Abstract: There is disclosed a method and device for non-invasively sensing a physical parameter within the body of a patient by employing a magnetically-based sensing device and monitoring device. The magnetically-based sensing device has a first magnet and a second magnet which generate a combined magnet field. The first and second magnets are positioned such that a change in a physical parameter causes a change in the combined magnet field, which change is monitored by the monitoring device.