Group 291 Wheelchair-to-Bed Transfer Assistance Device Engineering Team: Tyger Howell, Gary Ye Primary Mentor: David B. Gray, Ph. D Expert Consultant: Ruth Okamoto, Ph. D

Group 292 Outline Background Project scope Design Specifications Current Solutions Group Ideas Schedule Duties Questions

Group 293 Background Combined incidence of stroke, MS, ALS, traumatic brain injury, and spinal cord injury is cases per 100,000 Americans per year. Caregivers of these patients may be family members. Improper training in transfer technique may lead to injury of both patient and caregiver.

Group 294 Project Scope We aim to create a detailed schematic for a chair that will make chair to bed transfers easier for caregivers and patients of varying ability. Assumptions There is a caregiver available to help the patient. The patient is able to participate in the transfer. The patient weighs 300 pounds. The power chair weighs 250 pounds.

Group 295 Design Specifications Sturdy – the design must be able to support at least 300 pounds at all times. Simple – easy to use and maintain. Low profile – the device should not add more than 6 inches to the average seat height. Modest lifetime - the device should last at most twice the lifetime of the chair. Competitive pricing - The overall cost of the chair should not exceed $3,500.

Group 296 Current Solutions: Hoyer Lift Pros Can lift up to 400lbs Some have a hydraulic mechanism Cons Some have a hand crank mechanism Caregiver must move entire structure to move patient Not portable Bulky Not easy to store

Group 297 Current Solutions: Transfer Boards Pros Cheap Lightweight Portable Caregiver does not bear all of the weight of the patient Cons Some are made of solid wood, increasing price and weight Patient must be fairly strong in the upper body and able to sit upright independently

Group 298 Idea: Sliding Table/ Ramp Sliding Table Seat slides to the side, like pulling out a drawer. Outriggers simultaneously extend from the bottom of the chair. Ramp Board with a track extends from chair to bed. Seat slides along a track on the ramp.

Group 299 Ideas: Reverse Entry Back of power chair swings away. A stiff material is placed onto bed right behind patient. Seat detaches from chair and rolls backward off of power chair base and onto bed.

Group 2910 Ideas: Pivoting Seat Point of rotation is behind patient. Lever extends from headrest area. Caregiver pulls lever towards them, swinging the patient onto the bed.

Group 2911 Preliminary Analysis Basic Governing Equations: - Σ F = 0  Σ M = 0 Assume patient will be held out in free space 12 inches. Structural members must be able to withstand bending moment of 3600 inch- pounds.

Group 2912 Projected Schedule 9/26 – 10/5: Choose final design, launch webpage. 10/17: Present detailed concept to Drs. Gray and Okamoto for initial review; begin to work on progress report. 10/24 – 10/26: Progress presentation and report. 10/27 – 11/27: Developing schematic diagrams, choosing materials. 11/28 – 12/4: Finalize schematics, work on final reports. 12/5 – 12/7: Final presentation and report.

Group 2913 Division of Duties Tyger Howell Webmaster DesignSafe Correspondence Gary Ye AutoCAD Editing of reports Shared Design calculations Fact-checking

Group 2914 Thanks for listening.

Group 2915 References Slide 3: Hirtz, D., Thurman, D.J., Gwinn-Hardy, K., Mohamed, M., Chaudhuri, A.R., Zalutsky, R. How common are the “common” neurologic disorders? Neurology 2007;68: Slide 6: Image taken from Slide 7: Image on left taken from Image on right taken from transfer-boards.htmlhttp:// transfer-boards.html Slides 8 and 10: Images modified from US Patent Des. 397,645. Schaffner, Walter. Filed July 3, Issued September 1, Slide 13: Image taken from questions.html