This document summarizes the tasks and procedures involved in conducting research on reach and grasp movements using non-human primates. It describes repairing and calibrating objects used in experiments, developing a MATLAB program to randomize experimental conditions, and fabricating EMG electrodes to record muscle activity. The goal is to understand the daily challenges of conducting this research and ensure accurate and reliable data collection.
1. Behind The Scenes Of Reach
To Grasp Research
Petroula N Karagiannis
University of Minnesota-Fall 2006
Advisor: Dr. Timothy Ebner, MD PhD
Department of Neuroscience
Co-Advisor: Jodi Prosise
Department of Biomedical Engineering
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2. Outline
In depth examination of procedures and everyday
tasks critical to conducting the Reach to Grasp
research.
Investigation Requirements:
Non-human primates
Objects
Matlab Program
EMG Electrodes
Motion Analysis
The importance lies in the understanding of the
daily challenges encountered by the team, which
may be overlooked at times.
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3. Primary Objectives
Repair, verify and calibrate objects
Design a Matlab Program
Develop and test electrodes
Prosise 2006
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4. Repairing Objects
Materials Needed:
Screws 2nd object piece
Set screw
O-rings O-ring Force sensor
Force sensing resistors
Allen wrench
Wire cutter/striper Main object piece
3rd object piece
Heat shrink
Needle nose pliers
Standard rosin core solder
Electrical and padded tape
Solder tool stand/iron
Scissors
Screw driver
Colored wires
Alcohol wipes
Connectors and housing Prosise 2006
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9. “rangen”-Random Numbers
Generates a random matrix of a specified size and element interval
without repeats in the columns of the matrix.
function rangen()
clear all;
clc;
Objects_to_randomize = input('Enter the number of objects you
want to randomize:')
Days = input('Enter the number of days you want to output:')
Trays_to_randomize = input('Enter the number of trays you want to
randomize:')
[ignore, objects] = sort(rand(Objects_to_randomize, ceil(Days)))
[ignore, trays] =
sort(rand(Trays_to_randomize, ceil(Days)))
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11. “rangen”-Sample Output
Enter the number of objects you trays =
want to randomize:5 1 4 2
Objects_to_randomize = 4 1 5
5 5 5 1
3 2 4
2 3 3
Enter the number of days you want
to output:3
Days = objects =
3 2 3 5
4 5 1
3 2 4
Enter the number of trays you want 5 1 2
to randomize:5 1 4 3
Trays_to_randomize =
5
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13. EMG Electrodes
Requirements
3T wires ~ 3-4 ft long
Twist 2 wires ~ Drill
Hypodermic needle ~ Gage 25
Specific manufacturer
Procedures
Dull edge ~ Gage 27
Flush H2O ~ Syringe
Insert wire ~ Gage 25
Strip Teflon coating ~ 1 mm and 0.5 mm
Pull back wire ~ 1.5-2 mm
No contact
Verification
Test for signal ~ success!
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14. Closure Mmm, this hair net
sure feels tight…
Advancement and completion of the research conducted by the
Reach and Grasp team.
References/Acknowledgments:
Dr. Timothy Ebner, MD PhD
Jodi Prosise
Dr. Claudia Hendrix, PhD
Dr. Carolyn R. Mason, PhD
Sarah Jacobson
Mahdi Khorasani
Group at Ebner Lab
Thank you!
Questions/Comments?
kara0115@umn.edu
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Editor's Notes
Good morning everyone and thank you for attending my presentation. My name is Petroula Karagiannis and I’m going to talk about my research here in the lab behind the scenes of the Reach and Grasp.
Over the past months I’ve been performing the everyday tasks necessary for Reach to Grasp experiments that often overlooked. These tasks are important for the research to run smoothly and in a timely fashion. It involves non-human primates, objects, a matlab proram, EMG electrodes and motion analysis.
Specifically, my focus was on …
The objects require frequent repair, since they are consistently damaged by the monkeys as well as the lab team and myself. They are quite sensitive, so any twisting or pulling on the wires would potentially cause it to malfunction. If the force sensing resistors or the padded tape are out of place, then the object will not record voltages from the monkeys grasp. Here you can see the materials needed to repair the objects are quite small in size compared to the human hand, thus making it challenging to replace certain parts, for instance the o-rings and the screws.
…and to do this you connect the object to the relay box and open up the appropriate calibration file. Then you manually determine if the they work properly by pressing on the each of the object side pieces and detecting voltage outputs. The figures show what the screen output should look like when the object is working appropriately.
…and to do this you place an amount of weights on each object side piece, deviating from 1 to 1000 grams and record the corresponding voltage outputs.
This is sample a calibration graph for object 18 which shows the relationship of the force versus voltage of each force sensor.
The reach and grasp research requires a total of 3 trays and 23 objects. 2 trays will carry 8 objects each and 1 tray will carry 7 objects. The robot will rotates these objects for the monkey to grasp and the object will be placed in the tray in a random fashion. To accomplish this I wrote a matlab code called “rangen.”
Moving on the EMG electrodes, the figure shows different stages of making the electrode.
As a summary I’d like to emphasize the importance of my research behind the scenes of the Reach and Grasp team for the completion and advancement of their experimental prodecures.