Human factors considerations of Interaction between wearers and intelligent lower-limb prostheses: a prospective discussion

Table 1 A summary of the evaluation components of wearer-LLP interaction

	Direct Wearer-LLP Interaction		Indirect Wearer-LLP Interaction through UCIs
	Definition	Example evaluation methods	Definition	Example evaluation methods
Efficiency	Required mental efforts and demands from walking with the device	NASA-TLX [62]; EEG [63]; fNIRS [64]; AVF [65]; Pupillometry [66]; Skin conductance [67]	Time and effort needed to complete the tuning task	Tuning duration [68]; Lostness [69]
Use Error	Insufficient understanding of system behavior	Self-report, expert judgments [70]	Improperly tuning the parameters that make the device less safe to use	Step-by-step analysis [71]; Expert judgments [72]
Learnability	Speed of learning and improvement over time	Walking performance over time	Speed of learning and improvement over time	Performance over time [68]
Memorability	—*		Re-establishment of the knowledge	Knowledge of the UCI after some time [68]
Satisfaction	The subjective feeling of whether the LLP has fulfilled the needs	TAPES [73]; PEQ [74]; PEmbS-LLA** [75]; Think-aloud [76]	The subjective feeling of whether the interface is pleasant to use	SUS** [77]; interview; Think-aloud [76]

*The memorability criterion is less applicable to human-machine interaction in walking and thus not discussed here
**Note: NASA-TLX = NASA Task Load index; EEG = Electroencephalogram; fNIRS = Functional Near-infrared Spectroscopy; AVF = Attentional Visual Field; TAPES = Trinity Amputation and Prosthesis Experience Scales; PEQ = Prosthesis Evaluation Questionnaire; PEmbS-LLA = Prosthesis Embodiment Scale for Lower Limb Amputees; SUS = System Usability Scale

ISSN: 1743-0003