6–自由度上肢康复机包括手腕使用器18609.pdf

1、 Proceedings of the IEEE International Conference on Mechatronics & Automation Niagara Falls, Canada July 2005 0-7803-9044-X/05/$20.00 2005 IEEE A 6DOF Rehabilitation Machine for Upper Limbs including Wrists Using ER Actuators Junji Furusho, Chengqiu Li and Yuhei Yamaguchi Graduate school of Enginee

2、ring Osaka University 2-1 Yamadaoka, Suita, Osaka, Japan furushomech.eng.osaka-u.ac.jp Shinya Kimura, Kenji Nakayama Takaya Katuragi and Takamichi Oguri Graduate school of Engineering Osaka University 2-1 Yamadaoka, Suita, Osaka, Japan Ushio Ryu and Sadami Suzuki Asahi Kasei Engineering Co., Ltd. Ko

3、hnan 4-chome, Minatoku, Tokyo, Japan Akio Inoue ER tec Co., Ltd. 2-1-31, Sakuragaoka, Minoo, Osaka, Japan AbstractNew training methods and exercises for upper limbs rehabilitation are made possible by application of robotics and virtual reality technology. The technologies can make quantitative eval

4、uations and enhance the qualitative effect of training. This paper deals with the development of a 6-DOF rehabilitation machine for upper limbs including wrists using ER actuators ”Robotherapist”. Index TermsRehabilitation System, Upper Limb Rehabili- tation, Wrist Rehabilitation, Robotics, ER Actua

5、tor I. INTRODUCTION Movements of the upper limbs, such as eating and oper- ating appliances are complicated, various and indispensable for daily activities. It therefore is important for the aged to exercise to keep their upper limb function. Moreover, there are many patients of paralysis caused by

6、stroke. For example, in Japan more than two hundred and fi fty thousand people have stroke every year, and many of them are paralyzed. The human brain is capable of an extraordinary degree of plasticity (self-organization), enabling learning, and leaving open the possibility for motor recovery1. The

7、refore, neuro- rehabilitation for stroke-patients is effective. The physical therapy involves one-on-one interaction with a therapist who assists and encourages the patient through a number of repetitive exercises. A robotic therapist can eliminate unnecessary exertion by the therapist, quantitative

8、ly monitor patient progress, and ensure consistency in planning a therapy program. The percentage of aged persons in society and their number are increasing, and their physical deterioration has become a social problem in many countries. Early detection of function deterioration and suffi cient reha

9、bilitation training are necessary, not only to decrease the numbers of aged who are bedridden or need nursing care, but also to enable the aged to take an active part in society. Using apparatus that applies robotic technology and vir- tual reality makes new training methods and exercises in This wo

10、rk is supported by New Energy and Industrial Technology Development Organization (NEDO) under the Ministry of Economy, Trade and Industry of Japan rehabilitation possible2, 3. Feeding back the quantitative evaluations to the training by a computer can enhance the qualitative effect of training. Ther

11、efore, some rehabilitation systems using these technologies for upper limbs have been developed. However, most of them apply training within a two-dimensional horizontal plane. Many movements, how- ever, in daily activities need to move arms in a vertical direction. A system therefore that enables e

12、xercise in three- dimensions would seem to be more effective for such train- ing. Although the MIME system 3 using PUMA-560 by VA and Stanford Univ. can give training in three-dimensions, the PUMA-560 is a robot originally developed for industrial use and may not be suffi ciently safe to train the a

13、ged and/or disabled. Furusho, et al. of Osaka University developed two types of 2-DOF force display systems using ER actuators4, 5, 6, and have carried out clinical trials of rehabilitation for upper limbs 6. In these systems, ER actuators ensure the mechanical safety. Then, Osaka University and Asa

14、hi Kasei Group joined the 5-year NEDO Project and developed a 3-D rehabilitation apparatus for upper limbs based on this knowledge5. Then, we conducted the clinical evaluation at Hyogo Medical college7. In the rehabilitation system developed in the 5-year NEDO Project, the wrist of the rehabilitatio

15、n machine is not driven by actuators and rotate freely. So, the proper rehabilitation for upper limbs including wrists can not be attained. Krebs, et al. of MIT developed a wrist robot8 for rehabilitation, and then have developed a 5-DOF rehabilitation system consisting of MIT-MANUS2 and this wrist

