Non-invasive blood pressure monitors and methods of operating the same

Abstract

According to an aspect, there is provided a method of operating a non-invasive blood pressure, NIBP, monitor to measure the blood pressure of a subject, the NIBP monitor comprising a cuff, a pressure sensor for measuring the pressure in the cuff and for outputting a pressure signal representing the pressure in the cuff and a physiological parameter sensor, the method comprising obtaining a first measurement of a physiological parameter for the subject during inflation of the cuff, the first measurement being obtained from the pressure signal; obtaining a second measurement of the physiological parameter for the subject during inflation of the cuff, the second measurement being obtained from the physiological parameter sensor; comparing the first measurement and the second measurement; and estimating the reliability of a blood pressure measurement obtained by the NIBP monitor during inflation of the cuff based on the result of the step of comparing.

1 . A method of operating a non-invasive blood pressure, NIBP, monitor to measure the blood pressure of a subject, and including using a cuff that is to be placed around a limb of the subject, a pressure sensor for measuring the pressure in the cuff and for outputting a pressure signal representing the pressure in the cuff, and a physiological parameter sensor for measuring pulse rate or heart rate, the method comprising:
 obtaining a first measurement of pulse rate or heart rate for the subject during inflation of the cuff, the first measurement being obtained from the pressure signal;   obtaining a second measurement of the pulse rate or heart rate for the subject during inflation of the cuff, the second measurement being obtained from the physiological parameter sensor;   comparing the first measurement and the second measurement; and   estimating the reliability of a blood pressure measurement obtained by the NIBP monitor during inflation of the cuff based on the result of the step of comparing.   
     
     
         2 . A method as claimed in  claim 1 , wherein the step of obtaining a second measurement of the pulse rate or heart rate is performed at the same time or within a certain time window as the step of obtaining the first measurement. 
     
     
         3 . A method as claimed in  claim 1 , the method further comprising the step of correcting the timing of one of the first and second measurements to account for time delays in obtaining said measurement. 
     
     
         4 . A method as claimed in  claim 1 , the method further comprising the step of determining whether to obtain a blood pressure measurement during inflation of the cuff or during deflation of the cuff based on the estimated reliability. 
     
     
         5 . A method as claimed in  claim 1 , wherein a blood pressure measurement that is to be obtained by the NIBP monitor during inflation of the cuff is scheduled for a particular time, and the method further comprises the steps of:
 estimating the risk of arrhythmia occurring in the subject during the scheduled blood pressure measurement; and   adapting the scheduled blood pressure measurement according to the estimated risk.   
     
     
         6 . A method as claimed in  claim 5 , wherein the step of adapting comprises determining whether to reschedule the scheduled blood pressure measurement to a different time based on the estimated risk. 
     
     
         7 . A method as claimed in  claim 5 , wherein the step of adapting comprises determining whether to perform the blood measurement during deflation of the cuff instead of during inflation of the cuff based on the estimated risk. 
     
     
         8 . A computer program product comprising a computer readable medium having computer readable code embodied therein, the computer readable code being configured such that, on execution by a suitable computer, processor or control unit, the computer, processor or control unit is caused to perform the method of  claim 1 . 
     
     
         9 . A non-invasive blood pressure, NIBP, monitor for measuring the blood pressure of a subject, the NIBP monitor comprising:
 a control unit that is configured to:
 obtain a first measurement of the pulse rate or heart rate for the subject during inflation of a cuff that is to be placed around a limb of the subject, the first measurement being obtained from a pressure signal representing the pressure in the cuff output by a pressure sensor for measuring the pressure in the cuff; 
 obtain a second measurement of the pulse rate or heart rate for the subject during inflation of the cuff, the second measurement being obtained from a physiological parameter sensor for measuring a pulse rate or heart rate; 
 compare the first measurement and the second measurement; and 
 estimate the quality of a blood pressure measurement obtained by the NIBP monitor during inflation of the cuff based on the result of the comparison. 
   
     
     
         10 . A NIBP monitor as claimed in  claim 9 , wherein the control unit is configured to obtain the second measurement of the pulse rate or heart rate at the same time or within a certain time window of the first measurement. 
     
     
         11 . A NIBP monitor as claimed in  claim 9 , wherein the control unit is further configured to correct the timing of one of the first and second measurements to account for time delays in obtaining said measurement. 
     
     
         12 . A NIBP monitor as claimed in  claim 9 , wherein the control unit is further configured to determine whether to obtain a blood pressure measurement during inflation of the cuff or during deflation of the cuff based on the estimated reliability. 
     
     
         13 . A NIBP monitor as claimed in  claim 9 , wherein a blood pressure measurement that is to be obtained by the NIBP monitor during inflation of the cuff is scheduled for a particular time, and the control unit is configured to estimate the risk of arrhythmia occurring in the subject during the scheduled blood pressure measurement; and adapt the scheduled blood pressure measurement according to the estimated risk. 
     
     
         14 . A NIBP monitor as claimed in  claim 13 , wherein the control unit is configured to adapt the scheduled blood pressure measurement by determining whether to reschedule the scheduled blood pressure measurement to a different time based on the estimated risk. 
     
     
         15 . A NIBP monitor as claimed in  claim 13 , wherein the control unit is configured to adapt the scheduled blood pressure measurement by determining whether to perform the blood measurement during deflation of the cuff instead of during inflation of the cuff based on the estimated risk.