Integrated Fluorescent Probe Radiofrequency Ablator Rachel Riti Alex
Integrated Fluorescent Probe & Radiofrequency Ablator Rachel Riti & Alex Walsh Advisors: Bart Masters & Anita Mahadevan. Jansen 1
Outline • • • Background – RFA, Fluorescence Motivation Objective Performance Criteria Proposed Designs Future Work 2
Radiofrequency Ablation • Ablation of tissue using high frequency radio waves • Applied in lung, kidney, breast, bone and liver tumors 3
Fluorescence • Emission of light by a substance that has absorbed light of a different wavelength • Property of biological tissue – Collagen, NADH, Elastin 4
Motivation • Determination of ablated area • Current Method – Thermocouples • Alternative Methods – Tissue Markers, Thermal Camera • Proposed Method – Fluorescence 5
Temperature Dependence of Fluorescence Walsh A, Masters DB, Jansen ED, Welch AJ, Mahadevan-Jansen A, The Effect of Temperature on Fluorescence: An Animal Study, Lasers in Surgery and Medicine. Publishing Pending 6
Objective • Design a probe capable of both fluorescence and measurements of RFA • Build the designed probe • Test the probe 7
Size Constraints 8
Performance Criteria • Maintain RFA efficiency • Determine region of ablation • Accuracy – Within 10% of original fluorescence intensity – Determine margins of ablation within 5% Brainstorming Ideas 9
Prototype 1 RFA Probe 15 cm 19 cm Fiber optic 1 collection fiber, Laser 1 excitation fiber 10
Validation • • RFA functionality not compromised Fiber functional during RFA Probe entry not affected Observable significant difference between ablated and normal tissue • Measurement of ablation area 11
Fiber Geometry Collection Fibers Excitation Fibers 12
Fiber Dimensions 13
Prototype 2 Fiber enclosed 2 -5 cm 15 cm 2 excitation fibers, 2 collection fibers 14
Validation • • • RFA functionality not compromised Fiber functional during RFA Probe entry not affected Adjustable fiber length during procedure Fluorescence measurements accurately indicate ablation area 15
Timeline Process Description Attempt to answer the following questions: November Research What is an RFA? How is temperature measured during RF ablation? How can fluorescence be used to measure temperature? December January February March April Develop Preliminary Design Determine the best way to build a combined RFA and fiber optic so that both instruments are fully functional when integrated. Reevaluate Design Review the previous design with supervision of mentors and make necessary changes. Build Fiber Follow the necessary steps to create multiple fibers for collection. Integrate RF Ablator and Fiber Build the fibers into the prongs of the RFA. Test the functionality of the RFA and the fibers as an integrated unit using bovine livers. Design Critique Determine the functionality of the integrated unit and possible areas of redesign. Possible Further Research Expand research to include mechanical aspects of RFAs and fiber optics, as well as safer design techniques. Begin Redesign Begin constructing a revised design for the probe. Complete Redesign Test Complete revised design with supervision of mentors and make necessary changes. Test the functionality of the redesigned probe on bovine livers. 16
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