Artificial tactile sense in minimally invasive surgery

The operative diagnosis for the assessment of anatomical or pathological structures is particularly difficult in minimally invasive surgery due to the fact that direct palpation of these structures is not possible as it is in open surgery. In this project, novineon technologies attempts to regain a part of the tactile information that is not accessible in minimally invasive surgery. Current research focuses on artificial tactile feedback by means of a tactile sensor which measures tissue characteristics, the electronic analysis of the measured data and the subsequent account of the tactile information.

System components of an instrument system for producing artificial tactile feedback

A tactile sensor which is suitable for use in direct contact with biological tissue has been developed in order to analyse the artificial tactile feedback. 32 pressure-sensitive sensors were integrated in a laparoscopic 10-mm grasper. The tactile sensor is completely encapsulated in silicon. Furthermore, the tactile grasper avails of an electronic module for recording and processing the sensor data as well as a Bluetooth interface to transmit the data to an external computer (see picture, right). The entire weight of the instrument could be reduced to 269 g by using a lithium-ion accumulator.

Experimental prototype of the telemetric tactile laparoscopic grasper

The measured data of the tactile sensor are processed in an external computer.  Special software filters the data stream so that unspecified data are not visualized. The software extracts certain characteristics of the removed tissue, such as size, form, and degree of hardness and produces a graphic representation of the tactile data. This data can then be presented to the surgeon in various forms.

Tactile sensor data presented on the endoscopy monitor

This tactile instrument system is used to carry out studies of artificial tactile feedback. In such studies the effectiveness of artificial tactile feedback in the detection of foreign matter is analyzed, furthermore certain surgical maneuvers that may profit from the sensor as well as the prerequisites for the pulsation detection of arteries. The goal is to develop a system design for tactile instruments that has the potential of offering a significant value add in future clinical applications. In doing so, the suitability for use as well as the ergonomics of the instrument are taken into consideration.