System and method for determining patient posture based on 3-D trajectory using an implantable medical device

• US 7,149,584 B1
• Filed: 12/23/2002
• Issued: 12/12/2006
• Est. Priority Date: 12/23/2002
• Status: Expired due to Fees

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Inventors: Koh, Steve, Kroll, Mark W., Bornzin, Gene A., Park, Euljoon
• Primary Examiner(s): Bockelman, Mark
• Application Number:
  US10/328,642
• Time in Patent Office: 1,450 Days
• Field of Search: 607 30- 33, 607/60, 607/17, 607/19, 600/587, 600/595
• US Class Current: 607/60
• CPC Class Codes: A61N 1/36535 controlled by body position or posture
• CPC Class Codes: A61N 1/36542 controlled by body motion, e.g. acceleration
• CPC Class Codes: A61N 1/37235 Aspects of the external programmer
• CPC Class Codes: A61N 1/37252 Details of algorithms or data aspects of communication system, e.g. handshaking, transmitting specific data or segmenting data

Abstract

Time-varying spatial signals are detected by accelerometers mounted within the patient. The signals, representative of the actual 3-D trajectory of the patient, are compared with information representative of expected trajectories retrieved from memory to identify a current patient posture, which may be either a dynamic posture such as walking or running or a change in posture such as rising from a seated position to a standing position. In this manner, a change in posture of the patient is identified based upon a full 3-D trajectory, rather than merely the orientation of the patient at the beginning and the end of the change in posture. In an example described herein, the implantable device stores information representative of expected 3-D trajectories in the form of pre-calculated comparison matrices derived from orthonormal kernels employing Laguerre functions or Lagrange functions. A technique is also described for use by an external programmer for pre-calculating comparison matrices so as to reduce the processing burden within the implanted device during posture detection.

Claims

1. In an external programmer for use with an implantable medical device for implant within a patient wherein the implantable medical device comprises a trajectory-based posture detection system, a method comprising:

inputting parameters specific to the patient in which the implantable medical device is implanted;

generating trajectory-based posture detection information based on the patient parameters; and

transmitting the trajectory-based posture detection information to the implantable device for use therein in the detection of patient posture based on trajectory.

2. In an external programmer for use with an implantable medical device for implant within a patient wherein the implantable medical device comprises a trajectory-based posture detection system, a system comprising:

an input unit operative to input parameters specific to the patient in which in which the implantable medical device is implanted;

a posture determination set-up system operative to generate trajectory-based patent-specific posture detection information based on the patient parameters; and

a transmit unit operative to transmit to the trajectory-based patient-specific posture detection information to the implantable device for use therein in the detection of patient posture based on trajectory.