Strain monitoring system and apparatus

摘要

A system for monitoring strain as an indicator of biological conditions, such as spinal fusion, glucose levels, spinal loading, and heart rate. The system includes an inter-digitated capacitor sensor, and RF transmitter, and an associated antenna, all of which are microminiature or microscopic in size and can be implanted in a biological host such as a human or animal. An inductively coupled power supply is also employed to avoid the need for implantation of chemical batteries. Power is provided to the sensor and transmitter, and data is transmitted from the sensor, when an external receiving device, such as a handheld RF ID type receiver, is placed proximate the location of the implanted sensor, transmitter and inductively coupled power supply. The implanted sensor, transmitter and inductively coupled power supply can be left in place permanently or removed when desired.

主权项

1. A strain sensor apparatus configured for implantation into a biological host for detecting strain, the strain sensor apparatus comprising:
a plurality of free-standing, inter-digitated fingers arranged to form an area variation inter-digitated capacitor having a capacitance, the plurality of fingers configured to be coupled to a surface in a configuration to allow movement with bending of the surface, wherein the inter-digitated capacitor is configured to change its capacitance as a result of a change in area defined between fingers of the plurality of fingers due to lateral movement of the plurality of fingers; a transmitter coupled to the inter-digitated capacitor; and an antenna coupled to the transmitter, each of the inter-digitated capacitor, the transmitter, and the antenna being configured for implantation in a biological host.