Phantom Simulation of Liver Motion During Breathing Group Members: Ian Dallmeyer Tuta Guerra Ian Henderlong Advisor: Dr. Bob Galloway

Background Over 17,550 people in the U.S. diagnosed with primary liver cancer in 2005. 15,420 will die of liver cancer in 2005. Cancers often spread throughout the liver. Traditional surgery difficult/not possible.

Image Guided Liver Surgery Imaging Techniques CT, MRI, Ultrasound, X-ray angiography Use data to create 3-D registration of liver Surgical Therapy Radio Frequency Ablation (RFA) Chemoembolization Chemotherapy Embolization RFA make large-volume tissue ablation effective for local control of some cancer. Microwave, cryotherapy, and high intensity focused ultrasound devices as well as concentrated radio frequencies to kill localized tumor. Physicians insert a catheter through the patient's arteries to the liver and inject a high-dose of chemotherapy into the cancerous tissue. Next, the catheter releases an embolizing material that closes the blood vessels that feed the tumor. The result: the chemotherapy is trapped inside the tumor, and the tumor dies.

Success Rates of IGLS

Problem Need an anatomically correct model which accurately simulates liver motion due to breathing to test IGLS techniques.

Advantages of Phantom Model Porcine Liver Approx. $1,000 – $2,000 per liver Not anatomically correct Not reusable Phantom model Anatomically correct Reusable Time and space-saving Silicon Art Department

Market Potential Current methods too invasive Low survival rate Long recovery periods Estimated market for IGLS 10x current IGNS market ($3.0-$7.5 billion) Global Market Liver Cancer is 10X more common in developing countries Disadvantages with Competing Technologies – HFJV Duration of 45 min. Cardiovascular Complications Patient Response Expensive

Phantom Liver System Design Ground power source w/ switch 2N2222 NPN Transistor Muscle Wire (All encased in PVC housing)

Shape Memory Alloy Shape memory alloys deform upon heating Martensite – low T, soft, deformable Austenite – higher T, hard, non-deformable Other SMA’s - CuZnAl, and CuAlNi

Muscle Wire Specs Alloy: nitinol R 50 /m Activation T 70oC Diameter = 150mm Act. Current = 400 mA Vact =~ 10V Cooling time = 2 s

Design Specs 1-D Linear motion (cranial- caudal) 10.8 + 2.5 mm (ATLM) Breath Frequency ~= .11 Hz. (1 breath/9 sec) Active optical position sensor (Optotrak 3020)

Current Work Circuit Design Power Source Construction Rebuild Base and Track System

Future Work Construction of PVC housing Research for final paper/poster Total model assembly

References Herline AJ, Stefansic JD, Debelak JP, Hartmann SL, Wright Pinson C, Galloway RL, Chapman WC. Image Guided Surgery: Preliminary; Feasibility Studies of Frameless Stereotactic Liver Surgery. June 1999 Archives of Surgery 134:644-650 Tarczy-Hornoch P, Jones D, Zerom B, Woodrum D, and Berk R. Mechanical Ventilators. [Online] Available http://weber.u.washington.edu/~neonatal/NICU- WEB/vents.html, 1998.