16、robot9. In this paper, we present the development of a 6-DOF rehabilitation machine for upper limbs including wrists using ER actuators in a project for the Practical Application of Next Generation Robots. This machine will be exhibited at the 2005 International Exposition held in Aichi Prefecture,

17、Japan. 1033 Input Rotational Cylinder ER Fluid Electric Field Motor Output Rotational Cylinder Output Torque Input Torque Fig. 1.Conceptual Illustration of ER Actuator Fig. 2.Multi-cylindrical-type ER Actuator with Output Torque in Both-Rotational-Directions Fig. 3.Multi-cylindrical-type ER Clutch I

18、I. ER ACTUATORS ER fl uid is a fl uid whose rheological properties can be changed by applying an electrical fi eld10. Fig. 1 shows the conceptual illustration of an ER fl uid actuator. The ER actuator is composed of an ER clutch and its drive mechanism consisting of a motor and a reduction-gear-unit

19、. The rotational speed of the motor is kept constant. The output torque of ER actuator is controlled by the applied electric fi eld. The sectional view of ER actuator which is capable of producing output torque in both directions are given in Fig.2. The input rotational parts of Fig.2 (Part I and Pa

20、rt II) possess cylindrical structure. The input rotational PartI is rotated clockwise through a gear by an electric motor, and the input rotational Part II is rotated counterclockwise through a series of gears by the same motor. The input torque is transferred to the rotating cylindrical section of

21、the output axis via the particle-type ER fl uid fi lled in the rotating cylinder. Both the input axis cylinders and the output axis cylinder serve as electrodes, and output torque is controlled by the electric fi eld applied between the electrodes. The output cylinder is made of aluminum alloy in or

22、der to reduce the moment of inertia of the output axis. Fig.3 shows a ER clutch with cylindrical structure. An actuator using ER fl uid is effective for human- coexistent mechatronics systems like rehabilitation systems Fig. 4.Human-Machine-Coesistent-Mechatronics (HMCM) System using ER Actuators Fi

23、g. 5.Rehabilitation System NIOH-1 Fig. 6.Rehabilitation System NIOH-2 for upper limbs 4. Fig. 4 shows a conceptual illustration of Human-Machine-Coexistent-Mechatronics (HMCM) System using ER Actuators. Merits of ER actuators in applications to Human-Machine-Coexistent-Mechatronics (HMCM) system are

24、 as follows: 1) From the Viewpoints of the Characteristics of Opera- tion: (a) Since ER actuators have good back-drivability, the operator can easily operate HMCM system from its end-effector. (b) When HMCM system is driven by the operator from its end-effector, HMCM system can be moved quickly over

25、 the rotational speed of the input cylinder of the ER clutch. 2) From the Viewpoints of Performances in Force Display System: (a) Quick force response property originated from the low inertia property of ER actuator and the rapid response of ER fl uid make the force presentation with high fi delity

26、possible. (b) Force display systems with large-force presentation ability can be realized safely. 1034 Fig. 7.Passive-type Force Display System Fig. 8.EMUL in Rehabilitation III. REHABILITATION ANDFORCEDISPLAYSYSTEMS USINGER FLUIDS Furusho Lab. of Osaka University has been developing rehabilitation

27、systems and force display systems using ER fl uids since 199311. Fig. 5 shows the 2-DOF rehabilitation systems ”NIHO-1” using ER actuators shown in Fig. 24, 12. The rehabilita- tion training system was installed in a hospital for testing purpose. 13 patients volunteered to participate in several exp

28、eriments for evaluation of upper limbs physical capability and for rehabilitation training. The patients suffered from arm paralysis due to a damaged spinal cord or clogged brain artery. Fig. 6 shows the 2-DOF rehabilitation system ”NIHO- 2” using ER actuators shown in Fig. 35, 13. Fig. 7 shows a pa

29、ssive force display using ER brakes14. Passive force displays using brakes to present resistance force against operators force are quite safe14, 15. Furusho Lab. is going to examine a passive force display on rehabilitation for upper limbs. Fig. 8 shows the 3-D rehabilitation system for upper limbs

30、using ER actuators (EMUL)7. EMUL was developed in a 5-year NEDO project, and evaluated for stroke-patients by using Fugel-Meyer assessment16, Motricity Index17, and Ueda Stage18 in the clinical testing. The good results were obtained in the evaluation. Fig. 9.Hand-grip of EMULFig. 10.Drawing of the

