Abstract: This invention is an implantable sensor and system capable of measuring, controlling, monitoring and reporting blood constituent levels. The implantable sensor for sensing in vivo the level of at least one blood constituent in mammalian vascular tissue having at least one source of radiation from infrared through visible light, arranged to direct the radiation at the tissue where it is affected by interaction with the tissue, and at least one detector. The invention also encompasses a device for measuring and controlling the level of a blood constituent, such as glucose or oxygen, and includes an implantable infrared source module for generating an output signal representative of the sensed infrared radiation. The system includes a processor module responsive to the output signal which performs spectral analysis of the output signal and generates a control signal. The system further includes other devices for dispensing doses of medications or controlling organ function in response to the control signal.

Abstract: An in vivo implantable sensor obtains spectra of body fluid constituents and processes the spectra to determine the concentration of a constituent of the body fluid. The sensor includes an optical source and detector. The source emits light at a `plurality of different, discrete wavelengths, including at least one wavelength in the infrared region. The light interacts with the body fluid and is received at the detector. The light at the plurality of different wavelengths has a substantially collinear optical path through the fluid with respect to each other. When measuring fluid constituents in a blood vessel, such as blood glucose, the light at the plurality of different wavelengths is emitted in a substantially single period of time. The spectra is corrected for artifacts introduced from extraneous tissue in the optical path between the source and the detector. The sensor is fully implanted and is set in place to allow plural measurements to be taken at different time periods from a single in vivo position.

Abstract: A sectional form measuring apparatus measures perfect sectional forms of an object to be measured. The apparatus comprises a plurality of detectors for receiving reflected lights from the surface of an object, and a plurality of optical fibers with focusing lenses and light sources mounted on opposite ends thereof, or the like for measuring distances from a reference axis to the surface of the object to obtain the sectional forms at a plurality of positions on the reference axis. A marker may be applied to a specified measuring position on the surface of the object, thereby indicating a surface form of the measured object.

Abstract: A hot-wire flowmeter includes a hot wire heated pulsatively for heating a fluid being measured, and a thermosensitive detector located downstream of the hot wire for detecting the heated fluid. The hot wire is heated again in response to an output signal from the detector with the result that the hot wire is periodically heated at a rate that is dependent on the speed of flow of the fluid. The rate of flow of the fluid can be derived from the rate at which the hot wire is periodically heated.