog electronic signal;

d. analog electronic circuitry for processing said analog electronic signal; and

e. analog to digital converting means for converting said analog signal to a digital signal.

7. The apparatus of claim 6, wherein said pressure generator comprises a pneumatic pump and means for controlling said pneumatic pump.

8. The apparatus of claim 7, wherein said controlling means operates said pneumatic at a pre-determined supra-systolic pressure.

15. An apparatus for measuring oscillometric pulse waves from a blood pressure cuff and producing a digital suprasystolic signal, comprising;

(a) a blood pressure cuff applied to a human body part,

(b) a pressure generator pneumatically connected to said blood pressure cuff, for generating a determined supra-systolic pressure;

(c) an oscillometric pressure sensor pneumatically connected to said blood pressure cuff for measuring oscillometric pulse waves from said blood pressure cuff and generating an analog electronic signal; and

(d) analog to digital converting means for converting said analog signal to a digital signal.