A Force-sensing Bipolar Forceps to Quantify Tool-tissue Interaction Forces in Microsurgery
Kourosh Zareinia ; Yaser Maddahi ; Liu Shi Gan ; Ahmad Ghasemoonia ; Sanju Lama ; Taku Sugiyama ; Fang Wei Yang ; Garnette Sutherland
The ability to exert an appropriate amount of force on brain tissue during surgery is an important component of instrument handling. It allows surgeons to achieve the surgical objective effectively while maintaining a safe level of force in tool-tissue interaction. At the present time, this knowledge and hence skill is acquired through experience, and qualitatively conveyed from an expert surgeon to trainees. These forces can be assessed quantitatively by retrofitting surgical tools with sensors, thus providing a mechanism for improved performance and safety of surgery and enhanced surgical training. This paper presents the development of a force-sensing bipolar forceps, with installation of a sensory system, that is able to measure and record interaction forces between the forceps tips and brain tissue in real-time. This research is an extension of a previous research where a bipolar forceps was instrumented to measure dissection and coagulation forces applied in a single direction. Here, a planar forceps with two sets of strain gauges in two orthogonal directions was developed to enable measuring the forces with a higher accuracy. Implementation of two strain gauges allowed compensation of strain values due to deformations of the forceps in other directions (axial stiffening) and provided more accurate forces during microsurgery. An experienced neurosurgeon performed five neurosurgical tasks using the axial setup, and repeated the same tasks using the planar device. The experiments were performed on cadaveric brains. Both setups were shown to be capable of measuring real-time interaction forces. Comparing the two setups, under the same experimental condition, indicated that the peak and mean forces quantified by planar forceps were at least 7% and 10% less than those of axial tool, respectively, therefore utilizing readings of all strain gauges in planar forceps provide more accurate values of both peak and mean forces than axial forceps. Cross correlation analys- s between the two force signals obtained, one from each cadaveric practice, showed a high similarity between the two force signals.
KEYWORDS: Bipolar forceps; cross correlation; neurosurgery; sensors; surgical training; tool-tissue interaction forces