Resporite

Elisa FungLindsay Kugler

BeiXian TangGabriela Vargas

Little Patients, Big Demands

Motivation

• Mortality rate for children under the age of 5 in Africa is double that of the rest of the developing world– 166 deaths per 1000 children

• Respiratory distress syndrome (RDS) is the leading cause of death for underweight infants– Can be treated with ventilators

• Design a reliable, easy-to-use, and low-cost ventilator for use in the developing world

Design

Power source

Warning system/

system shut down

Tire pump

Pressure storage

chamber Valve 1: Regulates

pressure to 5psi

Valve 2: Regulates

pressure to 5cm H2O

Humidifier:Humidifies and

filters air

Nasal cannulae

Bubbling indicates system is working

Pressure, humidity, & temperature

sensors

Bike pump

Design

Midterm Goals

• Establish connections between components

• Test components individually and as a system• Determine length of time to fill & empty chamber• Set outgoing air pressure to 5-7 cmH2O• Determine flow rate• Humidify and filter air

Design Process

• Component 1: Air compressor– Attempt 1: Mattress pump– Attempt 2: Tire pump

• Component 2: Pressure storage chamber• Component 3: Valves

– Valve 1 (0-150 psi)– Valve 2 (0-2 psi)

• Component 4: Humidifier

Testing: Pressure Storage Chamber

• Purpose– Determine the time required to fill the pressure storage chamber.

• Results– Exponential relationship between time and pressure

Testing: Regulating Pressure

• Purpose– Determine if desired output pressure (5-7 cmH2O, or 0.07-0.10 psi)

• Results– Desired pressure achieved

0 cmH2O 5 cmH2O

Testing: Pressure Duration

• Purpose– Determine how long constant pressure will be observed at valve output with

varying chamber pressure

• Results– Determined that optimal starting pressure is 60 psi– Pressure in chamber does not last as long as desired

Time for Chamber Exhaustion

0

50

100

150

200

250

300

350

20 40 60 80Initial Pressure (psi)

Tim

e (s

econ

ds)

Time at 5 cmH2OTime until 0 psi

Testing: Humidifier

• Purpose– Determine effects of humidifier on system

• Results– Increases amount of time chamber can sustain desired pressure– Air is humidified

Time for Chamber Exhaustion with Humidifier

0

50

100

150

200

250

300

350

20 40 60Pressure (psi)

Tim

e (s

econ

ds)

Time at 5 cmH2OTime until 0 psi

Testing: Flow Rate

• Purpose– Determine flow rate at 5-7 cmH2O

• Results– Flow rate approximately 2.5 L/min

• Ideal flow rate is 5 L/min

Water (mL) Time (s)

100 2.07

200 4.34

300 7.13

400 9.88

500 12.34

Conclusion

• Macroscale Prototype– Major components of system connected– Pressure of 5-7 cmH2O achieved– Air flow rate of 2.5 L/min achieved– Humidified and purified air

Future Work

• Optimize flow rate for macroscale system• Incorporate temperature parameters• Backup system: bike pump, battery

• Microscale device to optimize current ventilator system– Electrical feedback system using LEDs and buzzer

Acknowledgments

• Dr. Gordana Vunjak-Novakovic• Dr. Samuel Sia• Dr. Helen Towers• Dr. Jen-Tien Wung• Yukkee Cheung• Keith Yeager• Sean Burgess• Rob Maidhof• Jonathan Belmont

Questions

?