隨著高齡社會的來臨使得照護需求快速增長，但同時全世界勞動人口下降，屆時將會有不足的照護人力，而輔具將會是協助高齡人口生活不可或缺的工具。輪椅床為了無行動能力者設計的輔具，此輔具可以滿足使用者躺姿、坐姿和移動，目前市面上的輪椅床機構可以分為馬達驅動及手動調整床板角度。電動輪椅床雖然方便調整坐姿，但價格昂貴且笨重，不利於一般民眾；而手動輪椅床有著輕巧的機身，但機構設計較為複雜，且較為費力。
因此，本研究將提出一種新型省力輪椅床機構設計，透過創意性機構設計方法(Creative Mechanism Design)設計史蒂芬森六連桿的輪椅床轉換機構，並且利用幾何約束程式(Geometric Constraint Programing)設計機構尺寸，接著進行力學、位能分析。本研究提出兩種省力方法，其一為利用單一彈簧和凸輪輪廓設計一靜力平衡機構；第二種為使用氣彈簧(gas spring)的省力機構，減少輪椅床機構姿勢轉換所需使用的力量。最後建立機構實體圖進行Adams機構軟體模擬，並製作原型機驗證輪椅床機構可行性。本研究完成兩個原型機製作，其一為縮小版靜力平衡機構原型機，結果顯示此機構在任意位置皆能處於平衡狀態；另一個為氣彈簧輪椅床原型機，經過測試原型機在安裝氣彈簧前後施力峰值對峰值的力量減少68%。

With the global aging society growth, assistive technology has important implications in supporting the aging population in institutions and at home. However, the advancement of healthcare systems is still facing enormous challenges related to the shortage of medical and human resources. Wheelchair-bed is an assistive device for patients who suffer from physical impairments and disabilities by providing them the opportunity to perform normal activities of daily living, such as lying down, sitting up, and movement. According to the power source, wheelchair-beds can be classified into two types, i.e., electric motor-driven and manual-operating types. In comparison with the motor-driven types, manual-operating wheelchair-beds are more advantageous in terms of lightweight structure and cost-effectiveness. However, current manual-operating wheelchair-beds require great human efforts and input forces for conducting their functions.
This research thesis aligns directly with the development of assistive devices by proposing an innovative mechanism design based on a Stephenson six-bar linkage for yielding a manual-operating wheelchair-bed. The mechanism architecture is created by using the Creative Mechanism Design (CMD) methodology, and its dimension is derived from Geometric Constraint Programing (GCP). For reducing the actuation forces (or torques) of the six-bar mechanism, this study then introduces two energy-saving methods: one uses an extension spring with a cam-follower to achieve a perfect static balancing, and the other one uses a single gas spring to realize a partial static balancing. The static balancing performance of these two designs was verified by MSC Adams and validated through experimental tests. The experimental results showed that the combination of a cam-follower and an extension spring could make the proposed six-bar mechanism perfectly balanced in any working positions. On the other hand, implementing a gas spring to a wheelchair-bed based on the proposed six-bar mechanism could produce a peak-to-peak force reduction of 68% during operation.

[1] 國家發展委員，2018，"中華民國人口推估"。
[2] He, W., Goodkind, D., and Kowal, P. R., 2016, An aging world: 2015 International Population Reports. U.S. Government Printing Office.
[3] Yang, L. "Innovative Hospital Bed Transform Wheelchair By Lirong Yang." https://homemydesign.com/2017/innovative-hospital-bed-transform-wheelchair-by-lirong-yang/.
[4] "CNS 15390 國家輔具分類標準"， https://newrepat.sfaa.gov.tw/home/cns15390。
[5] "【Panasonic 愛吉福立】樂休移離床輔助電動床"， https://www.furoto.com.tw/album_d.php?lang=tw&tb=1&id=24。
[6] "康陽潛隨挺502"， https://www.karma.com.tw/featured_item/km-5000-2/。
[7] "強生醫療儀器有限公司 澎澎123"， https://www.just4u.tw/products/ponpon123-2017。
[8] Duncan, J. H., 1926, "Convertible bed and chair," United States, Patent No. US1581994A.
[9] David, L. J., 1936, "Convertible bed and chair," United States, Patent No. US2034985A.
[10] Balluff, R. E., 1952, "Combination wheel chair and bed," United States, Patent No. US2607929A.
[11] Larrick, C. M., 1953, "Hospital bed convertible to chair," United States, Patent No. US2656876A.
