Megan Foran, Danny Jones, & Frank MoynihanDr. Bob Wilkinson, Ph.D.

Need

Starling’s Law can be difficult for cardiophysiology students to visualize

To aid comprehension, students need an interactive learning model to supplement the lecture and reading material

The model should allow the students to control the variables of mechanical circulatory regulation:Stroke Volume, Heart Rate, and

Peripheral Resistance

Specific Design Requirements

Design SpecificationsPortable & Easy to Use

2-5 kg; 1-2 m in circumferenceRelatively Inexpensive (<$500)SustainableDiscrete structures

Left ventricle, Arteries, Veins, Resistance Vessels (Capillary Bed)

Mechanical Pump (LV), controlled by student, supplies power to the system

Variable resistance in capillary bed: (0,∞)Variable fluid volume within the system: (0,3 L)

Details of the Chosen Design

Elements of the DesignBiological Component Mechanical AnalogFluid Left VentricleArteries and VeinsResistance Vessels

Variable Resistance Mechanism

WaterPrimer BulbChambersPVC TubingNeedle Pinch Valves

FluidWaterCheapSimpleAbundantSafe

Left VentricleSierra ¼’’fuel line primer bulbMechanical, controlled by the studentTwo valves allow for unidirectional flowBarbed fittings

Sierra ¼” Fuel Line Primer BulbMade by iBoatsFlouroelastomer$18.27 eachLead time: 2-5 days

Arteries and VeinsClear PVC chambersAir and water levels model compliance

Graduated markings Threaded cleanout adapter and plug

Arteries & Veins Variable compliance stopcock

Shallow base cap$171.81 eachLead time: 1-2 weeks

Resistance Vessels¼” PVC tubingLow rigidityDurableLow costsVariety of sizes and fittings

Lead time: 2-5 days

Resistance MechanismNeedle Pinch Valves

DurableLow cost: $41.00 Mechanical InputSafeCompact SizeResistance (0,∞)

Conclusions

Did we solve the problem?Improved sustainability Consistent visual feedbackImproved resistance mechanism

Increased user-friendliness and simplicity

Future DirectionsTeaching Heart team will not continue on to BME402

Willing to stay in touch with the client to provide necessary support

What was learned?Communication is key, working together much more effective

Realistic goals and deadlines

What would be done differently?

Improve communication with client, focus on the clients needs

More innovative design concept

More specific project management

Intellectual Property

Teaching Heart team not seeking IPRelinquishing any potential IP to the client

Works CitedChamber, luer valves and fittings, adapters

<http://www.coleparmer.com/>PVC pipe, fittings,valves

<http://www.muellerindustries.com/products>Tubing, valves, fittings

<http://www.mcmaster.com/>."Primer Bulb." EPA Certified S : Attwood

Marine. Attwood Marine Products. http://www.attwoodmarine.com/store/product/epa-certified-primer-bulb.

US Plastics <www.usplastic.com>.

Questions?