A disposable timing tag is provided, including a thin, flexible planar sheet member having first and second end sections, and a middle section. The optically transparent substrate includes an optically transparent plastic material, a photochemically active dye, and a protonated form of the photochemically active dye. The parameters are automatically adjusted so that images of the object fall within the both image sensing areas of the image sensors 102R and 102L and that they fall within the both focal depths of the image sensors 102R and 102L. The matching is done through a reference voltage source, that remains at a fixed value, and a calibration factor is successively adjusted through a feedback loop until an optimum value of the calibration factor is obtained. The liquid-dispensing system also includes a pump and control system to apply pressure on a reservoir that contains the liquid. The compounds are considered useful for the treatment of diseases associated with LRRK2 such a Lewy body dementia, Parkinson’s disease or cancer.