Inductive Encoders for Surgical Robotics

The Challenge

Position sensors are employed within surgical robot platforms both inside and outside of the operating room. Outside – they are integrated into teleoperated surgical consoles, controlled by a surgeon viewing the patient through the lens of the vision system. Inside the operating room, encoders are installed in manipulator arms of the multiport surgical robot performing minimally invasive surgery. This is maneuvered by the wrist and finger movements of the remote surgeon. Across this example platform, the key requirements of position sensors are common – enhanced reliability, highly repeatable measurement, and increasingly compact, lightweight form factors.

As the widespread adoption of laparoscopic surgical platforms accelerates, surgical robot OEMs are being tasked to develop systems for new surgical procedures, through the development of more compact, versatile, and ergonomic surgical robot platforms.

The Solution

The IncOder CORE, an inductive angle encoder, is a true absolute digital position sensor, requiring no motion at start-up, for safe position measurement. The 44mm OD sensor delivers up to 17-bit resolution with an output configurable with SSI, BiSS-C, SPI protocols as required.

Comprising of a hollow bore stator and rotor pair, the sensor is fully contained in a low-profile printed circuit board form factor. Optimized for low mass, the device is suited for integration into manipulator arm rotary joints.

IncOder CORE uses a robust, wear-free, inductive measurement technique and is insensitive to contamination, for rugged actuator design. The sensor delivers accurate position feedback at modest installation tolerances. Combined with no requirement for calibration, CORE ensures reliable, accurate position measurement with fast setup.

The Benefit

The compact circular wide thru bore shape is ideally suited for integration into surgical robot manipulator arms. The unpackaged circuit board design allows for rapid derivative customization of mounting features and shape for an exact system fit, enabling a more compact, lightweight actuator design.

With no requirement for calibration and specified measurement performance achieved, even if installed at the limits of prescribed tolerances (±0.2mm gap, 0.2mm radial offset), IncOder CORE can be installed quickly, reducing OEM production time and costs.

The proven-robust and reliable inductive position measurement technique of IncOder CORE results in reduced system down time, and enhanced reliability.

IncOder CORE Specifications