1. Advisor: Paul Thompson
TISSUE SAMPLE
PREPARATION DEVICE FOR
BIOCHEMICAL ANALYSIS
Clients: Dr. Jeff Ross, Charles Tessier
UW Medical School
Department of Oncology
Presented by: Sara Alford
Christine Koranda
Carla Maas
Ryan Roth
Advisor: Paul Thompson

2. PROJECT RATIONALE Biochemical analysis on tumor sample
Automation in preparation process
Potential clinical applications

3. PROBLEM STATEMENT
To design a device that completes the preparation process done manually to prepare a tissue sample for biochemical analysis.
Freeze tissue (with liquid nitrogen)
Grind tissue to a powder

4. EXISTING TECHNOLOGY Jet Pulverizer© Bio-Pulverizer© BeadBeater©
Accessed from
Bio-Pulverizer©
Accessed from
BeadBeater©
Accessed from

5. DESIGN
REQUIREMENTS
Freeze sample (<1 gram)
Grind to powder similar to powdered sugar (~10 mm)
Avoid sample loss

6. DESIGN CONSTRAINTS Materials must withstand cold temperatures (-196oC)
Device should fit on a lab bench
Components easy to clean

7. Pneumatic Impulse Sampler
DESIGN SOLUTION
Pneumatic Impulse Sampler
Strengths
Grinding pattern control
Inexpensive
Constant downward force
Weakness
Compressed air required

8. PROTOTYPE FEATURES Pneumatic cylinder Grinding head Electrical control
Grinding chamber
Insulating chamber

9. GRINDING CHAMBER AND HEAD
Matching contours
Minimal sample spray
Stainless steel design 4” 1”

10. INSULATING CHAMBER Stainless steel Polystyrene Inner shell
Provides support and connection
Polystyrene
Outer shell
Provides insulation for grinding chamber 4”
2.75”

11. PNEUMATIC SYSTEM COMPONENTS
air supply
regulator
solenoid valve
pneumatic
cylinder
pivot mount

12. Improvement on flasher Astable mode → pulses
ELECTRICAL CONTROL
Improvement on flasher
More control over time on/off
Astable mode → pulses
555 timer circuit → logic relay
Potentiometer to change values

13. R2, C – extend ON and OFF time Pot – extends only ON time

14. ELECTRICAL CONTROL

15. MISCELLANEOUS COMPONENTS
Christmas light flasher
Christmas lights
Spiked fitting off regulator
1/4” tubing
Ring clamps

16. OPERATIONAL PROTOTYPE
Cylinder pounds
3-4 times/second
Rod does not completely retract
Ideal: avoids sample spillage
Cylinder fitting and tubing
protrude too far
Interferes with alignment
Need elbow joint

17. OPERATIONAL PROTOTYPE

18. PROTOTYPE TESTING Preliminary Test: grinding
room temperature substance
Secondary Test: integrate cooling
meat or mouse liver with liquid nitrogen
Final Testing: quantify grinding
centrifuge and measure loose protein

19. FUTURE CONSIDERATIONS
Space constraints
Reduce excess base size to save lab space
Minimize buckling
Increase range of movement at current pivot joint
Temperature alarm
Informs technician to add more coolant
Integrate twisting motion
Shearing forces grind sample

20. QUESTIONS?