Ergonomic Housing improvements to Personal Smoke Monitoring Device

Team:

Evan WozniakSarah KostukChristina SmithAaron Prahst

Multidisciplinary Senior DesignSystems Level Design Review

Mid Quarter Systems Update

• Update on:– Hand piece Selection– Orifice Plate– Chest Belt

MouthPiece Selection

• Prototyped 18 designs • The designs were separated into 5 groups

depending on their type of grip• Participants were asked to score groups on 3

questions with a likert scale of 1-5 (1= strongly disagree, 5 =strongly agree) • Questions asked about the comfort, ease of

use, and the ability to be used in any environment

Results• 48 students participated• In order to score the mouthpiece the mean survey response

must be proven the be < or > the neutral response of 3 • This can be proven statistically using an hypothesis test ( 1

sample Z test)• The original hypothesis is that the mean (µ) of the survey

response of the design concept is “=“ 3• The alternative hypothesis (what we want to prove) is that

the mean (µ) of the survey response of the design concept is “>” or “<“3 (this will be 2 separate tests)

H0: µ0= 3 HA: µa > 3 or µa < 3 α= 0.05

Scoring Guidelines• The results from the survey were used to score each of the individual designs, to

reduce the 18 designs to 5 designs to move forward in the design process. • Designs were also scored on key engineering specs that the team made decisions

on. Criteria 1 3 5

Survey Question 1 µ<3 µ= 3 µ >3

Survey Question 2 µ<3 µ= 3 µ >3

Survey Question 3 µ<3 µ= 3 µ >3

Favorite in Group n/a n/a YES

Difference in prototype size and needed size Much larger size needed

Slightly more room needed

No additional room needed

Device hold was consistent person to person Not consistent Somewhat consistent

consistent

Device allows vent holes to be covered n/a YES n/a

Adding Space will change perceived ergonomics

Large Change Mild Change Slight- no change

Matrix Weighting• Weights were given to each of the criteria to show relative importance to the

success of the project.• The total group score from the questions was weighted x3, as the usability of the

device is a main customer need.• Favorite of the group as given a weight of x2 for the same reason of needing user

buy-in• All other criteria had a weight of x1• When choosing the hand pieces two ties came into play.

– The first tie was between IDs 12 and 14, due to extreme similarities only 1 was chosen to move on, referring back to the favorite option for the group 14 received more points and therefore was chosen to move forward of the two options.

– The second tie as a tree-way tie between 4, 7, and 15. Due to extreme similarities between 7 and another current device, cress; 7 was eliminated. Hand piece ID 15 was eliminated due to large confusion by participants using the device which lead to frustration. For this reason ID 4 was moved forward in the design development.

Moving Forward• The Five hand pieces moving into further

development are; 13, 1, 14, 11, and 4Hand Piece ID Total Survey

ScoreFavorite in Group Difference in

prototype size and needed size

Device hold was consistent person to person

Device allows vent holes to be covered

Adding space will change perceived ergonomics

Total

1 9 5 5 5 0 5 522 9 0 5 3 0 5 403 9 0 5 1 3 5 414 9 0 3 5 3 5 435 3 0 3 3 0 1 166 3 0 3 3 0 1 167 9 5 1 1 3 1 438 9 0 1 3 3 3 379 7 0 1 5 0 1 28

10 3 5 1 5 0 1 2611 7 5 3 5 0 5 4412 13 0 1 3 0 3 4613 13 5 1 3 0 5 5814 13 0 1 3 0 3 4615 9 5 1 1 3 1 4316 9 0 3 1 3 5 3917 7 0 1 5 0 5 32

Pressure Sensor Selection

Preliminary Orifice Plate Concepts

Chest Belt Concepts

Questions

• Is there any way that the space claim for the electrical components in the mouthpiece can be made smaller?