Home :: Biomedical Division :: FreeWalk™

Experimental Portable System for Gait Study


FreeWalk™ is an experimental system for gait study. The first system was developed for the Department of Physical Therapy, Haifa University. The main difference between FreeWalk™ and other systems is that FreeWalk™ is portable and not restricting a patient in his/her movement. Actually, the system can be used both indoor and outdoor without any special, bulky equipment attached to it.

FreeWalk™ uses an off-the-shelf Pocket PC computer to acquire signals from four pressure sensors (two on each foot). The signals are displayed in real time allowing easy control and problem detection. The signals are further stored on the Pocket PC computer and may be later transferred to PC for display and analysis.

FreeWalk™ system components

FreeWalk™ system with all its components is shown on the picture below.

FreeWalk System components
Figure 1. FreeWalk™ System components

FreeWalk™ simultaneous acquires signals from four pressure sensors (two from each foot). The sensors are built into thin insoles, one under the heel and another under the foot platform.

The sensors from each insole are connected to each own interface box. The interface boxes include microcontroller units, implementing analog-to-digital conversion of analog sensor signals, interface with Pocket PC computer and battery tests.

The Pocket PC computer is connected to the interface boxes with a thin cable. It provides necessary user interface capabilities as well as performs data acquisition, display and other associated functions.

Data acquired on the Pocket PC may be transferred to PC via a standard sync cable (not shown) and interface capabilities.

Wearing FreeWalk™ system

FreeWalk™ system is easy to set up and convenient to wear. The insoles are thin and fit any footwear. The interface boxes are fixed on the lower leg by "hook and loop" fastener belts. The Pocket PC computer is small and light and may be put into a small, waist worn pocket. Figure 2 illustrates the concept.

Wearing FreeWalk system
Figure 2. Wearing FreeWalk™ system


FreeWalk™ system software consists of two programs: Data acquisition program and Data viewer.

Data acquisition program runs on the Pocket PC computer. Before data acquisition starts, the user (physician, nurse, physiotherapist or researcher) shall fill in a form, identifying the patient. This information is stored together with the pressure sensor signals and transferred to PC for patient identification. For more information about FreeWalk™ acquisition software, see the user guide "Gait Research System. Data Acquisition Software. User's guide".

Data Viewer runs on a PC providing viewing and editing capabilities for the acquired data. More information about the Data Viewer may be found in "Gait Research Data Viewer. User's manual".

Examples of acquired data

Healthy patient

Healthy patient

Patient with problems

Patient with problems

For more information about the system please contact us at bio.info@softscientific.com.