Identification of Relevant ISO Standards
We identified ISO standards applicable to the knee brace's intended function and design to guide the testing process. These include:
- ISO 13485: Quality management for medical devices
- ISO 7250: Body measurements for ergonomic design
- ISO 11193: Specifications on material durability and safety
- ISO 10328: Structural testing for lower-limb orthotic devices
- ISO 10993: Biocompatibility testing for medical device materials
Each test ensures that the knee brace complies with these standards, covering all user safety, comfort, and reliability aspects.
ISO Testing Compliance Plan for Rehabilitative Knee Brace
This testing plan is developed to ensure that the rehabilitative knee brace design complies with ISO standards relevant to medical devices, orthotic supports, and rehabilitation equipment. The primary objectives are to verify the knee brace's structural integrity, user comfort, durability, and safety. The brace is tested under simulated and physical conditions to assess its ability to withstand daily usage and environmental factors.
The following sections outline the tests designed to verify compliance, which are divided into physical and simulated tests on SolidWorks. Each test addresses a specific aspect of ISO compliance.
Simulated Testing on SolidWorks
We will simulate key stressors in SolidWorks to complement physical testing, offering early validation and design insights.
Static Load Simulation
Purpose: Virtually test the knee brace's ability to bear static loads.
Method: Apply compressive forces in SolidWorks to model the weight-bearing capacity.
Expected Outcome: No permanent deformation in structural elements.
Fatigue Analysis (Cyclic Loading)
Purpose: Simulate repeated load cycles to predict long-term wear.
Method: Run fatigue simulations on the hinge, applying repetitive stress over simulated cycles.
Expected Outcome: Low degradation, with minimal signs of wear.
Pressure and Stress Distribution Simulation
Purpose: Verify even distribution of stress across contact areas.
Method: Simulate applied forces, observing stress patterns on the brace's surface.
Expected Outcome: Even distribution to prevent discomfort.
Physical Tests
Durability and Load-Bearing Tests
The knee brace's ratchet hinge and support structure must withstand repeated use without compromising functionality. I have planned the following tests to validate durability and load-bearing capacity:
Cyclic Loading Test
Purpose: Simulate the repetitive knee flexion and extension during daily activities.
Method: Subject the hinge mechanism to 10,000 loading cycles, mimicking long-term usage and identifying potential wear points.
Expected Outcome: Minimal wear or degradation in the hinge with no structural failures.
Static Load Test
Purpose: Test the brace's ability to support an average user weight (up to 100 kg).
Method: Apply a static load to the hinge and support elements to simulate body weight.
Expected Outcome: No visible deformation or cracking, confirming sufficient load-bearing capacity.
Biocompatibility Test (ISO 10993)
Purpose: Ensure materials in contact with the skin are non-toxic and hypoallergenic.
Method: Test the biocompatibility of the straps and pads, focusing on potential allergic reactions.
Expected Outcome: No adverse skin reactions, indicating materials are suitable for prolonged use.
Corrosion Resistance Test (ISO 10271)
Purpose: Assess the durability of metallic components in humid environments.
Method: Expose the ratchet hinge to controlled humidity for 72 hours to simulate sweat and environmental moisture.
Expected Outcome: No signs of corrosion, ensuring longevity and functionality in varied conditions.
Hinge Functionality Test
Purpose: Verify the reliability of the hinge's locking and unlocking mechanism.
Method: Operate the hinge through 1,000 cycles, monitoring for jamming or degradation.
Expected Outcome: Smooth engagement and hinge release without sticking or wear.
Torque Testing
Purpose: Measure the force needed to lock and unlock the ratchet hinge, ensuring it is user-friendly.
Method: Test the torque required to operate the hinge, simulating user interactions.
Expected Outcome: The torque remains within ergonomic limits, allowing easy use and safe operation.