Severity Table

Severity Table
Rating	Severity of Effect	Consequence	Treatment
Critical	Re-injury of the wound; fracture	Reversible injury	Hospital stay
Serious	Gash or severe muscle injury	Reversible injury	Ambulant treatment or self-treatment
Minor	Pressure marks, small cuts or scratches	Discomfort	Self-treatment
Negligible	No harm	–	–

Occurrence Table

Occurrence Table
Rating	Probability of Occurrence
Often	Likely to happen
Occasionally	Can happen, but not likely
Rarely	Unlikely to happen
Improbable	Highly unlikely to happen

RPN Table

		Severity
		Negligible	Minor	Serious	Critical
Probability	Often	R1	R2	R3	R3
	Occasionally	R1	R1	R2	R3
	Rarely	R1	R1	R1	R3
	Improbable	R1	R1	R1	R2

R1 – Acceptable Risk

R2 – As Low As Reasonably Practical

R3 – Unacceptable Risk

Hazard and Risk Assessment Spreadsheet + Mitigation

Hazard	Hazard Event	Harm	Severity	Occurence	Total Risk	Root Cause	Mitigation
Pinching between components	Skin caught in joint or strap	Pain, redness, bruising	Minor	Rarely	R1	Poor strap design	Cover exposed hinges, use soft padding
Ankle sprain	Joint is torqued beyond normal range	Bruising, ligament damage, pain	Serious	Occasional	R2	Potential software issues, or device failure	Addition of hard stop, clutch , and manual shutoff prevents continual torque beyond desired range
Electrical shock	Skin contact with electrical components	Small burns, muscle twitching	Minor	Rarely	R1	Skin contact with electronics	House major electronic components
Heat from electronics	Skin contact electrical components	Potential for 2nd to third degree burns	Serious	Occasional	R2	Overheating of electrical components	All major electrical components are housed, insulated, and properly ventilated; device power consumption does not exceed 50% of potential device draw to avoid excess heat output from electronics
Ankle Sprain	Joint is contorted uncontrolled beyond the acceptable range	Pain, Bruising, potential ligament and cartilage damage	Serious	Improbable	R1	Device failure to constrain lateral motion	Device is used within design range for weight and activity intensity to avoid frame level failures
Tightening/Strap Failure	Strap/ratchet mechanism used to tighten the device comes undone while in use	Sudden loss of support and risk of ankle injury	Serious	Rarely	R1	Improper fastening	Include clear fastening instructions, implement periodic inspection by clinicians for wear
Battery Failure (if going in powered system direction)	Battery dies while device is in use	Sudden loss of power may result in  ankle motion that is not normal	Minor	Occasional	R1	Low battery capacity or poor charge monitoring	Add battery-level indicator, low-battery notifications, and fail-safe default settings
Tripping Hazard	Things protruding out of the device or cables catching on things/clothes	Fall, sprains, bruising	Serious	Rarely	R1	Inefficient design, loose cables	Aim for minimal profile, route cables internally