Mixed reality temporal bone surgical dissector: mechanical design.
OBJECTIVE
The Development of a Novel Mixed Reality (MR) Simulation. An evolving training environment emphasizes the importance of simulation. Current haptic temporal bone simulators have difficulty representing realistic contact forces and while 3D printed models convincingly represent vibrational properties of bone, they cannot reproduce soft tissue. This paper introduces a mixed reality model, where the effective elements of both simulations are combined; haptic rendering of soft tissue directly interacts with a printed bone model. This paper addresses one aspect in a series of challenges, specifically the mechanical merger of a haptic device with an otic drill. This further necessitates gravity cancelation of the work assembly gripper mechanism. In this system, the haptic end-effector is replaced by a high-speed drill and the virtual contact forces need to be repositioned to the drill tip from the mid wand. Previous publications detail generation of both the requisite printed and haptic simulations.


METHODS
Custom software was developed to reposition the haptic interaction point to the drill tip. A custom fitting, to hold the otic drill, was developed and its weight was offset using the haptic device. The robustness of the system to disturbances and its stable performance during drilling were tested. The experiments were performed on a mixed reality model consisting of two drillable rapid-prototyped layers separated by a free-space. Within the free-space, a linear virtual force model is applied to simulate drill contact with soft tissue.


RESULTS
Testing illustrated the effectiveness of gravity cancellation. Additionally, the system exhibited excellent performance given random inputs and during the drill's passage between real and virtual components of the model. No issues with registration at model boundaries were encountered.


CONCLUSIONS
These tests provide a proof of concept for the initial stages in the development of a novel mixed-reality temporal bone simulator.
Neurotologic Surgery, Department of Otolaryngology Head and Neck Surgery, Faculty of Medicine, University of Manitoba, GB421, 820 Sherbrook Street, Winnipeg, Manitoba, Canada. jordanhochman@hotmail.com.|Laboratory for Surgical Modeling Simulation and Robotics, University of Manitoba, Winnipeg, Manitoba, Canada. jordanhochman@hotmail.com.
Jordan Brent
JB
Hochman
Faculty of Engineering, University of Manitoba, Winnipeg, Manitoba, Canada. nariman@cc.umanitoba.ca.
Nariman
N
Sepehri
Faculty of Engineering, University of Manitoba, Winnipeg, Manitoba, Canada. vivekrampersad@gmail.com.
Vivek
V
Rampersad
Department of Medical Education, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada. jaykraut@gmail.com.
Jay
J
Kraut
Faculty of Engineering, University of Manitoba, Winnipeg, Manitoba, Canada. miladkhazraee@gmail.com.
Milad
M
Khazraee
Surgical Hearing Implant Program, Department of Otolaryngology - Head and Neck Surgery, Health Sciences Centre, GB421, 820 Sherbrook Street, Winnipeg, Manitoba, Canada. jpisa@hsc.mb.ca.
Justyn
J
Pisa
Clinical Learning and Simulation Facility, Department of Medical Education, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada. bertram.j.unger@gmail.com.
Bertram
B
Unger
D003198:Computer Simulation; D004867:Equipment Design; D006801:Humans; D019635:Neurosurgical Procedures / Q000295:instrumentation*; D013701:Temporal Bone / Q000601:surgery*; D014584:User-Computer Interface