Devices and methods for monitoring physiological information relating to sleep with an implantable device

• US 8,903,483 B2
• Filed: 08/14/2013
• Issued: 12/02/2014
• Est. Priority Date: 02/09/2007
• Status: Active Grant

• Current Assignee: Neuropace Inc.
• Original Assignee: Neuropace Inc.
• Inventors: Sun, Felice, Pless, Benjamin D, Gibb, Barbara
• Primary Examiner(s): DIETRICH, JOSEPH M
• Application Number:
  US13/966,899
• Publication Number:
  US 20130345522A1
• Time in Patent Office: 475 Days
• Field of Search: 600/544, 600/545
• US Class Current: 600/544
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• 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 5/02438 with portable devices, e.g. worn by the patient
• CPC Class Codes: A61B 5/026 Measuring blood flow A61B3/1233, A61B3/1241 take precedence
• CPC Class Codes: A61B 5/11 Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb for measuring pulse A61B5/02 ;A61B5/1038 takes precedence; motion detection to correct for motion artifacts in physiological signals A61B5/721
• CPC Class Codes: A61B 5/1118 Determining activity level
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/291 for electroencephalography [EEG]
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/369 Electroencephalography [EEG] devices for psychotechnics A61B5/16
• CPC Class Codes: A61B 5/4812 Detecting sleep stages or cycles
• CPC Class Codes: A61B 5/4815 Sleep quality
• CPC Class Codes: A61B 5/686 Permanently implanted devices, e.g. pacemakers, other stimulators, biochips A61B5/6861 takes precedence
• CPC Class Codes: A61N 1/36082 Cognitive or psychiatric applications, e.g. dementia or Alzheimer's disease
• CPC Class Codes: A61N 1/36135 using physiological parameters

Abstract

Described here are implantable devices and methods for monitoring physiological information relating to sleep. The implantable devices are generally designed to include at least one sensor for sensing physiological information, a processor for processing the physiological information using low computational power to detect a sleep stage, and a battery. The detected sleep stage information may then be used to indicate sleep quality, identify or monitor a medical condition, or guide treatment thereof.

Claims

1. A method of detecting a sleep state or sleep stage with an active implantable medical device, said method comprising:

determining first and second parameters of each of a plurality of half waves resulting from sensed physiological information;

for each of the plurality of half waves, determining that the half wave is a qualified half wave when the first parameter of the half wave satisfies a first criterion and the second parameter of the same half wave satisfies a second criterion, wherein each of the first criterion and the second criterion are defined by a respective minimum parameter and a respective maximum parameter;

counting a number of qualified half waves that occur during a time window; and

detecting a particular sleep state or stage when a measure derived from the number satisfies a third criterion indicative of the particular sleep state or stage.

2. The method of claim 1, wherein:

the first parameter is a half-wave amplitude;

the minimum parameter of the first criterion is a minimum amplitude and the maximum parameter of the first criterion is a maximum amplitude; and

the first criterion is satisfied when a half-wave amplitude is between the minimum amplitude and the maximum amplitude.

3. The method of claim 1, wherein:

the second parameter is a half-wave duration;

the minimum parameter of the second criterion a minimum duration and the maximum parameter of the first criterion is a maximum duration; and

the second criterion is satisfied when a half-wave duration is between the minimum duration and the maximum duration.

4. The method of claim 1, wherein:

the measure derived from the number is an unsigned integer;

the third criterion is a threshold; and

the particular sleep state or stage is detected when the unsigned integer exceeds the threshold.

5. The method of claim 1, wherein:

the measure derived from the number is an unsigned integer;

the third criterion is one of a range of unsigned integers; and

the particular sleep state or stage is detected when the unsigned integer falls within the range.

6. The method of claim 1, wherein counting a number comprises:

classifying each qualified half wave as one of a plurality of half-wave types; and

for each of the plurality of half-wave types, determining a half-wave-type number corresponding to the number of qualified half waves classified as the half-wave type.

7. The method of claim 6, wherein:

the measure derived from the number is a ratio of two of the half-wave type numbers;

the third criterion is a threshold; and

the particular sleep state or stage is detected when the ratio satisfies the threshold.

8. The method of claim 6, wherein the plurality of half-wave types comprises at least two of the following half-wave types:

alpha half-wave, delta half-wave and theta half-wave.

9. The method of claim 1, wherein the particular sleep state or stage includes stage 1 sleep, stage 2 sleep, stage 3 sleep or stage 4 sleep.

10. An active implantable medical device for detecting a sleep state or sleep stage, said device comprising:

a sensor configured to sense physiological information; and

a processor connected to the sensor and configured to;

determine first and second parameters of each of a plurality of half waves resulting from sensed physiological information;

for each of the plurality of half waves, determine that the half wave is a qualified half wave when the first parameter of the half wave satisfies a first criterion and the second parameter of the same half wave satisfies a second criterion, wherein each of the first criterion and the second criterion are defined by a respective minimum parameter and a respective maximum parameter;

count a number of qualified half waves that occur during a time window; and

detect a particular sleep state or stage when a measure derived from the number satisfies a third criterion indicative of the particular sleep state or stage.

11. The device of claim 10, wherein:

the first parameter is a half-wave amplitude;

the minimum parameter of the first criterion is minimum amplitude and the maximum parameter of the first criterion is a maximum amplitude; and

the first criterion is satisfied when a half-wave amplitude is between the minimum amplitude and the maximum amplitude.

12. The device of claim 10, wherein:

the second parameter is a half-wave duration;

the minimum parameter of the second criterion a minimum duration and the maximum parameter of the first criterion is a maximum duration; and

the second criterion is satisfied when a half-wave duration is between the minimum duration and the maximum duration.

13. The device of claim 10, wherein:

the measure derived from the number is an unsigned integer;

the third criterion is a threshold; and

the particular sleep state or stage is detected when the unsigned integer exceeds the threshold.

14. The device of claim 10, wherein:

the measure derived from the number is an unsigned integer;

the third criterion is one of a range of unsigned integers; and

the particular sleep state or stage is detected when the unsigned integer falls within the range.

15. The device of claim 10, wherein to count a number, the processor is configured to:

classify each qualified half wave as one of a plurality of half-wave types; and

for each of the plurality of half-wave types, determine a half-wave-type number corresponding to the number of qualified half waves classified as the half-wave type.

16. The device of claim 15, wherein:

the measure derived from the number is a ratio of two of the half-wave type numbers;

the third criterion is a threshold; and

the particular sleep state or stage is detected when the ratio satisfies the threshold.

17. The device of claim 15, wherein the plurality of half-wave types comprises at least two of the following half-wave types:

alpha half-wave, delta half-wave and theta half-wave.

18. The device of claim 10, wherein the particular sleep state or stage includes stage 1 sleep, stage 2 sleep, stage 3 sleep or stage 4 sleep.