P 14006 Bath Tub Lift Phase IV Review

P 14006 Bath Tub Lift Phase IV Review Amos Baptiste Jeremy Czeczulin Andrew Hughes Richard Prilenski

Introductions Name Major/Role Amos Baptiste Industrial & Systems Engineer/Team Leader Jeremy Czeczulin Mechanical Engineer Andrew Hughes Mechanical Engineer Richard Prilenski Mechanical Engineer

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

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 • •

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 10 th-70 th percentile for both genders, regardless of age • Reasonably lightweight and portable, able to be transported • • •

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

Stakeholder(s) • Primary Customer: Theresa Loce • Contact: 585 -647 -2329 • Secondary Customer (s): Wheel chair users/handicap public & Elizabeth De. Bartalo, 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

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

Action Items from Phase III Action Item Owner Issue(s) to Address Create physical prototype of the bath tub lift. Richard & Jeremy • Create a design and prototype for controller Refine CAD design • • Trying two parallel rollers for stability Proof of design concept Determine position for actuator Amos • • Control module design Possible mock of how it feels Andrew • Ensure the chair fits the target percentile Determine location of bearing and pins Put a guard to prevent risk of hand injury when lowering device. • • Conduct stress analysis Richard • Stress from bending Refine BOM Amos • Fiber glass on seat may not be waterproof and itchy to user Steel and Aluminum together in water may cause corrosion. Specify grades • • Contact Linak & research actuator Richard & Jeremy • • Address the risk of shocking the user Electrical safety requirements

Refined CAD Model

Continued

Continued

Stress Analysis Figure 1: Maximum stress noted is 42. 18 ksi in the pin region. However it is “micro stress”.

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

Displacement Analysis Figure 3: Maximum displacement noted was 0. 03537 in. While scissor region obtained 0. 007 – 0. 023 in.

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

Stress Analysis (Maximum Extended Position)

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.

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

Displacement Analysis Figure 7: Max displacement at the edge of the extending pillar was 0. 1456 in.

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

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.

Materials Added Material Component Properties Polyamide • Chair seat • Back rest • Control module • Hard and brittle • Resistant to abrasion, shrinkage and heat • Water resistant Medium Carbon Steel • Scissor Lift • Beam • Outside Channel • Ductile • High strength • Good Wear resistance Rubber coating • Scissor Lift • Beam • Outside Channel • Can be applied to steel • Will help make steel water resistant

Bill of Materials

LA 31 Careline Linear Actuator • • • Provided by Linak 6, 000 N (1350 lb) max push, 4, 000 N (900 lb) pull IPX 6 protection class Emergency lowering/retraction 24 V DC magnet motor, 2. 25 m cable Max stroke length 250 mm

HB 70 Handset • • • Control from LINAK, compatible with LA 31 IPX 6 protection class Easy to use interface Hang-on clip Operate up multiple actuators 0. 6 m cord

IPX Ratings

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

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.

Prototype

Team Assessment Action Item Owner Status Create physical prototype of the bath tub lift Richard & Jeremy • In progress Create a design and prototype for controller Amos • In progress- currently waiting on 3 D print of controller Refine CAD design Andrew • In progress- Still making adjustment to design according to proof of concept Conduct stress analysis Richard • Completed Refine BOM Amos • Completed Contact Linak Richard & Jeremy • In progress- Need to consider looking at other options for backup.

WK 13 -15 Plan Task Name Purchase actuator Develop PVC Prototype Refine CAD designs Ensure device meet OSHA Electrical Safety Requirements Incorportate feedback from Phase 4 Review for Phase 5 Develop manufacturing design Have final meeting with Theresa before summer Owner (S) Jeremy & Richard Andrew Amos Team

Updated Customer Requirements

Updated Engineering Requirements

Updated Engineering Matrix

Risk Assessment

Risk Assessment