Team Leader: Megan O’ConnellMatt Burkell

Steve DigerardoDavid Herdzik

Paulina KlimkiewiczJake Leone

P13027: Portable Ventilator

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Technical Review OverviewEngineering SpecsProposed redesignBattery and Power CalculationsPower: ElectricalElectric Board LayoutMCU LogicPressure SensorThermal AnalysisHousing ModificationsProject ComparisonProject ScheduleQuestions?22 of 52

Engineering SpecificationsPortable Emergency Ventilator

Engineering Specifications - Revision 1 - 03/19/13

Specification Number Source Function Specification (Metric) Unit of Measure Marginal Value Ideal Value Comments / Status

S1 PRP System Volume Control Liters 0.2 ± 0.2

S2 PRP System Breathing Rate BPM, Breaths per Minute 4 -15

S3 PRP System Pick Flow Liter/Min 15 - 60

S4 PRP System Air Assist Senitivity cm H20 0.5 ± 0.5

S5 PRP System High Pressure Alarm cm H20 10 - 70

S6 PRP System DC Input Volts 6 - 16 Due to battery, must be greater than 9V

S7 PRP System DC Internal Battery Volts 12

S8 PRP System Elasped Time Meter Hours 0 - 8000

S9 PRP System Pump Life Hours 4500

S10 PRP System O2 / Air mixer O2 21% - 100 %

S11 PRP System Secondary Pressure Relief cm H20 75

S12 PRP System Timed Backup BPM

S13 PRP System Weight Kg ≤ 8

S14 Robustness Drop Height meter 1

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Revision B- Proposed RedesignUpdate:1. Battery Size-> Reduce Size & keep same capacity2. Reduce Circuit Board size-> Create custom board for all electrical

connects3. Phase motor driver to a transistor4. Display Ergonomics5. Overall Size and shape of PEV6. Instruction manual

Additions:7. Visual Animated Display-> Moving Vitals8. Memory capabilities9. USB extraction of Data10. Co2 Sensor as additional Feature to PEV11. Overload Condition due to Pump Malfunction

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Revision B- Proposed RedesignUpdate:1. Battery Size-> Reduce Size & keep same capacity2. Reduce Circuit Board size-> Create custom board for all electrical

connects3. Phase motor driver to a transistor4. Display Ergonomics5. Overall Size and shape of PEV6. Instruction manual

Additions:7. Visual Animated Display-> Moving Vitals8. Memory capabilities9. USB extraction of Data10. Co2 Sensor as additional Feature to PEV11. Overload Condition due to Pump Malfunction

NOT Discussed within Technical Review

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Battery Choice: Tenergy Li-Ion14.8 V4400mAh0.8375 lbs7.35cm x 7.1cm x

3.75cmRechargeable up to

500 timesPrice: $50.99

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Power CalculationCurrent (A)

Voltage (V)

Power (W)

Pump 3 11.1 16.65MCU + electronics 0.5 3.3 1.65LCD 0.15 10 1.5Total 3.65 19.8

Battery Voltage (V) 14.8Battery Capacity (Ah) 4.4Battery Capacity (Wh) 65.12Expected Battery Life (Hrs)

3.29

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Charger (Brick)HP AC Adapter18.5V3.5AmpsPower: 65WMax power: 70WPrice: $14.35

(Amazon)

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Regulation of Power

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Maxim Integrated MAX1737 Battery-Charge Controller

• Wide input voltage range (6-28 V)

• Charges up to four Li+ Cells (4-4.4V per cell)

• Provides overcharge protection

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Texas InstrumentsLM3940 Low Dropout Regulator

• Provides 3.3V from a 5V supply

• Low Dropout Regulator• Can hold 3.3V output

with input voltages as low as 4.5V

• Few external components needed for implementation

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ON SemiconductorMC7800 Voltage Regulator

5-18, 24 V Input voltage range

Can deliver output currents greater than 1 A

No external components needed for implementation

Internal thermal overload protection

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System Operation Flowchart

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Control System

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MCU Pinouts

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General PCB Parts Placement

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• Difference in Absorption between Red and Infrared is used to determine SpO2

SpO2 Sensor

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Simplified Design:

SpO2 Sensor Continued

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SpO2 Flow Chart

Source: Freescale Pulse Oximeter Fundamentals and Design

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Hardware/Software Feature Implementation Plan

1- High Priority- This will get implemented 2- Medium Priority- Foreseeable difficulties may prevent

proper implementation 3- Low Priority- Attempt to implement if time constraints

allow

Function Hardware SoftwareUser controllable

ventilator control system1 1

LCD Interface 1 1Audio Feedback 1 1

Memory retention/ transfer 1 2Touch Interface 1 3

Integrated Battery Charging

2 N/A

SpO2 2 2CO2 2 2

Audio Recording 3 3

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Initial strategy for Testing

