Rapid non-invasive blood pressure measuring device
View Patent ↗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.
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.