CHAPTER 3 BINGHAMTON UNIVERSITY Thomas J. Watson School of Engineering and Applied Science Department of Mechanical Engineering Binghamton, NY 13902-6000 Principal Investigator: Richard S. Culver (607)777-2880 rculver.bingtjw.cc.binghamton.edu

28 NSF 1995 Engineering Senior Design Projects to Aid the Disabled

Swing-Aid: An Articulated Frame For Moving Between A Wheelchair And A Car Designer: Richard Venable Supervising Pr@ssor: Richard Culver Mechanical Engineering Department Binghamton University Binghamton, NY 13902-6000

INTRODUCTION Swing-Aid is an articulated arm that assists in transferring a person from a wheelchair into a four-door sedan automobile. It consists of a bracket and lifting post, called the standard, attached to the B pillar of the car, an inner link which can be raised relative the standard, an outer link, and a liftframe that is attached to the user by a harness. The liftframe is attached to the outer link at a point slightly above the user’s center of gravity, which permits the user to be tipped in order to clear the doorframe while being loaded into the car. (Figure 3.1)

SUMMARY OF IMPACT Milrene is a lively, middle-aged woman with multiple sclerosis. She is entirely dependent upon Mary, her aide, for transfer into and out of her wheel chair. Mary places Milrene on her shoulder and picks her up. This is particularly difficult when moving into or out of an automobile. Since Milrene does not own a car, she is dependent upon friends for transportation. The Swing-Aid is made for people such as Milrene. It requires only the replacement of two hinge bolts to convert a regular car for its use. It is small enough to fit easily in the trunk of a car. It’s simple, light-weight design makes it easy for an average person to install and its projected cost of about $500 is within the budget of people who cannot afford an expensive specially-designed vehicle. The prototype is currently being field-tested by Milrene and Mary.

TECHNICAL DESCRIPTION

The Swing-Aid consists of an articulated steel cantilever arm mounted on the car door frame. The user rides in a cloth sling attached to a liftframe suspended from the end of the arm. The arm consists of two links. The inner link hinges on and rotates around an upright structural member, the standard, which fastens to the car doorframe. The outer link is attached by hinges to the inner link. The two hinged links provide sufficient maneuverability to move between a wheelchair placed beside the car and the front passenger seat. Horizontal movement is accomplished through manual manipulation of the links by an aide.

Figure 3.1. Loading with the Swing-Aid.

Vertical lift is accomplished by a threaded rod and crank integrated into the standard. The standard consists of two telescoping tubes. The inner tube bears on the ground and has a threaded nut welded to its top end. The outer tube is part of the inner link and is connected to the threaded rod and crank. The frame is raised and loared by rotating the threaded rod in the nut. This arrangement causes the force of the

Chapter 3: Binghalmton University 29

Figure 3.2. Geometry of the Swing Aid. lifted load to be transmitted directly to the ground, instead of the car. A small thrust bearing attached to the bottom of the inner tube allows the inner link to rotate freely when loaded. (Figure 3.2) The Swing-Aid is designed specifically for four-door sedans, since they are the most common form of car. The rear door hinge bracket bolts (which are visible on most four-door cars when the front door is open) provide a secure base for mounting the arm assembly. To install the Swing aid, two of the existing rear door hinge bracket bolts are replaced with bolts with special heads. During use, a mounting bracket is attached to the car using these special bolts. A tube attached to the bracket surrounds the outer tube of the standard. The mounting bracket opposes the bending moment on the arm when loaded, yet allows the arm to translate vertically and rotate around a vertical axis for lifting. We are currently investigating alternative anchoring systems for other vehicle body types. (Figure 3.3) A special liftframe/sling assembly is used to accommodate the limited space for movement through most car door frames. To enter a car, people normally bend at the waist and duck their heads. Standard sling systems for most lifting devices are attached at head level which will not accommodate this motion. The Swing-Aid‘s liftframe attaches to the outer link through a pivoting sleeve at a point slightly above the

