1. Integrated Fluorescent Probe & Radiofrequency Ablator
Rachel Riti & Alex Walsh
Advisors: Bart Masters & Anita Mahadevan-Jansen

2. Outline Background – RFA, Fluorescence Motivation Objective
Performance Criteria
Proposed Designs
Future Work

3. Radiofrequency Ablation
Ablation of tissue using high frequency radio waves
Applied in lung, kidney, breast, bone and liver tumors
Explain the protocol for RFA

4. Fluorescence
Emission of light by a substance that has absorbed light of a different wavelength
Property of biological tissue
Collagen, NADH, Elastin

5. Motivation Determination of ablated area Current Method
Thermocouples
Alternative Methods
Tissue Markers, Thermal Camera
Proposed Method
Fluorescence

6. 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

7. Objective
Design a probe capable of both fluorescence and measurements of RFA
Build the designed probe
Test the probe

8. Size Constraints

9. Performance Criteria Maintain RFA efficiency
Determine region of ablation
Accuracy
Within 10% of original
fluorescence intensity
Determine margins of
ablation within 5%
Brainstorming Ideas

10. Prototype 1 15 cm RFA Probe 19 cm Fiber optic 1 collection fiber,
1 excitation fiber
Laser

11. 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

12. Fiber Geometry
Collection Fibers
Excitation Fibers

13. Fiber Dimensions

14. Prototype 2 Fiber enclosed 2-5 cm 15 cm 2 excitation fibers,
Increase the gauge of the trocar shaft
2 excitation fibers,
2 collection fibers

15. Validation RFA functionality not compromised
Fiber functional during RFA
Probe entry not affected
Adjustable fiber length during procedure
Fluorescence measurements accurately indicate ablation area

16. Timeline Timeline Process Description November Research
Attempt to answer the following questions:
What is an RFA?
How is temperature measured during RF ablation?
How can fluorescence be used to measure temperature?
December
Develop Preliminary Design
Determine the best way to build a combined RFA and fiber optic so that both instruments are fully functional when integrated.
January
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.
February
Integrate RF Ablator and Fiber
Build the fibers into the prongs of the RFA.
Test
Test the functionality of the RFA and the fibers as an integrated unit using bovine livers.
March
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.
April
Complete Redesign
Complete revised design with supervision of mentors and make necessary changes.
Test the functionality of the redesigned probe on bovine livers.