Patent Publication Number: US-7218236-B2

Title: Vehicle ignition interlock systems that detect the presence of alcohol within vehicles

Description:
FIELD OF THE INVENTION 
   The present invention relates generally to sobriety testing devices and, more particularly, to vehicle ignition interlock systems. 
   BACKGROUND OF THE INVENTION 
   Vehicle operation by persons under the influence of alcohol is a well known safety problem in the United States and throughout the world. Thousands of deaths per year in the United States are attributable to drivers operating vehicles under the influence of alcohol. To address this problem, most states have established laws that prohibit operation of a vehicle by an individual with a blood alcohol content (BAC) greater than a preset value (e.g., 0.08% BAC). In addition, “ignition interlock” systems have been developed which are directly connected to a vehicle&#39;s ignition system and are designed to prevent vehicle operation by inebriated individuals. Many states require the installation of ignition interlock systems in the vehicles of individuals convicted of driving under the influence of alcohol, particularly repeat offenders. 
   Conventional ignition interlock systems include a breath analyzer which measures the alcohol content of the breath of an individual. It is well known that the alcohol content of gas present in the alveoli of the lungs has an alcohol content directly proportional to that of the bloodstream of an individual. Blood alcohol content, thus, can be accurately determined by measuring breath alcohol content with a breath analyzer. 
   Typically, in order to start a vehicle equipped with an ignition interlock system, the driver must first blow into the breath analyzer. If the driver&#39;s breath alcohol exceeds a preset limit, the vehicle&#39;s ignition is disabled and the vehicle is rendered inoperable. If the driver&#39;s breath alcohol is below the preset limit, ignition is permitted and the vehicle may be started. If a driver successfully passes an initial breath test and is allowed to start a vehicle, some ignition interlock systems will require one or more retests (typically random) of the driver after vehicle ignition. These retests may occur as the driver is operating the vehicle (referred to as “rolling retests”) or the driver may be required to stop the vehicle prior to taking the retest. If the driver either refuses to take a retest or if the driver&#39;s breath alcohol exceeds a preset limit, vehicle operation may be disabled or may become disabled within a preset period of time. Exemplary ignition interlock devices that utilize breath analyzers are described in, for example, U.S. Pat. Nos. 3,780,311; 3,824,537; 3,831,707; and 4,592,443. 
   Operation of conventional ignition interlock systems is unsupervised. This lack of supervision has led to various attempts to bypass the breath analyzer such as by using air or other gases from balloons, bicycle pumps, gas station air hoses, and other sources. As a result, conventional ignition interlock systems may include breath temperature and humidity detection sensors to deter the use of non-human breath samples. 
   The lack of supervision has also led to attempts by vehicle operators to circumvent ignition interlock devices by using breath samples of non-driving individuals. To deter a person other than a vehicle operator from taking a breath test in order to start a vehicle, conventional ignition interlock systems have utilized various ways for confirming the identity of the person providing the breath sample. For example, the use of retina scans, voice identification, and face recognition have all been utilized. See, for example, U.S. Patent Application Publication Nos.: 2002/0089660, 2002/0084130 and 2002/0117287. Unfortunately, many of these systems are complicated and expensive and, as such, may not be cost effective. 
   Accordingly, there exists a need for a cost effective and reliable ignition interlock system that is capable of discriminating, without human supervision, between a vehicle operator and other persons in order to prevent circumvention of the ignition interlock system. 
   SUMMARY OF THE INVENTION 
   In view of the above discussion, a vehicle ignition interlock system, according to embodiments of the present invention, includes a breath analyzer located within a vehicle and a controller that is operably connected to the breath analyzer and to an ignition system of the vehicle. The breath analyzer is configured to detect the breath alcohol level of an operator of the vehicle. The controller compares detected breath alcohol levels of the vehicle operator with a threshold value, and is configured to prevent vehicle ignition (i.e., prevent the vehicle from being started) if a breath alcohol level detected by the breath analyzer is greater than or equal to a threshold value. The controller is configured to require the vehicle operator to periodically take breath analyzer “retests” after vehicle ignition in order to allow vehicle operation to continue. 
   The breath analyzer is also configured to detect the presence of alcohol within the vehicle, such as alcohol emanating from an open container of alcohol. According to embodiments of the present invention, ambient air within the vehicle is drawn into the breath analyzer, for example via a pump, fan, etc. According to embodiments of the present invention, the controller may override the requirement for one or more periodic retests if alcohol is not detected within the vehicle, for example, over a predetermined period of time. In addition, the controller may be configured to increase the frequency of periodic retests of the vehicle operator in response to detecting alcohol within the vehicle. According to other embodiments of the present invention, the controller may be configured to trigger a retest of the vehicle operator if alcohol is detected in the vehicle. 
