Limits...
Robot-assisted arm assessments in spinal cord injured patients: a consideration of concept study.

Keller U, Schölch S, Albisser U, Rudhe C, Curt A, Riener R, Klamroth-Marganska V - PLoS ONE (2015)

Bottom Line: We investigated whether a set of robot-based assessments that encompasses kinematic, kinetic and timing metrics is applicable, safe, reliable and comparable to clinical metrics for measurement of arm motor function.In conclusion, the therapy robot ARMin provides a comprehensive set of assessments that are applicable and safe.The methods applied and results can serve as a basis for the future development of end-effector and exoskeleton-based robotic assessments.

View Article: PubMed Central - PubMed

Affiliation: Sensory-Motor Systems Lab, Department of Health Sciences and Technology ETH Zurich, Zurich, Switzerland; Balgrist University Hospital, University of Zurich, Zurich, Switzerland.

ABSTRACT
Robotic assistance is increasingly used in neurological rehabilitation for enhanced training. Furthermore, therapy robots have the potential for accurate assessment of motor function in order to diagnose the patient status, to measure therapy progress or to feedback the movement performance to the patient and therapist in real time. We investigated whether a set of robot-based assessments that encompasses kinematic, kinetic and timing metrics is applicable, safe, reliable and comparable to clinical metrics for measurement of arm motor function. Twenty-four healthy subjects and five patients after spinal cord injury underwent robot-based assessments using the exoskeleton robot ARMin. Five different tasks were performed with aid of a visual display. Ten kinematic, kinetic and timing assessment parameters were extracted on joint- and end-effector level (active and passive range of motion, cubic reaching volume, movement time, distance-path ratio, precision, smoothness, reaction time, joint torques and joint stiffness). For cubic volume, joint torques and the range of motion for most joints, good inter- and intra-rater reliability were found whereas precision, movement time, distance-path ratio and smoothness showed weak to moderate reliability. A comparison with clinical scores revealed good correlations between robot-based joint torques and the Manual Muscle Test. Reaction time and distance-path ratio showed good correlation with the "Graded and Redefined Assessment of Strength, Sensibility and Prehension" (GRASSP) and the Van Lieshout Test (VLT) for movements towards a predefined position in the center of the frontal plane. In conclusion, the therapy robot ARMin provides a comprehensive set of assessments that are applicable and safe. The first results with spinal cord injured patients and healthy subjects suggest that the measurements are widely reliable and comparable to clinical scales for arm motor function. The methods applied and results can serve as a basis for the future development of end-effector and exoskeleton-based robotic assessments.

No MeSH data available.


Related in: MedlinePlus

Example RPM plot for elbow flexion (60°/s) of two patients (A and B).The black dotted line shows the torque progression measured during the assessment. The blue dash-dotted line is the data from the calibration routine without the patient. The cyan dashed line is the estimated torque progression of the patient’s joint. The red line is the linear least square fit for the patient’s joint torques. The movement in the left picture was rated a 2 on the Tardieu scale. The movement on the right example was rated a 0 on the Tardieu scale. The measured stiffness by the robot assigned 0.93 Nm/rad to the left and 0.84 Nm/rad to the right movement.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4440615&req=5

pone.0126948.g007: Example RPM plot for elbow flexion (60°/s) of two patients (A and B).The black dotted line shows the torque progression measured during the assessment. The blue dash-dotted line is the data from the calibration routine without the patient. The cyan dashed line is the estimated torque progression of the patient’s joint. The red line is the linear least square fit for the patient’s joint torques. The movement in the left picture was rated a 2 on the Tardieu scale. The movement on the right example was rated a 0 on the Tardieu scale. The measured stiffness by the robot assigned 0.93 Nm/rad to the left and 0.84 Nm/rad to the right movement.

Mentions: Only one single patient showed a Tardieu and/or Ashworth Scale value higher than 0 (for shoulder extension, internal rotation, elbow flexion, supination and wrist extension), all other patients had no clinically detectable spasticity. Therefore, no further statistical analysis was possible to calculate the correlations. An example for RPM is shown in Fig 7. It represents both the elbow flexion data of a patient with a Tardieu score of 2 and a patient with a Tardieu score of 0.


