Assistive Multi-Purpose Mobility Device with Folding Temporary Seat A Major Qualifying Project Proposal Submitted to the Faculty of WORCESTER POLYTECHNIC INSTITUTE in partial fulfillment of the requirements for the Degree of Bachelor of Science by _________________________ Xinping Deng _________________________ Daniel Haley _________________________ Taylor Roseen Date: 4/30/15 Approved: ______________________________ Professor Allen H. Hoffman, Co-Advisor ______________________________ Professor Holly K. Ault, Co-Advisor Abstract Crutches and canes are widely used around the world as a means of providing stability and support for those who need them; the elderly population in particular utilizes these devices the most. There are numerous products on the market that attempt to add a seat to the crutch or cane in an effort to alleviate the stress of standing for too long. However, these products are oftentimes too cumbersome, heavy, or just simply unsafe. The goal of this project is to design and build a device that can be used as either a crutch or a cane that gives stability and helps support the weight of the user while standing and walking, additionally offering the ability for the user to rest comfortably and safely in a seated position when necessary. A first generation prototype was successfully manufactured using an existing forearm crutch and machined aluminum and steel components. The prototype underwent load and dimension tests in addition to students conducting overall usability tests. i Table of Contents Abstract .......................................................................................................................................................... i 1.0 Introduction ............................................................................................................................................. 1 2.0 Background ............................................................................................................................................. 2 2.1 Canes ................................................................................................................................................... 2 2.1.1 Purpose ......................................................................................................................................... 2 2.1.2 Ergonomics/Types ....................................................................................................................... 3 2.1.3 Demographic ................................................................................................................................ 4 2.1.4 Problems with Canes on the market ............................................................................................. 5 2.2 Crutches .............................................................................................................................................. 5 2.2.1 Purpose ......................................................................................................................................... 5 2.2.2 Types ............................................................................................................................................ 6 2.2.3 Demographics .............................................................................................................................. 8 2.2.4 Problems with Crutches on the market ........................................................................................ 8 2.3 Assistive Devices in the Medical Industry .......................................................................................... 9 2.4 Commercially Available Cane and Crutch Seats .............................................................................. 10 2.4.1 Cane/ Crutch with Seat .............................................................................................................. 10 2.4.2 Useful Cane/Crutch Designs ...................................................................................................... 12 2.5 Functional Limitations of Mobility Device Users ............................................................................ 13 2.6 Patents ............................................................................................................................................... 14 2.6.1 Collapsible cane and crutch construction ................................................................................... 14 2.6.2 Collapsible sectional Lofstrand type crutch ............................................................................... 16 2.6.3 Length Adjustable Crutch .......................................................................................................... 18 2.6.4 Crutch ......................................................................................................................................... 20 2.6.5 Telescopic and Foldable Crutch structure .................................................................................. 21 2.6.6 Ergonomic collapsible crutch ..................................................................................................... 22 2.6.7 Combined seat and walking-cane .............................................................................................. 24 2.6.8 Folding Stool .............................................................................................................................. 25 2.6.9 Seat suspended between crutches .............................................................................................. 26 3.0 Design Specifications ............................................................................................................................ 28 3.1 List of Design Specifications ............................................................................................................ 28 ii 3.1.1 Functional/Performance of Device ............................................................................................ 28 3.1.2 Operating Characteristics ........................................................................................................... 29 3.1.3 Operating Requirements ............................................................................................................ 30 3.1.4 Safety ......................................................................................................................................... 30 3.1.5 Reliability and Maintenance ...................................................................................................... 31 3.1.6 Human Factors ........................................................................................................................... 32 3.1.7 Cost ............................................................................................................................................ 33 3.1.8 Manufacturability ....................................................................................................................... 33 3.1.9 Durability ................................................................................................................................... 34 4.0 Preliminary Designs .............................................................................................................................. 35 4.1 Design 1 (Angled Leg Design) ......................................................................................................... 35 4.2 Design 2 (Umbrella Design) ............................................................................................................. 37 4.3 Design 3 (Slotted Shaft Design)........................................................................................................ 39 4.4 Design 4 (Kickstand Design) ............................................................................................................ 42 5.0 Preliminary Static Analysis for Designs ............................................................................................... 45 5.1 Kickstand Design .............................................................................................................................. 45 5.1.1 Problems with Kickstand Design ............................................................................................... 46 5.2 Slotted Shaft Design ......................................................................................................................... 47 5.3 Angled Leg Design ........................................................................................................................... 52 5.4 Umbrella Design ............................................................................................................................... 54 6.0 0th Order prototype ................................................................................................................................ 57 6.1 Kickstand .......................................................................................................................................... 57 6.2 Umbrella ........................................................................................................................................... 59 6.3 Angled Leg Design ........................................................................................................................... 61 7.0 Pairwise Comparison ...........................................................................................................................