Abstract: To control a lung ventilator comprising an inspiratory implement to be worn by the patient, an air supply system for supplying air to the inspiratory implement, and a control unit for controlling the air supply system, electromyographic signals produced by the patient's diaphragm are detected by an array of electrodes passing through the center of the patient's diaphragm depolarizing region. The position of the center of the patient's diaphragm depolarizing region is determined through detection of a reversal of polarity of the electromyographic component of the electrode-detected electromyographic signals.

Abstract: In the method and system for electromyographic analysis of a striated muscle, electromyographic signals produced by the muscle are detected by means of an array of electrodes passing through the center of the muscle depolarizing region. Each electromyographic signal comprises an electromyographic component and a noise component. The position of the center of the muscle depolarizing region is then determined by detecting a reversal of polarity of the electromyographic components of the signals. Finally, two signals of opposite polarities amongst the electromyographic signals are subtracted. The subtraction subtracts the noise components of the two signals from each other but adds the electromyographic components of the two signals together to produce an electromyographic signal of improved signal-to-noise ratio.