[12] Piazza, S. J., 1964, "Bed-wheelchair," United States,
[13] Macdonald, B. R., 1966, "Convertible hospital bed-chair," United States, Patent No. US3239853A.
[14] Peck, W. H., 1989, "Hospital bed convertible to chair," United States, Patent No. US4862529A.
[15] Luther, H. M., 1994, "Wheelchair/gurney," United States, Patent No. US5333887A.
[16] 陳彥銘，2017，"一種利用彈簧靜平機構設計之電腦椅"，碩士論文，製造科技研究所，國立臺北科技大學，台北市。
[17] 邱仕融，2014，"具移床功能之輔具設計"，碩士論文，機械與機電工程學系研究所，國立中山大學，高雄市。
[18] Herder, J. L., 2001, Energy-free Systems. Theory, conception and design of statically. Ph.D. dissertation, University of Technology Delft, Delft, The Netherlands.
[19] Deepak, S. R. and Ananthasuresh, G. K., 2012, "Static balancing of a four-bar linkage and its cognates," Mechanism and Machine Theory, vol. 48, pp. 62-80.
[20] Lin, P.-Y., Shieh, W.-B., and Chen, D.-Z., 2009, "Design of Perfectly Statically Balanced One-DOF Planar Linkages With Revolute Joints Only," Journal of Mechanical Design, vol. 131, no. 5.
[21] Cui, M., Wang, S., and Li, J., 2015, "Spring gravity compensation using the noncircular pulley and cable for the less-spring design," in Proceedings of the 14th IFTOMM World Congress, Taipei, Taiwan, pp. 25-30.
[22] Chu, Y.-L. and Kuo, C.-H., 2017, "A single-degree-of-freedom self-regulated gravity balancer for adjustable payload," Journal of Mechanisms and Robotics, vol. 9, no. 2, p. 021006.
[23] Bijlsma, B. G., Radaelli, G., and Herder, J. L., 2017, "Design of a Compact Gravity Equilibrator With an Unlimited Range of Motion," Journal of Mechanisms and Robotics, vol. 9, no. 6, p. 061003.
[24] Tseng, T.-Y., Lin, Y.-J., Hsu, W.-C., Lin, L.-F., and Kuo, C.-H., 2017, "A novel reconfigurable gravity balancer for lower-limb rehabilitation with switchable hip/knee-only exercise," Journal of Mechanisms and Robotics, vol. 9, no. 4, p. 041002.
[25] Gosselin, C. M. and Wang, J., 2000, "Static balancing of spatial six-degree-of-freedom parallel mechanisms with revolute actuators," Journal of Robotic Systems, Article vol. 17, no. 3, pp. 159-170.
[26] van Dorsser, W. D., Barents, R., Wisse, B. M., and Herder, J. L., 2007, "Gravity-Balanced Arm Support With Energy-Free Adjustment," Journal of Medical Devices, vol. 1, no. 2, pp. 151-158.
[27] Kuo, C.-H. and Lai, S.-J., 2015, "Design of a Novel Statically Balanced Mechanism for Laparoscope Holders With Decoupled Positioning and Orientating Manipulation," Journal of Mechanisms and Robotics, vol. 8, no. 1, p. 015001.
[28] Phu, N. M. and Lee, G. S., 2014, "Characteristics of pressure and force considering friction in a closed cylinder with a holed piston," Journal of Mechanical Science and Technology, vol. 28, no. 6, pp. 2409-2415.
[29] Yan, H.-S. and Chiu, Y.-T., 2015, "On the number synthesis of kinematic chains," Mechanism and Machine Theory, vol. 89, pp. 128-144.
[30] 顏鴻森，2013，機械裝置的創意性設計，東華書局。
[31] Kinzel, E. C., Schmiedeler, J. P., and Pennock, G. R., 2005, "Kinematic Synthesis for Finitely Separated Positions Using Geometric Constraint Programming," Journal of Mechanical Design, vol. 128, no. 5, pp. 1070-1079.
[32] De Leva, P., 1996, "ADJUSTMENTS TO ZATSIORSKY-SELUYANOV'S SEGMENT IN ERTIA PARAMETERS," Journal of Biomechanics, vol. 29, no. 9, pp. 1223-1230.
[33] DICTATOR, "Advice for Calculating and Selecting the Right Gas Spring." [Online]. Available: https://en.dictator.de/.
[34] Camloc Motion Control, "Technical guide-Edition 1.2 Gas Spring Overview".