Heart Phantom Client: Orhan Unal Advisor: Willis Tompkins Peter Strohm – Team Leader Lacey Halfen – Team Leader Jessica Hause – Communicator Fan Wu – BWIG Erin Main – BSAC

Outline Background Information Design Constraints Tube Design Atrial Fibrillation Client’s Research Heart Phantoms Design Constraints Tube Design Polymer Block Design Design Comparison Design Matrix Tubing Polyethylene vs. Polyurethane Connections Heart Chamber High Resolution Aspect Future Work

Atrial Fibrillation Affects over 2 million Americans Characterized by Irregular atrial beating Disordered electrical signals Poor blood flow to body Increased blood clot risk Possible symptoms/complications Heart palpitations Shortness of breath Fatigue/lightheadedness Chest pain Stroke (blood clots) Heart Failure

Client’s Research Treat atrial fibrillation MRI imaging Catheter Begin at femoral vein End at left atrium Scar heart tissue Disrupt electrical signals MRI imaging Catheter not visible Risk of puncture Solenoid-tipped catheter FDA approval required Protocol Animal/phantom testing Human testing http://intensivecare.hsnet.nsw.gov.au/five/images/suction_catheter.jpg

Heart Phantoms Commercially available Other phantoms Ultrasound compatible Unnecessarily complex Do not allow ‘blood’ flow No openings for catheter Expensive Other phantoms Not MRI compatible Specific uses Unavailable http://www.cirsinc.com/067_ultra.html

Design Constraints MRI compatible Leak proof All parts transparent

Tube Design Twisting vessels and inlet/outlet vessels made of tubes 3” diameter acrylic sphere to resemble heart Tubes either glued together or attached with connectors Container filled with agarose gel

Polymer Block Design Hollow “tunnels” inside a Polymer block Procedure: Construct and insert dummy vasculature into a container Pour liquid polymer into the container Wait for the polymer to solidify Remove dummy vasculature

Polymer Block Design (Cont) Difficulties: Dummy vessels need to be fixed before the polymer solidifies and easily separated from the polymer after it solidifies

Tubing Polyethylene Polyurethane Thick More rigid Strong, non-leaking Opaque Polyurethane Thin Flexible Strong, non-leaking Clear

Connections Twist Connect Quick Connect Side Connect Quick detachment Simple Water Tight Very small hole for catheter Solid colors Limited angles Quick Connect Quick but complicated detachment Water tight Very small hole for catheter Most are metal Solid colors Limited angles Side Connect Slower detachment Simple Water tight Large hole for catheter Clear Variety of different angles Colder.com Clearpvcpipe.com Legris.com

Heart Chamber Hemisphere Model 2 Hemispheres with ridge Sealed together with an o-ring and plastic screws and bolts Diaphragm placement Continual fluid flow through heart

High Resolution Aspect Visualization of catheter and other vasculature on MRI Large hole in center for catheter to pass through Small holes represent additional vasculature Material Acrylic Block

Future Work Optimize materials and methods for tube design Tubing connections Heart connections Sealing techniques Construct and test prototype Possibility of developing second prototype for polymer design depending on budget