1. Syringe for Injectable Fillers
Advisor: Dr. Paul Thompson
Client: Dr. Justin Piasecki
Therese Rollmann ~ Team Leader
Joseph Cabelka ~ Communicator
Jennifer Wager ~ BWIG
Mark Yarmkovich ~ BSAC

2. Problem Statement
Our goal is to develop a simple syringe device that has a ratchet or incremental mechanism for which a depressed plunger or button will administer a known volume (i.e., 0.1 mL) of an injectable filler such as autologous fat or Sculptra®.

3. Design Constraints Delivers known increment (50-100 µL)
Withstands high temp (121°C) or disposable
Volume 1cc or 5 cc syringes
Sufficient force to dispel filler
Minimize unfamiliar motion

4. Procedure Motivation Lipoatrophy restoration and lip augmentations
Simple procedure
~15 minutes
Quick recovery
Very few risks involved
low risk of allergic reaction, minimal risk of infection
Less permanent than plastic surgery (face lift)

5. Background-Procedure
Transfer to a 1 or 5cc syringe
Insert needle to dermis or subcutaneous fat layer
Inject filler as needle is pulled out
Repeat procedure until visual results

6. Injectable Fillers-Fat
Harvested from abdomen
40-50% rate of cell survival expected
Cell size = µm
Viscosity = 3 Pa·s

7. Injectable Fillers- Sculptra®
Composed of synthetic poly-L-lactic acid
Stimulates body to produce its own collagen
Results last 2 years
Side effects: small bumps under skin, other injection-related effects
Biocompatible and biodegradable

8. Suggested Materials Stainless Steel Grade 420 Plastic: Fluoropolymers
Temper pt./ Melting pt. ºC ºC
Density
7.75 g/cm3
1.5 g/cm3
Cost (per in3)
$4.88
$2.41
Elastic Modulus
200 GPa
0.393 GPa

9. Force
Tested expired collagen
Minimum force: 4.19N

10. Current Device - Dispos-A-Ject™
Advantages
Dispenses uniform increments
Made from surgical stainless steel that is autoclavable.
Disadvantages
Does not fit 3 or 5cc syringes
Bulky
Expensive at $375
Many parts

11. Current Device-Step Meister 1.0
Advantages:
Known increment volume
Effective in dispensing filler
Size and weight
Disadvantages:
Manual rotation
Ergonomics

12. Design I: Step-Meister 2.0
Similar to Step-Meister 1.0
Use of a torsion spring for rotation
Smaller increment sizes (0.1ml0.07ml)

13. Step-Meister 2.0 Advantages: Eliminates manual rotation
Smaller increment sizes
Familiar with design
Disadvantages:
Manufacturing
Torsion spring may cause unwanted movement

14. Design II Button devices advances plunger
Bar locks into increment until button is pushed

15. Design II Advantages: Familiar motion Few parts
Accurate and varied increments
Disadvantages:
Requires practice
Large force may hinder function

16. Design III
Squeeze tabs to unlock plunger
Push to expel filler

17. Design III Advantages: Simple mechanism
Multiple increments can be expelled
Disadvantages:
Unfamiliar motion
Small parts
Manufacturing

18. Design Matrix 8 6 3 5 4 2 7 20 21 17 Step-Meister 2.0 Design II
Design III
Many, small parts (10) 8 6 3
Back pressure (5) 5 4
Varied increments (5) 2
Manipulation (10) 7
Total (30) 20 21 17

19. Future Work Finalize design Research manufacturing possibilities
Test force for autologous fat and Sculptra®
Construction of prototype
Test increment accuracy

20. References
A.D.A.M. Weight Control and Obesity. 11 Oct
Byron Medical. 16 September
Campbell, N and J Reece. Biology. San Francisco: Pearson, 2005.
Encyclopedia of Sports Medicine and Science. 17 September
Dr. Joseph Niamtu. 22 September Phone Interview
Dr. Justin Piasecki. 28 September Interview
Dr. Steve Byrd. 17 September
MSNBC: Fill ‘er up Roundup of Wrinkle Plumpers. 11 Oct
Resitape. 15 February
Sculptra. 16 February
The TexLoc Closet. 15 Febuary