STEPSCAN FAQs
Technical
Stepscan® is a plantar pressure measurement device and gait analysis system.
The Stepscan® system calculates key measurements with respect to sway/balance, temporal and spatial gait statistics, and key plantar pressure measurements.
The sensors are piezoresistive.
The sensors are placed 5 mm apart, beginning at 2.5 mm in from each edge of the tile. This provides a seamless measurement area with no dead zones, on or between tiles.
Stepscan® systems operate at 100 Hz. This is the recommended scan rate for measuring human walking ability.
The Stepscan system has a calibrated pressure range of 10-1400 kPa (1.5-203 psi), extended by extrapolation up to 1500 kPa (210 psi).
The tiles are wired (one power cord and one Ethernet connection per contiguous group of 16 or less tiles).
The medical grade power supply accepts 100-240VAC (50/60Hz), suitable for use around the world.
The surface of the tile is made of commercially available rubber flooring.
Product Usage
The Stepscan® system is a registered Class I medical device with the U.S. Food and Drug Administration (FDA) and Health Canada.
Clean the Stepscan® tile and cables with 70% medical grade alcohol. UV disinfectant wands may also be suitable.
For more detailed instructions, read our blog post on the matter, or refer to your Stepscan User Manual.
The software used to read the hardware was developed on Windows. We have no immediate plans for migrating the software-hardware interface to work on other operating systems.
It is not necessary to install the Stepscan® tiles into the floor. The device can be laid on top of any flooring surface.
Should you want to install the device into the floor as you would a force plate, you certainly can do so.
Accuracy
Calibration is the process of determining the numerical relationship between the observed sensor output (i.e. voltage measured across the sensor) and the known value of pressure being applied to the particular sensor.
The accuracy and repeatability of measurements obtained on a PMD will vary among:
- levels of applied pressure,
- duration of pressure application,
- frequency of pressure application (i.e. static or dynamic),
- calibration procedure used.
Calibration should be performed under conditions that are as close as possible to the actual measurement conditions.
The Stepscan® tile is considered calibrated if its pressure measurements are within a predetermined range of the known applied pressure. The system must be carefully calibrated to obtain the best results in terms of accuracy and repeatability for the end user.
Yes, all Stepscan systems are calibrated before they leave us. Each of the 14,400 sensors in a Stepscan® tile is individually calibrated across the entire pressure range before being delivered to the end user.
Our latest sensor specifications include the following:
Pressure Range: 10-1400 kPa (calibrated) extended by extrapolation to 1500 kPa
Accuracy (Pressure RMSE): <5% of Full Scale Pressure
Creep: <0.25 kPa/s @ <= 200 kPa/s
Hysteresis: <5%
Pressure Resolution: < 13 kPa
Durability testing of the Stepscan sensors shows that the Stepscan tiles can withstand:
3,600 patient visits (approximately 3.5 years of clinical use) before a recommended recalibration, and an estimated 15000 patient visits (i.e., 15+ years) before a sensor layer replacement.
Stepscan is so confident in this that we have a Brand Promise Guarantee around it:
If a tile fails, we will ship you a new one right away, for free.
Want to learn more about the Stepscan Guarantee? Contact us.
Stepscan users cannot calibrate tiles themselves; they must be shipped back to us.
However, should any tile in your Stepscan system require recalibration, we'll ship you a fresh one in the meantime, minimizing your downtime. Want to learn more about the Stepscan Guarantee? Contact us.
Stepscan has developed Standard Operating Procedures to test for the following technical parameters:
- Accuracy
- Repeatability
- Pressure Range
- Creep
- Hysteresis
- Center of Pressure Precision and Accuracy
- Pressure resolution
The results of these tests must conform to Stepscan's internal production quality requirements, which have been heavily influenced by the i-FAB standards. The equipment used to perform these tests is the same as that used to calibrate the tiles.
Each tile is composed of four "quarter tiles", with 60 rows of 60 sensors each (3600 sensors total). For each image, the quarter tile scans through its sensors, one row of 60 sensors at a time, but very rapidly (<100us per row). Each of the quarter tiles perform this process independently and send the data to a central processor in the tile, which combines them and forwards the full-tile data to the Stepscan® Software application.
The Stepscan software then combines and synchronizes data from multiple tiles to give multi-tile images, where the sensor data is collected within the same time slice (e.g., a 10ms period, for the system's 100Hz sampling rate).
Clinical & Research
The Stepscan® system provides measures of underfoot pressures and the spatial/temporal parameters of gait, whereas a VICON camera provides kinematic data, particularly joint angles.
These technologies complement each other to give you a more detailed 'image' of a person’s movement. They can be used together or apart, depending on your data needs (what you want to measure).
Stepscan offers an optional external device that will enable you to synchronize the start of a recording with another technology (e.g., VICON). Please contact us for further details.
We see ourselves as a complimentary technology to other movement/mobility measurement devices, including force plates.
A force plate can measure force and the vectors of force (i.e., the angles of those forces). The Stepscan® measures underfoot pressures in addition to the spatial and temporal parameters of gait.
Yes, the raw data can be exported from Stepscan® to the HDF5 format. There are methods of loading such data with data analysis packages/languages such as R, Python, and MATLAB.
Yes, you can put a chair at the edge of the tile, sit a subject in the chair and then have them stand up on the tile. The tile will measure their underfoot pressures, as well as balance and sway parameters.
If you are interested in custom report development, contact our Product Specialist team.
Our Product Specialists are always happy to meet to discuss your specific needs and demonstrate the Stepscan system. Click here to connect with us and learn more.
If you are interested in the Stepscan system, get in touch with our Product Specialist team to discuss your needs, product options, and financing.