Exoskeleton Robotic arm to help with rehabilitation
Through a research at Tokyo Institute of Technology which has been funded by NEDO (New Energy and Industrial Technology Development Organization), Professor Hideyuki Tsukakoshi has developed a prototype robotic arm device which is name “Tail-wrist-II”. Tail-wrist-II is a wearable robotic arm which is designed to help patients with the rehabilitation effort away from hosiptal confinment. The rehabilitation effort is targeted toward hemiplegic or bedridden patients or the elderly who can not move the joints as a result of prolong staying in bed which causes a secondary symptom such as contracture of muscles and the economy-class syndrome. Normally to overcome and prevent this symptom hospitals provide programs that include a range of motion exercises by physical therapists and use of CPM devices (Continuous Passive Motion). However use of CPM devices causes a heavy burden to some patient especially the ones with brain disorders. This is due to the facts that CPM devices are heavy and expensive and their fitting procedures are complicated. Finally the CPM devices postion control method. Tail-Wrist-II was desined to address all these issues by making it lighter and easy to fit and operate so the patients can continue their rehabilitation program away from hospital at the comfort of home. Even if the device is used by patients who are suffering from brain disorder there is no risk of injuries to these patients such as damage to their joint due to joint movement in an unintended direction. To prevent such situation the device absorbs the patient’s force directed against the movement of the device. Tail-Wrist-II is a helical and flat wearable actuator using resin tubes. Due to reduced use of metal components in its deisng is very light. The way the movement inducing works in “Tail-wrist-II,” is that elongation force of four actuators located in the forearm area is converted to the wire tensile force to create two-degree-of-freedom turning movements. The movement is flexible and does not place undue stress on the wrist. In addition to this the device is accompanied by “Fit-band,” a fitting band that automatically grasps and fixes the patient’s body to the device with a push of a button. This will enable paralyzed patients to wear the device without difficulty. This was made possible by using the characteristics of a flat tube which its cross section shape changes to a circular shape when its inner pressure is increased. There are series of flat tubes that are positioned on the band where the band changes its shape from a belt to a cylinder when it is inflated. If the patient decide to shift his/her weight while moving the joints, the grasping force will be controlled by a valve which is equiped with a sensor to keep a constant grasping force. The device is still a long way to its commertialization. But an effort is on the way for its clinical testing through collaboration between hospital and the university. This research originally inteneted for rehabilitation of wrist joint but it can easly be extende to leg joints as well. On the way to its commertialization effort there is a plans to enhance the technology so that it can be used for rehabilitation at home in combination with remote operations by hospitals via the Internet. I can’t wait to see the commertialized version of this product, I also hope there will be more collaboration in this area from companies such as Honda and Panasonic in its further development due to their Robotic technology know how. I really think this type of effort in introducing robotic technology as an Excoskeleton in merits at least far exceeds the development of the robotic servents or pets which most of us can do without.