Method and apparatus for operating therapy system

• US 6,099,479 A
• Filed: 06/26/1996
• Issued: 08/08/2000
• Est. Priority Date: 06/26/1996
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Neisz, Johann J., Christopherson, Mark A.
• Primary Examiner(s): O'Connor, Cary
• Assistant Examiner(s): CARTER, RYAN CHRISTOPHER
• Application Number:
  US08/683,808
• Time in Patent Office: 1,504 Days
• Field of Search: 607/42, 607/46, 607/48, 600/529, 600/532, 600/534, 600/538, 128/897-898
• US Class Current: 600/529
• CPC Class Codes: A61N 1/3601 of respiratory organs

Abstract

A method for operating an implantable therapy system to conserve energy includes providing an implantable sensing device that generates a signal as a function of a physiological parameter of a patient during a treatment period. The signal is monitored during at least portions of the treatment period to detect a physiological event for use in controlling therapy of the patient during the treatment period. Energy consumption by the sensing device is terminated during the treatment period for at least portions of the treatment period when signal monitoring is not performed. Another method for operating an implantable therapy system for conserving energy includes providing an implantable component for performance of a function during a treatment period for the therapy system. The implantable component is operable in at least a first state during the treatment period and a second state outside of the treatment period; the first state using more energy than the second state. The implantable component is operated in the first state when performance of the function during a treatment period is required and operated in the second state when performance of the function is not required outside the treatment period. Another method of operating an implantable therapy system includes monitoring a periodic physiological parameter for controlling therapy of a patient during a treatment period. The measured physiological period for the parameter of the patient is compared to at least one predetermined period threshold to determine nonperiodic behavior of the monitored periodic physiological parameter and suspending therapy of the patient as a function thereof. Systems for use with such methods are also provided.

Claims

1. A method for operating an implantable therapy system to conserve energy, the method comprising the steps of:

providing an implantable sensing device that generates a signal as a function of a physiological parameter of a patient during a treatment period;

monitoring the signal during at least portions of the treatment period to detect a physiological event for use in controlling therapy of the patient during the treatment period; and

terminating energy consumption by the sensing device during the treatment period for at least portions of the treatment period when signal monitoring is not performed.

2. The method according to claim 1, wherein the signal is characteristic of respiratory effort of the patient resulting in a respiratory effort signal.

3. The method according to claim 2, wherein the monitoring step includes the step of detecting inspiration offset from the respiratory effort signal, and further wherein the terminating step includes the step of terminating energy consumption by the sensing device during a period of time immediately following detection of inspiration offset.

4. The method according to claim 2, wherein the monitoring step includes the step of defining a refractory period somewhere between inspiration offset and inspiration onset of the respiratory effort signal, during at least a portion of the refractory period therapy is prohibited, and further wherein the terminating step includes terminating energy consumption by the sensing device during the at least a portion of the refractory period.

5. The method according to claim 4, wherein the refractory period includes a hard refractory period during which time therapy is prohibited and a soft refractory period following the hard refractory period, and further wherein the terminating step includes terminating energy consumption by the sensor during at least a portion of the hard refractory period.

6. The method according to claim 2, wherein the monitoring step includes the step of comparing a measured respiratory period of the patient to at least one predetermined respiratory period threshold and suspending therapy of the patient as a function of such comparison.

7. The method according to claim 6, wherein during suspension of therapy, the monitoring step includes the steps of detecting offsets, both inspiration and artifact offsets, and counting the detected offsets, and further wherein a therapy delay period is initiated upon reaching a predetermined number of counted offsets, during which therapy delay period therapy is continued to be suspended and energy consumption by the sensor is also terminated.

8. The method according to claim 7, wherein suspension of therapy is continued after the therapy delay period until the comparison of the measured respiratory period of the patient to at least one predetermined respiratory period threshold indicates that a periodic respiratory signal is reestablished.

9. The method according to claim 6, wherein the measured respiratory period of the patient is compared to predetermined maximum and minimum respiratory period values and if the measured respiratory period does not fall within the bounds of the maximum and minimum respiratory period values, therapy of the patient is suspended.

10. The method according to claim 6, wherein the step of comparing includes determining whether the measured respiratory period falls within a particular tolerance value of a running average of measured respiratory periods and if the measured respiratory period falls outside of the tolerance, stimulation of the patient is suspended.

11. The method according to claim 10, wherein the running average of measured respiratory periods is a weighted sum average.

12. The method according to claim 6, wherein stimulation is suspended upon initialization of the treatment period.

13. The method according to claim 6, wherein the measured respiratory period is measured from a detected inspiration offset to the next detected inspiration offset.

14. The method according to claim 2, wherein the monitoring step includes monitoring the respiratory effort signal for controlling stimulation to treat respiratory disorders.

15. The method according to claim 1, wherein the method includes duty cycling the sensing device.

16. The method according to claim 15, wherein the first and second state include on and off states, respectively.

17. A method of operating an implantable therapy system for conserving energy, the method comprising the steps of:

providing an implantable component for performance of a function during a treatment period for the therapy system, the implantable component operable in at least a first state during the treatment period and a second state outside of the treatment period, the first state using more energy than the second state; and

operating the implantable component in the first state when performance of the function during a treatment period is required and operating the implantable component in the second state when performance of the function is not required outside the treatment period;

wherein the implantable device is a processing device, and

wherein the operating step includes the step of operating the processing device in the second state until the therapy system detects communication from a source external to a patient.

