Apparatus and method for determining a physiological condition

Abstract

An apparatus for detecting a physiological condition in a person, comprising input means for receiving at least two physiological parameters, processing means for determining, from the received physiological parameters, a result signal indicative of the presence or onset of said physiological condition, and output means for generating an output indicative of the result signal. The apparatus further comprises storage means for storing a look-up table comprising a plurality of entries, each entry corresponding to a pre-calculated probability of the presence or onset of said physiological condition, the pre-calculated probabilities being determined by means of a mathematical process from previously monitored physiological parameters; and the processing means is adapted to process the received at least two physiological parameters to identify one of the plurality of entries of the look-up table, and to determine said result signal from the identified entry of the look-up table.

1 . An apparatus for detecting a physiological condition in a person, the apparatus comprising 
 processing means ( 102 ) adapted to receive at least two physiological parameters, and to determine, from the received physiological parameters, a result signal indicative of the presence or onset of said physiological condition; and    output means ( 108 ,  109 ) for generating an output indicative of the result signal;    characterised in    that the apparatus comprises storage means ( 103 ) for storing a look-up table ( 214 ) comprising a plurality of entries, each entry corresponding to a pre-calculated probability of the presence or onset of said physiological condition, the pre-calculated probabilities being determined by means of a mathematical process from previously monitored physiological parameters; and    that the processing means is adapted to process the received at least two physiological parameters to identify one of the plurality of entries of the look-up table, and to determine said result signal from the identified entry of the look-up table.    
     
     
         2 . An apparatus according to  claim 1 , wherein the mathematical process comprises an adaptive learning algorithm.  
     
     
         3 . An apparatus according to  claim 1 , wherein the mathematical process comprises a reinforcement learning process.  
     
     
         4 . An apparatus according to  claim 2 , further comprising input means for receiving a user input indicative of the presence or absence of said physiological condition.  
     
     
         5 . An apparatus according to of  claim 2 , further comprising input means for receiving a measured quantity indicative of the presence of the physiological condition.  
     
     
         6 . An apparatus according to  claim 5 , wherein the measured quantity is a measured blood glucose level.  
     
     
         7 . An apparatus according to  claim 4 , wherein the processing means is further adapted to update at least the identified entry of the look-up table according to the adaptive process and in response to a user input indicative of the presence or absence of said physiological condition and/or a received measured quantity indicative of the presence of the physiological condition.  
     
     
         8 . An apparatus according to  claim 1 , wherein the processing means is further adapted to discretize the received physiological parameters to obtain one of a plurality of possible combinations of discrete physiological parameters, each of the plurality of combinations being associated to a corresponding one of the plurality of entries of the look-up table.  
     
     
         9 . An apparatus according to  claim 8 , wherein the processing means is adapted to discretize the received physiological parameters by identifying, for each of the received physiological parameters, one of a corresponding number of intervals in which the received physiological parameter is determined to fall; resulting in a combination of identified intervals, the combination identifying a corresponding entry in the look-up table.  
     
     
         10 . An apparatus according to  claim 9 , wherein each of the physiological parameters are discretized with respect to 2-10 respective intervals, preferably, 3-6 intervals, more preferably 3-5 intervals, most preferably 4 intervals.  
     
     
         11 . An apparatus according  claim 1 , further comprising input means ( 104 ,  105 ,  106 ,  107 ,  116 ) for receiving the at least two physiological parameters.  
     
     
         12 . An apparatus according to  claim 1 , wherein the at least two physiological parameters consist of 2-10 parameters, preferably 3-6 parameters, more preferably 4-5 parameters.  
     
     
         13 . An apparatus according to  claim 12 , where the at least two physiological parameters are selected from the set of parameters consisting of pulse, heart rate variability, skin temperature, skin impedance, respiration frequency, eye movements, muscle tonus, a parameter determined by ECG, a parameter determined by Electroencephalography (EEG), CO 2  content of the blood, a blood glucose measurement.  
     
     
         14 . An apparatus according to  claim 13 , wherein one of the at least two physiological parameters is a non-invasive blood glucose measurement.  
     
     
         15 . An apparatus according to  claim 1 , wherein the at least two parameters further include the rate of change of at least one of the physiological parameters.  
     
     
         16 . An apparatus according to  claim 1 , wherein the processing means is further adapted to compare the identified entry of the look-up table with a predetermined threshold and where the result signal is indicative of the result of said comparison.  
     
     
         17 . An apparatus according to  claim 1 , wherein the physiological condition is hypoglycaemia or the onset of hypoglycaemia.  
     
     
         18 . An apparatus according to  claim 1 , wherein the output means comprises a means for generating an audible alarm.  
     
     
         19 . A method of alerting a patient to the risk of the presence of a physiological condition, the method comprising 
 receiving at least two physiological parameters;    determining, from the received physiological parameters, a result signal indicative of the presence of said physiological condition;    notifying the patient in response to the result signal;    characterised in that    the step of determining the result signal comprises    processing the received at least two physiological parameters to identify one of a plurality of entries of a look-up table, each entry of the look-up up table corresponding to a calculated probability of the presence of said physiological condition; and    determining said result signal from the identified entry of the look-up table.    
     
     
         20 . A computer program comprising program code means for performing all the steps of: 
 receiving at least two physiological parameters;    determining, from the received physiological parameters, a result signal indicative of the presence of said physiological condition;    notifying the patient in response to the result signal;    characterised in that    the step of determining the result signal comprises    processing the received at least two physiological parameters to identify one of a plurality of entries of a look-up table, each entry of the look-up up table corresponding to a calculated probability of the presence of said physiological condition; and    determining said result signal from the identified entry of the look-up table