Ergonomic Housing improvements to Personal Smoke Monitoring Device

Team:

Evan WozniakSarah KostukChristina SmithAaron Prahst

Multidisciplinary Senior DesignSystems Level Design Review

Background

• Device measures:– Puff volume– Volume drawn into lungs

PurposeCurrent cigarette testing may not reflect actual smoker puff profiles. The personal monitoring device will be used as part of a clinical study to gather information on real smoker puff profiles.

History

P10054

•Produced Proof of concept

P10057

•Improved upon Proof of concept

FSI

•Developed proof of concept further and produced a functional first generation Prototype

P12056

•Will take the First Generation Prototype and improve on the ergonomics of the device including moving the pressure sensor into the hand piece. A wire will be used to transmit data rather than the current tubes. This project will also allow room in this hand piece for wireless components.

Generation

Three

•Will integrate wireless components into system.

Customer Needs

1. Cigarette holder does not alter the smoking behavior or manner in which the smoker smokes the cigarette.

2. Cigarette holder is ergonomic. For example it is lightweight and feels like holding a cigarette.

3. Cigarette holder will support the cigarette independent of the user4. Cigarette holder will not hinder the act of lighting the cigarette.5. Cigarette holder includes a flow path with and orifice plate to

measure flow rate.6. Cigarette holder encompasses the pressure sensor for flow rate

measurements.

See Appendix A of Preread.

Customer Needs7. Cigarette holder has room for all the wireless electronic components

needed to record and transmit the signal to the base unit and support any additional desired indicator lights.

8. Cigarette holder transmits pressure signal by wire to the base unit or an external fixture for testing.

9. Cigarette holder can handle a wide range of cigarettes including electronic cigarettes.

10. Cigarette holder and base unit are easy to maintain by the user. For example there is an easy way to store the holder to avoid loss. There is a comfortable way to attach the base unit to the subject

11. Base unit housing size is minimal yet has room for all wireless components. Preferably the size is no bigger than a cellphone

12. The final design includes ergonomic considerations, and potentially an improved solution for the chest bands to enhance wearability.

See Appendix A of Preread.

Risks

1. Lead time on Pressure sensor causes delays on analysis for decision

2. Requirements are too large for ergonomic hand hold

3. Might not have means to survey a "powerful" sample size

4. Smoker does not want to use the product

See Appendix B of Preread.

Risks

5. Rapid prototyping does not allow for accurate tolerances on orifice plate

6. Design hinders smoker ability to cover/ not cover vent holes

7. Not all plastic is FDA approved8. Smoker does not hold ergonomic hand hold

the way it was intended9. Handhold is too heavy and breaks the cigarette

See Appendix B of Preread.

OverviewDecomposition

See Appendix C of Preread.

P12056 Decomposition

See Appendix D of Preread.

Benchmarking Current Prototype

Benchmarking Current Prototype

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.90

1

2

3

4

5

6

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

Non Smoker Simulation (machine not calibrated)

Time (Minutes)

Puff

Flow

rate

(ml/

s) R

ed L

ine

Volu

me

draw

n in

to L

ungs

(lite

rs) B

lue

Line

Existing Pressure Sensor Specifications

• Measurement Range– 0-2” H2O

• Differential Pressure Resolution– Typ. 0.1% of Full-Scale

Benchmarking Current Prototype

Benchmarking Existing Smoke Monitoring Devices

• CReSS Pocket by Borgwaldt

• Mobile SPA/M by Sodim

FSI Software Flowchart

Benchmarking Current Prototype

See Appendix E of Preread.

Benchmarking Results: Previous project

• 9 people were surveyed• Avg. Age: 23.11yrs (Std. Dev 3.58 years)• 8 Males, 1 Female• Answer questions on scale 1-5 (1= BEST ,

5=Worst)• Questions regarding comfort of; hand piece,

chest belt, and belt pack• Results were inconclusive

• Survey Plan:– Usability of current plan• Survey data• Actual device data

– Calibrate sensor– Calibrate chest band

• Survey can be seen in appendix F of Preread

Benchmarking Current Prototype

Benchmarking Marking Sample Size• One way to prove that the new design is an improvement of

the current design is to do an hypothesis test to show a statistically significant difference

• The original hypothesis is that the mean (µ) of the survey response of original product is “=“ the mean of the survey response of the new product

• The alternative hypothesis (what we want to prove) is that the mean (µ) of the survey response of original product is “≠ “ the mean of the survey response of the new product

H0: µ0= µa HA: µ0 ≠ µa

• Yield a standard deviation of 1.3 (from results of previous project’s survey)• Calculate the sample size needed to prove a statistically significant

difference of 1.0 or 0.5 • With an alpha (α) = 0.5• And a Power (confidence level) of 90%, 95%, or 99%

