Methods and apparatuses for measuring multiple vital signs based on arterial pressure waveforms

Abstract

Vital sign sensor apparatuses which measures vital signs based on arterial pressure waveforms are described. In some embodiments, the apparatus includes an infrared sensor configured to capture at least a portion of an arterial pulse pressure waveform from a user. The apparatus further includes a processor configured to determine a maximum point for each of a plurality of peaks of the arterial pulse pressure waveform, and a corresponding first timestamp. The processor also determines one or more vital signs (e.g., a heart rate for a user, a heart rate variation of the user, a respiration rate of the user, and/or an arterial pulse pressure of the user) based at least in part on the plurality of maximum points and the plurality of corresponding timestamps. Related systems, methods, and articles of manufacture are also described.

1 - 21 . (canceled) 
     
     
         22 . An apparatus for remotely monitoring a health of a user, the apparatus comprising:
 a sensor configured to capture an electrical signal from the user, the electrical signal comprising a plurality of groups of related points; and   a processor coupled to the sensor, the processor configured to cause operations comprising:
 determining whether to calculate a maximum pressure value or a minimum pressure value for each of the plurality of groups of related points; 
 determining, based on a determination to calculate the maximum pressure value, the maximum pressure value for each of the plurality of groups of related points, wherein the determination of the maximum pressure value comprises:
 determining for a current group of the plurality of groups of related points of the electrical signal, whether a current sample has a current maximum pressure value that is greater than a prior maximum pressure value from a prior sample within the current group of related points that was previously received by the sensor; 
 storing the current maximum pressure value when the current maximum pressure value is greater than the prior maximum pressure value; and 
 setting the stored current maximum pressure value as the maximum pressure value when the current maximum pressure value of a threshold number of samples is not greater than the stored current maximum pressure value; 
 
 determining, based at least in part on the maximum pressure values, vital sign information indicative of the health of the user; 
 determining, based on the vital sign information, that an alert condition is met; and 
 providing, to at least a member of a medical team of the user and based on the determination that the alert condition is met, an alert indicating that the alert condition has been met. 
   
     
     
         23 . The apparatus of  claim 22 , wherein the electrical signal comprises an arterial pulse pressure waveform. 
     
     
         24 . The apparatus of  claim 22 , wherein the vital sign information comprises one or more of a heart rate of the user, a heart rate variation of the user, and a respiration rate of the user. 
     
     
         25 . The apparatus of  claim 24 , wherein determining the vital sign information comprises generating a plurality of peak rates by at least subtracting, for each of the plurality of groups of related points, a first timestamp of the maximum pressure value of an immediately preceding group of related points from a second timestamp of the maximum pressure value of an immediately subsequent group of related points. 
     
     
         26 . The apparatus of  claim 25 , wherein determining the vital sign information further comprises averaging the plurality of peak rates. 
     
     
         27 . The apparatus of  claim 25 , wherein determining the vital sign information comprises:
 determining a maximum rate from the plurality of peak rates;   determining a minimum rate from the plurality of peak rates; and   determining a standard deviation from the plurality of peak rates.   
     
     
         28 . The apparatus of  claim 24 , wherein determining the vital sign information comprises determining a fundamental frequency of the electrical signal. 
     
     
         29 . The apparatus of  claim 22 , wherein the operations further comprise:
 determining to calculate the minimum pressure value;   determining, for each of a plurality of troughs of the electrical signal, the minimum pressure value;   determining, for each of the minimum pressure values, a first timestamp; and   wherein the determining the vital sign information is further based at least in part the plurality of minimum pressure values and the first timestamp of each of the minimum pressure values.   
     
     
         30 . The apparatus of  claim 22 , wherein the sensor is configured to capture the electrical signal from the user's finger by providing signals from a light emitting diode; and measuring reflections via a phototransistor. 
     
     
         31 . The apparatus of  claim 30 , further comprising:
 a peripheral capillary oxygen saturation sensor configured to measure oxygen saturation from the user's second finger; and   one or more electrocardiography sensors configured to measure an electrocardiography waveform from the user's third finger.   
     
