System and method for determining patient posture based on 3-D trajectory using an implantable medical device
US7149584B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 23, 2002 |
| Grant date | Dec 12, 2006 |
| Priority date | — |
| Expiry date | Nov 9, 2024 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61N1/37235
- WIPO fieldMedical technology
- WIPO sectorInstruments
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.