Clinical trials employ a variety of approaches to measure the health status of patients and changes in their health due to treatment. In many therapy areas, subjective ratings based on observations made by a clinician are used to measure status and changes over time.
There are a large number of validated subjective measurement scales are used in clinical trials to assess aspects of movement such as balance, specific movements, walking and mobility based on observation of the patient conducting a specified movement or activity.
Being subjective, these scales may not be very sensitive to detecting small improvements, and different investigators may rate patients differently based upon their interpretation of the scale requirements. For this reason it is sometimes difficult to find measurements that are sensitive enough to detect treatment-related changes and are able to conclusively show treatment effects when they exist. In addition, using investigator observation it is less likely that detailed or subtle aspects of movement and mobility can be recorded.
Within ICON’s Innovation lab, we have begun to develop prototype solutions that could be easily used in clinic to make objective assessments of aspects of movement and mobility. One approach leverages components of the Microsoft Xbox gaming platform. This motion-based gaming platform has brought with it the opportunity to use the same technology using in the gaming industry to assess motion and mobility in patients across a variety of conditions and application areas.
The Microsoft Kinect sensor, a component of the Xbox gaming system used to detect movement, has been particularly successful in enabling the development of health applications due to the ability of the Kinect to operate on a PC platform and the utility of its associated Software Development Kit (SDK) to facilitate the development of applications that track body movements.
A skeletal tracking module within the Kinect SDK enables the 3D position of 26 body joints to be tracked over time without the need for the patient to wear sensors, special clothing or special markers. Leveraging this has been the basis of our work to develop applications to assess movement.
In our proof of concept system, we convert the 3D coordinates of body joints provided by the Microsoft Kinect into vectors to enable us to calculate simple range of motion angles whilst the subject performs a number of shoulder movements:
C. Forward Flexion
E. Internal and External rotation in abduction
While more testing is needed to assess the accuracy and utility of the application we have developed to measure shoulder range of motion, it is clear that the Microsoft Kinect platform offers a versatile and low-cost approach to measure novel health outcomes.
This may add significant value and utility to clinical drug development, in particular in replacing conventional subjective measures and enabling sophisticated measures of movement outside specialist laboratory settings.