     
         32 . The apparatus of  claim 23 , wherein the operations further comprise:
 determining, based at least in part on the arterial pressure waveform, an arterial audio waveform; and   determining, based at least in part on the arterial pressure waveform and the arterial audio waveform, one or more cardiac events of the user,   wherein the one or more cardiac events comprises at least one of an aortic valve opening or closing, a mitral valve opening or closing, an isovolumetric contraction or relaxation, an ejection, a rapid inflow, diastasis, and an atrial systole.   
     
     
         33 . The apparatus of  claim 22 , wherein the alert condition comprises a vital sign value being greater than or equal to a predefined threshold vital sign value. 
     
     
         34 . A method for remotely monitoring a health of a user, the method comprising:
 capturing, via a sensor, an electrical signal from the user, the electrical signal comprising a plurality of groups of related points;   determining, via a processor in communication with the sensor, whether to calculate a maximum pressure value or a minimum pressure value for each of the plurality of groups of related points;   determining, based on a determination to calculate the maximum pressure value, the maximum pressure value for each of the plurality of groups of related points, wherein the determination of the maximum pressure value comprises:
 determining for a current group of the plurality of groups of related points of the electrical signal, whether a current sample has a current maximum pressure value that is greater than a prior maximum pressure value from a prior sample within the current group of related points that was previously received by the sensor; 
 storing the current maximum pressure value when the current maximum pressure value is greater than the prior maximum pressure value; and 
 setting the stored current maximum pressure value as the maximum pressure value when the current maximum pressure value of a threshold number of samples is not greater than the stored current maximum pressure value; 
   determining, based at least in part on the maximum pressure values, vital sign information indicative of the health of the user;   determining, based on the vital sign information, that an alert condition is met; and   providing, to at least a member of a medical team of the user and based on the determination that the alert condition is met, an alert indicating that the alert condition has been met.   
     
     
         35 . The method of  claim 34 , wherein the electrical signal comprises an arterial pulse pressure waveform. 
     
     
         36 . The method of  claim 34 , wherein the vital sign information comprises one or more of a heart rate of the user, a heart rate variation of the user, and a respiration rate of the user. 
     
     
         37 . The method of  claim 36 , wherein determining the vital sign information comprises generating a plurality of peak rates by at least subtracting, for each of the plurality of groups of related points, a first timestamp of the maximum pressure value of an immediately preceding group of related points from a second timestamp of the maximum pressure value of an immediately subsequent group of related points. 
     
     
         38 . The method of  claim 37 , wherein determining the vital sign information further comprises averaging the plurality of peak rates. 
     
     
         39 . The method of  claim 37 , wherein determining the vital sign information comprises:
 determining a maximum rate from the plurality of peak rates;   determining a minimum rate from the plurality of peak rates; and   determining a standard deviation from the plurality of peak rates.   
     
     
         40 . The method of  claim 34 , wherein the alert condition comprises a vital sign value being greater than or equal to a predefined threshold vital sign value. 
     
     
         41 . A non-transitory computer program product storing instructions which, when executed by at least one hardware data processors, result in operations comprising:
 capturing, via a sensor, an electrical signal from the user, the electrical signal comprising a plurality of groups of related points;   determining, via a processor in communication with the sensor, whether to calculate a maximum pressure value or a minimum pressure value for each of the plurality of groups of related points;   determining, based on a determination to calculate the maximum pressure value, the maximum pressure value for each of the plurality of groups of related points, wherein the determination of the maximum pressure value comprises:
 determining for a current group of the plurality of groups of related points of the electrical signal, whether a current sample has a current maximum pressure value that is greater than a prior maximum pressure value from a prior sample within the current group of related points that was previously received by the sensor; 
 storing the current maximum pressure value when the current maximum pressure value is greater than the prior maximum pressure value; and 
 setting the stored current maximum pressure value as the maximum pressure value when the current maximum pressure value of a threshold number of samples is not greater than the stored current maximum pressure value; 
   determining, based at least in part on the maximum pressure values, vital sign information indicative of the health of the user;   determining, based on the vital sign information, that an alert condition is met; and   providing, to at least a member of a medical team of the user and based on the determination that the alert condition is met, an alert indicating that the alert condition has been met.