18. The method according to claim 17, wherein the operating step includes the step of operating the implantable component in the first state upon initialization of a treatment period and operating in the second state upon termination of the treatment period.

19. The method according to claim 17, wherein the source may include one of a patient programmer and a physician programmer.

20. The method according to claim 17, wherein the implantable component is at least one of a sensor, an input circuit component, a microprocessor, and an output circuit component.

21. A method for operating in an implantable therapy system, by which a patient is stimulated, the method comprising the steps of:

monitoring a respiratory effort waveform to detect respiratory characteristics for controlling therapy of a patient; and

comparing a measured respiratory period of the patient to at least one predetermined respiratory period threshold and suspending stimulation of the patient as a function thereof.

22. The method according to claim 21, wherein during suspension of stimulation, the method further includes the steps of:

detecting inspiratory artifact offsets;

counting the detected offsets; and

initiating a therapy delay period when a predetermined number of offsets are counted.

23. The method according to claim 22, wherein during the therapy delay period stimulation is suspended and energy consumption by a sensing device for providing a signal characteristic of the respiratory effort waveform is terminated.

24. The method according to claim 23, wherein suspension of stimulation is continued after the therapy delay period until the comparison of the measured respiratory period of the patient to the at least one predetermined respiratory period threshold indicates that a periodic respiratory effort waveform is reestablished.

25. The method according to claim 21, wherein the measured respiratory period of the patient is compared to predetermined maximum and minimum respiratory period thresholds and if the measured respiratory period does not fall within the bounds of the maximum and minimum respiratory period thresholds, stimulation of the patient is suspended.

26. The method according to claim 21, wherein the comparing step includes determining whether the measured respiratory period falls within a particular tolerance value of a running average of measured respiratory periods and if the measured respiratory period falls outside of the tolerance, stimulation of the patient is suspended.

27. The method according to claim 26, wherein the running average of measured respiratory periods is a weighted sum average.

28. The method according to claim 21, wherein stimulation is suspended upon initialization of the implantable system for a predetermined period of time.

29. The method according to claim 21, wherein the measured respiratory period is measured from a detected inspiration offset to the next detected inspiration offset.

30. A method for operating an implantable therapy system, the method comprising the steps of:

monitoring a periodic physiological parameter for controlling therapy of a patient during a treatment period; and

comparing a measured physiological period for the parameter of the patient to at least one predetermined period threshold to determine nonperiodic behavior of the monitored periodic physiological parameter and suspending therapy of the patient as a function thereof.

31. The method according to claim 30, wherein suspension of therapy is continued until the comparison of the measured physiological period to the at least one predetermined period threshold indicates that periodicity of the parameter is reestablished.

32. The method according to claim 30, wherein the measured physiological period of the patient is compared to predetermined maximum and minimum period thresholds and if the measured physiological period does not fall within the bounds of the maximum and minimum period thresholds, therapy of the patient is suspended.

33. The method according to claim 30, wherein the comparing step includes determining whether the measured physiological period falls within a particular tolerance value of a running average of measured physiological periods and if the measured physiological period falls outside of the tolerance, therapy of the patient is suspended.

34. The method according to claim 33, wherein the running average of measured physiological periods is a weighted sum average.

35. The method according to claim 30, wherein therapy is suspended upon initialization of the implantable therapy system for a predetermined period of time.

36. An implantable therapy system, the system comprising:

a sensing device for generating a signal characteristic of a periodic physiological parameter of a patient;

detection means for monitoring the signal and for controlling therapy of the patient, the detection means includes means for comparing a measured physiological period of the patient to at least one predetermined physiological period threshold and means for suspending therapy of the patient as a function of the comparison; and

means for providing therapy to the patient in response to the detection means.

37. The system according to claim 36, wherein the physiological parameter is respiratory effort.

38. The system according to claim 37, wherein the detection means further includes:

means for detecting events in the signal characteristic of offsets;

an artifact counter for counting the offsets detected during suspension of therapy; and

means for initiating a therapy delay period when a predetermined number of offsets have been counted, the initiating means including means for continuing suspension of therapy to the patient and means for terminating energy consumption by the sensing device.

39. The system according to claim 38, wherein the detection means further includes means for continuing suspension of therapy after the therapy delay period until the comparison means indicates that periodic respiratory effort is reestablished.

40. The system according to claim 36, wherein the comparing means includes means for comparing the measured physiological period of the patient to predetermined maximum and minimum physiological period thresholds and if the measured physiological period does not fall within the bounds of the maximum and minimum physiological period thresholds, therapy of the patient is suspended.

41. The system according to claim 36, wherein comparison means includes means for determining whether the measured physiological period falls within a particular tolerance of a running average of measured physiological periods and if the measured physiological period falls outside of the tolerance, therapy of the patient is suspended.

42. The system according to claim 36, wherein the running average of measured physiological periods is a weighted sum average.

43. The system according to claim 36, wherein therapy is suspended upon initialization of the implantable therapy system.

44. An implantable therapy apparatus for conserving energy, the apparatus comprising:

a processing device for implantation in a patient operable in at least a first state and a second state, the first state using lesser energy than the second state;

means for detecting attempted communication with the implantable therapy apparatus from a source external to the patient; and

means for operating the processing device in the first state until the detection means detects such external communication.

45. The apparatus according to claim 44, wherein the source may include one of a patient controller and a physician controller.