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Development of a Device for Neurochemical Sample Collection from Freely Moving Monkeys. Angwei Law Cole Drifka Lauren Eichaker Paul Schildgen. Team Members :. Client:. Dr. Ei Terasawa, Dept. of Pediatrics. Advisor:. Professor John G. Webster, Dept. of BME. Outline. Client Research
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Development of a Device for Neurochemical Sample Collection from Freely Moving Monkeys Angwei Law Cole Drifka Lauren Eichaker Paul Schildgen Team Members: 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 • 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 • 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 • Ease of manufacture • Ease of use • Cons • Safety • Not very adjustable
Cylindrical Top Alternatives • Cylindrical Top • 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
Interface 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)
Design Matrix-Cylindrical Top Vest with rod and ring Cushion Cylinder Helmet Security from Monkey (30) 15 18 18 Security from Slip (20) 7 15 10 Ability to Withstand Force (30) 25 25 25 Ease of Use (10) 3 7 8 Ease of Construction (10) 3 5 6 Safety Total 53 70 67
Future Work • Test on monkey • 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