Posture state responsive therapy delivery using dwell times

Patent metadata

Field	Value
Publication number	US-9776008-B2
Application number	US-43301709-A
Country	US
Kind code	B2
Filing date	Apr 30, 2009
Priority date	Jul 11, 2008
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

Techniques related to classifying a posture state of a living body are disclosed. One aspect relates to sensing at least one signal indicative of a posture state of a living body. Posture state detection logic classifies the living body as being in a posture state based on the at least one signal, wherein this classification may take into account at least one of posture and activity state of the living body. The posture state detection logic further determines whether the living body is classified in the posture state for at least a predetermined period of time. Response logic is described that initiates a response as a result of the body being classified in the posture state only after the living body has maintained the classified posture state for at least the predetermined period of time. This response may involve a change in therapy, such as neurostimulation therapy, that is delivered to the living body.

First claim

What is claimed is:

1. A medical device system, comprising:
a sensor configured to sense at least one signal indicative of a posture state of a living body;
posture state detection logic configured to classify the living body as being in a posture state based on the at least one signal and to determine whether the living body is classified in the posture state for at least a predetermined period of time; and
response logic configured to initiate a response as a result of the living body being classified in the posture state, the response being initiated only after the living body has maintained the classified posture state for at least the predetermined period of time.

2. A medical device system, comprising:
a sensor configured to sense at least one signal indicative of a posture state of a living body;
posture state detection logic configured to classify the living body as being in a posture state based on the at least one signal and to determine whether the living body is classified in the posture state for at least a predetermined period of time;
response logic configured to initiate a response as a result of the living body being classified in the posture state, the response being initiated only after the living body has maintained the classified posture state for at least the predetermined period of time; and
a therapy delivery module configured to deliver therapy to the living body, and wherein the response is a change in the therapy delivered by the therapy delivery module.

3. The system of claim 2 , wherein the posture state detection logic comprises at least one of a posture classifier configured to classify the posture of the living body and an activity classifier configured to classify the activity state of the living body, and wherein the classification of the living body as being in a posture state is based on at least one of the posture classification and the activity state classification.

4. The system of claim 2 , wherein the posture state detection logic comprises dwell time logic having one or more timers, each configured to measure a respective dwell time that commences at the time the living body is classified in the posture state; and
wherein upon expiration of each of the one or more timers, the response logic initiates a respective response as a result of the body being classified in the posture state only if the living body has not exited the posture state during the respective dwell time.

5. The system of claim 2 , wherein the posture state detection logic comprises dwell time logic configured to automatically select a dwell time as the predetermined period of time, selection being based on the posture state in which the living body is classified.

6. The system of claim 5 , wherein the dwell time logic is further configured to select the dwell time based on a posture state in which the living body was previously classified.

7. The system of claim 2 , wherein the posture state detection logic comprises dwell time logic configured to automatically select a dwell time as the predetermined period of time, selection being based on at least one of a type of the response and a type of change in the response.

8. The system of claim 2 , further comprising a user interface configured to allow a user to select the predetermined period of time.

9. The system of claim 2 , wherein at least one of the sensors, the posture state detection logic and the response logic are implantable in the living body.

10. The system of claim 2 , wherein the posture state detection logic comprises an M-of-N filter that indicates that the living body is in the posture state only if M of a most-recent N posture states in which the living body was classified are a same posture state.

11. The system of claim 10 , wherein at least one of M and N are automatically selected based on at least one of the posture state in which the living body is classified and a posture state in which the living body was previously classified.

12. The system of claim 10 , wherein at least one of M and N are selectable by a user.

13. The system of claim 2 , wherein the posture state detection logic comprises an episode detector that detects a posture state episode based on a definition of the posture state, and a transition threshold that adjusts a boundary of the definition.

14. The system of claim 13 , wherein the episode detector automatically selects the transition threshold based on a direction in which the at least one signal crosses the adjusted boundary.

15. The system of claim 13 , wherein the predetermined period of time is a transition duration, and wherein the episode detector classifies the living body as being in the posture state if the at least one signal crosses the adjusted boundary and does not re-cross the adjusted boundary for at least the transition duration.

16. The system of claim 2 , wherein the sensor is a three-axis accelerometer.

17. The system of claim 2 , wherein the therapy delivery module is configured to deliver electrical stimulation to the living body.

18. The system of claim 2 , wherein the response logic initiates a notification as a result of the living body being classified in the posture state.

19. The system of claim 2 , wherein the response logic initiates storing of data as a result of the living body being classified in the posture state.

20. A medical system to provide therapy to a living body, comprising:
a sensor;
posture state detection logic configured to receive at least one signal from the sensor and to employ the at least one signal to classify a posture state of the living body;
a therapy module configured to control the therapy provided to the living body based on the classification; and
one or more processors configured to determine whether, after the living body is classified in a posture state, the living body maintains the posture state for a predetermined period of time, and wherein the therapy module is further configured to adjust the therapy in response to the posture state if the living body maintains the posture state for the predetermined period of time, and otherwise, to allow the therapy to remain unchanged.

21. The system of claim 20 , wherein at least one of the sensor, posture state detection logic, one of the one or more processors and therapy module are implantable within the living body.

22. The system of claim 21 , wherein the sensor is a three-axis accelerometer.

23. The system of claim 21 , further comprising dwell time logic configured to automatically adjust the predetermined period of time based on the posture state in which the living body is classified.

24. The system of claim 21 , wherein the dwell time logic automatically selects the predetermined period of time based on whether levels of the therapy will increase or decrease in response to the posture state.

25. The system of claim 20 , further comprising a user interface configured to allow a user to select the predetermined period of time.

26. The system of claim 20 , wherein the posture state detection logic classifies the posture state based on one or more posture state definitions defined by a user.

27. The system of claim 20 , wherein the posture state detection logic comprises an M-of-N filter configured to determine whether M of the last N posture state classifications is a same posture state, and if so, to provide an indication to allow the therapy module to adjust t

Assignees

• Skelton Dennis M
• Davis Jon P
• Panken Eric J
• Medtronic Inc

Inventors

• Skelton Dennis M
• Davis Jon P
• Panken Eric J

Classifications

• G16H50/20

  for computer-aided diagnosis, e.g. based on medical expert systems · CPC title

• A61N1/36542 Primary

  controlled by body motion, e.g. acceleration · CPC title

• A61B5/686

  Permanently implanted devices, e.g. pacemakers, other stimulators, biochips (A61B5/6861 takes precedence) · CPC title

• A61B5/1118

  Determining activity level · CPC title

• A61N1/36535

  controlled by body position or posture · CPC title