Metabolic monitoring, a method and apparatus for indicating a health-related condition of a subject

Abstract

An apparatus for indicating a health-related condition of a subject has an input interface for receiving a sequence of samples of a first biological quantity derived by a first measurement method, the first measurement method being an invasive measurement and having a first impact on the subject, and for receiving a sequence of samples of a second biological quantity derived by a second measurement method, the second measurement method being a non-invasive measurement and having a second impact on the subject, wherein the first biological quantity gives a more accurate indication of the health-related condition of the subject than the second biological quantity, wherein the first biological quantity and the second biological quantity have a correlation to the health-related condition of the subject, and wherein the second impact is smaller than the first impact; a predictor for providing, for a certain time, for which no sample for the first biological quantity exists, an estimated value of the first biological quantity using samples for the first biological quantity and, as far as available, samples for the second quantity; and an output interface for outputting the estimated value or data derived from the estimated value so that an indication for the health-related condition of the subject is obtained.

1 . An apparatus for indicating a health-related condition of a subject, comprising:
 an input interface for receiving a first raw sequence of samples of a first biological quantity derived by a first measurement method, and for receiving a second raw sequence of samples of a second biological quantity derived by a second measurement method;   a predictor for providing, for a certain time, for which no sample for the first biological quantity exists, an estimated value of the first biological quantity as a predicted sample using samples for the second biological quantity and, as far as available, samples for the first biological quantity;   a filter for filtering a sequence having samples of the first biological quantity and at least one predicted sample to obtain a filtered sequence, the filtered sequence having a useful variation and a reduced non-useful variation compared to the sequence before filtering, and   an output interface for processing the filtered sequence and for outputting an indication of the health-related condition of the subject based on the filtered sequence.   
     
     
         2 . The apparatus in accordance with  claim 1 , further comprising an analytical device for sampling at least one of the first biological quantity and the second biological quantity, wherein the input interface is configured for receiving at least one of the first raw sequence of samples and the second raw sequence of samples from the analytical device. 
     
     
         3 . The apparatus in accordance with  claim 1 , in which the output interface is configured for outputting at least an increase indication, a decrease indication or a remain unchanged indication as a trend of the filtered sequence, the trend being representative of a useful variation of the health-related condition of the subject. 
     
     
         4 . The apparatus in accordance with  claim 3 , in which the output interface is arranged to derive and output the trend from an actual value of the filtered sequence and a timely preceding value of the filtered sequence. 
     
     
         5 . The apparatus in accordance with  claim 3 , in which the output interface is arranged to indicate the trend by an acoustic indicator, an optical indicator or a mechanical indicator, so that the decrease indication, the increase indication or the remain unchanged indication are acoustically, optically or mechanically different from each other. 
     
     
         6 . The apparatus in accordance with  claim 1 , in which the filter is a low-pass filter. 
     
     
         7 . The apparatus in accordance with  claim 6 , in which the low-pass filter has a cut-off frequency, which is set such that the low frequency energy for frequencies of a raw sequence or a processed sequence has a predetermined portion of a total energy of the raw sequence or the processed sequence. 
     
     
         8 . The apparatus in accordance with  claim 1 , in which the predictor is arranged to receive, as a training phase, several samples derived by the first measurement method, and to receive, after the training phase, one or more samples derived by the second measurement method for a running period. 
     
     
         9 . The apparatus in accordance with  claim 8 , in which the running period extends until a time instant, at which a sample derived by the first measurement method is received as a predictor update value, or in which the running period is unlimited, so that the predictor is a free-running predictor after the training phase. 
     
     
         10 . The apparatus in accordance with  claim 1 , further comprising a first combiner or a signal conditioning means for modifying the filtered sequence to derive an enhanced sequence from the filtered sequence; and
 wherein the output interface is further configured for processing the enhanced sequence and for outputting the indication of the health-related condition of the subject based on the enhanced sequence.   
     
     
         11 . A method of indicating a health-related condition of a subject, the method comprising:
 receiving, at an input interface, a first raw sequence of samples of a first biological quantity derived by a first measurement method;   receiving, at the input interface, a second raw sequence of samples of a second biological quantity derived by a second measurement method;   using a processor, providing by prediction, for a certain time, for which no sample for the first biological quantity exists, an estimated value of the first biological quantity as a predicted sample using samples for the second biological quantity and, as far as available, samples for the first biological quantity;   using a processor, filtering a sequence having samples of the first biological quantity and at least one predicted sample to obtain a filtered sequence, the filtered sequence having a useful variation and a reduced non-useful variation compared to the sequence before filtering; and   processing the filtered sequence and outputting, at an output interface, an indication of the health-related condition of the subject based on the filtered sequence.   
     
     
         12 . A non-transitory digital storage medium having stored thereon a computer program having a program code for performing a method for indicating a health-related condition of a subject, the method comprising:
 receiving a first raw sequence of samples of a first biological quantity derived by a first measurement method;   receiving a second raw sequence of samples of a second biological quantity derived by a second measurement method;   providing, by prediction, for a certain time, for which no sample for the first biological quantity exists, an estimated value of the first biological quantity as a predicted sample using samples for the second biological quantity and, as far as available, samples for the first biological quantity;   filtering a sequence having samples of the first biological quantity and at least one predicted sample to provide a filtered sequence, the filtered sequence having a useful variation and a reduced non-useful variation compared to the sequence before filtering; and   processing the filtered sequence and outputting an indication of the health-related condition of the subject based on the filtered sequence, when the computer program is running on a computer.