   According to embodiments of the present invention, an operator identification device (e.g., a fingerprint identification device, hum-tone device, voice print device, face recognition device, PIN device, etc.) is operably connected to the controller and is configured to verify the identity of the vehicle operator via the operator identification device. 
   According to other embodiments of the present invention, the ignition interlock system includes a user selectable option that allows an individual to perform a breath alcohol test via the breath analyzer without enabling the vehicle ignition system. As such, the individual can use the ignition interlock system as a “personal”, stand-alone breath analyzer. 
   According to other embodiments of the present invention, the vehicle ignition interlock includes a user interface that is operably connected to the controller and that is configured to display operational messages. The controller may also provide audible operational messages and prompts via the user interface, including voice messages in one or more languages. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a block diagram that illustrates an ignition interlock system, according to embodiments of the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The present invention now is described more fully hereinafter with reference to the accompanying drawing, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. 
   It will be understood that when an element is referred to as being “on” another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present. It will be understood that when an element is referred to as being “connected” or “attached” to another element, it can be directly connected or attached to the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly connected” or “directly attached” to another element, there are no intervening elements present. The terms “upwardly”, “downwardly”, “vertical”, “horizontal” and the like are used herein for the purpose of explanation only. 
   Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the description of the invention and the appended claims, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. All publications, patent applications, patents, and other references mentioned herein are incorporated herein by reference in their entirety. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
   Referring now to  FIG. 1 , a vehicle ignition interlock system  10 , according to embodiments of the present invention, is illustrated. The illustrated system  10  includes a sample head  20  that serves the function of a breath analyzer that is configured to measure breath alcohol levels of an operator of a vehicle  40 . The terms “sample head” and “breath analyzer” are synonymous as used herein and are intended to be interchangeable. Exemplary sample head devices and their operation are described in U.S. Pat. Nos. 4,093,945; 4,902,628; and 4,901,058. 
   The sample head  20  is operably attached to an ignition control module  30 . The ignition control module  30  may be operably attached to various components of a vehicle&#39;s ignition and electronics system  48 , which may include, but is not limited to, the battery, vehicle starter switch, tachometer, starter solenoid, etc. The ignition control module  30  may be operably connected to various vehicle systems/components, without limitation, to prevent starting and operation of the vehicle if the vehicle operator fails a breath alcohol test, as would be understood by those skilled in the art. The ignition control module  30  includes a controller  34 , which preferably includes a processor and/or other suitable programmable or non-programmable circuitry, including suitable software. The controller  34  may also include other devices as appropriate to control various devices described herein. The controller  34  may be one or more processors or circuitry designed to implement the various functions described herein. Moreover, the functions of the controller  34  may be performed by circuitry or processor(s) located within the various components of the ignition interlock system  10  described herein. 
   The sample head  20  is located within a vehicle  40  and is typically in a convenient location for use by an operator of the vehicle. Preferably, the sample head  20  is a handheld apparatus that can be easily handled by a vehicle operator prior to and during vehicle operation. According to embodiments of the present invention, the sample head  20  includes a user interface  22  that is operably connected to the controller  34  and that is configured to display and/or perform operational messages in any of a number of formats. This includes messages in one or more languages on a text display (e.g., Liquid Crystal Display) and/or audible operational messages and prompts, including voice messages in one or more languages. At various times, instructions and prompts can be provided to the vehicle operator via the sample head  20  regarding when the next breath alcohol content retest is required, system status, etc. This can make vehicle operation safer, as the vehicle operator does not always need to actually look at the user interface  22  while driving. The user interface  22  may also include one or more push-button switches that the operator can depress to respond to various conditions or requests from the system  10 , including the need to enter operator identification information (e.g., an entry code number or a thumbprint scan) 
   According to embodiments of the present invention, the sample head  20  includes a mouthpiece  24 , which is used by the vehicle operator to blow a breath sample (e.g., a “deep lung” breath sample) into one or more alcohol sensors  32  in the sample head  20 . The mouthpiece  24  communicates with the alcohol sensor(s)  32  via a breath tube  26  and a delivery system  28  (solenoid, syringe, etc.) that delivers a portion of a breath sample to the alcohol sensor(s)  32  for analysis. A deep lung breath sample is an expiratory sample of alveolar air (i.e., air from the alveolar region of the lungs) which is known to have an alcohol concentration proportional to blood alcohol concentration of an individual. According to embodiments of the present invention, the sample head  20  may also include various features in the breath tube  26  that are configured to thwart circumvention by a vehicle operator, such as breath temperature sensors, breath humidity sensors, pressure sensors, etc., as would be understood by those skilled in the art. 
