The Royal Institution for the Advancement of Learning / Mcgill University

Universitéde Montreal

Sven Friberg

Christer Sinderby

Lars Lindstrom

Alejandro Grassino

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. First and second electromyographic signals detected by the electrodes of the array on opposite sides of the patient's diaphragm depolarizing region are subtracted from each other, this subtraction cancelling the noise components of the first and second electromyographic signals but adding the respective electromyographic components of these first and second signals together to produce an electromyographic signal having an improved signal-to-noise ratio, having a reduced electrode-position-induced filter effect, and being representative of a demand to inspire from the patient's brain. The electromyographic signal of improved signal-to-noise ratio is finally supplied as input signal to the control unit of the lung ventilator for controlling the air supply system and therefore the inspiration assist in relation to the electromyographic signal of improved signal-to-noise ratio and of reduced electrode-position-induced filter effect, and therefore in relation to the demand to inspire from the patient's brain.

Inspiratory proportional pressure assist ventilation controlled by a

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. Advantageously, the array of electrodes is a linear array of successive electrodes, the center of the muscle depolarizing region is located between the electrodes of a given pair of successive electrodes, and the two signals of opposite polarities detected through the two pairs of successive electrodes adjacent to the given pair on opposite sides thereof are subtracted.

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Moindal, Sweden

Sven Friberg