A force sensor includes an annular diaphragm that includes an inner perimeter and an outer perimeter; the diaphragm has an outer annular portion having a tapered thickness that increases with decreasing radial distance from the outer perimeter; the diaphragm has an inner annular portion having a tapered thickness that increases with decreasing radial distance from the inner perimeter; a first strain gauge at the outer annular portion; and a second strain gauge at the inner annular portion.

The sensor assembly comprises a sensor die comprising first and second members. The first member accommodates an actuation element on a second surface of the first member and in contact with a diaphragm that is integral with the first member. The second member is bonded to a first surface of the first member opposite the second surface, and sensing elements are positioned adjacent the diaphragm along the first surface and interposed between the first and second members. The second member also includes a recessed section that forms a cavity adjacent the diaphragm to accommodate and/or limit diaphragm deflection. An internal electrical connection is made between first and second member electrical contacts disposed along the interface between the first and second members to avoid external wires. The second member further includes external electrical terminals to facilitate an electrical surface connection with the sensor assembly without the need for external wires.

A force sensor includes an annular diaphragm that includes an inner perimeter and an outer perimeter; the diaphragm has an outer annular portion having a tapered thickness that increases with decreasing radial distance from the outer perimeter; the diaphragm has an inner annular portion having a tapered thickness that increases with decreasing radial distance from the inner perimeter; a first strain gauge at the outer annular portion; and a second strain gauge at the inner annular portion.

A force sensor includes a force-sensing elastomer, a thermal conductivity component adapted to transfer an external load to the force-sensitive elastomer, a plurality of strain gauges attached to the force-sensitive elastomer, and a circuit board. The circuit board electrically connects the plurality of strain gauges to a detection circuit adapted to detect a strain of the force-sensitive elastomer. A peripheral part of the force-sensitive elastomer is in contact with the thermal conductivity component, and a remaining part of the force-sensitive elastomer is separated from the thermal conductivity component. The plurality of strain gauges are attached to the remaining part of the force-sensitive elastomer and do not contact the thermal conductivity component.

A load sensor element includes a substrate made of a ceramic material; an inorganic layer having a surface configured to receive a load, the inorganic layer covers a portion of the substrate; a thin-layer resistance body whose resistance value changes in accordance with the load received by the inorganic layer, the thin-layer resistance body having a main body portion and a pair of end portions, the main body portion mounted on the covered portion of the substrate and sandwiched between the substrate and the inorganic layer, the pair of end portions mounted on an exposed portion of the substrate, and the exposed portion free of the inorganic layer; and a pair of electrodes electrically connected to the pair of end portions of the thin-layer resistance body and separated away from the inorganic layer and on one side of the substrate.

A device for measuring a strain of an object independently of temperature variations includes: at least one strain gauge that is attachable directly or indirectly to the object whose strain is to be measured; a first temperature sensor for measuring a temperature of the at least one strain gauge; read-out electronics for measuring a change of electrical resistance of the at least one strain gauge as a measured electrical resistance change, the read-out electronics including at least one fixed resistor whose value is relied upon when obtaining a value of the change of electrical resistance of the strain gauge as a result of the measurement, the read-out electronics being such that a temperature of the at least one fixed resistor is known and/or obtainable by measurement; and an evaluation unit for: correcting the measured electrical resistance change, and/or a strain of the strain gauge and/or the strain of the object.

A patient support apparatus comprises a base supported by caster assemblies with each caster assembly comprising a stem, a caster wheel, and a caster wheel axle. A patient support surface is coupled to the base and is configured to receive a load. One or more load sensors are integrated with at least one of the stem, the caster wheel, or the caster wheel axle for measuring the load. One or more of the caster assemblies can be coupled to a steering motor, which controls orientation of the caster assembly. A controller can control the steering motors based on analyzing the measurements of the load sensor. The load sensors can produce measurements indicative of both vertical load and non-vertical load applied to the caster assembly. The controller can also analyze the measurements of the load sensor to determine the load received by the patient support surface by negating the non-vertical load.

Provided is a torque sensor which enables the allowable torque and sensitivity of a strain sensor to be independently set, or for which the mechanical strength can be independently set. The torque sensor comprises a first region, a second region, and a plurality of third regions which connect the first and second regions, wherein the torque to be measured is transmitted between the first and second regions through the third regions. A first strain generation part is provided between the first region and the second region, and is equipped with a first resistor. A second strain generation part is provided between the first region and the second region at a location separated from the first strain generation part, and is equipped with a second resistor.

In a particular embodiment, a force sensor apparatus is disclosed that includes a force-compliant element that deforms in response to forces applied to the force sensor apparatus. The apparatus also includes a sensing element coupled to the force-compliant element and is configured to generate a signal indicating the degree that the force-compliant element deforms in response to the applications of forces to the force sensor apparatus. In this embodiment, the apparatus also includes a printed circuit board configured to receive the signal from the sensing element and a support structure having a surface on which the printed circuit board is coupled. The support structure has an outer rim that is attached to the force-compliant element. The apparatus also includes a sensor housing that covers the printed circuit board. The sensor housing has an outer rim attached to the force-compliant element.

A drive unit for providing drive from a robot arm to an instrument comprises a plurality of drive elements for engaging corresponding elements of the instrument, and a load cell structure. Each drive element is movable along a drive axis and the drive axes of each of the drive elements are substantially parallel to each other. The load cell structure includes a plurality of deflectable bodies coupled to the drive elements for sensing load on the drive elements parallel to their drive axes, and a frame. The frame includes an integral member supporting the deflectable bodies in such a way as to isolate each deflectable body from the load applied to the or each other deflectable body.