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 blood pressure, the measurement device comprising:
an apparatus adapted to provide an oscillating volumetric signal to a volume of a patient's artery at a measurement site on the patient, wherein the oscillating volumetric signal comprises a frequency; and
a detector placed sufficiently near the measurement site to detect a pressure signal, wherein the pressure signal comprises an amplitude, and wherein the measurement device is coupled to a processor, which determines when the amplitude of the pressure signal is smallest, thereby also determining when transmural pressure is about zero.
2. The measurement device of claim 1 , wherein the apparatus comprises a piezo-electric speaker.
3. The measurement device of claim 1 , wherein the apparatus is attached to a cuff.
4. The measurement device of claim 1 , wherein the apparatus provides a constant amplitude volume perturbation.
5. The measurement device of claim 1 , wherein the frequency is about 25 Hz.
6. The measurement device of claim 1 , wherein the detector comprises a pressure transducer.
7. The measurement device of claim 1 , further comprising a high pass filter, which substantially removes pulsatile components from the pressure signal.
8. The measurement device of claim 1 , wherein the processor digitally filters the pressure signal.
9. The measurement device of claim 1 , wherein the amplitude comprises a peak-to-peak amplitude.
10. The measurement device of claim 1 , further comprising an accelerometer.
11. The measurement device of claim 1 , wherein the pressure signal comprises at a least a component of the oscillating volumetric signal.
12. A method of determining the blood pressure of a patient from an arterial pressure indicative signal, the method comprising:
inducing a high-frequency pressure wave onto an artery;
detecting a signal indicative of arterial pressure, wherein the signal includes a high-frequency component from the pressure wave;
filtering low-frequency components from the signal, thereby providing a filtered signal, wherein the filtered signal comprises an amplitude;
determining when the amplitude of the filtered signal is smallest; and determining when transmural pressure is about zero.
13. The method of claim 12 , wherein the filtering is performed digitally.
14. The method of claim 12 , wherein the signal is detected with a pressure detector.
15. The method of claim 12 , wherein the amplitude comprises a peak-to-peak amplitude.
16. The method of claim 12 , further comprising changing a pressure induced onto the artery by an external pressure application device to determine at least one of systolic and diastolic blood pressure.
17. The method of claim 12 , further comprising changing a pressure induced onto the artery by an external pressure application device to ensure the pressure induced is between systolic and diastolic blood pressure.
18. A method of determining the blood pressure of a patient, the method comprising:
inducing a volumetric perturbation onto an artery, wherein the volumetric perturbation comprises a frequency;
detecting a signal indicative of pressure;
filtering low-frequency components from the signal thereby providing a filtered signal, wherein the filtered signal comprises an amplitude;
determining when the amplitude of the filtered signal is lowest; and determining when transmural pressure is about zero.
19. The method of claim 18 , further comprising determining blood pressure based upon the time when the transmural pressure is about zero and a cuff pressure.