VELOMIR: Fast microrheology sensor with high temporal and spatial resolution reveals onset of drug effects on single cell level

Continuous high speed, high precision video tracking of particles is challenging due to the associated data rates. This currently limits passive and active microrheology to short tracking times and sophisticated setups. We present VELOMIR, VEry LOngtime MIcroRheology, a compact tool that tracks multiple particles in real time with up to 10 kHz sampling rate for almost infinite long tracking times. It uses a CMOS sensor tightly coupled with an FPGA to achieve real-time data processing. This captures the microrheological properties of biological tissue and cells with a dynamic range of up to 8 decades. Despite this remarkable increase, we show that the precision of the sensor is comparable to that of current systems. By analyzing short time slices, we show the time evolvement of drug-induced changes in viscoelastic properties of adherent living cells over long timespans in the hour-range. This technology will enable faster testing of the effectiveness of some drugs and better characterization of their effects.