Electrostimulator capable of outputting stable electric stimulus

An electrostimulator, comprising:

• a boost circuit with no transformer, which receives power supply from a battery and supplies a stimulus signal;
• a first electrode and a second electrode which are disposed on a skin surface and detect a voluntary myoelectric signal;
• an amplification circuit which amplifies the detected voluntary myoelectric signal;
• a fourth electrode and a fifth electrode which are disposed on a skin surface and give the stimulus signal supplied from the boost circuit;
• a controller which controls the stimulus signal in accordance with the voluntary myoelectric signal detected by the first and the second electrodes;
• an H-bridge circuit which comprises a first switch and a third switch that are connected in series while a common connection terminal thereof is connected to the fourth electrode, and a second switch and a fourth switch that are connected in series while a common connection terminal thereof is connected to the fifth electrode, the first switch, the second switch, the third switch and the fourth switch being connected in parallel, the H-bridge circuit being controlled by the controller;
• an isolated DC-DC converter which receives the power supply from the battery and supplies a power to the controller and the amplification circuit;
• a regulator which outputs a midpoint voltage of a power-supply voltage outputted by the DC-DC converter;
• and
• a third electrode which is connected to the regulator and a reference terminal of the amplification circuit and disposed on the skin surface.

An electrostimulator, comprising:

• a boost circuit with no transformer, which receives power supply from a battery and supplies a stimulus signal;
• a first electrode and a second el- ode which are disposed on a skin surface, detect a voluntary myoelectric signal, and give the stimulus signal supplied from the boost circuit;
• an amplification circuit which amplifies the detected voluntary myoelectric signal;
• a controller which controls the stimulus signal in accordance with the voluntary myoelectric signal detected by the first and the second electrodes;
• an H-bridge circuit which comprises a first switch and a third switch that are connected in series while a common connection terminal thereof is connected to the second electrode, and a second switch and a fourth switch that are connected in series while a common connection terminal thereof is connected to the first electrode, the first switch, the second switch, the third switch and the fourth switch being connected in parallel, the H-bridge circuit being controlled by the controller;
• a fifth switch which is connected between the common connection terminal of the second and the fourth switches and the first electrode;
• a sixth switch which is connected between the common connection terminal of the second and the fourth switches and the second electrode;
• an isolated DC-DC converter which receives the power supply from the battery and supplies a power to the controller and the amplification circuit;
• a regulator which outputs a midpoint voltage of a power-supply voltage outputted by the DC-DC converter;
• and
• a third electrode which is connected to the common connection terminal of the first and the third switches, the regulator and a reference terminal of the amplification circuit and disposed on the skin surface.