Authors Joel Rotroff Ben Moga Tom Pearce Hani Bou-Reslan BME 402 April 30th, 2004

National Student

Design Competition:

Wheelchair Platform

Device

Advisor Mitch Tyler Department of Biomedical Engineering Clients Frank Fronczak Department of Biomedical Engineering & Jack WintersJohn Enderle National Design Student Competition

Abstract Hospitals and clinics require a method to provide elevation and rotation to wheelchair patients. Currently there is no existing device that is capable of providing this movement. The goal of this project is to create a transportable platform that is capable of lifting the wheelchair and its occupant 3 to 9 in. above ground level and provide 360  rotation. The device needs to be controlled by either the patient or doctor.

Problem Statement It can be difficult for wheelchair patients to be positioned for diagnosis. A platform device is desired that enables wheelchair users access to health care procedures. The device should have two-degrees of freedom (rotation of 360° and vertical translation from 3-9 in. above the floor). It should be motorized, transportable, easy to use, and safe.

Background Designed for health care setting: Designed for health care setting: dentist’s office dentist’s office hospital hospital No existing device No existing device Closest examples allow only for vertical translation Closest examples allow only for vertical translation $2000 grant awarded $2000 grant awarded ( Adaptative Engineering 2003)

Design Criteria Device must: elevate in. and rotate 360° elevate in. and rotate 360° achieve max. height in 7 seconds achieve max. height in 7 seconds rotate 360° in 15 seconds rotate 360° in 15 seconds lock wheelchair in position for safety lock wheelchair in position for safety operate using battery power operate using battery power meet safety regulations meet safety regulations

Design Criteria be easily cleaned be easily cleaned transport by rolling transport by rolling operate quietly operate quietly withstand loads up to 500 lbs withstand loads up to 500 lbs move smoothly and safely move smoothly and safely be operated easily by patient and doctor be operated easily by patient and doctor

Design Components Base: Provide structural support to the upper-half of the platform during normal operation. Upper frame: Support the circular disk and transmit load to the lifting mechanisms. Lifting mechanism: Allow the upper frame to translate vertically and provide the necessary support to maintain elevation. Transportation features: Allow the device to be easily transported from one location to the other.

Market Research Findings Wheelchairs disrupt most imaging systems Wheelchairs disrupt most imaging systems Does not reduce potential law suits and insurance costs Does not reduce potential law suits and insurance costs Lack of rotation on a third axis reduces market potential Lack of rotation on a third axis reduces market potential Result: Not a marketable product Result: Not a marketable product

Final Design: Underside of upper platform

Final Design: Bottom frame and lifting mechanism

Final Design: Side view of rotation and lifting mechanisms

Final Design – In use

Final Design: In transport

Learning Experience Specific prototype variations - Rotate internal structure 90 degrees - Extend range and reduce lifting force - Alignment issues= amateur craftsmen Specific prototype variations - Rotate internal structure 90 degrees - Extend range and reduce lifting force - Alignment issues= amateur craftsmen Aspects of getting a project to market Aspects of getting a project to market Importance of producing a prototype Importance of producing a prototype

Cost Table ComponentAmountPrice Structural steel platform 32 x 36 x 0.25 in Solid steel arms 11.5 x 1.25 x 0.5 in Bearings + Bushings Steel tubing 48 ft. of 1.25 x 2 in Stainless steel rod in. diameter Steel Brace Hydraulic cylinders (2500 psi) Hydraulic motor (2500 psi) E-rings, superglue and shiny primer Rechargeable battery + Charger + Starter Additional components Approximate Total

Special Thanks To: ME Shop (including staff) ME Shop (including staff) Frank Fronzcak Frank Fronzcak Mitch Tyler Mitch Tyler Glenn Bauer Glenn Bauer Corrine Bahr Corrine Bahr National Design Competition (NIDRR) National Design Competition (NIDRR) Tong Prototype & Schoofs Competition Tong Prototype & Schoofs Competition WARF WARF