Rapid non-invasive blood pressure measuring device

• US 7,618,375 B2
• Filed: 04/28/2006
• Issued: 11/17/2009
• Est. Priority Date: 06/26/1996
• Status: Expired due to Fees

• Current Assignee: Masimo Corporation
• Original Assignee: Masimo Corporation
• Inventors: Sher, Mark Henry, Caro, Richard G., Flaherty, Bryan Patrick
• Primary Examiner(s): Nasser; Robert L
• Application Number:
  US11/413,718
• Publication Number:
  US 20060206030A1
• Time in Patent Office: 1,299 Days
• Field of Search: None
• US Class Current: 600/485
• CPC Class Codes: A61B 5/02133 by using induced vibration of the blood vessel
• CPC Class Codes: A61B 5/022 by applying pressure to close blood vessels, e.g. against the skin; Ophthalmodynamometers

Abstract

A measurement device for generating an arterial volume-indicative signal includes an exciter and a detector. The exciter is adapted to receive an oscillating signal and generate a pressure wave based at least in part on the oscillating signal on the artery at a measurement site on a patient. The pressure wave includes a frequency. The detector is placed sufficiently near the measurement site to detect a volumetric signal indicative of arterial volume of the patient.

Claims

1. A measurement device for determining the blood pressure of a patient by finding a time when transmural pressure is approximately equal to zero, the measurement device comprising:

a piezo-electric speaker, configured to perturbs at least one of pressure and volume of an artery of a patient;

a pressure transducer configured to be placed sufficiently near a measurement site to detect a signal indicative of an oscillation response when the piezo-electric speaker perturbs the at least one of pressure and volume; and

a processor coupled to the pressure transducer, wherein the processor is configured to identify a time when transmural pressure is approximately equal to zero.

2. The measurement device of claim 1, wherein the piezo-electric speaker is attached to a cuff.

3. The measurement device of claim 1, wherein the piezo-electric speaker provides a constant amplitude volume perturbation.

4. The measurement device of claim 1, wherein the piezo-electric speaker provides an oscillating volumetric signal to a volume of the artery, wherein the oscillating volumetric signal comprises a frequency.

5. The measurement device of claim 4, wherein the frequency is about 25 Hz.

6. The measurement device of claim 1, further comprising a high pass filter, which substantially removes pulsatile components from the signal.

7. The measurement device of claim 1, wherein the processor digitally filters the signal.

8. The measurement device of claim 1, wherein the processor determines an amplitude of the signal.

9. The measurement device of claim 8, wherein the amplitude comprises a peak-to-peak amplitude.

10. The measurement device of claim 1, further comprising an accelerometer. pg,28

11. The measurement device of claim 1, wherein the signal comprises at least a component of an oscillating volumetric signal.

12. A method of determining the blood pressure of a patient by finding a time when transmural pressure is approximately equal to zero, the method comprising:

perturbing at least one of pressure and volume of an artery of a patient with a piezo-electric speaker;

detecting a signal indicative of an oscillation response resulting from said perturbing;

filtering the signal; and

determining when an amplitude of the filtered signal is lowest, thereby determining when transmural pressure is about zero.

13. The method of claim 12, further comprising determining blood pressure based upon a time when the transmural pressure is about zero and a cuff pressure.

14. A measurement device for determining the blood pressure of a patient by finding a time when transmural pressure is approximately equal to zero, the measurement device comprising:

means for perturbing at least one of pressure and volume of an artery of a patient;

means for detecting a signal indicative of an oscillation response resulting from said means for perturbing;

means for filtering the signal; and

means for determining when an amplitude of the filtered signal is lowest, thereby determining when transmural pressure is about zero.

15. The measurement device of claim 14, further comprising means for determining blood pressure based upon a time when the transmural pressure is about zero and a cuff pressure. pg,29

16. The measurement device of claim 14, wherein the means for filtering the signal and the means for determining when an amplitude of the filtered signal is lowest comprise a single device.

17. The measurement device of claim 14, wherein the means for filtering the signal and the means for determining when an amplitude of the filtered signal is lowest comprise separate devices.