Hazards | Initial risk level | Solution | Final risk level | |||||||
---|---|---|---|---|---|---|---|---|---|---|
LOa | FEb | DPHc | HRd | LO | FE | DPH | HR | |||
(a) Excessive torque is applied to the ankle, causing foot pain when the machine is working | 5 | 5 | 0.5 | 12.5 | Mechanically restrict the maximum pneumatic force (ISO 13482) | 0.5 | 5 | 0.5 | 1.25 | |
(b) The foot is moved more than the natural ankle range of motion when the machine is working | 5 | 5 | 0.5 | 12.5 | Use a mechanical limiter to restrict the range of motion of the machine’s moving part | 0.1 | 5 | 0.5 | 0.25 | |
(c) The user tries to reach a controller placed away from the body and falls, causing pain in the fixed ankle | 2 | 5 | 0.5 | 5 | Use a remote controller that can be operated by hand | 0.1 | 5 | 0.5 | 0.25 | |
(d) The foot is fixed in a non-relaxed posture owing to machine malfunction | 1 | 5 | 0.5 | 2.5 | Install a function to move the foot back to a relaxed posture | 0.1 | 5 | 0.5 | 0.25 | |
(e) The stop button does not work correctly | 0.5 | 5 | 0.5 | 1.25 | Install an emergency stop button to block the input voltage of the air-regulator | 0.1 | 5 | 0.5 | 0.25 |