Abstract: The present invention provides a medical sensor for detecting a blood characteristic. The sensor includes a transducer for producing an analog signal related to the blood characteristic. The analog signal is converted into a transmission signal which is in amplitude-independent form for transmission to a remote analyzer. In one embodiment, a current-to-frequency converter converts a signal from a pulse oximeter sensor into a frequency signal which can be transmitted over a transmission line to a remote pulse oximeter.

Abstract: The present invention provides an encoding mechanism for a medical sensor which uses a modulated signal to provide the coded data to a remote analyzer. The modulated signal could be, for instance, a pulse width modulated signal or a frequency modulated signal. This signal is amplitude independent and thus provides a significant amount of noise immunity.

Abstract: An adapter which actively connects a 2-lead oximeter probe or monitor to a 3-lead monitor or probe. This is done actively, with the alternating drive signals from the oximeter monitor providing a control signal for switching the adapter connections. The adapter connections are preferably made with diodes, transistors, or other active devices.

Abstract: The present invention provides a medical sensor for detecting a blood characteristic. The sensor includes a transducer for producing an analog signal related to the blood characteristic. The analog signal is converted into a transmission signal which is in amplitude-independent form for transmission to a remote analyzer. In one embodiment, a current-to-frequency converter converts a signal from a pulse oximeter sensor into a frequency signal which can be transmitted over a transmission line to a remote pulse oximeter.

Abstract: The present invention provides an adapter which actively connects a two terminal oximeter probe or monitor to a three terminal monitor or probe. This is done actively, with the alternating drive signals from the oximeter monitor providing a control signal for switching the adapter connections. The adapter connections are preferably made with diodes, transistors, or other active devices.

Abstract: A sensor probe operable to transmit light of a first wavelength for scattering by a tissue sample is described for use with a pulse oximeter designed to operate with another type of sensor probe which transmits light of a second wavelength. The sensor probe includes at least one source of light for transmitting light of the first wavelength for scattering and/or absorption by the tissue sample. At least one detector is included for detecting light of the first wavelength affected by the tissue sample and generating a signal in response thereto. An encoder in the sensor probe transforms the signal to a form which may be employed by the oximeter.

Abstract: The present invention provides an encoding mechanism for a medical sensor which uses a modulated signal to provide the coded data to a remote analyzer. The modulated signal could be, for instance, a pulse width modulated signal or a frequency modulated signal. This signal is amplitude independent and thus provides a significant amount of noise immunity.

Abstract: A connector for a medical sensor is provided. The connector includes a number of contacts, and includes an electronic device for encoding a characteristic of the medical sensor. The electronic device is insertable into the connector. This simplifies the design of a sensor, which no longer needs to include a calibration element. In addition, the sensor can be made more cheaply, which is especially important for disposable sensors.

Abstract: The present invention provides an encoding mechanism for a medical sensor which uses a modulated signal to provide the coded data to a remote analyzer. The modulated signal could be, for instance, a pulse width modulated signal or a frequency modulated signal. This signal is amplitude independent and thus provides a significant amount of noise immunity.

Abstract: The present invention provides a medical sensor for detecting a blood characteristic. The sensor includes a transducer for producing an analog signal related to the blood characteristic. The analog signal is converted into a transmission signal which is in amplitude-independent form for transmission to a remote analyzer. In one embodiment, a current-to-frequency converter converts a signal from a pulse oximeter sensor into a frequency signal which can be transmitted over a transmission line to a remote pulse oximeter.

Abstract: An apparatus for detecting movement in patients coupled to pulse oximeters and a method for using the signal generated by the apparatus to filter out the effects of motion from the test results generated by the pulse oximeter are disclosed. In a preferred embodiment, a piezoelectric film located in close proximity to the pulse oximeter's sensor provides a voltage signal whenever movement occurs near the sensor. This voltage signal is processed and the resulting signal is used to correct the oximeter's measurements. In addition to piezoelectric film, accelerometers and strain gauges are also usable to provide a signal indicative of motion.