Dynamic Weight Bearing 2.0

Version history

• 2006 - Incapacitance Test / Static Weight Bearing (SWB) : The first instrument measuring spontaneous pain for your research on nociception and analgesia. Our system allows you to measure the weight distribution of a rodent comfortably maintained on its hind paws in a dedicated holder.
• 2008 - Basic Dynamic Weight Bearing test (BDWB): This new instrument allows you to measure the weight distribution on all four paws without a restrainer.
• 2011 - Advanced Dynamic Weight Bearing test (ADWB): A new software version of the DWB allowing video tracking of the animal for running the test semi-automatically
• 2018 - Dynamic Weight Bearing test 2.0 (DWB2): New 3-tab software with improved automation behavior and major, new, innovative functionalities.

Presentation

Advanced Dynamic Weight Bearing test
Detail with a mouse

Ethical considerations as well as the necessity to study comfort and non-evoked pain levels on rodents lead to the development of tests and procedures allowing researchers to conduct pain assessment without having to apply a stimulus on the animals. These tests, called 'Incapacitance' tests, measure the weight distribution on both hind paws of rodents maintained in a restrainer. Restraining, however, induced higher level of stress for the test subjects.

Since its launching in 2008, Bioseb's Dynamic Weight Bearing test is the only rodent non-evoked pain test not requiring animal restraint. It is also the only instrument allowing you to precisely measure changes in Postural Equilibrium in rodents by assessing their weight distribution on each one of their 4 paws.

Bioseb's DBW thus allows you to work with freely moving animals in a transparent cage adapted to the animal being tested (rats or mice). This unique characteristic significantly reduces restrainer-induced stress levels and therefore greatly increases the reliability of the results.

This instrument, after having been validated in over thirty publications, has enabled researchers to answer numerous interrogations pertaining to non-evoked pain models, as well as neuropathic, inflammatory or osteoarthritic conditions. More recently, the application framework of our DWB (Dynamic Weight Bearing) has been extended: the instrument is not only a must-have for pain models, but its postural analysis ability has proven to be an ideal tool for studies on skeletal diseases (fractures, cancers, arthritis...), CNS (Central Nervous System) pathologies, as well as diseases connected to the vestibular system (vertigo).

Operating principles

The animal is placed into the DWB (Dynamic Weight Bearing) enclosure for a duration of approximately 5 minutes.

During the test, the DWB relies on two different technologies :

• A matrix comprising around 2000 high precision force sensors (0.02 g for mice and 0.15 g for rats): this matrix is embedded in the floor of the enclosure where the animal is free to move as it pleases. The force sensors measure the weight distribution on each of the four paws of the animal in grams. The instrument uses different sensors for rats or mice in order to provide a suitable sensitivity level (0-4g for mice and 0-40g for rats).

• Video monitoring : the animal is filmed from above using a high definition camera. The video feed is analyzed in real-time during the test thanks to our tracking software allowing a precise analysis of the animal's posture.

Our software can accurately analyze the animal's position during the entire duration of the test in order to automatically identify the location of each of the four paws on the force sensors.

Data acquisition from the force sensors and the camera happens at a high frequency (30 Hz): the DWB is able to analyze rapid position changes, thus providing complete measurements allowing a precise tracking of postural evolutions in moving or still rodents.

Instrument versions and installation

All DWB1 users are eligible for an upgrade to the new DWB2 version. Your hardware is 100% compatible - a simple software upgrade will be required.

Acquisitions from the DWB1 can be analyzed using the DWB2 software in order to benefit from the new interface and powerful analysis modules.

The DWB is available in 3 different versions: RAT (BIO-DWB-AUTO-R), MICE (BIO-DWB-AUTO-M), RAT-MICE COMBO (BIO-DWB-AUTO-DU).

New Advanced Weight Bearing System for Mouse and Rat, by Bioseb: camera, cover, cage and animal