1. Device to Improve Diagnostic Yield of Fine Needle Aspiration
Client: Dr. Frederick Kelcz
Advisor: Professor Naomi Chesler
Team Members: Jason Tham
Chou Mai
Robyn Hrobsky
Aaron Freis

2. Fine Needle Aspiration (FNA)
Biopsy method
Performed in:
Lymph Nodes
Neck Cysts
Thyroid Gland
Breast Tissue
Types of Samples:
Malignant
Benign
Test Inconclusive

3. FNA Procedure Small needle inserted into tissue mass
Mass isolated by hand
Needle moved in and out
Sample examined for abnormal cells
Multiple procedure passes typical

4. Problem Statement Improve FNA procedure: Devise: Test on:
Single timely procedure
Maximize sample yield
Devise:
Automated needle oscillation device
Automated vacuum mechanism
Test on:
Phantom tissue
Human tissue in clinical setting

5. Design Constraints Test Variables Performance Requirements
Needle oscillation frequency (0 – 10 Hz)
Needle stroke length (5 – 20 mm)
Performance Requirements
Reusable and repeatable
Easily sanitized between procedures
Handheld size
Safety Standards

6. Previous Achievement Motor-wheel model Vacuum by hand
Yielded sample size of 0.63mm3
Maximum Frequency: 7Hz

7. Prototype Complications
Gear grinding
Difficulty adjusting stroke depth
Inertial vibration
Poor repeatability

8. Design 1: Improved Motor and Wheel
Improve alignment of mechanical components
Implement ABS plastic encasement
Implement Delrin plastic bearings

9. Design 1: Pro’s and Con’s
Common components
Internal power source
Never been patented
Con’s
Force inconsistency
Vibration
Motion not entirely linear

10. Design 2: Pneumatic Device
Pneumatic Implementation
Control Components
Gas Pressure
(0-30 PSI)
Signal Control
Flow
Signal
Signal
Pneumatic Valves
Op Amp
Dell Latitude
Flow
-Valve Control VI Software
-LabJack Interface
-Signal Amp or
Mosfet / Relay
Device Actuator

11. Design 2: Pro’s and Con’s
Frequency is exact
Needle stroke easily adjusted
Ergonomics, acoustics and fluidity
Consistent needle force
Cons
Tubes and cords
Limited to square wave drive

12. Design 3:Conceptual Designs
Sonic Scaler
Dentistry
Air-powered
Vibration at 6000 Hz
Vibration Motor
Linear force ≈ N
Weight less than a gram
Radius ≈ 4 mm
Vibration motors

13. Improved Motor and Wheel
Design Matrix
Feature
(possible points)
Improved Motor and Wheel
Pneumatic
Safety (Essential)
Yes
Ergonomics (10) 2 7
Durability (10) 5
Repeatability (22) 14 17
Frequency Adjustability (22) 16 20
Stroke Adjustability (22) 10 15
Patient Comfort (10) 6
Cost (4) 4
TOTAL (100) 56 76

14. Competition Cameco Syringe Pistol Tao Aspirator
Close hand-to-needle distance
Automatic plunger withdrawal
No drive mechanism

15. Future Work Construct pneumatic prototype
Test on animal and human tissues
Clinical trial
Develop automated vacuum system
Research conceptual improvements
Patent design ideas

16. Reference
BME Website. < March 6, 2007
Breast Cancer Awareness. < March 5, 2007
Breast eNotes < March 6, 2007
Chris Goplen. Solid Works Model of Wheel and Motor design. 12/2006.
Designs and Technology. < March 3, 2007
Fine Needle Aspiration Biopsy of the Thyroid Gland Mayo Foundation. < March 5, 2007.
Minebea-Matsushita Motor Corporation [ VIBRATION MOTOR FEATURES ] Minebea-Matsushita Motor Corporation. < March 5, 2007.
Pneutronics-Miniature Fluidic Control. < March 3, 2007
Sergei Egorov’s Lego Page. < March 2, 2007
Sonic Scalers and Air Scalers from Lone Star Dental Corp. Lone Star Dental Corporation. < March 5, 2007.
Tao Aspirator Tao & Tao Technology, Inc. < March 5, 2007.