Validation process with Qualisys and results
To validate the Ledsreact Pro we wanted to benchmark it against a golden standard technology with high accuracy data processing. That's why we chose the Qualisys Motion Capture system.
1. Set up
The setup for the Qualisys Motion Capture system comprises a configuration of multiple cameras strategically positioned around the testing area. These cameras meticulously track the athlete's spatial coordinates in three dimensions, ensuring precision down to 0,5MM with 650 fps. While unparalleled in accuracy, it's important to note that this system carries a higher cost and demands the longest setup time, a process that includes the meticulous blocking of natural sunlight. Given its ability to comprehensively capture motion in three dimensions, the Qualisys Motion Capture system serves as a valuable benchmark for validation purposes. It effectively authenticates exercises necessitating directional changes across one or two dimensions, contributing to the overall reliability of the assessment.
1.1 Set up cameras Qualisys system
1.2 Calibration process Qualisys system
- Each new test the Qualisys system needed to be validated to reach the highest accuracy
- The calibration process is done with a calibration stick and 3-D motion capture markers
- Each calibration is double checked via software
1.3 How are tests run?
- Each test was run with different persons
- 4 markers are positioned on each person: left shoulder, right shoulder, on the back, on the belly
2. Validation results
2.1 Sprint test 10M
Time
Average time difference: -0.031s seconds
Std time difference: 0.018 seconds
—> Reported time of LR will fall within -0.049sec and -0.013sec bracket of Qualisys time
Speed
MAE (Mean Absolute Error): For every timestamp we took the absolute difference between the Qualisys and Ledsreact Pro devices and took the average of all these differences
The red line is the speed measured by the Ledsreact Pro
The green line is the speed measured by the Qualisys system.
The green line starts earlier because the Qualisys starts measuring before the Ledsreact started the countdown. This first part has not been taken into account.
MEA: 0,20 M/S
2.2 Sprint test 20M
Time
Average time difference: -0.029s seconds
Std time difference: 0.045 seconds
—> Reported time of LR will fall within -0.073sec and -0.015sec bracket of Qualisys time
Speed
MAE (Mean Absolute Error): For every timestamp we took the absolute difference between the Qualisys and Ledsreact Pro devices and took the average of all these differences
The red line is the speed measured by the Ledsreact Pro
The green line is the speed measured by the Qualisys system.
The green line starts earlier because the Qualisys starts measuring before the Ledsreact started the countdown. This first part has not been taken into account.
MAE: 0,23M/S
2.3 Change of Direction test
Time
Average time difference: -0.055s seconds
Std time difference: 0.057 seconds
—> Reported time of LR will fall within -0.112sec and -0.002sec bracket of Qualisys time
Speed
MAE (Mean Absolute Error): For every timestamp we took the absolute difference between the Qualisys and Ledsreact Pro devices and took the average of all these differences
The red line is the speed measured by the Ledsreact Pro
The green line is the speed measured by the Qualisys system.
The green line starts earlier because the Qualisys starts measuring before the Ledsreact started the countdown. This first part has not been taken into account.
MAE: 0,13M/S
2.4 5-10-5 test
Time
Average time difference: 0.072s seconds
Std time difference: 0.024 seconds
—> Reported time of LR will fall within 0.048sec and 0.095sec bracket of Qualisys time
Speed
MAE (Mean Absolute Error): For every timestamp we took the absolute difference between the Qualisys and Ledsreact Pro devices and took the average of all these differences
The red line is the speed measured by the Ledsreact Pro
The green line is the speed measured by the Qualisys system.
The green line starts earlier because the Qualisys starts measuring before the Ledsreact started the countdown. This first part has not been taken into account.
MAE: 0,61M/S
2.5 T-test
Time
Average time difference: -0.003s seconds
Std time difference: 0.073 seconds
—> Reported time of LR will fall within -0.076sec and 0.070sec bracket of Qualisys time
Speed
MAE (Mean Absolute Error): For every timestamp we took the absolute difference between the Qualisys and Ledsreact Pro devices and took the average of all these differences
The red line is the speed measured by the Ledsreact Pro
The green line is the speed measured by the Qualisys system.
The green line starts earlier because the Qualisys starts measuring before the Ledsreact started the countdown. This first part has not been taken into account.
Related Articles
How to filter in the Activity log?
In the activity log you can filter out test moments based on time, type of test or by player name. 1. Select the date Select the time window between which you would like to filter your tests 2. Select the exercise Select the exercises for which you ...How can I consult my data?
Bellow all the steps are described to view the results from testing. 1 Open the activity log and select your testing moment Click on the activity log icon Select the test you would like to evaluate The overview of your selected test will open 2 View ...How to activate your account and login?
Congratulations on your Ledsreact Pro! To ensure you have full access to its incredible features, let's walk through the simple and secure process of account activation and login. 1. Receive Your Account Activation Link Upon shipping your Ledsreact ...How to connect your Ledsreact Pro with WiFi?
You can use the Ledsreact Pro without WiFi connection. The connection is key to use several features and upload your data to the web platform. 1. Search a WiFi network Connect to your Ledsreact Pro Tap continue to search for a wifi network (this is ...How to setup a Sprint Test?
When you are following all the mentioned steps the sprint test will run smoothly and all the data will be available in the web application 1. Position the Ledsreact Pro on the tripod on average hip hight of your team 2. Position the Ledsreact Pro ...