Abstract: Disclosed is a telemetry system (10) with a receiver unit (50) and a plurality of transmitters (20-40), each adapted for providing a wireless communicating with the receiver unit (50). The receiver unit (50) comprises a plurality of transmitter holding positions (52-56), such as insertion slots, for receiving one of the transmitters (20-40), and means for assigning one of the transmitter holding positions (52-56) to the transmitter (20-40) received in the assigned transmitter holding position (52-56).

Abstract: A coincidence recognition unit receives a first signal indicative of a pulse rate derived from pulse oximetry and a second signal indicative of a heart rate. A coincidence detection unit generates a third signal indicative of the coincidence between the first signal and the second signal. The pulse rate of a patient (detected by pulse oximetry) can thus be compared with the heart rate of the patient (e.g. from EKG or ultrasound). An indicator is preferably generated when the pulse rate and the heart rate do not match e.g. within a pre-given limit. A warning signal might further be generated indicating that the oxygen saturation value as measured by the pulse oximetry is not sufficiently accurate and/or invalid. A pulse oximetry unit according to the invention comprises a pulse oximeter for generating the first signal, a heart rate determination unit for generating the second signal, and the coincidence recognition unit receiving the first and second signals.

Abstract: A medical monitor, such as a fetal monitor, is provided with a code reader, e.g. a bar code reader. A manual contains clear text instructions as well as predefined codes in their correct sequential form. The instructions help the unskilled user to operate the monitor, and the actual monitor functions are triggered by scanning the codes, instead of pushing buttons, turning knobs etc. A questionnaire may also be provided to enter answers to anamnesis data. These answers, together with vital signs data, may be transmitted via telephone lines to a hospital, which makes the medical monitor ideally suited for home monitoring applications.

Abstract: Determining the fetal heart rate comprises irradiating an ultrasound beam in the direction of the fetal heart. The moving parts of the fetal heart cause a Doppler shift which is used to determine the fetal heart rate via an autocorrelation function. Moving parts of the fetal heart with different velocities and Doppler shifts originating from other physiological sources generate secondary maxima in the autocorrelation function, so that an accurate heart rate determination becomes nearly impossible. This problem is overcome by parallel processing of the demodulated ultrasound signal in various pass-bands, for which purpose the signal is fed to filters (28, 30) of different frequency characteristics. The output of the pass band with the better result is used for fetal heart rate circulation.