Biaxial Testing Apparatus
Project Manager
Reverse Shoulder Arthroplasty (RSA) restores the range of motion for patients with significant shoulder damage. Presence of dissociation at component interfaces of an RSA can be disastrous, therefore, a testing apparatus is to be developed.
A biaxial testing apparatus is to be developed to perform and reconfigure between two test setups – a displacement test and a cyclic test.
My role included overseeing all phases of design, manufacturing, and testing. Specifically, I utilized Agile-Kanban management software to ensure the project was meeting the client's deadlines. In addition, I led all design reviews with the client and head machinist to receive constructive feedback. To do so, I actively participated in all CAD and assisted with machining and fabrication.
Final Assembly Design
Displacement Test
The initial test performed on each sample with the following loads:
Transverse shear load of 350 N
Compressive load ranging from 430-650 N
Cyclic Test
The continuous test to simulate the rocking motion with the following loads:
Compressive load of 750 N
Continuous cyclic articulation from 45-60 degrees for 10,000 cycles
Sub-Mechanism Design
Spring Mechanism
Applies compressive load within the displacement test.
Spring compressed via a Delrin nut
Adjustable axial load ranging from 430 - 650 N via standoffs
A slotted bottom plate for adjustability
Oscillatory Mechanism
Sub-assembly that performs continuous cyclic articulation.
Controlled via a stepper motor and gearbox
Cradle-like design
Oscillates for 10,000 cycles from 0-60 degrees
Testing Pot Mechanism
The testing pot holds each reverse prosthetic component sample.
Secures and centers the reverse prosthetic glenoid component
Two adjustable side plates in the horizontal axes
L-plate is secured diagonally, via a set screw
Analysis and Testing
To analyse our apparatus through different stages of design, both hand calculations and Finite Element Analysis (FEA) were utilised.
Hand calculations were mainly used to determine design parameters; additionally, FEA was used to ensure that the current design could withstand all applied loads.
I played a predominant role in all FEA analysis.