Abstract: A retractor has an oximeter sensor at its tip, which allows measuring of oxygen saturation of a tissue being retracted by the retractor. The tip includes one or more openings for at least one source and detector. A specific implementation is a spinal nerve root retractor with an oximeter sensor.

Abstract: A probe for a medical device with source and detector sensors is used to monitor or measure, or both, oxygen saturation levels in a tissue. In various specific implementations, the probe has at least two sources and at least one detector, at least one source and at least two detectors, and at least two sources and at least four detectors. A source of the probe is connected to at least one radiation source, which is external to the probe. A detector of the probe is connected to a photodetector, which is external to the probe.

Abstract: A surgical elevator has an oximeter sensor at its tip, which allows measuring of oxygen saturation of a tissue.

Abstract: A device has various arrangements of source and detector sensors. In specific implementations, the device has at least four structures, one source and three detectors, two sources and two detectors, and other arrangement variations. In a specific implementation, between a source structure and a detector structure, there are not any other intervening sensor structures. The device may be part of a medical device that is used to monitor or measure oxygen saturation levels in a tissue.

Abstract: A probe for a medical device with source and detector sensors is used to monitor or measure, or both, oxygen saturation levels in a tissue. In various specific implementations, the probe has at least two sources and at least one detector, at least one source and at least two detectors, and at least two sources and at least four detectors. A source of the probe is connected to at least one radiation source, which is external to the probe. A detector of the probe is connected to a photodetector, which is external to the probe.

Abstract: A retractor has an oximeter sensor at its tip, which allows measuring of oxygen saturation of a tissue being retracted by the retractor. The tip includes one or more openings for at least one source and detector. A specific implementation is a spinal nerve root retractor with an oximeter sensor.

Abstract: A device includes source and detector sensors. In a specific implementation, the device has two near detectors, two far detectors, and two sources. The two near detectors are arranged closer to the two sources than the two far detectors. A light-diffusing layer covers the two near detectors. The device may be part of a medical device that is used to monitor or measure oxygen saturation levels in a tissue. In a specific implementation, light is transmitted into the tissue and received by the detectors. An attenuation coefficient is first calculated for a shallow layer of tissue. The attenuation coefficient is then used to calculate an attenuation coefficient for a deep layer of tissue.

Abstract: Methods and apparatus for monitoring oxygen saturation levels in tissue are disclosed. According to one aspect of the present invention, a sensor arrangement for use in an optical imaging system includes a first source structure, a second source structure, and a detector arrangement. The first source structure provides a first beam of light and the second source structure provides a second beam of light. The detector arrangement includes detector structures that have centerpoints, and receives the first and second beams of light after the first and second beams of light are reflected off of an external surface. The detector arrangement is arranged to define a first axis that passes through the centerpoint of each detector structure, and a distance from a centerpoint of the first source structure to the first axis is not equal to a distance from a centerpoint of the second source structure to the first axis.

Abstract: A smokeless, low noise electrosurgical device includes a tubular housing having a passage extending axially therethrough, with one end of the passage connected to a source of negative gauge pressure. The other, inlet end of the housing is provided with an electrosurgical cutting device or cauterizing probe extending therefrom. The inlet to the passage comprises a wide opening having side walls which converge to a relatively narrow port in flow communication with the passage in the housing. The port is significantly narrower than the passage, resulting in significantly reduced noise generated by the fluid flow into the inlet and through the passage.