A method of and apparatus for determining the physical posture of a patient's body, having a superior-inferior body axis, an anterior-posterior body axis and a lateral-medial body axis, in relation to earth's gravitational field. A medical device having first, second and, optionally, third accelerometers...http://www.google.com/patents/US6044297?utm_source=gb-gplus-sharePatent US6044297 - Posture and device orientation and calibration for implantable medical devices
