Introduction

The device thanks to its surface electrodes is able to read the residual and insufficient muscle signal generated during the muscle contraction; as the myo-electrical signal is still correctly modulated by the brain. This signal is then amplified and returned- non-invasively – to the muscles to be activated, enabling the user to grab a bottle, a pen to write, or gently squeeze a paper cup of coffee, as per normal.

Technical features

The invention allows both EMG recording and electrical stimulation to be transmitted on several channels simultaneously, this activating several muscles in unison, which is fundamental to enable a user to carry out day-to-day activities. The use of FES systems presents a technological challenge: acquiring an EMG signal with amplitudes of the order of a hundred µV and at the same time stimulating the muscles with signals that even reach 300V with currents up to 200mA. The patented solution duplicates n-times the current stimulation block that uses a single monopolar generator driven by a multiplexer that directs the stimulus towards the correct channel. This solution introduces the problem of leakage currents. It is therefore necessary a MUX which can drive current signals and which is virtually floating towards GND. This limit has been overcome by the patent which improves the performance of the devices currently on the market and in particular: it has no significant leakage towards ground and allows relatively high rise/fall times without deforming the input signal; it has low current consumption both in standby and in operation; it guarantees high voltage (± 250V) and small dimensions.

Possible Applications

• Neuromuscular stimulation devices with electromyographic control;
• Applicable in those areas where high voltage multiplexers are needed (e.g. ultrasound machines or ink jet printers).

Advantages

• Low consumption;
• Small size;
• Low invasiveness;
• Force modulation directly performed by the patient;
• Ecological use of the technology;
• High grasp capability.