Infrastructure |
 |
[ gait analysis ] - [ image processing ]
Gait Analysis
[ top ] - [ gait analysis ] - [ image processing ]
 |
The infrastructure of the laboratory consists of a 21.5m long walkway. This walkway is at least 1.2m wide, over the whole length, with centrally a wider platform of 2.4m by 4.8m. This way, a wide variety of situations can be monitored and measured, for example, standard gait analysis, specific (professional) sports applications, ergonomics, also in wheelchair applications.
This walkway is positioned centrally in the lab, enabling the possibility of measurements on both sides. |
The equipment available at the lab consists of:
- mobile 3D kinematics measurement system from CODAmotion, based on active infrared markers, to be placed on any subject to be measured. The fact that the markers are active ones, simplify a quasi real-time visualization and evaluation of the measurements
- inserted into the walkway, an AMTI force platform of 0.4m by 1m measures the size and orientation of the ground reaction force during gait
- on top of the force plate, a RSscan pressure distribution plate of the same size measures the plantar pressure distributions during gait
- adding to the equipment a wireless 8 channel Myomonitor IV EMG measurement system from Delsys, makes it feasible to extend the possibilities of the research projects further with the synchronized measurement of muscular activity
|
 |
Integration of all the systems enables all eventually interesting biomechanical calculations to be made, for a specific research project.
 |
RSscan pressure distribution plate (left):
- Dimensions: 1 x 0.4 x 0.008 (m)
- Active sensor surface: 0.98 x 0.32 (m)
- Amount of sensors: 8192
- Sensitivity: 0.27 – 127 N/cm²
- Max frequency: 500 Hz
AMTI force plate (right, under the pressure distribution plate):
- Dimensions: 1 x 0.4 x 0.12 (m)
- Amount of sensors: 4 three-dimensional sensors (strain gages)
|
 |
 |
CODA CX1 (left):
- Three flat-windowed sensors on a rigid frame
- Pre-calibrated
- Use of cross-correlation techniques between mask and shadow
- Very high resolution over large volume (0.05mm in several m)
- Two sensors for horizontal movement, one for vertical movement
Markers and drive boxes (right):
- Small infrared LED’s (Light Emitting Diodes)
- Up to 56 markers activated in a rapid time multiplexed sequence
- Drive boxes with rechargeable batteries
- Charger unit to fully recharge drive boxes overnight
|
 |
 |
System integration
- RSscan 3D interface box:
- Triggering tool for integration with other measurement equipment
- Tools for synchronizing with force platform
- Specific sampling frequency definition possible
- Both static and dynamic measurements
- Analyzing tools integrated into the software, including comparing measurements
- AMTI MSA-6 amplifier:
- Jumper selectable gain
- Jumper selectable excitation voltage
- Low-pass filtering of all channels (1000Hz)
- Output: +/- 10VDC into min. 10K load, or digital RS232
- 15V external power supply
- CODAMOTION active hub:
- 19” rack mountable industrial computer
- Up to 4 CX1 units (expandable to 8 units)
- Analogue inputs for force platforms, EMG, …
- Programmable sync generator, sync in/out, …
|
Image Processing
[ top ] - [ gait analysis ] - [ image processing ]
In the Mobilab laboratory there are two different camera setups available for hig quality image/video aquisition. Both systems are capable the get high frame rates, therefore the recording equipment is choosen in that way that it can handle this large amount of data at in short time slots.
- The first system consists of a Guppy F080 collor camera.
Camera IEEE1394 color 1/3"
GUPPY F080C
Lens man.iris C 2/3" / 16,0 mm C1614A
Manual Iris C-mount 2/3" 16,0 mm/ F1,4-22 |
|
 |
On the left image the label equipment is showed, which provide a simple way to label the recorded images.
On the right image the recording equipment is showed. This equipment has a raid-0 configured data storage device which consists of three hard disks to be able to store the large amount of date at high frame rates.
The label and recording equipment can communicate with each other via a secured wireless connection.
The comuters used in these equimpents are: Dell Dimension 9200 Core 2Duo |
 |
- The second setup is a Cypress evaluation kit.
 |
Cypress Stereo XAECK10005 Features
- Quick and easy evaluation of Cypress’s automotive
imaging technology
- Up to 120 dB dynamic range
- Autobrite® intelligently adapts to lighting conditions
perfect for extreme mixed lighting situations
- High sensitivity and near-infrared response
- Parallel and IEEE 1394 connections for high quality digital
image capture
- Analog NTSC video
- Control settings through IEEE 1394 or I2C
- 8-and 12-bit image capture modes
- Multiple data formats
- Single frame, consecutive frame and AVI capture modes
- User-friendly Windows® software
- API for camera control and image capture through customer-built
software
- Small and convenient form factor
- Monochrome, color, and stereo options
available
|
[ top ] - [ gait analysis ] - [ image processing ]
|
