Assessment of Robotic Patient Simulators for Training in Manual Physical Therapy Examination Techniques

Abstract

Robots that simulate patients suffering from joint resistance caused by biomechanical and neural impairments are used to aid the training of physical therapists in manual examination techniques. However, there are few methods for assessing such robots. This article proposes two types of assessment measures based on typical judgments of clinicians. One of the measures involves the evaluation of how well the simulator presents different severities of a specified disease. Experienced clinicians were requested to rate the simulated symptoms in terms of severity, and the consistency of their ratings was used as a performance measure. The other measure involves the evaluation of how well the simulator presents different types of symptoms. In this case, the clinicians were requested to classify the simulated resistances in terms of symptom type, and the average ratios of their answers were used as performance measures. For both types of assessment measures, a higher index implied higher agreement among the experienced clinicians that subjectively assessed the symptoms based on typical symptom features. We applied these two assessment methods to a patient knee robot and achieved positive appraisals. The assessment measures have potential for use in comparing several patient simulators for training physical therapists, rather than as absolute indices for developing a standard.

Clasp-Knife Model of Muscle Spasticity for Simulation of Robot-Human Interaction

“…Increase in muscle tone, commonly presented in subject with motor impairment, is generally rooted from muscle spasticity and rigidity upon passive mobilization [6]- [11]. Spasticity is a phenomenon that contributes to the increase in muscle tone proportional to the velocity of passive mobilization, whilst rigidity or resistance contributes to the increase in muscle tone due to hypertonia [3], [7], [9]- [11]. However, muscle tone increment does not develop linearly.…”

“…Throughout the passive mobilization, a spike in moment feedback may occur at a certain angular position. This spike is described as the catch phase [6], [11]- [15]. Additionally, a release phase is presented post catch phase, generating a form of sudden drop in muscle tone before slowly stabilizing as it approaches the maximum functional range of motion (ROM) [6], [9], [14]- [17].…”

“…A simulation model is necessary to replicate the standard pattern of each MAS and its responses upon passive mobilization. A thorough research has been done to understand the gross kinematics and dynamics of the extremity for different MAS level [6], [11], [12]. However, the simulation model presented in [10], [11] was formulated from kinematic response of induced motion, rather than from the moment response of the muscle.…”

“…The clasp-knife phenomenon is indistinguishable in the simulation model presented in [12] without the jerk effect in the gross kinematics and dynamics. Nevertheless, the presented methodology of muscle tone model by [11], [12] requires a simpler form of features extraction compared to the methodology presented by [16], which necessitates electromyogram (EMG) signal extraction. Thus, an improvised simulation model from the same basis as [10], [11] was necessary to replicate the muscle tone pattern of subject according to MAS criterion, whilst fulfilling the condition required for the simulation studies of robotic assisted training platform interaction.…”

Development of a novel massage platform for medical training

“…Saverio Farsoni from the University of Ferrara designed an ultrasound training system to provide high-quality training scenarios to improve the effectiveness of ultrasound education [20]. Shun Ishikawa from Nagoya University developed a training robot that helps therapists perform manual examinations of human joints [21]. The robot allows students to touch and feel real human bodies, thereby providing a perception of the complex movements of the joints and bone of the human body.…”