P14006 Bath Tub Lift Phase II Reviewedge.rit.edu/edge/P14006/public/P14006 Phase II Final 2.0.pdf• Bathtub lift – a device that provides assistance to an individual with physical

P14006 Bath Tub Lift Phase II 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 I Overview

• Problem Definition • Customer & Engineering Requirements • Action Items • Customer Update

• Functional Decomposition • Concept Generation • Concept Selection • Project Plan (WK 6-9) • Team Assessment

P14006 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

Project 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

Current State • Current device is not stable; client

feels unsafe • Current model not in production • Parts have been replaced/fixed due

to wear & do not always work • User has difficulty accessing chair • New toilet device introduces new

design issues

Stakeholders Power

Interest

• Sonaris • Hoyer • Other Bath Tub

Manufacturers

• Wheel chair users/handicap

• Hospitals (RGH) • Nursing Homes • Suppliers/Vendors

(Southside Medical Supply)

• Theresa Loce • Elizabeth

DeBartolo • Art North • R.I.T

Action Items • Completed Since Phase I Review

• Updated & refined Customer and Engineering Requirements.

• Updated Risk Assessment by identifying owners and implementing a scoring system.

• Explored how the current device is cleaned. • Research battery power vs. water power

(hydraulic).

Customer Requirements Customer Need Importance Description

CN01 1 Chair turns 180-360 degrees

CN02 1 Chair has handles/armrests

CN03 1 Requires minimal setup

CN04 1 Comfortable and safe to use

CN05 1 Operates through a water-powered system

CN06 1 Sturdy attachment to tub; cannot move

CN07 1 Non-corrosive

CN08 1 Easy to use

CN09 1 Easy to clean

CN10 1 No use of Nickel - allergic

CN11 1 Able to lift at least 150 lbs

CN12 1 Accessible to 10th percentile women (height)

CN13 1 Controls/handles must be easy to use

CN14 1 Compatible with existing tub/system

CN15 2 Easy to maintain/fix

CN16 1 Takes 0-5 minutes to rise

CN17 2 Minimal noise

CN18 2 Flexible temperature control

CN19 1 Can recline to lay user flat in tub

CN20 2 Can fold down to fit in car

CN21 2 Lightweight

CN22 1 Partially/fully powered by battery (water alternative)

Engineering Requirements Number Source Function Specification (metric) Unit of Measure Marginal Value Ideal Value Comments/Status

S1 CN01/CN11/CN17 System Rotation of chair degrees 180 >= 180

S2 CN02/CN04/CN08/CN12/CN12/CN14 System Width of armrests in 17-19 17 1/2

S3 CN03/CN09/CN15 System Time to get device in/out of tub minutes 0-2 1

S4 CN04/CN12/CN14 System Correctly dimensioned seating area in^2 < 17 x 15 17 x 15 Must fit within tub

S5 CN03/CN04/CN05/CN06/CN08/CN11/CN13/CN14/CN16/CN17 System Uses faucet to raise client psi 30-80 60

S6 CN02/CN07/CN08/CN09/CN14 System Chair secured to tub using suction cups psi secure equivalent of

150 lbs secure equivalent

of 150-250 lbs

S7 CN02/CN07 System Long lasting material year 100-120 120-260

S8 CN04/CN15/CN08 System Time to engage hydro lift seconds 5-Jan 3-Jan

S9 CN04/CN07/CN09/CN10/CN15 System Material use, fixture design minutes 2-5 3

S10 CN02/CN04/CN10 System Concentration of nickel % 0 0 Client allergy

S11 CN11 System Lifting capabilities lbs 150 >= 150

S12 CN12/CN04 System Height of user in 58 - 62 60 Women's 10th percentile

S13 CN13/CN04 System Diameter of lever in 1.5 - 2.5 2

S14 CN14 System Dimensions of device/fixture in 18 - 19 19

S15 CN16 System Rising time minutes 5 <= 5

S16 CN17 System Noise dB 30 <= 30

S17 CN18 System Operates on wide range of temperatures Fahrenheit 70-110 60-130

S18 CN19/CN04/CN08/CN11/CN12/CN14/CN15/CN16/CN17 System Chair reclining ability degrees 40-90 90

S19 CN20/CN03 System Compact transport design ft^3 (LxWxH) 20-27(L) x 16-19(W) x 20-30(H)

25(L) x 17.5(W) x 30(H)

Dimensions restricted to tub size

S20 CN21/CN09 System Lightweight system design lbs 20-30 25

S21 CN22/CN01/CN04/CN08/CN13/CN19 System Device powered by battery V 12-15 13.2 Alternative to hydraulic

