Posture state responsive therapy delivery using dwell times

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.

1 - 20 . (canceled). 
     
     
         21 . A system, comprising:
 a sensor configured to sense a signal indicative of at least one of a posture state or an activity state of a patient;   control logic configured to determine whether a first number (M) of samples of the signal out of a most recent number (N) of samples of the signal are indicative of at least one of a first posture state of a plurality of posture states or a first activity state of a plurality of activity states;   response logic configured to automatically initiate an action in response to the control logic determining that the first number (M) of samples of the signal out of the most recent number (N) of samples of the signal are indicative of at least one of the first posture state or the first activity state.   
     
     
         22 . The system of  claim 21 , further comprising a therapy module configured to deliver therapy to the patient, and wherein the action is a change, by the therapy module, in the therapy delivered to the patient from a second therapy level associated with at least one of a second posture state of the plurality of postures states or a second activity state of the plurality of activity states to a first therapy level associated with the at least one of the first posture state or the first activity state. 
     
     
         23 . The system of  claim 22 , wherein the most recent number of samples is a first most recent number of samples, and wherein:
 the control logic is further configured to determine whether a second number of samples of the signal out of a second most recent number of samples of the signal are indicative of at least one of a third posture state of the plurality of posture states or a third activity state of the plurality of activity states; and   the response logic is further configured to not change the therapy delivered to the patient from the first therapy level to a third therapy level associated with the at least one of a third posture state or the third activity state in response to the control logic determining that the second number of samples of the signal out of the second most recent number of samples of the signal are not indicative of at least one of the third posture state or the third activity state.   
     
     
         24 . The system of  claim 22 , further comprising an implantable medical device comprising the therapy module. 
     
     
         25 . The system of  claim 21 , further comprising notification logic configured to deliver a notification associated with care of the patient, and wherein the action is the notification automatically issued by the notification logic. 
     
     
         26 . The system of  claim 21 , wherein at least one of the first number (M) of samples or the most recent number (N) of samples is programmable. 
     
     
         27 . The system of  claim 21 , further comprising a memory configured to store at least one of a definition of the first posture state and a definition of the second posture state or a definition of the first activity state and the second activity state, and wherein the control logic is configured to determine whether a first sample of the signal is indicative of at least one of the first posture state or the first activity state based on whether the first sample meets at least one of the definition of the first posture state or the definition of the first activity state. 
     
     
         28 . The system of  claim 27 , further comprising an external programmer for an implantable medical device, wherein the external programmer is configured to program, for the implantable medical device, at least one of the definition of the first posture state, the first number (M) of samples, or the most recent number (N) of samples transition threshold. 
     
     
         29 . The system of  claim 27 , further comprising a user interface configured to receive user selection of at least one of the definition of the first posture state, the first number (M) of samples or the most recent number (N) of samples transition threshold. 
     
     
         30 . The system of  claim 21 , wherein the sensor comprises an accelerometer. 
     
     
         31 . A method, comprising:
 sensing a signal indicative of at least one of a posture state or an activity state of a patient;   determining whether a first number (M) of samples of the signal out of a most recent number (N) of samples of the signal are indicative of at least one of a first posture state of a plurality of posture states or a first activity state of a plurality of activity states; and   automatically initiating an action in response to determining that the first number (M) of samples of the signal out of the most recent number (N) of samples of the signal are indicative of at least one of the first posture state or the first activity state.   
     
     
         32 . The method of  claim 31 , further comprising delivering therapy to the patient, and wherein the action is a change in the therapy delivered to the patient from a second therapy level associated with at least one of a second posture state of the plurality of postures states or a second activity state of the plurality of activity states to a first therapy level associated with the at least one of the first posture state or the first activity state. 
     
     
         33 . The method of  claim 22 , wherein the most recent number of samples is a first most recent number of samples, further comprising:
 determining whether a second number of samples of the signal out of a second most recent number of samples of the signal are indicative of at least one of a third posture state of the plurality of posture states or a third activity state of the plurality of activity states; and   not changing the therapy delivered to the patient from the first therapy level to a third therapy level associated with the at least one of a third posture state or the third activity state in response to the control logic determining that the second number of samples of the signal out of the second most recent number of samples of the signal are not indicative of at least one of the third posture state or the third activity state.   
     
     
         34 . The method of  claim 32 , wherein the method is performed by an implantable medical device comprising a therapy module. 
     
     
         35 . The method of  claim 31 , wherein the action comprising automatically delivering a notification associated with care of the patient. 
     
     
         36 . The method of  claim 31 , wherein at least one of the first number (M) of samples or the most recent number (N) of samples is programmable. 
     
     
         37 . The method of  claim 31 , further comprising storing at least one of a definition of the first posture state and a definition of the second posture state or a definition of the first activity state and the second activity state and wherein determining whether the first number (M) of samples of the signal out of the most recent number (N) of samples of the signal are indicative of at least one of the first posture state or the first activity state comprises determining whether a first sample of the signal is indicative of at least one of the first posture state or the first activity state based on whether the first sample meets at least one of the definition of the first posture state or the definition of the first activity state. 
     
     
         38 . The method of  claim 37 , further comprising at receiving from an external programmer at least one of the definition of the first posture state, the first number (M) of samples or the most recent number (N) of samples transition threshold. 
     
     
         39 . The method of  claim 27 , further comprising receiving from a user interface a selection of at least one of the definition of the first posture state, the first number (M) of samples or the most recent number (N) of samples transition threshold. 
     
     
         40 . The method of  claim 21 , wherein the sensing is performed by an accelerometer.