A rotary fluid machine, such as a pump or motor, is provided with a fluid flow control mechanism that allows the flow of fluid to be easily and precisely controlled. The apparatus includes a device for monitoring, on a regular basis the levels of volatiles in the users breath and a comparator for comparing the test results with anticipated results and producing a non-compliance output when a non-compliance event is detected. A central computer system includes software which enables management and execution of financial transactions between the entities, such as debiting or crediting of accounts held by these or other entities, or creating an invoice for one entity to present to another entity.