Abstract: An examination apparatus for measuring the oxygenation in body organs by the near infrared light transmission spectrophotometry. The invention relates to an improvement of an illumination-side fixture and a detection-side fixture. In order to hold optical fibers for introducing infrared light in their natural conditions, the fixtures are equipped with respective prisms for changing light paths by prescribed angles. Also, the fixtures are equipped with respective light-emitting diodes for indicating if the examination apparatus is in its operating condition.

Abstract: An examination apparatus which measures the oxygenation in objects with near infrared light transmission spectrophotometry and that automatically adjusts a transmission light quantity to a magnitude suitable for detection by a photomultiplier tube. The examination apparatus comprises a ring-like ND filter whose transmission factor varies along its circumference, a filter driver for automatically setting a transmission factor of a filter, and a light source control device for automatically controlling output powers of light sources.

Abstract: An examination apparatus measures the oxygenation in body organs by the near infrared light transmission spectrophotometry. To inspect the examination apparatus itself before the oxygenation measurement, an illumination-side fixture and a detection-side fixture have such structures that these fixtures can be assembled together in such a manner that near infrared light is directly made incident on the detection-side fixture from the illumination-side fixture. In the midst of the measurement, the examination apparatus is regularly inspected and a photomultiplier tube can be separately inspected by employing a separate light source for inspection.

Abstract: An examination apparatus measures the oxygenation of body organs by using the near infrared transmission spectrophotometry. To assure the measurement reliability and the object person's safety, the examination apparatus monitors the variation of the fitting position of an illumination-side fixture by detecting the reflection light quantity from the measuring object.

Abstract: An air cleaner to remove particulate matter from an air stream, and to dampen sounds emitted to the air cleaner by an internal combustion engine receiving air from the air cleaner. Such sounds are commonly conducted upstream through conventional air cleaners and are heard emitting from the inlet of the air cleaner. The air cleaner of this invention both effectively cleans the air and diminishes said sounds. The air cleaner has a partition dividing its interior into a unit chamber holding a filter element unit, and a passage chamber receiving air to be cleaned and conveying it to an opening in the partition leading to the unit chamber. The shape and location of the passage chamber assist in the reduction of sound transmitted upstream.