A Transcutaneous Fetal Visual Stimulator

An infant's brain effortlessly acquaints to a motion. Fetuses in the third trimester of pregnancy can also exhibit similar capacity, but further investigations on this matter are needed. Literature studies have assessed fetal response to visual stimulus experiments, but the known setups are reinforced with fixed illumination points and cannot be used to render generic motion visually. This work presents a system to overcome this limitation, i.e., provide dynamic motion as a visual stimulus for fetuses in the third trimester of pregnancy when they can process visual stimulus, and thus biological motion can be used for assessing fetal reactions. Our Transcutaneous Fetal Visual Stimulator (TCFVS) uses two high-resolution LED arrays (16 \times 20), a reconfigurable SoC (Xilinx FPGA and ARM core), and intuitive software to provide flexible control and ease of operation analyzing fetal reactions in response to visual stimulation. The paper details the TCFVS hardware and software architecture and presents benchmarks on the software toolchain to import generic patterns or motion capture in the visual stimulation domain. Our ad-hoc pixel remapping technique, an important component to precisely visualize stimulations in our hardware, is necessary and results in higher performance with respect to conventional downscaling techniques. To provide the first validation of our device in view of a systematic study, we verified real fetus movements when stimulated with TCFVS.