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

• US 8,858,435 B2
• Filed: 07/23/2010
• Issued: 10/14/2014
• Est. Priority Date: 02/26/2004
• Status: Expired due to Fees

• Current Assignee: Diabetes Tools Sweden AB
• Original Assignee: Diabetes Tools Sweden AB
• Inventors: Liljeryd, Lars Gustaf, Magnusson, Ulf Frederik
• Primary Examiner(s): Natnithithadha, Navin
• Assistant Examiner(s): WEARE, MEREDITH H
• Application Number:
  US12/842,831
• Publication Number:
  US 20110166791A1
• Time in Patent Office: 1,544 Days
• Field of Search: 600/309, 600/316, 600/319, 600/345, 600/347, 600/365, 600/483, 600485-499
• US Class Current: 600/365
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/222 combined with detection or measurement of physiological parameters, e.g. heart rate
• CPC Class Codes: A61B 5/4866 Evaluating metabolism A61B5/083 takes precedence
• CPC Class Codes: A61B 5/7225 Details of analog processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation A61B5/30, A61B5/316 take precedence; transformers for specific applications H01F38/00; amplifiers H03F
• CPC Class Codes: A61B 5/7267 involving training the classification device
• CPC Class Codes: A61B 5/7275 Determining trends in physiological measurement data; Predicting development of a medical condition based on physiological measurements, e.g. determining a risk factor
• CPC Class Codes: A61B 5/746 Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms alarms per se G08B
• CPC Class Codes: G16H 50/30 for calculating health indices; for individual health risk assessment
• CPC Class Codes: G16Z 99/00 Subject matter not provided for in other main groups of this subclass

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.

Claims

1. An apparatus for indicating a health-related condition of a subject, comprising:

an input interface for receiving a raw sequence of samples of a biological quantity derived by a measurement method and a further raw sequence of a different biological quantity derived by a further measurement method;

a first processor for processing the raw sequence of samples to obtain a processed sequence, the first processor comprising an interpolator for providing data on an interpolated sample for a missing sample of the biological quantity using one or more samples at a preceding time instant or one or more samples at a subsequent time instant to obtain an interpolated sequence representing samples of the raw sequence and the interpolated sample;

a filter for filtering the processed sequence provided by the first processor to obtain a filtered sequence, the filtered sequence having a useful variation and a reduced non-useful variation compared to the processed sequence before filtering, wherein the filter is configured for filtering the further raw sequence to obtain a further filtered sequence;

an output interface for processing an enhanced sequence derived from the filtered sequence and for outputting at least an increase indication, a decrease indication or a remain unchanged indication as a trend of the enhanced sequence, the trend being representative of a useful variation of the health-related condition of the subject; and

a second processor for deriving the enhanced sequence from the filtered sequence, wherein the second processor comprises a combiner, for combining the filtered sequence and the further filtered sequence to derive the enhanced sequence.

2. Apparatus in accordance with claim 1, in which the measurement method is a blood or plasma glucose measurement, and

in which the further measurement method is a heart rate measurement, a blood pressure measurement or a method for obtaining a product of heart rate and blood pressure.

3. Apparatus in accordance with claim 1, in which the combiner is arranged for performing a sample-wise multiplication.

4. Apparatus in accordance with claim 1, in which the biological quantity is a blood glucose level, a blood lipid level or a blood insulin level of the subject.

5. Apparatus in accordance with claim 1, in which the health-related condition is a diabetes-related or glucose-related or insulin-related metabolic disorder.

6. Apparatus in accordance with claim 1, in which the filter is a low-pass filter and has a cut-off frequency, which is set such that the low frequency energy for frequencies of the raw sequence or the processed sequence provided by the first processor has a predetermined portion of a total energy of the raw sequence or the processed sequence.

7. Apparatus in accordance with claim 6, further comprising a cut-off frequency calculator being arranged to determine the cut-off frequency, using;

determining different cut-off frequencies for a low-pass filter for filtering the samples to obtain filtered test signals;

for each filtered test signal, deriving residual values based on the difference of the raw sequence and a filtered test signal to obtain a residual representation;

based on the residual representation, determining a cut-off frequency individually adapted to the raw sequence of samples.

8. Apparatus in accordance with claim 7, in which the cut-off frequency calculator is arranged to determine the cut-off frequency by:

determining a first line using residual energies for low cut-off frequencies;

determining a second line using residual energies for high cut-off frequencies; and

finding an intersection point of the first line and the second line, the intersection point indicating the cut-off frequency.

9. Apparatus in accordance with claim 1, 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.

10. Apparatus in accordance with claim 1, in which the output interface is arranged to derive and output the trend from an actual value of the enhanced sequence, and a timely preceding value of the filtered sequence or the enhanced sequence.

11. A method for indicating a health-related condition of a subject, comprising:

receiving, at an input interface, a raw sequence of samples of a biological quantity derived by a measurement method and a further raw sequence of a different biological quantity derived by a further measurement method;

processing the raw sequence of samples using a processorto obtain a processed sequence, comprising providing data on an interpolated sample for a missing sample of the biological quantity using one or more samples at a preceding time instant or one or more samples at a subsequent time instant to obtain an interpolated sequence representing samples of the raw sequence and the interpolated sample;

filtering the processed sequence, which was obtained by said processing of the raw sequence of samples, using a filter to obtain a filtered sequence, the filtered sequence having a useful variation and a reduced non-useful variation compared to the processed sequence before filtering and filtering the further raw sequence to obtain a further filtered sequence;

processing an enhanced sequence derived from the filtered sequence by combining it with the further filtered sequence, and outputting, at an output interface, at least an increase indication, a decrease indication or a remain unchanged indication as a trend of the enhanced sequence, the trend being representative of a useful variation of the health-related condition of the subject.

