Method and circuit for indicating quality and accuracy of physiological measurements

Abstract

Sensors and monitors for a physiological monitoring system having capability to indicate an accuracy of an estimated physiological condition. The sensor senses at least one physiological characteristic of a patient and is connectable to a monitor that estimates the physiological condition from signals detected by the sensor. The sensor includes a detector for detecting the signals from the patient which are indicative of the physiological characteristic. The sensor is associated with a memory configured to store data that defines at least one sensor signal specification boundary for the detected signals. The boundary is indicative of a quality of the signals and an accuracy of the physiological characteristic estimated from the signals by the monitor. The sensor further includes means for providing access to the memory to allow transmission of the data that defines the at least one sensor boundary to the monitor.

1 - 22 . (canceled) 
     
     
         23 . A method of manufacturing a system, comprising:
 providing a sensor comprising a detector configured to generate signals that are indicative of a physiological characteristic of a patient;   providing a memory coupled to the sensor, the memory storing data defining at least one sensor signal specification boundary for the signals, the at least one sensor signal specification boundary being indicative of a quality of the signals and an accuracy of an estimated physiological condition of the patient; and   providing a monitor configured to receive the signals indicative of the physiological characteristic from the sensor, to provide the estimated physiological condition of the patient based on the signals, to receive the data defining the at least one sensor signal specification boundary for the signals from the sensor, to compare the signals against the at least one sensor signal specification boundary, and to generate an indication of the accuracy of the estimated physiological condition.   
     
     
         24 . The method of  claim 23 , wherein the sensor signal specification boundary includes one or both of limits for an AC modulation component and limits for a DC component. 
     
     
         25 . The method of  claim 24 , wherein the monitor is configured to calculate values having AC and DC components from the signals. 
     
     
         26 . The method of  claim 25 , wherein the AC and DC components are dependent on either a physiological status of the patient, sensor type, or sensor location. 
     
     
         27 . The method of claim  22 , wherein the physiological characteristic comprises arterial oxygen saturation. 
     
     
         28 . A method of operating a system for detecting at least one physiological characteristic of a patient, comprising:
 generating, with a sensor, signals from the patient that are indicative of the physiological characteristic;   accessing a memory coupled to the sensor to facilitate transmission of data defining at least one sensor signal specification boundary, the at least one sensor signal specification boundary being indicative of a quality of the signals and an accuracy of an estimated physiological condition of the patient;   transmitting from the sensor to a monitor the signals indicative of the at least one physiological characteristic;   determining the estimated physiological condition of the patient via the monitor based on the signals;   transmitting data defining the at least one sensor signal specification boundary for the signals from the sensor to the monitor;   comparing via the monitor the signals against the sensor signal specification boundary; and   generating via the monitor an indication of the accuracy of the estimated physiological condition.   
     
     
         29 . The method of  claim 28 , wherein the sensor signal specification boundary includes one or both of limits for an AC modulation component and limits for a DC component. 
     
     
         30 . The method of  claim 29 , comprising calculating via the monitor values having AC and DC components from the signals. 
     
     
         31 . The method of  claim 30 , wherein the AC and DC components are dependent on either a physiological status of the patient, sensor type, or sensor location. 
     
     
         32 . The method of  claim 28 , wherein the physiological characteristic comprises arterial oxygen saturation. 
     
     
         33 . A monitor for providing an indication of an accuracy of an estimated physiological condition of a patient, the monitor being coupleable to a sensor that generates signals indicative of at least one physiological characteristic of the patient, the monitor comprising:
 a first receiving circuit configured to receive the signals from the sensor;   a first processing circuit configured to provide an estimated physiological condition of the patient based on the signals;   a second receiving circuit configured to receive data defining at least one sensor signal specification boundary for the signals from the sensor, the sensor signal specification boundary being indicative of a quality of the signals and an accuracy of the estimated physiological characteristic; and   a second processing circuit configured to compare the signals against the at least one sensor signal specification boundary and to generate an indication of the accuracy of the estimated physiological condition.   
     
     
         34 . The monitor of  claim 33 , wherein the sensor signal specification boundary includes one or both of limits for an AC modulation component and limits for a DC component. 
     
     
         35 . The monitor of  claim 34 , comprising a third processing circuit configured to calculate values having AC and DC components from the signals. 
     
     
         36 . The monitor of  claim 35 , wherein the AC and DC components are dependent on either a physiological status of the patient, sensor type, or sensor location. 
     
     
         37 . The monitor of  claim 33 , wherein the physiological characteristic comprises arterial oxygen saturation. 
     
     
         38 . A system for detecting at least one physiological characteristic of a patient, comprising:
 a sensor, comprising:
 a detector configured to generate signals that are indicative of the at least one physiological characteristic; 
 a memory coupled to the sensor, the memory storing data defining at least one sensor signal specification boundary for the signals, the sensor signal specification boundary being indicative of a quality of the signals and an accuracy of an estimated physiological condition of the patient, wherein the sensor signal specification boundary includes limits for an AC modulation component and DC component of the signals; and 
 an integrated circuit providing access to the memory to facilitate transmission of the data defining the at least one sensor signal specification boundary; and 
   a monitor, comprising:
 a receiving circuit configured to receive communications relating to signals indicative of the at least one physiological characteristic from the sensor and data defining the at least one sensor signal specification boundary for the generated signals from the sensor; and 
 a processing circuit configured to determine the estimated physiological condition of the patient based on the signals, compare the signals against the at least one sensor signal specification boundary, generate an indication of the accuracy of the estimated physiological condition, and determine whether the received signals are within a normal signal regime or an abnormal signal regime. 
   
     
     
         39 . The system of  claim 38 , wherein the processing circuit is configured to calculate values having AC and DC components from the signals. 
     
     
         40 . The system of  claim 39 , wherein the AC and DC components are dependent on either a physiological status of the patient, sensor type, or sensor location. 
     
     
         41 . The system of  claim 38 , wherein the monitor comprises an alarm that is triggered when the signals move from the normal regime to the abnormal regime. 
     
     
         42 . The system of  claim 38 , wherein the physiological characteristic comprises arterial oxygen saturation.