| 摘要 |
PCT No. PCT/AU86/00236 Sec. 371 Date Apr. 10, 1987 Sec. 102(e) Date Apr. 10, 1987 PCT Filed Aug. 18, 1986 PCT Pub. No. WO87/01123 PCT Pub. Date Feb. 26, 1987.A monitoring device for detecting muscle strain, which might lead to repetitive strain injury includes EMG sensors which generate an EMG signal, signal processing circuitry to derive a signal or signals representative of undesirable strain conditions and an acoustic signal generator which produces a signal to indicate when undesirable strain conditions exist. The signal processor includes a band pass filter to band limit the EMG signal, a rectifier and low pass filter to produce an envelope signal and a minimum signal level tracking circuit comprising amplifiers, capacitor, diodes and resistors. The minimum signal level tracking circuit produces a minimum level signal which tracks the envelope signal, with a short time constant while the minimum level signal is greater than the envelope signal, and with a long time constant when the minimum level signal is less than the envelope signal. The acoustic signal generator produces an acoustic alarm signal when the minimum level signal exceeds a preset threshold level.
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