The development of a haptic interface for the Virtual Translumenal Endoscopic Surgical Trainer (VTEST.

Natural orifice translumenal endoscopic surgery (NOTES) is an experimental surgical technique with benefits including reduced pain, post operative recovery period and better cosmesis compared to traditional laparoscopic procedures. In a pure NOTES procedure, a flexible endoscope is used for performing the surgery and visualization. The Virtual Translumenal Endoscopic Surgical Trainer (VTEST(TM)) is being developed as a platform to train for NOTES procedures and innovate NOTES tools and techniques. In this work we report the design specification for the hardware interface to be used for VTEST(TM).

Characterization of force and torque interactions during a simulated transgastric appendectomy procedure.

We have developed an instrumented endoscope grip handle equipped with a six-axis load cell and measured forces and torques during a simulated transgastric natural orifice translumenal endoscopic surgery appendectomy procedure performed in an EASIE-R ex vivo simulator. The data were collected from ten participating surgeons of varying degrees of expertise which was analyzed to compute a set of six force and torque parameters for each coordinate axis for each of the nine tasks of the appendectomy procedure. The mean push/pull force was found to be 3.64 N (σ = 3.54 N) in the push direction and the mean torque was 3.3 N · mm (σ = 38.6 N · mm) in the counterclockwise direction about the push/pull axis. Most interestingly, the force and torque data about the nondominant x and z axes showed a statistically significant difference (p < 0.05) between the expert and novice groups for five of the nine tasks. These data may be useful in developing surgical platforms especially new haptic devices and simulation systems for emerging natural orifice procedures.