users center of gravity. Thus, the aide can easily tip the user backwards to permit head clearance while moving through the door frame. The liftframe, which is made from 1” O.D. plastic pipe, spreads the attachment points for the supporting sling to hold the body in a seated position and avoid pinching. (Figure 3.4) To load a user with the Swing-Aid, a sling made of 2inch webstrap and quick-release hooks is placed on the wheelchair seat and the user is seated on it. (Figure 3.5) The liftframe is then positioned directly over the user’s torso and thighs. The hooks are then connected to the rails of the liftframe and the straps adjusted for fit. The liftframe is then connected to the outer link of the swing arm, and lifting begins by rotating the crank. Then clear of the wheel chair, the aide rotates the user so that her back faces the door frame. She is tipped backward until her head clears the frame and she is moved into the car. Next, she is loared into the seat, the hooks are removed from the liftframe and it swings clear. The anchoring bolts for the bracket are released and the entire swing aid is removed. It may be folded as a single unit or disassembled for storage in the trunk.

30 NSF 1995 Engineering Senior Design Projects to Aid the Disabled The Swing-Aid is intentionally designed to require complete removal before the car door can be closed. Are it anchored in place while the car is in motion, it might break loose in a crash, creating a severe hazard to people in the car.

The cost of building the prototype was approximately $500, including a substantial cost for commercial machining and welding. Development is ongoing. A patent has been applied for. We fully expect SwingAid to be produced commercially and expect it to sell for about $500.

Figure 3.3. Swing Aid Anchoring System.

I Chapter 3: Binghamton University 31

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Figure 3.4. Liftframe Schematic.

Figure 3.5. Harness for Liftframe.

b

32 NSF 1995 Engineering Senior Design Projects to Aid the Disabled

Wheel Chair Simulator Designers: Duane Holze, Tomas Pino, Crystal Heshma t, Chris tina Engels Client Coordinator: Virginia Rodner Broome Development Center Supervising Prqfkssor: Dr. Richard Culver Binghamton University Binghamton, NY 13902

INTRODUCTION A wheel chair simulator has been built which permits rapid adjustment of seat contour for clients with special seating needs. The simulator was built on a frame of a tilt-in-space wheel chair. The depth and height of the seat, as well as the angle between seat and back, are adjustable. Foot supports are also adjustable. Cushions made from rubber .bags filled with styrene beads, placed on the seat and back, can be evacuated to hold the contour once the therapist has established the optimum configuration. A plaster mold of the bead bags contour can be used to guide an NC mill which produces the final foam cushion. Vacuum is pulled on the bead bags by a modified fish tank pump.

SUMMARY OF IMPACT Jesse has severe scoliosis and requires a specially configured chair seat for his wheel chair in order to sit comfortably. Two possible solutions are considered. First, to make a flexible seat which will directly conform to Jesse’s back and hold its shape for a limited period of time. Second, to make a mold of Jesse’s back and send the mold to a manufacturer who will machine a foam block to the proper configuration. In both cases, an adjustable chair with a formable cushion is required. Commercially available wheel chair simulators cost over $3,000. The low cost version made in this project can be used either to make the pattern for the plaster mold, or it can serve as a temporary seat for Jesse, allowing the therapist to evaluate his optimum support geometry over several days.

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Figure 3.7. Schematic of Seat Frame.

TECHNICAL DESCRIPTION

Figure 3.6. Wheel Chair Simulator Frame.

The base of the wheelchair simulator is a tilting frame wheel chair. On to this frame, a sliding track was built which accommodates a vertical frame to hold the back. The track is made of 1.5” wide, “C” shaped

Chapter 3: Binghamton University 33 aluminum channel. Plates on the base of the vertical frame, with knob shaped threaded anchors, move on the tracks to adjust the depth of the seat according to the length of the client’s upper leg. The vertical frame also has an angle adjustment that permits the angle between seat and back to be changed. Horizontal slats of differing widths slide into “C” shaped channels in the vertical frame, permitting variation of the back height from 8 to 18 inches. Spacers can be placed between the slats in order to allow adjustment access to the bead bag from behind the simulator. The various angles of adjustment are shown in Figures 3.8 and 3.9.

