Development of a Device for Neurochemical Sample Collection from Freely Moving Monkeys Team Members: Angwei Law Cole Drifka Lauren Eichaker Paul Schildgen Client: Dr. Ei Terasawa, Dept. of Pediatrics Advisor: Professor John G. Webster, Dept. of BME

Outline Client Research Experimental Setup Current Design Problem Statement Design Requirements Strap Alternatives Cylindrical Alternatives Modification and Testing Ethical Considerations

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 2008. <www.foxnews.com/story/0,2933,265907,00.html>.

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: 10.1016/j.jneumeth.2007.09.001 SAEN. The Mary T. and Frank L. Hoffman Family Foundation. 11 Feb 2008. 4 Mar 2008. <www.all-creatures.org/saen/res-fr.html>.

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

Current Design “Cushion and Shell” design Cushion: silicone rubber core Shell: thin aluminum 3 components interlock at an interface Base is form fitting around head Total Weight: 475.5 g

Current Problem Statement Improve on the device created last semester Involves making the device: Lighter More secure Better able to cushion the microdrive unit

PDS Safe for monkey Safe from monkey Promotes mobility Weight: Under 500 g Safe from monkey Force: Withstand 100 N Stable Promotes mobility

Strap Design Alternatives Configuration needs to fit on multiple monkeys with variable head sizes Design features a single piece Fastens on each side of base and in back of the collar Nylon material

Lock and Key Pros Cannot be opened without key so monkey cannot open it Easy to use Cons Keeping track of key Restricted adjustability Determining increments

Zip Tie Pros Cons Adjustable in small increments Easy to use Can not disengage without scissors Cons Wasteful with respect to the number of zip ties used

Belt Loop Pros Cons Ease of manufacture Ease of use Safety Not very adjustable

Design Matrix-Straps CRITERIA WEIGHT LOCK & KEY ZIP TIE BELT LOOP Security from Monkey 30 28 25 20 Adjustability Ease of Use 17 22 Ease of Construction 15 13 TOTAL 100 83 95 80

Cylindrical Top Alternatives Protects the upper extension of the microdrive unit 15 cm tall cylindrical shell 5 cm outside diameter 3 mm thick lip on lower end Threaded holes on the top for tether attachment Aluminum Porous Aluminum Plastic

Cylindrical Top Alternative Aluminum Pros Strength Easy of manufacture Cons Weight Estimated-117.6 g Measured-110.9 g Potential for anaerobic bacteria

Cylindrical Top Alternative Porous Aluminum (3 mm Holes) Pros Strength Easy of manufacture Overall Safety Cons Weight Estimated (60 holes)-115.6 g Only 2.03 g difference/60 holes

Cylindrical Top Alternative Plastic (HDPE) Pros Strength Twice as thick Weight Estimated-84.4 g 34.4 g difference Cons Ease of manufacture Safety (Interface) Interface

Design Matrix-Cylindrical Top CRITERIA WEIGHT ALUMINUM POROUS ALUMINUM PLASTIC Weight 30 20 22 25 Ability to Withstand Force 28 26 Safety Ease of Construction 10 9 4 TOTAL 100 85 87 81 Vest with rod and ring Cushion Cylinder Helmet Security from Monkey (30) 15 18 Security from Slip (20) 7 10 Ability to Withstand Force 25 Ease of Use (10) 3 8 Ease of Construction 5 6 Safety Total 53 70 67

Future Work Test on monkey Incorporate straps Available beginning of November Incorporate straps Make design modifications Weight considerations Non-specific use Swivel system Microdrive visibility

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

Credits Ei Terasawa Kim Keen Bruce Pape Professor Webster Primate Center Staff Last Semester’s Design Team

Questions?