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Table 2 Summary of possible performance metrics that could be used in assessment tasks and fun therapy tool [41]

From: Potential of a suite of robot/computer-assisted motivating systems for personalized, home-based, stroke rehabilitation

Assessment Category

Metric Name

Definition

Remark

Range of Motion (ROM)

ROM Area Ratio

The ratio of the area size of user capability space to the input device work space.

Reflects the user's Movement Range in the range [0, 1]; ideally this value should be close to 1.

Discrete Tracking

Reaction Time

The time from the jump of the target to the first significant movement by subject.

Reflects the human machine system response Capability (Reaction quickness).

 

Movement Time

The time between the end of the reaction time to the time after the human subject stayed within the target stably.

Reflects the Movement Quickness.

 

Movement Speed

Movement speed is the average speed within the movement time window.

Reflects the Movement Quickness in the movement time window.

 

Error

The average distance from the target position to the subject position.

Reflects overall performance Accuracy.

 

Deviation

The average distance from the subject position to straight target path line.

Reflects Movement Curvature. This metric is for Joystick only.

 

Peak Speed Number

The number of peaks in the speed profile within the movement time window.

Fewer PN represent fewer periods of acceleration and deceleration, making a more Smoothness movement.

 

Dwelling Percentage Time in Target

The percentage of time subject staying in the target during the dwell window period.

The metric is in the range [0, 1]; ideally this value should be close to 1.The higher value indicates a better Stability performance.

Continuous Tracking

Percentage Time on Target

The percentage time the human subject staying within the target

Reflects overall performance Accuracy and Stability.

 

Root Mean Square Error

The squared root of the mean-squared distance from subject position to the target position.

Reflects movement Accuracy.

 

Average Deviation

The average deviation distance from the subject position to straight target path line.

Reflects Movement Curvature. This metric is for Joystick only.

System Identification

Perturbation Range

The movement range of the human subject in the perturbation direction.

Depends on the instruction to human subject. In case "holding" instruction, the bigger value

 

Perturbation Standard Deviation

The standard deviation value of the human subject position in the perturbation direction.

indicates weak Strength; in case "relax" instruction, the bigger value indicates less Muscle Stiffness.

Fun Therapy

ROM Intensity Image

The human subject ROM movement image with the high intensity indicates intensive human movement area.

Reflects Movement Range and Intensity without overwhelming with movement data when task context is unknown.

 

Motivation Score

Used as a multidimensional assessment tool to evaluate subjects' subjective experience related to a target activity in laboratory experiments

Reflects Motivation