Sponsor
Team Members
Tristan Richards
Jessica Murdoch
Dana Oxenberg
Faculty Coaches
Dr. Nadine Smith
&
Ricardo Silva
Acknowledgements
Gene
Gerber
&
Don Natale
Design of a Linear Behavioral Chamber with a Drosophila
Tracking Device
Spring 2005
|
|
|
Team Members Tristan Richards Jessica Murdoch Dana Oxenberg |
Faculty Coaches Dr. Nadine Smith & Ricardo Silva |
Acknowledgements Gene
Gerber |
|
Executive Summary |
| The study of movement in mutated Drosophila
(fruit flies) under different stresses and conditions (cocaine,
alcohol) is important because it can clarify how receptors react to
these stimuli. Due to the fact that Drosophila receptors
and human receptors have a great amount in common, human disorders and
addictions may be understood and prevented. Previously,
fruit flies were being monitored by a graduate student observing a
single fly through a camera. A few disadvantages to this method were
that light was required, it was hard to keep track of the
individual fly being observed, and the process was very time consuming. A fruit fly tracking device has been designed in order to track a fruit fly's motion under different conditions. It's velocity and distance traveled is displayed in a user-friendly manner for further studies. The device designed contains a wire-wrapped circuit board, signal acquisition card, and computer output. The wire-wrapped circuit board consists of optocouplers holding a tube in place. As the fly moves down/up the tube, the optocouplers track any disruptions. Four OR gates are used in order to distinguish exactly which optocoupler is being disrupted. As the disruptions occur, the signal acquisition card along with its software convert the binary code to the specific optocoupler and save the data being taken. Previously written code then converts the set of data into the needed distance, velocity, and amount of turn measurements. |
|
Design Criteria |
| The device is designed to monitor one fruit fly's motion. The fruit fly is placed in a capillary tube, which is approximately 5 mm in diameter and 13 cm long. Fifteen optocouplers hold the tube in place in order to track the fruit fly's movement. The device is able to work in a room temperature of 20±2°C, with vapor conditions (water, alcohol, etc.), with all mutated Drosophila ranging from 0.724mm-0.981mm in size, and in all lighting conditions. |
|
Alternative Designs |
| Rather than choosing a signal acquisition card to calculate the fly's velocity, a multi-meter could have been used. Two major downfalls for the multi-meter were the amount of code that would have been needed, and the device itself would have been under-used. The multi-meter was capable of doing a much more complex function than what was needed for the design. |
|
Evaluation & Calibration |
| After the OR gates were connected to the circuit, the design was tested by placing a plastic ruler in between the optocouplers. The LEDs, controlled by the binary number system, were monitored to make sure the correct ones would light up depending on which optocoupler was disrupted. The Digital to Analog converter chip and signal acquisition card were then installed. With the circuit connected to the signal acquisition card and computer, the optocouplers were disrupted, by the ruler once again. This first set of data was saved. The data was then put through the written code in order to calculate distance, time, and velocity. The preliminary data and code displayed correct results. After preliminary data was taken, timed measurements were performed, by running a ruler through the optocouplers. Because velocity = distance/time, the actual velocity was calculated and compared to the design's output velocity. The measurements were found to be accurate, but slightly delayed due to the computer software used. Final evaluations included bead and fly measurements, which also produced accurate results. |
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Final Budget |
|
Item |
Quantity |
Price per Unit |
Total Price |
| Signal Acquisition Card | 1 | $76.00 | $76.00 |
| Optocoupler | 10+ | $1.98 - $2.27 | $47.04 |
| OR Gates | 10 | $0.50 | $5.00 |
| Precut wire - small | 1 | $7.97 | $7.97 |
| Precut wire - medium/large | 2 | $9.21 | $18.42 |
| Circuit Board | 1 | $4.29 | $4.29 |
| Project Enclosure | 1 | $9.49 | $9.49 |
| Banana Jacks | 2 | $2.59 | $5.18 |
|
Total Budget |
$173.39 |
|
Deliverables & Summary |
| The final Drosophila tracking device... - Calculates the total and individual velocities the fly has moved - Calculates the time it takes for the fly to move the measured distance - Calculates the individual and final average velocities of the fly - Monitors the number of turns the fly makes during its timed movement The device may be improved even more by including more than one tube. This addition would allow for the observance of many fruit flies simultaneously. |