1. Development of a Device for Neurochemical Sample Collection from Freely-Moving Monkeys
Client: Dr. Ei Terasawa, Department of Pediatrics
Advisor: Prof. Brenda Ogle, Department of Biomedical Engineering
Group Members: Lauren Eichaker, Sarah Springborn, Ben Fleming, Cole Drifka, and Adam Pala

2. Presentation Outline Background (Research, Experimental Setup)
Client’s Project Goals
Current Design (Components, Problems)
Current Problem Statement
Product Design Specifications (PDS)
Strap Design (Elastic Configuration, Hard Plastic Configuration, Nylon Configuration)
Padding Design (Memory Foam, Silicone, Silicone-Memory Foam Combination, Air Bladder)
Helmet Design (Existing Model, Conical Design, Boxing Helmet)
Solution: Design Decisions
Future Work (Tether System, Non-Specific Use)
Ethical Considerations
Credits
Questions?

3. Background: Research Control of growth and development
Brain’s role in triggering puberty
Measures neuropeptides in hypothalamus for neuroendocrine studies
Rhesus monkeys as model system for humans
Associated Press. “Scientists Map Genome of Rhesus Monkey” 13 Apr 2007.
4 Mar <

4. Background: Experimental Setup
Metal ring implanted into skull
Microdrive unit attached
Monkey transferred to chair
Microdialysis probe inserted
Tubing attached to fraction collector and pump
Monkey confined to chair for 12 hours
Forst SI, et al., Microdialysis methods for in vivo neropeptide measurement in the Stalk-median eminence in the Rhesus monkey, J Neurosci Methods (2007), doi: /j.jneumeth
SAEN. The Mary T. and Frank L. Hoffman Family Foundation. 11 Feb Mar <

5. Client’s Project Goals
Construct protective device for microdrive unit
Free monkey from chairing
Protects microdrive unit from damage

6. Current Design: Components
Cushion-and-Shell Design
Three aluminum pieces: two base halves and porous cylinder
Pieces fit together at an interface
Silicone rubber interior protects the microdrive device
Hose clamp secures the two base halves around interior
Nylon straps for vertical stability
Secured with zip ties
Tether attaches to cylinder via custom interface

7. Current Design: Problems
Ineffective weight distribution
Currently g
Nylon straps do not contribute to support of device
Adjustability
Must be able to accommodate a wide range of monkey sizes

8. Current Problem Statement
To improve on the device created last semester
This involves the following:
Weight reduction
A more secure attachment around monkey’s head
Better cushioning of the microdrive unit

9. Product Design Specifications (PDS)
Safe for monkey
Weight: under 500 g
No sharp edges or toxic components
Safe from monkey
Able to withstand 100 N force
Securely fitting and stable
Promotes mobility

10. Strap Design: Elastic Configuration
Pros:
Accommodates various chin sizes and easy to adjust
Under Armour would minimize discomfort felt by the monkey
Cons:
Monkey would be able to damage the apparatus
Reduced degree of stability

11. Strap Design: Hard Plastic Configuration
Pros:
Monkey would not be able to damage or loosen
Added foam would provide comfort for the monkey’s chin
Cons:
Very difficult to manufacture
Would introduce extra weight and gaudiness

12. Strap Design: Nylon Configuration
Pros:
Easy to adjust in tiny increments
Not much complexity in construction (zip ties)
Cons:
Wastefulness
Puts pressure on facial nerves of the monkey

13. Strap Design: Design Matrix
Security from Monkey (40)
Ease of Use (15)
Adjustability/Comfort (30)
Ease of Construction (15)
Total (100)
Elastic – No Clasp 27 14 22 77
Hard Plastic with Foam 36 10 12 80
Nylon Reconfiguration 32 64

14. Padding Design
The helmet design needs to fit snugly on a wide range of monkey head sizes
The padding will play a large role in keeping the helmet design secure to the monkey’s head
The padding of the design must also be relatively comfortable for the monkey
The padding must be sufficiently lightweight

15. Padding Design: Memory Foam
Pros:
Highly customizable
Easy and cheap to obtain
Cons:
Could pose a one-time use quality that would be wasteful
Monkey could tear off foam and ingest it

16. Padding Design: Silicone
Pros:
Extremely protective of micro drive
Provides exceptional stability to helmet device
Cons:
Silicone is, by nature, very heavy
Does not adjust to fit different monkey head sizes

17. Padding Design: Silicone-Memory Foam Combination
Pros
Easy to obtain
Relatively comfortable
Secure
Cons
Not customizable to different monkey head sizes
Heavy
Expensive and wasteful

18. Padding Design: Inflatable Air Bladder
Pros
Most adjustable design
Lightweight
Easy to manufacture
Cons
May not wick away perspiration from monkey’s head
May not be “monkey proof”

19. Padding Design: Design Matrix
Safety from Monkey (40)
Ease of Use (15)
Adjustability/Comfort (30)
Ease of Construction (15)
Total (100)
Memory Foam 27 13 28 14 82
Silicone 35 8 15 72
Combination (Memory Foam and Silicone) 30 9 19 12 70
Inflatable Bladder 31 26 84

20. Helmet Design: Existing Model
Pros
Available/modifiable
Cons
Too heavy for use
No obvious way to further reduce weight
Silicone insert is very heavy and the device is unwieldy in general
Semi-specific use
Straps did not serve their purpose
A cutaway view of the current design displaying: the tree components, the silicone insert and the tether attached to the top.

21. Helmet Design: Conical Design
Pros
Addresses issue of being unwieldy
Two-component design
Opens up idea of using new materials
Better center of gravity
Cons
Needs a strap system
The Conical Design features a simple cone shape that needs straps to affix it to a monkey’s head.

22. Helmet Design: Boxing Helmet Design
Pros
Encases the monkey’s head
Distributes the weight of the device evenly
Two-component design
Small strap: spanning only the chin
Cons
This could increase total weight
Unique shape requires extra dimensions of the monkey’s skull
Extra padding considerations
This model would encase the monkey’s head. With a boxing helmet as the conceptual model, we will modify it to suit our needs.

23. Helmet Design: Design Matrix
Weight (50)
Ease of Construction (20)
Safety (20)
Ability to Withstand Force (10)
Total (100)
Boxing Helmet Design 42 15 18 9 84
Conical Design 40 7 83
Cylinder Design 30 19 16 6 71

24. Solution: Design Decisions
Boxing Helmet Design
Inflatable Air Bladder
Roller-blade strap
Still considering the use of a watch band as a strap
Materials: either Titanium or a Polymer
Still under investigation/consideration

25. Future Work: Tether System
Majority of the weight located in the tether
Need to reduce this weight to alleviate strain on the monkey’s neck
Possibilities:
Dual Swivel System
Counterweight

26. Future Work: Non-Specific Use
Ideally this helmet would fit monkeys from adolescence to adulthood
Skull size and shape grow considerably during this time
Current design incorporates an inflatable air bladder
This can be altered to fit a variety of head sizes
Still a great deal of variability

27. Ethical Considerations
Research abides by strict federal regulations
Monkeys under constant supervision and care
Monkeys are not harmed or ill-treated during the experiment

28. Credits Dr. Terasawa Kim Keen Professor Ogle Primate Center Staff
Last Semester’s Design Team

29. Questions?