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Problem Statement. The purpose of this project is to develop a low resistance breath condensate system that can handle the very high ventilations of human exercise. The system must allow for simultaneous exhaled gas and condensate collection during exercise. . Background Information.
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Problem Statement The purpose of this project is to develop a low resistance breath condensate system that can handle the very high ventilations of human exercise. The system must allow for simultaneous exhaled gas and condensate collection during exercise.
Background Information • Cells in lungs produce fluid containing mediators, ions, and cytokines • Analysis of the fluid can be used to diagnose respiratory ailments • Currently, only invasive procedures are used to obtain this fluid • bronchoalveolar lavage • induced sputem
Background Information • Exhaled breath contains small amounts of the respiratory fluid that can be condensed out of breath non-invasively and analyzed • Currently there is a system to do this but only at rest, not while exercising (Jaeger system)
Design Criteria • Minimal resistance during expiration • Visible condensate collection • Must cool condensate without freezing • Minimum sample size 5mL collected in 7 minutes • Compatible with current system • Does not compromise patient safety
Prototype History • Initial Prototype • Copper v-shape tube submerged in ice water bath • Limitations • Cumbersome cooling system • Invariable cooling temperature • Hidden condensate collection • Faulty test tube attachment • Unsophisticated heating section
Current Prototype • Collection Vial Attachment • Plastic cap cemented to PVC • Spout leads condensate into vial • Assembly Method • Epoxy copper fittings • Cemented PVC joints • Caulk sealant
Accomplishments this Semester • Optimized the system • Added a water pump to circulate ice water • Considered using electrically controlled peltier devices for cooling • Designed/redesigned a plunging device to extract all condensate • Built a second identical prototype to use in series with the first so that while one is being plunged the other is in use • Compared test data to theoretical values
Continued Accomplishments • Filed Invention Disclosure • Unfortunately WARF chose not to pursue a patent or licensing for our device • Completed Outreach Presentations
Prototype Characterization • Coolant temperature: 33o F • Air temperature at apex: 69o F • Cooled from exhaled breath at 98.6o F • Resistance added is 16% • Calculated from pressure drop through the system
Theoretical Heat Transfer • Q/t = (kA (Th-Tc)) / d • Q/t is heat transfer per unit of time • k is the thermal conductivity • A is the area • T is the temperature • d is the thickness of the barrier • Our Q/t value is 196kW
Theoretical Resistance • Head Loss • Due to contraction = 1.52 m • Due to 90o bend = 1.42 m • Total minor head loss = 1.94 m • Pressure drop = (h*p*g)/100000 =3.62 mm H2O
Human Subject Protocol • Drafted a research protocol to incorporate device in testing • Study will investigate the correlation between histamine levels and bronchospasm severity in asthma, and the refractory period theory • Visit 1: Baseline testing • Visit 2: • 90% of max for 10-12 minutes • 15 minutes of rest • 90% of max for 10-12 minutes
Thank you! • Dr. Marlowe Eldridge • Hans Haverkamp • Dave Pegelow • Dr. Glennys Mensing • Dr. Naomi Chesler