The bead bags are purchased from Pindot for $200. Twenty pounds of small styrene beads are contained in a rubber bladder, which is attached by hose to a vacuum pump. In operation, the bead bags are placed loosely on the frame and the back height, angle and depth are set on the frame. Next, the client is placed on the bead bags and a gentle vacuum is pulled on the bags, sufficient to make them formable, but not sufficient to make them rigid. The bags are then formed around the client to achieve the desired geometry. Then a full vacuum is pulled on the bags to fix the beads in place. With the client removed, plaster-soaked gauze is laid on the contoured rubber bead bags and allowed to set. Sufficient layers are built on the bead bag frame to create a rigid mold of the seat contour. This mold is then used as the pattern for a CNC mill that cuts the final seat cushions from foam blocks. The vacuum pump is made from a Dynamaster II fish tank pump. Valves are reversed in order to convert it to pull a vacuum instead of pumping water. The pump was mounted in a box with control valves that allows independent control of the vacuum in the bags on the seat and the back. 3/S” I.D. Tygon tubing was used to connect the pump to the bead bags. The cost of the simulator as constructed is as follows:

Figure 3.8. Schematic of Simulator Showing Potential Adjustments.

Figure 3.9. Simulator Foot Support.

wheel chair frame donated by BDC fish tank vacuum pump

$45

Bead Bags

$200

Miscellaneous parts and structural materials

$100

34 NSF 1995 Engineering Senior Design Projects to Aid the Disabled

Modified Mountain Bike For Cerebral Palsy Child Designers: Justin Lis, Eric Strq%, JflSchake, Steve Bodine Client Coordinator: Rachael Wolgemuth Handicapped Children’s Association Supervising Pr@ssor: Dr. Richard S. Culver Department ofMechanical Engineering Binghamton University Binghamton, New York 13902-6000

INTRODUCTION Keith, a fourteen year-old boy with cerebral palsy, lives in a rural neighborhood with rough roads. The tricycle he has used for transportation is now too small and does not work well on uneven surfaces. To increase Keith’s mobility and allow him to travel with his peers, a mountain bicycle has been modified to provide adequate support so that he can ride on rmeven pavements. (Figure 3.10) The modifications include: out-rigger wheels to provide lateral stability, wide seat with hip support to hold him on the bicycle, shortened cranks, and foot straps on the pedals to hold feet in proper alignment. The outriggers, which weigh about 5 pounds each, can be removed to facilitate transportation. The ldinch outboard wheels have special quick release hubs to permit easy removal. The outrigger frames are mounted to the bicycle frames by hinges and are spring loaded to accommodate an uneven surface in the manner of shock absorbers. A wide seat, commonly used on stationery

Figure 3.10. Outriggers.

exercise bicycles, is used to provide better support. A bracket, attached to the rear frame holds a standard car seat belt at an angle that holds the rider on the seat and prevents sliding off the seat to the front or the side. The pedal cranks have been shortened so that the rider does not have to move his legs so far. Straps, attached to the pedals, have Velcro connectors to hold the rider’s feet in proper alignment on the pedals.

SUMMARY OF IMPACT For years, Keith has ridden a tricycle when playing with his siblings and as a means of transportation, which is more practical than his limited walking ability. He was teased about his tricycle and as it wore out and became too small, he requested that he be given a “real“ bike. In order for him to ride on the bike, he would need additional hip and back bracing, a means to secure his feet to the pedals, a system to provide lateral stability, handle bar alignment which

Chapter 3: Binghamton University 35 would allow him to sit upright, and a low crossbar to facilitate mounting. A mountain bike with a low crossbar was purchased and provided for the B.U. students to modify.

TECHNICAL DESCRIPTION

Outriggers - The major modification to the bike was the installation of outriggers. As shown in Figure 3.11, a frame was mounted to the back of the bike made from 1/4”xl” steel bar. The outriggers, made from l/16” sheet steel are attached to the frame by standard door hinges. Each outrigger is attached through a spring-loaded arm to the top of the frame, so that the wheel can move up or down when it hits a rough spot in the road. The springs are preloaded to about 20 pounds to insure vertical alignment under normal riding. With no load on the seat, the back wheel is supported about 2” off the floor by the side wheels. Universal connectors are used on the ends of the spring-loaded arm and the front stabilizer bar to allow free rotational motion of the total rotating assembly. The front stabilizing bar, which withstands loads from frontal impact on the support wheel, was added when preliminary tests on the bike found that the support wheels bent outward rather than riding up over obstructions. The stabilizing bar increased the resisting moment arm from 3” to 11” and insured stable operation.