Robot-assisted arm assessments in spinal cord injured patients: a consideration of concept study.

Keller U, Schölch S, Albisser U, Rudhe C, Curt A, Riener R, Klamroth-Marganska V - PLoS ONE (2015)

Example RPM plot for elbow flexion (60°/s) of two patients (A and B).The black dotted line shows the torque progression measured during the assessment. The blue dash-dotted line is the data from the calibration routine without the patient. The cyan dashed line is the estimated torque progression of the patient’s joint. The red line is the linear least square fit for the patient’s joint torques. The movement in the left picture was rated a 2 on the Tardieu scale. The movement on the right example was rated a 0 on the Tardieu scale. The measured stiffness by the robot assigned 0.93 Nm/rad to the left and 0.84 Nm/rad to the right movement.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4440615&req=5

pone.0126948.g007: Example RPM plot for elbow flexion (60°/s) of two patients (A and B).The black dotted line shows the torque progression measured during the assessment. The blue dash-dotted line is the data from the calibration routine without the patient. The cyan dashed line is the estimated torque progression of the patient’s joint. The red line is the linear least square fit for the patient’s joint torques. The movement in the left picture was rated a 2 on the Tardieu scale. The movement on the right example was rated a 0 on the Tardieu scale. The measured stiffness by the robot assigned 0.93 Nm/rad to the left and 0.84 Nm/rad to the right movement.
Mentions: Only one single patient showed a Tardieu and/or Ashworth Scale value higher than 0 (for shoulder extension, internal rotation, elbow flexion, supination and wrist extension), all other patients had no clinically detectable spasticity. Therefore, no further statistical analysis was possible to calculate the correlations. An example for RPM is shown in Fig 7. It represents both the elbow flexion data of a patient with a Tardieu score of 2 and a patient with a Tardieu score of 0.

Bottom Line: We investigated whether a set of robot-based assessments that encompasses kinematic, kinetic and timing metrics is applicable, safe, reliable and comparable to clinical metrics for measurement of arm motor function.In conclusion, the therapy robot ARMin provides a comprehensive set of assessments that are applicable and safe.The methods applied and results can serve as a basis for the future development of end-effector and exoskeleton-based robotic assessments.

View Article: PubMed Central - PubMed

Affiliation: Sensory-Motor Systems Lab, Department of Health Sciences and Technology ETH Zurich, Zurich, Switzerland; Balgrist University Hospital, University of Zurich, Zurich, Switzerland.

ABSTRACT
Robotic assistance is increasingly used in neurological rehabilitation for enhanced training. Furthermore, therapy robots have the potential for accurate assessment of motor function in order to diagnose the patient status, to measure therapy progress or to feedback the movement performance to the patient and therapist in real time. We investigated whether a set of robot-based assessments that encompasses kinematic, kinetic and timing metrics is applicable, safe, reliable and comparable to clinical metrics for measurement of arm motor function. Twenty-four healthy subjects and five patients after spinal cord injury underwent robot-based assessments using the exoskeleton robot ARMin. Five different tasks were performed with aid of a visual display. Ten kinematic, kinetic and timing assessment parameters were extracted on joint- and end-effector level (active and passive range of motion, cubic reaching volume, movement time, distance-path ratio, precision, smoothness, reaction time, joint torques and joint stiffness). For cubic volume, joint torques and the range of motion for most joints, good inter- and intra-rater reliability were found whereas precision, movement time, distance-path ratio and smoothness showed weak to moderate reliability. A comparison with clinical scores revealed good correlations between robot-based joint torques and the Manual Muscle Test. Reaction time and distance-path ratio showed good correlation with the "Graded and Redefined Assessment of Strength, Sensibility and Prehension" (GRASSP) and the Van Lieshout Test (VLT) for movements towards a predefined position in the center of the frontal plane. In conclusion, the therapy robot ARMin provides a comprehensive set of assessments that are applicable and safe. The first results with spinal cord injured patients and healthy subjects suggest that the measurements are widely reliable and comparable to clinical scales for arm motor function. The methods applied and results can serve as a basis for the future development of end-effector and exoskeleton-based robotic assessments.

No MeSH data available.


Related in: MedlinePlus