Abstract: An electrostimulator includes a boost circuit supplying a stimulus signal, first and second electrodes disposed on a skin surface, detecting a voluntary myoelectric signal and giving the stimulus signal, an amplification circuit amplifying the voluntary myoelectric signal, a controller controlling the stimulus signal in accordance with the voluntary myoelectric signal, an H-bridge circuit including first and third switches connected in series and connected to the second electrode, and second and fourth switches connected in series and connected to the first electrode, the first to the fourth switches being connected in parallel, an isolated DC-DC converter supplying a power to the controller and the amplification circuit, a regulator outputting a midpoint voltage of a power-supply voltage, and a third electrode connected to the regulator and a reference terminal of the amplification circuit and disposed on the skin surface.

Abstract: A penetration-type pipe strain gauge easily transportable and easily installable in various places at low cost in a short period of time to measure strain produced in a shallow layer of the ground. Strain gauges are attached to the outer peripheral surface of an inner pipe, and a pipe strain gauge body is formed by integrally incorporating the inner pipe in an outer pipe. A boring screw is provided at the forward end of the pipe strain gauge body. A rotary tool mounting part for mounting a tool for rotating the pipe strain gauge body is formed at the rear end of the strain gauge body. The pipe strain gauge body is buried in the shallow layer of the ground by using the rotary tool.

Abstract: A penetration-type pipe strain gauge easily transportable and easily installable in various places at low cost in a short period of time to measure strain produced in a shallow layer of the ground. Strain gauges are attached to the outer peripheral surface of an inner pipe, and a pipe strain gauge body is formed by integrally incorporating the inner pipe in an outer pipe. A boring screw is provided at the forward end of the pipe strain gauge body. A rotary tool mounting part for mounting a tool for rotating the pipe strain gauge body is formed at the rear end of the strain gauge body. The pipe strain gauge body is buried in the shallow layer of the ground by using the rotary tool.