Seat - Keith has to be lifted on to the bicycle and strapped in before he can ride in order to insure that he does not fall off the seat or have his feet slip off the pedals. He can now hold his back upright sufficiently that he does not require lateral back support. Therefore, the seat modification consists of a low back support plate made from 0.093” Lexan, which is attached to the seat post and is supported by the seat. An aircraft type seat belt is used to hold Keith in the seat and prevent him from sliding off sideways. Earlier versions with side support made entry into the seat difficult.

Crank and Pedal - Keith wears braces on his ankles which prevent flexure. To permit him to turn the crank, it was necessary to reduce the crank swing. New holes are drilled in the cranks, shortening the radius by 2 inches. The line of action for cranking runs straight up the anklebone instead of the normal position through the ball of the foot. The pedal support is based on a standard toe clip that is mounted on a 3-inch spacer to place Keith’s foot in the right position. Lexan tabs attached to a rear extension block complete the alignment structure. Straps secured with Velcro hold the foot to the pedal. (See Figure 3.12)

Figure 3.12. Crank and Pedal. Although students did most of the design, construction was performed by the university technical staff because of the safety implications of the bicycle. The materials for the modifications cost approximately $300. The wheels and hubs cost nearly $200. The bicycle was provided by Keith’s parents.

Figure 3.1 1. Mountain Bike Seat.

36 NSF 1995 Engineering Senior Design Projects to Aid the Disabled

An Arm Support/Restraint For Clients With Parkinson’s Disease Junior Designers: Paul Kondrat, Christopher Kopec, Scott Pecullan Client Coordinator: Ed Krukowski Broome Development Center Supervising Prq%sor: Dr. Richard Culver Binghamton University Binghamton, NY 13902

INTRODUCTION An arm support has been built for a client at Broome Development Center with Parkinson’s disease. The arm support designed controls arm and wrist tremors to facilitate simple operations such as eating, consists of a shaft with friction-loaded ball-and-socket joints at either end. The bottom ball is welded to a short post that is attached to a table mount. The top ball is welded to a second post connecting the support to an arm plate. The plastic arm plate is molded to the shape of the client’s arm. Straps attached to the arm plate are wrapped around the client’s arm to stabilize it. The friction in the arm support sockets restrains the arm, controlling tremors while allowing a full range of motion.

SUMMARY OF IMPACT Because of tremors and uncontrolled motion, many individuals with Parkinson’s disease cannot perform what most people would consider routine tasks such as feeding. Constant aid must be administered by therapists and personal caregivers. By providing increased control of hand and arm motion, the arm support makes simple actions possible, thereby increasing personal independence and self esteem.

TECHNICAL DESCRIPTION The shaft of the arm support consists of two parallel plates, 5.0x1.0 inches, made of 16 gage 6061-T6 aluminum. The plates have 0.75~inch holes in each end that support two 1.0~inch diameter steel balls, forming two ball and socket joints. Screws press the plates against the two balls, permitting an adjustable level of drag on the two ball-and-socket joints. The bottom ball is welded to a short, 3/S-inch diameter post that is threaded to screw into a table mount. The top ball is welded to a second post connecting the support to an arm plate. The arm plate is made of a 0.125 inch thick PVC, thermo-plastic material which has been heated and molded to the shape of the client’s arm. A rubber boot surrounds the parallel plates for safety. Shock absorbing straps, made of 1.5 inch wide woven nylon, are attached to the bottom of the mold and are wrapped around the client’s arm and held in place with Velcro connectors. Approximate cost of arm support is $40, including the cost of commercial welding.

Chapter 3: Binghamton University 37

Spherical Ball Joints

/ G Base Bolted to Desktop