Rapid non-invasive blood pressure measuring device

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.

1 . A measurement device for determining blood pressure, the measurement device comprising:
 an external pressure device configured to apply a first external pressure to an artery and subsequently apply a second external pressure to the artery, the first external pressure and the second external pressure being such that the artery experiences a range of transmural pressures; and   a processor, wherein the processor is configured to identify a first time when transmural pressure is approximately equal to zero and a second time when transmural pressure is approximately equal to zero.   
     
     
         2 . The measurement device of  claim 1 , wherein the external pressure device comprises a cuff. 
     
     
         3 . The measurement device of  claim 1 , wherein the applied second external pressure is greater than the applied first external pressure. 
     
     
         4 . The measurement device of  claim 1 , wherein the applied first and second external pressures are between a systolic and diastolic arterial pressure. 
     
     
         5 . The measurement device of  claim 1 , wherein the processor is configured to determine a first arterial pressure at the first time and a second arterial pressure at the second time. 
     
     
         6 . The measurement device of  claim 5 , wherein the processor is configured calibrate a pressure-indicative signal using the first and second arterial pressures. 
     
     
         7 . The measurement device of  claim 5 , further comprising a detector to produce a pressure-indicative signal, wherein the processor is further adapted to determine a user's blood pressure based on the pressure-indicative signal and the first and second arterial pressures. 
     
     
         8 . The measurement device of  claim 7 , wherein the detector comprises a tonometer. 
     
     
         9 . The measurement device of  claim 7 , wherein the detector comprises a pressure wave velocity measurement system. 
     
     
         10 . The measurement device of  claim 5 , wherein the processor is configured to determine a patient's blood pressure based on a pressure-indicative signal received from a detector and the first and second arterial pressures. 
     
     
         11 . The measurement device of  claim 5 , wherein the processor is configured to determine an offset of a pressure-indicative signal. 
     
     
         12 . The measurement device of  claim 5 , wherein the processor is configured to scale a pressure-indicative signal. 
     
     
         13 . The measurement device of  claim 1 , wherein the processor is adapted to identify a change in the viscoelastic properties of an artery. 
     
     
         14 . The measurement device of  claim 1 , further comprising a first detector electrically connected to the processor to produce a signal indicative of arterial pressure and a second detector electrically connected to the processor to produce a signal indicative of an arterial volume. 
     
     
         15 . The measurement device of  claim 1 , further comprising an exciter configured to perturb at least one of pressure and volume of a patient's artery with an oscillating perturbation signal. 
     
     
         16 . A method of determining arterial pressure, comprising:
 applying a first external pressure to an artery, the first external pressure being such that the artery experiences a range of transmural pressures;   identifying a first time when transmural pressure is approximately equal to zero;   applying a second external pressure to the artery, the second external pressure being such that the artery experiences a range of transmural pressures; and   identifying a second time when transmural pressure is approximately equal to zero.   
     
     
         17 . The method of  claim 16 , wherein the second external pressure is greater than the first external pressure. 
     
     
         18 . The method of  claim 16 , wherein the first and second external pressures are between a systolic and diastolic arterial pressure. 
     
     
         19 . The method of  claim 16 , further comprising determining a first arterial pressure at the first time and a second arterial pressure at the second time. 
     
     
         20 . The method of  claim 19 , further comprising determining a patient's blood pressure based on a pressure-indicative signal received from a detector and the first and second arterial pressures.