Engineering Matrix

Engi

neer

ing

Requ

irem

ent

Rota

tion

of c

hair

Wid

th o

f arm

rest

s

Tim

e to

get

dev

ice

in/o

ut o

f tub

Corr

ectly

dim

enio

ned

seat

ing

area

Use

s fa

ucet

to ra

ise c

lient

Chai

r sec

ured

to u

sing

suct

ion

cups

Long

last

ing

mat

eria

l

Tim

e to

eng

age

hydr

o lif

t

Mat

eria

l use

, fix

ture

des

ign

Conc

entr

atio

n of

nic

kel

Lift

ing

capa

bilit

ies

Heig

ht o

f use

r

Diam

eter

of l

ever

Dim

ensio

ns o

f dev

ice/

fixtu

re

Risin

g tim

e

Noi

se

Ope

rate

s on

wid

e ra

nge

of te

mpe

ratu

res

Recl

inin

g ab

lity

Com

pact

tran

spor

t de

sign

Ligh

twei

ght

syst

em d

esig

n

Devi

ce P

ower

ed b

y Ba

tter

y

# S1

S2

S3

S4

S5

S6

S7

S8

S9

S10

S11

S12

S13

S14

S15

S16

S17

S18

S19

S20

S21

Customer Need Priority #

Device turns at least +/- 90 degrees 1 CN01 x x

Device has handles/armrests 1 CN02 x x x

Requires minimal setup 1 CN03 x x x

Comfortable and safe to use 1 CN04 x x x x x x x x x x

Operated through a water-powered system 1 CN05 x

Sturdy attachment to tub; cannot move 1 CN06 x x

Non-corrosive 1 CN07 x x x

Easy to use 1 CN08 x x x x x x

Easy to clean 1 CN09 x x x x

No use of nickel - allergic 1 CN10 x x

Able to lift at least 150 lbs 1 CN11 x x x x

Accessible to 10th percentile women (height) 1 CN12 x x x x

Controls/handles must be easy to use 1 CN13 x x x x

Compatible with existing tub/system 1 CN14 x x x x x x x

Easy to maintain/fix 2 CN15 x x x x

Takes 0-5 minutes to rise 1 CN16 x x x

Minimal noise 2 CN17 x x x

Flexiblle temperature control 2 CN18 x

Can recline to lay user flat in tub 1 CN19 x x

Can fold down to fit in car 2 CN20 x

Lightweight 2 CN21 x

Partially/fully powered by water (altenrative) 1 CN22 x

Uni

t

Deg

in

min

in^2

psi

psi

year

sec

min

%

lbs in

in

in

min

dB

F deg

ft^3

lbs V

Customer Update • Follow up questions to initial interview • Explain the broadened project scope • Explain the new project direction • Obtain client opinion on system design

• Battery vs. hydraulic, rotate vs slide, etc. • New restrictions due to new bathroom setup

Functional Decomposition

Raise Device

Raise device

Engage switch

Water power Battery power

Transfer to Device

Transfer to the device

Get to device

Transfer/slide arms to device

Assist user's legs to device

Platform/seat extension comes

out

Rotate Device

Rotate device

Use battery Use water power

User manually rotates

Lower/raise device

Lower/raise device

Engage switch

Water power Battery power

Transition from Device

Transition from device

Rotate user Let user's legs down

Extensions lower

Get off device

Manually transfer from device

Lower device

Disengage switch

Morphological Analysis

1 Raise Device Water Power Battery Power Inflation Power Remote Control Magnetic Repulsion Chair Crane

2 Transfer DeviceGetting items for support (trapeze

handle)Use of crutches Automation to lift user to

the devicePersonal assistant to help

user to deviceIncorporate user's assist

device

3 Assist Legs ManuallyPersonal

Assistant to help legs be secured

Water power Battery power (platform slides out)

Remote control Reclining Platform

4 Rotate/Slide Device

Manually Water power Battery power Personal assistant Spring loaded Remote Control

5 Lower Device Water Power Battery Power Inflation Under chair Remote Control Magnetic Repulsion Chair Crane

6 Turn on Water to fill tub

Manually turn knob

Personal Assistant

Remote Control Relocate knobs

61 2 3 4 5Sub function

Solutions

Sub function

Solutions

Base Design

Base Design

1 Raise Device Water Power Battery Power Inflation Power Remote Control Magnetic Repulsion

Chair Crane


handle)Use of crutches Automation to lift

user to the device

Personal assistant to help

user to device

Incorporate user's assist

device



Water powerBattery power

(platform slides out)



Manually Water power Battery power Personal assistant

Spring loaded Remote Control

5 Lower Device Water Power Battery Power Inflation Under chair

Remote Control Magnetic Repulsion

Chair Crane


Manually turn knob

Personal Assistant



Solutions

Base Battery Design

Base Battery Design


Chair Crane



user to the device


user to device


device











Chair Crane


Manually turn knob

Personal Assistant



Solutions

Fully Battery Powered

Fully Battery Powered


Chair Crane



user to the device


user to device


device

3 Assist LegsPersonal










Chair Crane


Manually turn knob

Personal Assistant



Solutions

Crane Device

Crane Device


Chair Crane



user to the device


user to device


deviceChair Crane

3 Assist LegsPersonal







Spring loaded Remote Control No rotation/sliding



Chair Crane


Manually turn knob

Personal Assistant


5 6 71 2 3 4Sub function

Solutions

Concept Selection # 1 Criteria

Base (Existing) Design Base Battery Design Fully Battery Powered Design Crane Design