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 raw sequence of samples of a biological quantity derived by a measurement method and a further raw sequence of a different biological quantity derived by a further measurement method;

processing the raw sequence of samples to obtain a processed sequence, comprising providing data on an interpolated sample for a missing sample of the biological quantity using one or more samples at a preceding time instant or one or more samples at a subsequent time instant to obtain an interpolated sequence representing samples of the raw sequence and the interpolated sample;

filtering the processed sequence to obtain a filtered sequence, the filtered sequence having a useful variation and a reduced non-useful variation compared to the processed sequence before filtering and filtering the further raw sequence to obtain a further filtered sequence; and

processing an enhanced sequence derived from the filtered sequence by combining it with the further filtered sequence, and outputting at least an increase indication, a decrease indication or a remain unchanged indication as a trend of the filtered sequence or the enhanced sequence, the trend being representative of a useful variation of the health-related condition of the subject, when the computer program is running on a computer.

13. An apparatus for indicating a health-related condition of a subject, comprising:

an input interface for receiving a raw sequence of samples of a biological quantity derived by a measurement method and a further raw sequence of a different biological quantity derived by a further measurement method;

a processor for processing the raw sequence of samples to obtain a processed sequence, the processor comprising;

an interpolator for providing data on an interpolated sample for a missing sample of the biological quantity using one or more samples at a preceding time instant or one or more samples at a subsequent time instant to obtain an interpolated sequence representing samples of the raw sequence and the interpolated sample; and

a combiner for combining the raw sequence and the further raw sequence to obtain a combined raw sequence to be filtered by the filter;

a filter for filtering the combined raw sequence to obtain a filtered sequence, the filtered sequence having a useful variation and a reduced non-useful variation compared to the processed sequence before filtering; and

an output interface for processing the filtered sequence or for processing an enhanced sequence derived from the filtered sequence and for outputting at least an increase indication, a decrease indication or a remain unchanged indication as a trend of the filtered sequence or the enhanced sequence, the trend being representative of a useful variation of the health-related condition of the subject.

14. Apparatus in accordance with claim 13, in which the measurement method is a blood or plasma glucose measurement, and

in which the further measurement method is a heart rate measurement, a blood pressure measurement or a method for obtaining a product of heart rate and blood pressure.

15. Apparatus in accordance with claim 13, in which the combiner is arranged for performing a sample-wise multiplication.

16. Apparatus in accordance with claim 13, in which the biological quantity is a blood glucose level, a blood lipid level or a blood insulin level of the subject.

17. Apparatus in accordance with claim 13, in which the health-related condition is a diabetes-related or glucose-related or insulin-related metabolic disorder.

18. Apparatus in accordance with claim 13, in which the filter is a low-pass filter and 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.

19. Apparatus in accordance with claim 18, further comprising a cut-off frequency calculator being arranged to determine the cut-off frequency, using;

determining different cut-off frequencies for a low-pass filter for filtering the samples to obtain filtered test signals;

for each filtered test signal, deriving residual values based on the difference of the raw sequence and a filtered test signal to obtain a residual representation;

based on the residual representation, determining a cut-off frequency individually adapted to the raw sequence of samples.

20. Apparatus in accordance with claim 19, in which the cut-off frequency calculator is arranged to determine the cut-off frequency by:

determining a first line using residual energies for low cut-off frequencies;

determining a second line using residual energies for high cut-off frequencies; and

finding an intersection point of the first line and the second line, the intersection point indicating the cut-off frequency.

21. Apparatus in accordance with claim 13, 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.

22. Apparatus in accordance with claim 13, in which the output interface is arranged to derive and output the trend from an actual value of the filtered sequence or the enhanced sequence, and a timely preceding value of the filtered sequence or the enhanced sequence.

23. A method for indicating a health-related condition of a subject, comprising:

receiving, at an input interface, a raw sequence of samples of a biological quantity derived by a measurement method and a further raw sequence of a different biological quantity derived by a further measurement method;

combining the raw sequence and the further raw sequence using a combiner to obtain a combined raw sequence;

processing the combined raw sequence of samples using a processor to obtain a processed sequence, comprising providing data on an interpolated sample for a missing sample of the biological quantity using one or more samples at a preceding time instant or one or more samples at a subsequent time instant to obtain an interpolated sequence representing samples of the combined raw sequence and the interpolated sample;

filtering the processed sequence using a filter to obtain a filtered sequence, the filtered sequence having a useful variation and a reduced non-useful variation compared to the processed sequence before filtering; and

processing the filtered sequence or processing an enhanced sequence derived from the filtered sequence and outputting, at an output interface, at least an increase indication, a decrease indication or a remain unchanged indication as a trend of the filtered sequence or the enhanced sequence, the trend being representative of a useful variation of the health-related condition of the subject.

24. 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 raw sequence of samples of a biological quantity derived by a measurement method and a further raw sequence of a different biological quantity derived by a further measurement method;

combining the raw sequence and the further raw sequence to obtain a combined raw sequence;

processing the combined raw sequence of samples to obtain a processed sequence, comprising providing data on an interpolated sample for a missing sample of the biological quantity using one or more samples at a preceding time instant or one or more samples at a subsequent time instant to obtain an interpolated sequence representing samples of the combined raw sequence and the interpolated sample;

filtering the processed sequence to obtain a filtered sequence, the filtered sequence having a useful variation and a reduced non-useful variation compared to the processed sequence before filtering; and

processing the filtered sequence or processing an enhanced sequence derived from the filtered sequence and outputting at least an increase indication, a decrease indication or a remain unchanged indication as a trend of the filtered sequence or the enhanced sequence, the trend being representative of a useful variation of the health-related condition of the subject, when the computer program is running on a computer.