P14006 Bath Tub Lift Phase IV Review

1. P14006Bath Tub Lift Phase IV Review Amos Baptiste Jeremy Czeczulin Andrew Hughes Richard Prilenski

2. Introductions

3. Agenda • Phase III Overview • Problem Definition • Action Items • Refined Drawings • Stress Analysis • Materials • Prototype • Team Assessment • Schedule • Customer/Engineering Requirement • Risk Assessment

4. Problem Statement • Bathtub lift – a device that provides assistance to an individual with physical disabilities, including limited balance, coordination, or mobility • Can reduce the difficulties of raising and/or lowering an individual into the tub by utilizing a powered seat and a simple control module • As population grows the number of aged individuals will greatly increase making demand for assist devices increase • Project motivation – Theresa Loce • Improve the current design • Current device does not meet her needs • Powered lift that is sturdy, comfortable, easy to use/clean, makes minimal noise, and takes into account physical limitations of user • Ultimate goal – user maintains autonomy and privacy

5. Deliverables • Effectively assist the user for bathing purposes • Device is easy to access from starting position • Minimized operating time • Provide a comfortable and supportive seating area • Accessible to 10th-70th percentile for both genders, regardless of age • Reasonably lightweight and portable, able to be transported

6. Current and Desired State Current Desired Easy use Easy access Portable Lightweight • Unstable • Out of production • Damaged • Difficult access • Obstructions prevent full use

7. Stakeholder(s) • Primary Customer: Theresa Loce • Contact: 585-647-2329 • Secondary Customer (s): Wheel chair users/handicap public & Elizabeth DeBartalo, Hospitals (RGH), Nursing Homes, suppliers/vendors, & individuals recovering from knee surgeries. • Contact: eademe@rit.edu • Faculty Guide: Art North • Contact: ajnddm@rit.edu • Sponsor (financial support): RIT & Theresa Loce

8. Issues to Address from Phase III • Fiber glass needs to be looked more into as It may not be water resistant and itchy • Need to calculate bending stress • Put a guard to prevent hand or body part to be between scissor lift • Look at backup plan if suction cups fail & how to reinforce the suction cup base • Control module • Make a design • Buttons • Possible mock to see how it feels • Where will the actuator be positioned? • How to eliminate the risk of the user being shocked? • Consider twisting a central axis • Try two parallel roller/tracks for stability • Electrical safety requirements • Battery design and wiring • Bottom of bath tubs are textured look in to for suction cups • When the actuator is at the top will it lock in place or slowly go back down? • Steel and Aluminum together in water may cause corrosion. Be more specific on grade of material • Need bearings and pins for detailed designs of the model • Plan for where and corrosion issues with reflective motion parts

9. Action Items from Phase III

10. Refined CAD Model

11. Continued

12. Continued

13. Stress Analysis (Initial Position)

14. Stress Analysis Figure 1: Maximum stress noted is 42.18 ksi in the pin region. However it is “micro stress”.

15. Stress - Modified Analysis Figure 2: Pin stress exceeds 36 ksi. Stress values of the scissor region ranges from 5-20 ksi.

16. Displacement Analysis Figure 3: Maximum displacement noted was 0.03537 in. While scissor region obtained 0.007 – 0.023 in.

17. F.O.S. Analysis Figure 4: *Note: For medical devices the FOS range is usually 2-4.

18. Stress Analysis (Maximum Extended Position)

19. Stress Analysis Figure 5: Max stress occurred in the upper pin region. After observing this analysis of Figure 1 and Figure 5, it is evident that a high grade of steel must be used for the pins.

20. Stress Analysis - Modified Figure 6: Stress values in the scissor region were around 3-22 ksi.

21. Displacement Analysis Figure 7: Max displacement at the edge of the extending pillar was 0.1456 in.

22. Displacement Analysis - Modified Figure 8: Better shows the displacement dispersion.

23. Factor of Safety Figure 9: FOS range in the scissor region was around 1.5 to 6 ( Increasing the thickness of the scissor frame by 1/8” will increase the lower FOS values to the desired range). The FOS values for the pins dropped below 1 due to the lower grade of steel used for this analysis and thus farther confirms a high grade of carbon steel must be used for the pin region.

24. Materials Added

25. Bill of Materials

26. LA31 Careline Linear Actuator • Provided by Linak • 6,000N (1350lb) max push, 4,000N (900lb) pull • IPX6 protection class • Emergency lowering/retraction • 24V DC magnet motor, 2.25m cable • Max stroke length 250mm

28. HB70 Handset • Control from LINAK, compatible with LA31 • IPX6 protection class • Easy to use interface • Hang-on clip • Operate up multiple actuators • 0.6m cord

30. IPX Ratings

31. Controller • Consist of: • Power button • Directional pads to move the chair • Home button

32. Prototype Built a prototype using: • PVC pipes • Rollers • Rope • Pulley • PVC Cement and Primer • Screws All the materials were purchased at Home Depot on Jefferson Rd.

33. Prototype

34. Team Assessment

35. WK 13-15 Plan

36. Updated Customer Requirements

37. Updated Engineering Requirements

38. Updated Engineering Matrix

39. Risk Assessment

40. Risk Assessment