Embodiments herein relate to the field of weapon accessories, and, more specifically, to modular, electrically powered weapon accessories. Specifically, this invention relates to a system and method for providing a verification system and method for use, primarily, at locations and venues serving alcoholic beverages. A trend determining unit determines trends in the medical parameter by analyzing the relation between the characteristic property of the sensed signal obtained at different times and the reference property. The packed bed may be formed from boron, silicon or other appropriate materials. When feed data rows match conditions, the computer system places feed data row information into an alert table that includes references to the blob table with blob data, thereby triggering an alert. The token may be destroyed manually by some user activity or may be terminated automatically.