The TriKinetics Drosophila Activity Monitoring System consists of one or more Activity Monitors, a Power Supply Interface Unit and Power Supply, and a host Macintosh or Windows PC for data collection. Each monitor uses an onboard microprocessor to independently detect and count activity events, and at periodic intervals to upload the activity totals to the host computer.

The monitors are connected to the Power Supply Interface Unit by a network of conventional 4-wire telephone cables which supply operating power and lines for data transmission. Monitors may be plugged and unplugged from the network at will without disturbing the activity of other monitors.

Data Collection
At periodic intervals, ranging from 1 second to 60 minutes, the DAMSystem program in the host computer transmits a command to all monitors to simultaneously ‘freeze’ their current count totals. The monitors set aside these ‘frozen’ counts, reset the totals to zero, and begin counting again for the next measurement period.

Meanwhile, the host begins a sequence of requests from each monitor in turn (by address number) to transmit its ‘frozen’ counts to the computer for storage and later output. This data collection or ‘reading’ sequence requires about 2/3 second per monitor, placing a lower limit on the reading interval if multiple monitors are used.

Data Storage
The DAMSystem3 program stores the retrieved monitor data in a folder on the hard drive which is automatically created: DAMSystem3Data. Individual text files for each monitor accumulate successive readings for as long as the program operates, and these files may grow without limit to the capacity of the disk drive.

At the conclusion of an experiment, perhaps covering several weeks of continuous data collection, these monitor text files containing the captured data should be moved out of the DAMSystem3Data folder for processing and analysis. The DAMSystem3 program will create new files as necessary to store additional data as it is collected.

File Scan
Prior to processing and analysis, the data files should be scanned using the DAMFileScan program to insure that the data records are complete, with no gaps or duplicate readings.

This program produces a new set of output files from the input monitor files, and in addition to cleanup, allows for the extraction of data within a specified date/time range, as well as compression to a longer bin length if desired. Thus, for example, activity data collected at 1-minute intervals may be converted to 30- minute intervals for analysis or plotting purposes.

The program also allows input monitor files to be converted to legacy Channel files (as produced by the earlier DAMSystem2 program) for compatibility with existing analysis procedures.

Data Analysis
Outputs from the DAMSystem3/DAMFileScan software suite are essentially columns of numbers, with each entry corresponding to an activity total recorded by a single monitoring channel over a short period of time (collection bin.) These individual columns or files may be plotted or analyzed in various ways, in- cluding import into Excel, ClockLab, FlyTools, or other software.

Download pdf Drosophila Activity Monitoring System User’s Guide