In described examples, a circuit includes an analog frontend arranged to generate an analog stress compensating signal in response to a to-be-compensated analog signal and a first-axis stress sensing signal. The analog frontend can comprise a first precision component (e.g., 220) arranged on a piezoelectric material and arranged to generate the to-be-compensated analog signal that is affected by a stress exerted in the piezoelectric material and a directional stress sensor arranged on the piezoelectric material and coupled to the first precision component. The directional stress sensor is arranged to generate the first-axis sensing signal in response to a longitudinal resultant of a stress exerted in the piezoelectric material. A compensating circuit is arranged to generate a compensated output signal in response to the compensating analog signal and to-be-compensated analog signal.

The present disclosure relates to force sensors and force sensor substrates for use with surgical devices.

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.

The present disclosure relates to a compensation circuit for compensating for an offset voltage that is present in an output signal output by a force sensor. The compensation circuit comprises: voltage divider circuitry, the voltage divider circuitry configured to receive a bias voltage that is also supplied to the force sensor and to output a control voltage derived from the bias voltage, wherein a component mismatch ratio of the voltage divider circuitry is adjustable to correspond to a component mismatch ratio of the force sensor; current generator circuitry configured to receive the control voltage and to generate a compensating current based on the received control voltage; and amplifier circuitry configured to receive the differential signal output by the force sensor and the compensating current and to output a compensated differential output signal in which the offset voltage is at least partially cancelled.

The present disclosure provides digital to analog conversion circuitry comprising: a set of input nodes for receiving a digital input code; an output node for outputting an analog output signal representative of the input code; and a plurality of selectable conversion elements, wherein a parameter of each of the plurality of selectable conversion elements is configured such that a transfer function between the input code and the output analog signal is non-monotonic.

A force sensor, flexible sensing element, and method for the force sensor are disclosed. The force sensor uses a flexible sense element with two flexible arms dedicated to measuring strain related to a pitch force and two flexible arms dedicated to measuring strain related to roll force. The use of two channels for each measurement provides a command lane and a monitor lane for strain measurements. Strain gauges are disposed on both the top and the bottom surfaces of each arm, thus providing two completely redundant systems. When a failure is detected in one of the systems, the redundant system can be implemented.

An apparatus for sensing a physical attribute is shown, that includes a first track (511) defining a first electrode on a substrate (512), a second track (513) defining a second electrode on said substrate and an active film (514) in cooperation with a first sensor portion (516) of the first electrode and a second sensor portion (517) of the second electrode. The second electrode includes a first extended portion (517) to establish a first additional resistance not cooperating with the active film.

A control apparatus controls an array-type sensor. The control apparatus includes: a first selector/driver that is configured to select and drive one of a plurality of first lines; a second selector/driver that is configured to select and drive at least one of a plurality of second lines; a read/arithmetic circuit that is configured to read outputs of respective unit cells and perform a correction operation on the outputs; and a nonvolatile storage device that is configured to store reference data. The sensor outputs of the respective unit cells with respect to two or more reference inputs are stored as reference data in the nonvolatile storage device in a calibration mode, and a correction operation is performed on the sensor outputs of the respective unit cells using the stored reference data and results of the correction operation are output in a measurement mode.

A force balance sensor including a mechanical strain amplification system including a sensor torsion member having a first end and a second end spaced from one another along a longitudinal axis of the sensor torsion member, at least one strain sensor coupled to the sensor torsion member between the first and second ends, a first torsional stiffening member coupled to the first end of the sensor torsion member, and a second torsional stiffening member coupled to the second end of the sensor torsion member, wherein the first torsional stiffening member and the second torsional stiffening member are coupled to a torque member.

The present disclosure relates to circuitry for biasing a sensor comprising: a bias generator module configured to receive a supply voltage and to generate a bias voltage for biasing the sensor. The circuitry further comprises a control module configured to compare a voltage indicative of the supply voltage to a threshold voltage and to output a control signal to the bias generator module based on the comparison. The bias generator module is configured to control the bias voltage based on the control signal.