07204335 is referenced by 12 patents and cites 28 patents.

An interlock device for measuring the sobriety of a potential vehicle operator is coupled to the starting mechanism of the vehicle. The interlock device includes a microprocessor controlled handset and base unit. The base unit encloses relays to preclude the starting mechanism from engaging if a predetermined acceptable threshold level of blood alcohol content has been exceeded. The relays receive a signal, through the base unit microprocessor, from the handset microprocessor which has calculated the blood alcohol content of a breath sample introduced into the handset by the vehicle operator. A breath sampling housing is enclosed within the handset in axial alignment with an intake port of the handset. A water filter and valve are positioned upstream from an electrochemical fuel cell. The fuel cell is coupled to the microprocessor. A pressure transducer measures the pressure of the breath sample. The handset microprocessor calculates a pressure offset through an algorithmic equation and applies the offset to the variable reading across the fuel cell to provide a normalized blood alcohol content measurement.

Title
Vehicle sobriety interlock device
Application Number
10/485041
Publication Number
7204335 (B2)
Application Date
October 31, 2003
Publication Date
April 17, 2007
Inventor
Charles E Smith
Melbourne
FL, US
James McClelland
Cocoa
FL, US
Jeffrey Stewart
Melbourne
FL, US
Agent
Herbert W Larson
James E Larson
Larson Larson PA
Assignee
Sheram Enterprises
GA, US
IPC
B60K 28/00
View Original Source