31、1st Prototype Fig. 11.Movement of Link 2 IV. THE1STPROTOTYPE OF6-DOF REHABILITATION SYSTEM Fig. 12.Movement of Link 3 In the 3-DOF rehabilitation system (EMUL), the proper rehabilitation for upper limbs including wrists can not be attained since EMUL has the free-rotation wrist as shown in Fig. 9. S

32、o, we have developed a 6-DOF machine using ER actuators in a project for the Practical Application of Next Generation Robots. In this chapter, we present the develop- ment of the 1st prototype machine using servo motors. Fig. 10 shows drawings of the 1st prototype machine. The mechanism of the proto

33、type machine is as in the following. 1) It has 2-DOF the horizontal rotation and 1-DOF for the vertical movement in the arm part. 1035 Fig. 13.Wrist Part and Link 3 of the 1st Prototype Fig. 14.Side View of the Link 3 2) Actuators and belt-pulley-reduction systems for the arm motion are set on the b

34、ase in order to reduce the inertia of the moving parts. The vertical rotation part adopts a parallel link mechanism consisting of link 2(1) and link 2(2) as shown in Fig. 10. This makes the gravity- effect compensation by counter-balance weight in all posture possible (see Fig. 11). 3) Link-3 driven

35、 by the spatial link mechanism rotates in the horizontal plane as shown in Fig. 12. 4) Actuators for the wrist motion are mounted on link 1 in order to reduce the inertia of the moving parts. The motor torques are transmitted to the wrist by using universal joints, driving shafts, and wire-pulley sy

36、stem (see Fig. 13). 5) Fig. 14 shows the wire-pulley system for the wrist. Fig. 15 shows the pathways of wires for roll, pitch, yaw, (a) Roll(b) Pitch Fig. 15.Wires for Roll, Pitch and Yaw Rotation (c) Yaw Fig. 16.Twist of Wire-rope Fig. 17.The 6-DOF Rehabilita- tion System ”Robotherapist” Fig. 18.E

37、R Actuator respectively. 6) The roll motion of the wrist causes the relative rotation between the part A and the part B of Fig. 14. As the result of this relative rotation, the driving wires for the pitch and yaw motions are twisted as shown in Fig.16. In order to reduce the variation of wire length

38、 caused by this roll motion, these wires are placed near the roll axis as possible. V. 6-DOF REHABILITATIONMACHINE ”ROBOTHERAPIST” Fig. 17 shows a photo of ”Robotherapist”. This system is driven by ER actuators. Fig. 18 shows the ER actuator for the arm motion. The mechanism of the grip handle and t

39、he wrist was changed to the cantilever-type from the both- Fig. 19.Wrist Part of ”Robotherapist” 1036 Fig. 20.Composition of 6-DOF Rehabilitation System Fig. 21.Construction of Wrist Part side-support-type. Fig. 19 shows the mechanism of the grip handle and the wrist. Fig. 20 shows the conceptual il

40、lustration of the total system. The gravity composition is required in the cantilever-type grip handle, as shown in Fig. 21. When we adopt such mechanism, the weight near the grip handle increases, and the performance as a force display system and the safety property as Human-Machine-Coexistent-syst

41、em are deteriorated. So, we placed the balance weight in the ER actuator box as shown in Fig. 22. We are developing rehabilitation training software which requires the dexterity of upper limbs including wrists. Fig. 23, Fig. 24 and Fig. 25 show a part of training software. Fig. 22.Arrangement of bal

42、ance weight Fig. 23.Virtual Hitting Fig. 24.Virtual SprinkleFig. 25.Virtua Wipe VI. CONSIDERATION ABOUTSAFETY A rehabilitation system for upper limbs which has large working area can be regarded as a kind of robots. In such a human-coexistent robot system where an operator must be in contact with or

43、 close to the robot, the safety-securing system is necessary in order that an operator can use the robot safely19. In industrial robots, an operator cannot access a robot except for teaching in order to avoid hazardous conditions. Fig.26 shows the structure of safety in human- coexistent robots. ER