1 Raise Device + + +

2 Transfer Device S + +

3 Assist Legs S + +

4 Rotate/Slide Device - + +

5 Lower Device + + +

6 Turn on Water to Fill Tub S S +

7 Affordable - - -

8 Fits Time Constraints + - -

9 Safety - + -10 Light Weight - - -11 Portable - - -

+ 3 6 6- 5 4 5

DATU

M

Concept Selection # 2

Criteria

Base (Existing) Design Base Battery Design Fully Battery Powered Design Crane Design

1 Raise Device - S S

2 Transfer Device - - +

3 Assist Legs - - -

4 Rotate/Slide Device - - +

5 Lower Device - S S

6 Turn on Water to Fill Tub S S +

7 Affordable + + -

8 Fits Time Constraints + + -

9 Safety - - -10 Light Weight + S +11 Portable + S -

+ 4 2 4- 6 4 5

DATU

M

Risk Assessment ID Risk Item Cause Effect Likelihood Severity Importance Actions to minimize Owner

1 User injury due to falling/slipping off device

No adding arm rails. Combination of material, water and human skin not having enough friction causing user to slip.

Minor to severe injury to the customer/user 1 3 3 Implement a safety device and use high

friction materials Team

2 Moderate the water temperature

Water temperature is not properly set

User may sustain burns or experience cold temperatures 1 2 2 Test water before getting into the tub Team

3 Water power supply inconsistent

Psi level jump due to drop in water pressure

User may experience discomfort while operating device due to rough motions

1 1 1 Run a test to see if users water pressure is consistent Team

4 Electric power supply inconsistent

Charge from battery may not be sufficient to operate device when running low

User may experience longer operation times or may become trapped in tub

2 3 6 Apply a warning system/visual indicator that the battery is low. Team

5 Device weight capacity Device not able to lift well over the minimum requirement

Device fails under heavy loading, trapping and possibly injuring user 1 3 3 Through testing device must lift >150

lbs Team

6

Not being able to fulfill requirements of broad user base (height/weight differences)

Not conducting an ergonomics study on the stature of the users percentile and their reach

User may be too big or too small for device. User may get injured due to lack of space or not being able to reach certain items. Customer dissatisfaction

2 2 4

Have multiple team members measure the dimension of the tub and for every step of the process, re-measure to verify meeting constraints

Team

7 Fixture dimensions

Measurement errors of the bath tub and the device. Not considering thickness of materials in specs.

Device not able to fit in the tub. Customer not being able to use the device.

2 3 6

Have multiple team members measure the dimension of the tub and for every step of the process, re-measure to verify meeting constraints

Team

8 Safety of user’s legs When fixture is lowering it does not allow enough room for legs

Minor to sever injury to the customer/users legs 1 3 3

Apply a foot rest at the base of the device so the user can place their feet before operating

Team

9 Transfer from starting position to the device

Unsafe transition from starting position to the device Possible falling injury 1 3 3

Option1: Having the device being able to slide out the tub for the user to access. Option 2: Ensure that the device can rotate out of the tub and is stable for users that can stand to use as support.

Team

10 Not being able to meet deadlines/milestones

Not having a well developed project plan and keeping it updated

Product delay which may lost customers trust 2 2 4 Have daily or weekly updates on

assignments and if help is needed Team

11 Going over budget Not keeping track of budget or knowing what the budget is

Having to ask for more or falling short on supplies to develop the product.

1 1 1 Schedule to audit budget every 2 weeks. Team

12 All team members not being able to meet

Miscommunication or lack of communication between team members

Team members missing meetings or not being active in their roles 2 1 2

Communicate with team verbal and text/email when and where will meetings will take place.

Team

Benchmarking • Current Models:

• Maximum weight supported 200-375 lbs • Uses suction cups for stability • Uses a waterproof hand remote • Powered by a rechargeable battery • Minimum lift height range 2.5”-5” • Maximum lift height range 17”-21” • Product total weight 19-27.5 lbs • Around 7 lifts per battery charge • Duration of Stroke: Up-50s Down-35s

Benchmarking • Went to South Side Medical Supply that provided assisting

devices • The devices in the store were not powered, they were only

stationary • Thus, no readily available powered bathtub lift device to

consumers

Benchmarking

Specifications

Battery Power

Benchmarking

Many accessories

Portable

Benchmarking (Battery)

Benchmarking (Battery)

Benchmarking (Hydraulic)

Project Plan (WK 6-9)

Project Plan (WK 6-9)

Team Assessment • Team has become better at communicating, coordinating

meetings, and openly sharing ideas • Members are further finding their roles/strengths within the

team • Additionally, members are willing to step in to help other team

mates • Though team communication has improved, it has become

more difficult for all members to attend meetings due to increase in workload/outside obligations

• Team has become closer as a whole, but has many new challenges thanks to changes in the client situation

Questions?

Documents

P14006 Bath Tub Lift Phase II Reviewedge.rit.edu/edge/P14006/public/P14006 Phase II Final 2.0.pdf• Bathtub lift – a device that provides assistance to an individual with physical