Abstract: The invention relates to a charging method and a charging arrangement for a measuring system which measures the heart rate. The functional unit of the measuring system comprises at least a transmitter unit (100) and/or a receiver unit. The charging arrangement comprises a charging unit (340). The charging coil (320) of the charging unit is arranged to transfer electric energy inductively to the power source (302) of the functional unit (100) via an induction coil (310). The induction coil (130) of the functional unit (100) used for charging is connectable to more than one inductively active function in addition to charging.

Abstract: The present invention relates to a method and an apparatus for determining exertion levels in fitness or athletic training and for determining the stress caused by training. According to the invention, the ECG signal of a person and the timing moment of at least one waveform of the ECG signal, for instance the QRS complex, are measured by means of a heartbeat rate monitor during a training period. The heartbeat rate is calculated on the basis of corresponding ECG signal waveform distances, and a value proportional to the magnitude of the heartbeat rate variation or to that of a total or partial power of a spectrum derived from the heartbeat rate is provided by means of a mathematical function. Those exertion levels of the person which are essential as regards to training period or the stress caused by the training in relation to the exertion levels are determined on the basis of the heartbeat rate variation.

Abstract: A device for measuring heartbeat rate that includes a device casing or wrist strap with skin contact electrodes, and a coil receiver for receiving telemetrically transmitted heartbeat signals for displaying heartbeat data either from the receiver, or the skin contact electrodes. The signals from the skin sensor are filtered, and subjected to an AGC device and pulse shaper. The received signals are amplified. A microcomputer, memory, and display are common to both the pulse shaped detected heartbeat signal and the amplified signal received from the transmitter.

Abstract: A method of interference-tolerant heartbeat measurement comprises the steps of measuring the person's heartbeat signal at a suitable part of the body and transmitting the signal by telemetric transmission from a transmitter to a receiver as a pulse message formed by successive measuring pulses. A transmission interval of at least some pulse signals is proportional to the person's measured heartbeat rate. Each measuring pulse is formed of at least two identification pulses (C1 and C2), whereby the time interval (t.sub.x) between the identification pulses corresponds to a specific time interval determined for each transmitter-receiver pair, on the basis of which specific interval the receiver identifies the pulse signals intended for itself.