   Exemplary types of alcohol sensors  32  that can be used in accordance with embodiments of the present invention include, but are not limited to, electrochemical fuel cells, infrared sensors, and metal oxide semiconductor sensors (e.g., a Taguchi sensor, available from Figaro USA, Inc., Glenview, Ill.). Fuel cell technology, infrared technology and metal oxide semiconductor technology for use in detecting breath alcohol is well known in the art, and need not be described further herein. 
   The controller  34  is configured to compare detected breath alcohol levels of a vehicle operator with a threshold value, and to prevent vehicle ignition (e.g., by opening a circuit in the vehicle ignition system, etc.) if a breath alcohol level of the vehicle operator, as measured by the sample head  20 , is greater than or equal to the threshold value (e.g., 0.08% breath alcohol content, etc.). The term “prevent vehicle ignition” is intended to mean preventing a vehicle from being started, according to embodiments of the present invention. How a vehicle is prevented from being started may be accomplished in any of various ways known to those skilled in the art, and all of such ways are intended to be included within the scope of the present invention. 
   The ignition control module  30  contains relays  42  that are operably attached to a vehicle&#39;s ignition system  48 . The relays  42  are actuated by the controller  34  to open or close a circuit in the vehicle ignition system  48 . As would be understood by those skilled in the art, the circuit enables the ignition system  48  to start the engine of the vehicle  40 . 
   If vehicle ignition is allowed (i.e., the breath alcohol level of the vehicle operator is below the threshold value) the controller  34  periodically requires the vehicle operator to take a breath alcohol content retest in order to allow vehicle operation to continue. The retesting periodicity preferably is random, but can also be regular. A retest may be a “running” retest wherein the vehicle operator can continue to drive the vehicle  40 , or have the vehicle  40  “stand” while running, and blow a breath sample into the sample head  20 . A retest may also be an “engine off” test where the operator stops the vehicle  40  and turns off the engine prior to blowing a sample into the sample head  20 . 
   According to embodiments of the present invention, both the sample head  20  and the control module  30  have the capability to detect and log data into memory that may include system performance and conditions, conditions and results related to breath alcohol tests, functions of the vehicle, and possible evidence of system tampering or circumvention as detected by various anti-tamper devices (sensors)  36  in the system  10 . 
   According to embodiments of the present invention, the sample head  20  may be equipped with a fan, pump or other device  38  that can draw ambient air within a vehicle  40  into the alcohol sensor  32  of the sample head  20 . As such, the sample head  20  can serve the function of an “ambient air sniffer” and can detect the presence of alcohol within the vehicle, such as alcohol emanating from an open alcoholic beverage container, and from expired air emanating from a person in the vehicle  40 . Ambient air can be drawn into the sample head  20  periodically or continuously. 
   According to embodiments of the present invention, the controller  34  can be configured to override the requirement for one or more periodic retests if alcohol is not detected within the vehicle. Because running retests can be a distraction to the driver of a vehicle, this aspect of the present invention is advantageous in that it can eliminate the need for running retests. In addition, the controller  34  may be configured to increase the frequency of periodic retests of the vehicle operator in response to detecting alcohol within the vehicle. According to other embodiments of the present invention, the controller  34  may be configured to trigger a retest of the vehicle operator if alcohol is detected within the vehicle. 
   According to embodiments of the present invention, an operator identification device  23  (e.g., a fingerprint identification device, hum-tone device, voice print device, face recognition device, PIN entry device, etc.) is operably connected to the controller  34  and is configured to verify the identity of the vehicle operator via the operator identification device  23 . The operator identification device  23  is configured to ensure that the vehicle operator is the one taking the breath alcohol tests and operating the vehicle  40 . According to other embodiments of the present invention, the operator identification device  23  may be an input device that is configured to receive input (e.g., a PIN code) from a user. Failure to verify the identity of the vehicle operator can prevent the vehicle  40  from being started and operated. Some number of retry attempts may be allowed, as would be understood by those skilled in the art. Moreover, failure to verify the identity of the vehicle operator may result in a lockout period that prevents further attempts from being made, as would be understood by those skilled in the art. 
   According to embodiments of the present invention, the vehicle ignition interlock system  10  may also include a user selectable menu option that instructs the controller  34  to disable the vehicle ignition system and to allow an individual to perform a “personal inquiry” breath alcohol content test via the sample head  20 . Accordingly, an individual can utilize the ignition interlock system  10  as a personal, stand-alone breathalyzer; however, the vehicle cannot be started or operated in this mode. 
   The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. Although a few exemplary embodiments of this invention have been described, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the claims. The invention is defined by the following claims, with equivalents of the claims to be included therein.