44、actuators have the following merits from the viewpoint of safety. (a) The maximum driving speed of the output shaft of the ER actuator is restricted by the rotational speed of the input shaft of the ER clutch. Therefore, when the rotational speed of the input shaft is set slow, HMCM systems using ER

45、 actuators are safe for operators. (b) The inertia of the output part can be made very small. So, in the case of unexpected accidents, the impact force caused by the inertia of the actuator can be reduced. Since International Safety Standards for human-coexistent robots have not been established yet

46、, we have no other choice but to use the ISO and domestic standards for machines working close to human beings (see Table I). The developed rehabilitation system can assure these standards of Table I by the usage of ER actuators and the mechanical design as follows: 1 The items (a) and (b) of Table

47、I are satisfi ed by setting the rotational speed of the input cylinder slow. 2 The item (c) is satisfi ed by using a 60-watt motor for the drive of the input rotational cylinder. 3 Risk Reduction by Design (item (d) is realized by mechanical limitation of each joint, mechanical gravity- compensation

48、 and the usage of ER actuators. Safety from the viewpoint of Information Safety from the viewpoint of Control Safety from the viewpoint of Mechanism and Actuators Safety from the viewpoint of Operation Condition Fig. 26.Structure for Securing Safety in Human-Coexistent Robots VII. CONCLUSIONS We hav

49、e developed a 6-DOF rehabilitation machine for upper limbs including wrists as in the following. 1) The 1st prototype machine using servo motors was developed for the purpose of confi rming a novel mech- anism for the rehabilitation system. 1037 TABLE I INTERNATIONAL ANDDOMESTICSAFETYSTANDARDS (a) E

50、nd-effector Speed is less than 0.25 m/s ISO10218:Manipulating industrial robotsSafety (b) Low Energy PropertyISO14121:Safety of machineryPrinciples of risk as- sessment (c) Actuator Power is less than 80 W JAPAN, JIS B 8433, 1983.:General Code for Safety of Industrial Robots (d) Risk Reduction by De

51、signISO12100:Safety of machineryBasic conceptsCgen- eral principles for design 2) Then, the 6-DOF rehabilitation machine for upper limbs including wrists using ER actuators ”Robothera- pist” has been developed based on the knowledge ob- tained from the development of the prototype machine. 3) we are

52、 developing the rehabilitation software upper limbs including wrists at present. REFERENCES 1 Carr, Janet, and Roberta Shepherd, Neurological Rehabilitation: Opti- mizing Motor Performance, Butterworth-Heinemann, Boston, 1998. 2 H. I. Krebs, B. T. Volpe, M. L. Aisen, and n. Hogan, ”Increasing produc

53、- tivity and quality of care : Robot-aided neuro rehabilitation,”Jurnal of Rehabilitation reseach and development, vol. 37, no.6,pp.639652,2000. 3 C. G. Burgar, P.S.Lum, P. C. Shor, and H. M. V. der Loos, ”Devel- opment of robots for rehabilitation therapy : The palo alto va/stanford experience,” Ju

54、rnal of Rehabilitation Reseach and Development, vol. 37, no.6, pp.663673, 2000. 4 J. Furusho and M. Sakaguchi, ”New actuators using ER fl uid and their applications to force disply devices in virtual reality and medical treat- ments,” Proc. of the International Conferance on Electro-Rheological Flui

55、ds, Magneto-Rheological Suspensions and their Applications, 755- 763, 1997 (Int. J. of modern physics B, vol.13, no. 14,15&16, pp.2151- 2159, 1999). 5 J. Furusho, K. Koyanagi, U. Ryu, A. Inoue, and K. Oda, ”Development of rehabilitation robot system with functional fl uid devices for upper limbs,”In

56、ternational Journal of Human-friendly Welfare Robotic System, vol. 32, no .6, pp.23-27, 2003. 6 J. Furusho, ”Mechatronics system using ER fl uids (review paper),”J. of Japan Hydraulics and Pneumatic Society,vol. 32, no .6, pp.390-395, 2001,(In Japanese) 7 J. Furusho, K. Koyanagi, Y. Imada, Y. Fujii, K. Nakanishi, K. Domen, K. Miyakoshi, U. Ryu, S. Takenaka, A, Inoue, A 3-D Rehabilitation system for Upper Limbs Developed in a 5-year NEDO Project and its Clinical Testing, ICORR2005, in press. 8 J. Celestino, H.