Redesign of Otologic Surgical Instruments Brian Chow and
Redesign of Otologic Surgical Instruments Brian Chow and Joy Nystrom Mechanical Engineer: Ryan Josefovsky Advisor: Russ Johnson, Ph. D-Smith and Nephew BME 273 March 19, 2001
Ear Surgery • Otitis Media (Middle Ear Infection) – Upwards of 800, 000 surgeries/year – Around 11 million cases total • Closure of Tympanic Membrane Perforations
Ear Surgery • Otosclerosis – 10 -18% of women aged 30 -50 – 7 -9% of men aged 30 -50 • Removal of Tumors • Cochlear Implants – 14, 000 Americans • • The Boys Town Research Registry for Hereditary Hearing Loss http: //www. nidcd. nih. gov/health/pubs_hb/coch. htm#c
Potential Market • 100, 000 Ear, Nose, and Throat (ENT) Physicians • 1000 Neurosurgeons
Problem • Otologic surgery requires delicate maneuvering in limited space – ossicles <3 mm – cavities ~1 cm www. earsurgery. org • Current method requires large hand movement
1 inch A large hand movement (1 cm) causes a small tip movement (4 mm). Movement requires compensation by user.
Proposal • Create a system that will allow identical movement of the instrument in an ear of a patient with a fingertip-controlled drive mechanism Brackmann, Otologic Surgery
The Task • Redesign the back end and drive mechanism for fingertip control Tip • Maintain tip movement identical to current instruments Back End/ Drive Mechanism
The Task • There are different kinds of tips – grasping – cutting – spreading Courtesy of Smith and Nephew
Reasons Fingertip control allows for: • Steadier hand control • Higher precision with finger movement • Better access to inner ear
Advantages Reduced motion of surgeon’s arm results in: • A lowered margin of error • A potential for reducing amount of training required for proficiency • A potential for better ergonomics • Similar cost
Research and Brainstorming
Patent Search • New problem, few previous patents, little information • Similar to laparoscopic surgery
Possible solutions • Screw mechanism • Pulleys (#5, 976, 122) • Gears • Slide • Concentric Wheels • Levers
Concentric Wheel Design Concentric wheels designed to scale motion. Solid metal shafts
Concentric Wheel Flaws • Requires larger handle (about the size of a fountain pen) • Finger moves in a sliding motion
Current Design
Advantages • More compact • Push-button mechanism • Fewer, more stable parts
Future Work • Obtain Specifications • Complete design on CAD program • Consult with manufacturing • Evaluate safety of design
Questions?
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