P13027: Portable Ventilator

transcript

Team Leader: Megan O’ConnellMatt Burkell

Steve DigerardoDavid Herdzik

Paulina KlimkiewiczJake Leone

1 of 52

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

33 of 52

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

44 of 52

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

55 of 52

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

3.75cmRechargeable up to

500 timesPrice: $50.99

66 of 52

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)

77 of 52

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

(Amazon)

88 of 52

Regulation of Power

99 of 52

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

1010 of 52

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

1111 of 52

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

1212 of 52

System Operation Flowchart

1313 of 52

1414 of 52

1515 of 52

1616 of 52

1717 of 52

1818 of 52

Control System

1919 of 52

MCU Pinouts

2020 of 52

General PCB Parts Placement

2121 of 52

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

SpO2 Sensor

2222 of 52

Simplified Design:

SpO2 Sensor Continued

2323 of 52

SpO2 Flow Chart

Source: Freescale Pulse Oximeter Fundamentals and Design

2424 of 52

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

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

SpO2 2 2CO2 2 2

Audio Recording 3 3

2525 of 52

Initial strategy for Testing

2626 of 52

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

2727 of 52

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

2828 of 52

Freescale-mpxv5050dp Pressure Sensor

2929 of 52

Temperature Compensation

3030 of 52

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

3131 of 52

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

3232 of 52

EXPECTED Total Head Loss

3333 of 52

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

3434 of 52

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

3535 of 52

Exhaust Pressure Sensor

3636 of 52

Mechanical Relief Valve

Pressure Release at 1 psi Reusable

3737 of 52

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

④ Control Volume Schematic:

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

3838 of 52

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:

3939 of 52

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.

4040 of 52

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

4141 of 52

Housing Modifications

4242 of 52

Speaker

O2 Sensor port

CO2 Sensor port

Mask tube ports

BPM Flow Rate Pressure Limit

CPR Compression #

Manual

4343 of 52

4444 of 52

4545 of 52

4646 of 52

4747 of 52

4848 of 52

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

4949 of 52

Summary:

5050 of 52

13027 – Project Schedule through MSD 1

END OF

Project Familiarization/ Research:

5151 of 52

END OF

Technical Evaluations/ Begin Prototyping:

5252 of 52

P13027: Portable Ventilator

Documents