Force Plate Actimeter

Hongping Dai

July 18, 2005

Schematic Diagram of A Force-Plate Actimeter

1. Four Force Sensors2. Force Plate3. Four Pre-Amplifier4. Data Acquisition System5. Application Software

Data Acquisition Four Independent A/D Converters of 16-Bit Raw Data as 16-bit WORD Calculation of Force:

Calculation of Position

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Movement Analysis

• Traveled Distance • Triangle Area of three adjacent movement

positions-Drunken Man Walking• Rotation of three adjacent movement as

rotation• Bouts of Low Mobility• Spatial Statistics

Force Analysis

• Force Change• Force Variance

• Frequency Domain Analysis Tremor Studies

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FPARun Application Software

FPARun for Measurement• System Setup

Calibration of Force SensorsBalancing Force PlateOffsets of Force Plate

• Run Setup • Run a Measurement• Data File

System Setup1-Calibration of Force Sensors

System Setup2-Balancing Force Plate

System Setup3-Offsets of Force Plate

System SetupWeighing a Subject

System SetupWeighing a Subject

System SetupFinal Points

• Force Sensor Calibration data is stored in the registry as binary data

• Calibration in registry is used as the default every time FPARun is started

• Update in Calibration is updated in the registry

• No need to calibrate the force sensor every time FPARun is started

Ready for Run Setup

Setup of a Run

Setup of a Run

Ready TO Run

Real-Time Display of A Measurement

Runtime Note

Animal Behavior Marker

Raw Data File (.FPA)• Header of FPA data as text: "BAS-FPA-Data File-1". • Measurement setup information

Raw data file name, set before starting the measurement, as text Project information as text Operator name as text Animal Information

– Animal ID as text– Animal Sex as integer (4 bytes)---0 for female and 1 for male – Animal DOB as double (8 bytes)

• Pre-run note as text• Measurement start time as double (8 bytes)• Runtime note (refer to §5.6 Write Runtime Notes As Part of Raw

Data File)• Data acquisition rate: number of points per second as WORD• Number of data points per frame, as WORD• Number of Frames, as WORD• Raw Data of Forces

Self-Guided FPARun

• Sequence of Operations in FPARun is self-guided with enable/disable of menu items/toolbar buttons

FPAAnalysis

• Open FPA Data File• Presentation of Report Front Page and

Various Calculated Results• Print, Print Preview and Copy of Report• Replay Measurement Processes

FPAAnalysisReport Front Page

FPAAnalysisSystem Setup Information

Review of Movement Trajectories

Print Preview of Movement Trajectories

Copy One Frame of Movement Data to Excel

Movement Trajectories of Whole Session

3D-Movement Localization

Review of Frame Data

Print Preview of Frame Data

Tabular Summaries of Data of All Frames

Print Preview of Tabular Summaries

Copy Frame Summaries

Copy to Excel

Graphical Frame Summaries

Print Preview of Graphic Frame Summaries

Traveled Distance in Whole Session

Force Changes in Whole Session

Stereotype Scores

Replay of Measurement

What to do next?

• Add Sensor Calibration Date to CFPACalib • Averaging Positions for Movement Calculations • CRC32 for the FPA Report File • More Force Analysis To Implement