Benchmarking Sample Size

Alpha = 0.05 Assumed std dev= 1.3Factors: 1 Number of levels: 2

Maximum Sample Target ActualDifference Size Power Power 1.0 37 0.90 0.903914 1.0 45 0.95 0.950397 1.0 64 0.99 0.990815 0.5 144 0.90 0.901930 0.5 177 0.95 0.950364 0.5 250 0.99 0.990146 1.21.00.80.60.40.20.0

1.0

0.8

0.6

0.4

0.2

0.0

Maximum Difference

Pow

er

Alpha 0.05StDev 1.3

# Levels 2

Assumptions

374564

144177250

SizeSample

Power Curve for One-way ANOVA

Rapid Prototyping Concerns

• Lead time on Prototyping• Strength of Parts– Strength of multiple part connections

• FDA approval of plastic for oral use• Tolerances

Professor Cormier’s Input

• RIT’s equipment is better for larger parts• Fastline is a company that does FDA approved

rapid prototying• Rapid prototyping is feasible outside RIT– Definitely cheaper that injection molding– Cost is dependent on material height

Input from FSI

• Needed wireless components– Physical room needed to be allotted for wireless

components• Are our prototypes sizes appropriate or do they need to

be modified

• Do we design and fabricate the belt pack and if so what are the internal dimensions that FSI needs– If we are not fabricating it is it a purchased part?

FSI’s Input

• Rechargeable battery would be smaller than supplied dimensions

• 2 week life cycle with battery recommended• Belt pack can be made smaller

– Half the size in the x and y direction– Use mockup from previous group

• Chest belt:– How to make more user friendly

• Rather than spend a lot of money on a orifice plate that is exact, each mouth piece can be calibrated in a lab setting before use

FSI Input

Could split board in half if needed.

Hand Piece Concepts1 2

3

4

Hand Piece Concepts

5 6

78

Hand Piece Concepts

9

10

1112

Hand Piece Concepts

13

14

1516

Hand Piece Concepts

17

18

1920

Hand Piece Concepts21

22

23

Hand Piece SelectionBrainstorm hand piece concepts (15 to 20)

Produce prototypes of concepts

Conduct Survey using prototypes

Analyze Survey

Create scoring matrix to narrow down concepts to final selections

Create 5 prototypes with full scale space claim

Conduct Survey In Ergonomics Class

Narrow Down to Three results

Input from Professor Marshal

• Have no more than 5 options for final survey• Rigid finger holds are frowned upon for

ergonomics• Don’t need smokers to narrow down hand

pieces• Look at similar productions like a hookah

mouthpiece.

• A survey will be conducted where smokers are asked to simulate smoking using the 24 prototypes.

• They will be asked three questions about each object.

• The survey questions can be found in appendix G of the preread.

Hand Piece Survey Plans

Handpiece Survey Plan• In order to score the handpieces 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

• Yield a standard deviation of 1.3 (from results of previous project’s survey)

• Calculate the sample size needed to prove a statistically significant difference of 1.0 or 0.5 ( -1.0 or -0.5; alternative hypothesis of < 3)

• With an alpha (α) = 0.5• And a Power (confidence level) of 90%, 95%, or 99%

Testing mean = null (versus > null)Calculating power for mean = null + ΔAlpha = 0.05 Assumed std dev = 1.3 Sample Target ActualDifference Size Power Power 1.0 15 0.90 0.908958 1.0 19 0.95 0.956195 1.0 27 0.99 0.990668 0.5 58 0.90 0.900480 0.5 74 0.95 0.951917 0.5 107 0.99 0.990193

Hand Piece Survey Plans

1.21.00.80.60.40.20.0

1.0

0.8

0.6

0.4

0.2

0.0

Difference

Pow

er

Alpha 0.05StDev 1.3

Alternative >

Assumptions

1519275874

107

SizeSample

Power Curve for 1-Sample Z Test

Pressure Sensor Selection ProcessSee Appendix H of Preread.

Please see next slide for graph with losses using discharge coefficient.

Pressure Sensor Selection Process

Pressure Sensor Selection Process

• Criteria for picking a differential pressure sensor:– It should have an operating pressure of at least 0

to 2.0” H2O– It should be small enough to fit inside the hand

piece – It should be able to run off of a future battery

inside hand piece

Sources

• http://www.servoflo.com/downloads/item/mb-lps1-01-r-datasheet.html

• http://edge.rit.edu/content/P10057/public/Home

• http://edge.rit.edu/content/P10054/public/Home

• Incropera, Frank P., David P. Dewitt, Theodore L. Bergman, and Adrienne S. Lavine. Fundamentals of Heat and Mass Transfer. 6th ed. Wiley, 2007. Print.

• The team would also like to thank Dr. Robinson and FSI for their support in this project.

• Thank you for your time• Questions/Comments