The IN191 / ML191 Blood FlowMeter
and the MSP100XP Standard Surface Probe
are suitable for use on stationary subjects only. The primary reason for this is that the probe is extremely susceptible to movement artefacts. Any minor movement is likely to cause large artefacts that will bury any actual signal. Securing the probe with adhesive rings / surgical tape may reduce the artefacts slightly, but this will likely still not be sufficient to reduce the artefacts to acceptable levels.
It is therefore recommended that the IN191 / ML191 be used on stationary subjects only.