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Mass Flow Analysis(Between Pump outlet and Ventilator outlet)

Replacing Mass Flow Sensor with Venturi Analysis•Assume incompressible flow, 10 diameters of straight tube, C=.99

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Option 1 Option 2 Option 3 Option 4

FreeScale MPXV7007

FreeScale MPXV7002

FreeScale MPX12

FreeScale MPXV5010

Score Score Score ScoreCost $13.94 $13.94 $8.67 $12.81 Physical Size (in 3̂) 0.084 0.084 0.292 0.084Compensated (˚C) 0-85 10-60 XXX 0-85Sensitivity (mV/kPa) 286 1000 5.5 450Operating Range (˚C) -40-125 10-60 -40-125 -40-125Operating Pressure (kPa) -7-7 -2-2 0-10 0-10Accuracy 5% 6.25% XXX 5%Output (V) .5-4.5 .5-4.5 Fullscale .2-4.7Easy to Amplify No No No Yes

Rank 2 3 4 1

Pressure Sensor: Selection Criteria

Differential pressure sensor selection

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Freescale-mpxv5050dp Pressure Sensor

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Temperature Compensation

3.3 V

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Expected Pressure change & voltage output

D1 D2 D1 D2 A1 A2 vdot vdot mdot ΔP ΔP Voltagein in m m m^2 m^2 l/min m^3/sec kg/s Pa PSI mV

0.375 0.25 0.0095 0.00635 7.13E-05 3.17E-05 1 1.67E-05 1.97E-05 0.13 1.95E-05 0.0610 1.67E-04 1.97E-04 13.42 1.95E-03 6.0425 4.17E-04 4.93E-04 83.90 1.22E-02 37.76

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Expected Centerline Velocity

Q Q D D A avg V Re n Centerline V Centerline V Mach

l/min m^3/sec in m m^2 m/s m/s mph

25 0.000416667 0.25 0.00635 3.16692E-05 13.15683 5328.183 5.007842 17.3600175 38.83435915 0.050583

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EXPECTED Total Head Loss

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Expected Major Head LossBernouli’s Equation Assumptions

• Constant velocity, height and air densityMajor Head Loss:

• Dependent on length of tube between ventilator and pump exit

Q Q D D L A avg V Re f hl ΔP ΔPl/min m^3/sec in m m m^2 m/s m2/s2 Pa PSI

25 4.17E-04 0.25 0.0064 0.1 3.17E-05 13.16 5328.18 0.0370 50.41 59.69 0.009

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Expected Minor Head LossBernouli’s Equation Assumptions

• Constant velocity, height and air densityMinor Head Loss

• Dependent on the expansion and contraction for Reducer and Diffuser

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Exhaust Pressure Sensor

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Mechanical Relief Valve

Pressure Release at 1 psi Reusable

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Thermal Analysis Heat Dissipation① System Components:

② Applied Heat Loads:

③ Assumptions:1. Neglect Radiation2. Casing acts as a control volume3. System Location at hottest temp every recorded for U.S 330K 4. Heat flux is applied at bottom surface where all components will rest on.5. Free External Convection

T∞=330Kh= 5 W/m^2K(Applied to all

surfaces)Q flux=80 W

PEV

④ Control Volume Schematic:

GOAL: Analyze worst case thermal analysis of system to understand effects of system heat dissipation.

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High Temperature: 359 K 86 ⁰C

For our material, Polystyrene,The glass transition temperature is 95 ⁰C. Therefore at worst case scenario, the material will hold shape without deforming.

Top of enclosure shows little heat transfer concern to handle so user can carry device. A rubber handle will be included on prototype as a precautionary measure as well as usability purposes.

⑤ Heat Dissipation Results:

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Another approach…① Bottom Surface Heat Dissipation:

② Assumptions:

1. Component temperature is worst case.

2. System has been under worst case condition for extended period of time.

3. Neglect convection and radiation on bottom surface.

③ Results:1. Plastic temperature at worst case will never

exceed 120⁰F due to component heating alone.2. This temperature is not enough to deform the

polystyrene surface or cause damage to surrounding components.

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Housing Modifications13026 Physical Extremes:

15in long X 10in high X 7in deep

Projected 13027 Physical Extremes:12in long X 7.5in high X 7in deep

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Housing Modifications

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Housing Modifications

Speaker

O2 Sensor port

CO2 Sensor port

Mask tube ports

BPM Flow Rate Pressure Limit

Mode

CPR Compression #

Manual

Power

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Housing Modifications

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Housing Modifications

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Housing Modifications

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Housing Modifications

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Housing Modifications

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Project ComparisonGOAL: Analyze the size and weight reduction between major contributing components of MSD 13026 PEV to our projected design.

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Summary:

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13027 – Project Schedule through MSD 1

END OF

MSD 1

Project Familiarization/ Research:

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END OF

MSD 1

Technical Evaluations/ Begin Prototyping:

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