The design of an in-vivo rotator cuff measuring tool
PROJECT UPDATE
Kathleen Bieryla, Katie Fronczak, Martha Loehr, Eric Rainis
University of PittsburghSenior Design - BioE1161
Overview- Problem
• Surgical methods dependent upon ratio of a/b
• Currently there is no tool available to measure these dimensions Humer
us
Scapula
a) Length of torn tendon edge
b) Size of avulsed humeral insertion
c) Retraction of tendon
Overview- Proposed Solution
• The Arthromeasure is a one-handed tool for surgeons to use during arthroscopic surgery in order to measure the extent of rotator cuff tears
• Provides accuracy as specified by the user
• Allows for correct classification of size of tear, which aids in surgical treatment
Description
Initial Design
•Shaft
•Length: 15 cm (13 cm exposed)
•OD: 4 mm
•ID: 0.51 mm (0.020 in)
•Handle
•18 cm x 4 cm x 4 cm
Current Design
Alterations:
• Dimensions
• Propulsion System
• Wire Ejection Location
• Measurement System
Gear Mechanism
Features & Benefits
• Convenient moving mechanism on the handle
• Provides desired accuracy• a: +/- 1 cm• b: +/- 5 mm
• Gives surgeon an easy way to determine the best method of repair
Competitive Analysis• Currently, no tool is available
• 3mm hook - surgery• String and digital caliper – cadaveric
research• Strengths
• More accurate• Easy to use
• Weaknesses• Inaccuracy comes from surgeon
Team/Resources• MSRC
• Patrick McMahon M.D.• Richard Debski Ph.D• Lab and equipment
• Swanson Center• Rapid prototyping process
• Bioengineering Department• Funding
• Limitations• Money • Size of handle
Schedule•February—Initial prototype
• Choose final wire material• Purchase gears and assemble•Testing – accuracy and repeatability
•March—Cadaveric testing•April—Final product and grant proposal
Team Responsibilites
Katie B • Determine materials for measuring device
• Testing of wire and shaft materials• Help with SolidWorks model
Katie F • Keep quality controlled documents up to date• Final design history file
• Write protocols for cadaveric testing of reliability/accuracy
Martha • Design handle of measuring device
• Complete SolidWorks design
• Structural testing in SolidWorks
Eric • Design gear system for measuring device• Scheduling and external relations
• Physical cadaveric testing
Road Blocks • Meeting with advisor• Redesign of gear system
• Changed based on surgeon’s input
• Lack of knowledge
Current Status and Milestones• Solidifying final design
• Gear system• Sample materials for shaft and wire
• Viewed surgery – ask us what it’s like to be med students!
• Updated responsibilities and working plan• First draft of SBIR phase I proposal
Acknowledgements
• Dr. Patrick McMahon
• Dr. Richard Debski
• MSRC
• Department of Bioengineering, University of Pittsburgh
