Shota Miyaguchi

Impedance control of CPM device with flex-/extension and pro-/supination for upper limbs

Continuous Passive Motion (CPM) is a surgical treatment or physiotherapy after surgery or trauma. Most of the CPM devices used for treatment of the elbow joint have one degree of freedom in flex-/extension. For this reason, the patients are limited in pro-/supination of the forearm with flex-/extension of the elbow joint according to the arm movement of the CPM device. In this paper, a novel impedance control scheme of pro-/supination is proposed for CPM device with flex-/extension and pro-/supination. Impedance control is designed for the reference trajectory measured from a normal subject, and the parameters for impedance control are designed in order to suppress the excessive force at the limitation of range of motion. The effectiveness of the proposed scheme is evaluated by experiments.

On effective movement in CPM for shoulder joint

Continuous passive motion (CPM) is an orthopedic treatment or physiotherapy method that promotes recovery of impaired joints, and is tried to apply for treatment of the shoulder joint disorders. The shoulder joint has a complex structure, where the inner/outer rotation torque of the shoulder joint varies due to ad-/abduction angle. Wrong ad-/abduction angle causes the excessive inner/outer rotation torque of the shoulder joint, and aggravates joint disorders. So, it is required to adjust suitably the ad-/abduction angle to suppress the inner/outer rotation torque. In this paper, the ad-/abduction motion that suppresses the inner/outer rotation torque is clarified. The variation of the inner/outer rotation torque due to ad-/abduction angle is analyzed in experiments with fixed ad-/abduction. From the experiments, we clarify the ad-/abduction motion suppressing the inner/outer rotation torque. To realize the clarified ad-/abduction motion, we developed the CPM device that has two d.o.f with the inner/outer rotation and the ad-/abduction. Finally, the experiment with the CPM device is performed in order to confirm that this motion is effective to suppress the excessive inner/outer rotation torque of the shoulder joint.

Control scheme of two d.o.f. CPM device to suppress the extension of ligament of the elbow

Abstract Continuous passive motion (CPM) is an orthopedic treatment or a physiotherapy and has been applied after surgery. After surgery for the injured ulna collateral ligament (UCL) which is a major clinical case in the elbow joint, the reaction force at the hand of the patient increases and may be excessively large due to an increase of the joint stiffness. For this, it will be effective to reduce the excessive reaction force by controlling pro-/supination of forearm. The UCL in the elbow joint is extended due to pro-/supination of forearm, but the excessive extension may aggravate the injury of the UCL. Thus, it is required to suppress both the excessive extension of the UCL and the reaction force. In this paper, a control scheme of CPM device that can suppress both the excessive extension of the UCL and the reaction force is proposed, and its effectiveness is confirmed from the experimental results.

Impedance control of pro-/supination based on the skeleton model of upper limbs

Continuous passive motion (CPM) is an orthopedic treatment or physiotherapy method after surgery or injury by external continuous force. In CPM for the elbow joint, it is effective to reduce an excessive reaction force from a subject by controlling pro-/supination of forearm. The ulna collateral ligament in the elbow joint is extended due to pro-/supination of forearm, and it appears that extension of the ligament aggravate contracture disorders. Thus, it is required to suppress the excessive extension of the ligament. In this paper, an impedance control which suppress the excessive extension of the ligament due to the pro-/supination of CPM device is proposed, and the trajectory of extension of the ligament while CPM training with proposed controller is clarified by skeleton model.

Impedance control of CPM device with flex-/extension an pro-/supination of upper limbs

Continuous passive motion (CPM) is an orthopedic treatment or physiotherapy after injury or operation. Most of CPM devices used for treatment of the elbow joint have one degree of freedom in flex-/extension. This causes that the patients are limited in pro-/supination of the forearm with flex- /extension of the elbow joint due to the movement of CPM device. In this paper, a novel impedance control scheme of pro- /supination is proposed for CPM device with flex-/extension and pro-/supination. Impedance control is designed for the reference trajectory measured from normal subject, and the parameters for impedance control are determined in order to suppress the excessive force at the end of the range of motion. The effectiveness of the proposed scheme is evaluated by experiments.

Impedance Control of Two d.o.f CPM Device for Upper Limb Disorders

Abstract Continuous passive motion (CPM) is an orthopedic treatment or a physiotherapy and is tried to apply after surgery for the injured radial collateral ligament (RCL) in the elbow joint. After the surgery, the reaction force at hand of the patient increases due to an increase of the joint stiffness and may be excessively large. For this, it is effective to reduce the excessive reaction force by controlling pro-/supination of forearm. Also, the RCL in the elbow joint is extended due to pro-/supination of forearm, and the extension may aggravate the injury of the RCL. Thus, it is required to suppress both the excessive extension of the RCL and the reaction force. In this paper, a novel impedance control of CPM device that can suppress both the excessive extension of the RCL and the reaction force is proposed.