Apparatus and method for determining a person's sobriety

• US 6,026,674 A
• Filed: 08/20/1998
• Issued: 02/22/2000
• Est. Priority Date: 08/20/1998
• Status: Expired due to Term

• Current Assignee: 1A Smart Start, LLC
• Original Assignee: Smart Start Corporation
• Inventors: Gammenthaler, Robert Scott
• Primary Examiner(s): Williams, Hezron
• Assistant Examiner(s): Wiggins, J. David
• Application Number:
  US09/136,837
• Time in Patent Office: 551 Days
• Field of Search: 73/19.01, 73/23.3, 422/84, 180/272, 128/730, 128/719, 340/576, 436/132, 436/900
• US Class Current: 73/19.01
• CPC Class Codes: B60K 28/063 preventing starting of vehicles
• CPC Class Codes: G01N 33/4972 Determining alcohol content for vehicle safety devices B60K28/06
• CPC Class Codes: Y10S 436/90 Breath testing
• CPC Class Codes: Y10T 436/204165 Ethanol

Abstract

An apparatus and method for determining the concentration of alcohol present in a gaseous mixture wherein an electronic device employing a fuel cell determines the concentration of alcohol present in the gaseous mixture is disclosed. In particular, the device may be used to determine a person'"'"'s sobriety by determining the alcohol concentration in a breath sample. To determine the alcohol concentration, the device must be able to accurately determine the volume of breath in the breath sample. The device controls the volume of the breath sample by measuring the pressure of the breath flow through the device and, in response to the pressure, electronically controlling a valve diverting a portion of the breath flow into the fuel cell thereby indicating and ensuring that a predefined requisite amount of breath flow has passed thru the fuel cell. One application of the invention is a sobriety interlock for a machine where the machine remains disabled unless the operator is first determined to have an alcohol concentration below a predetermined level.

Claims

1. An apparatus for measuring the concentration of alcohol in a gaseous mixture, comprising:

(a) a gas induction tube for channeling a flow of the gaseous mixture, the gas induction tube defining a gas flow channel;

(b) a pressure sensor connected to the gas induction tube, the pressure sensor capable of generating an electrical pressure signal in response to the pressure in the gas flow channel;

(c) a fuel cell connected to the gas induction tube, the fuel cell capable of producing an electrical alcohol volume signal proportional to the total volume of alcohol present in a gaseous mixture sample;

(d) a valve disposed between the gas induction tube and the fuel cell, the valve capable of preventing flow between the gas flow channel and the fuel cell;

(e) a computing device electrically connected to the pressure sensor and to the fuel cell, the computing device capable of generating an electrical valve open signal, further capable of determining the alcohol volume in the gaseous mixture sample in response to the electrical alcohol volume signal, further capable of determining a gaseous mixture sample volume in response to the electrical pressure signal, further capable of generating an electrical valve close signal when the gaseous mixture sample volume exceeds a predetermined level ensuring that a predefined requisite volume of gaseous mixture has passed thru the fuel cell, and still further capable of calculating the concentration of alcohol in the gaseous mixture sample from the alcohol volume in the gaseous mixture sample and the gaseous mixture sample volume; and

(f) a valve controller connected to the valve and to the computing device, the valve controller capable of opening the valve in response to the electrical valve open signal and capable of closing the valve in response to the electrical valve close signal.

2. The apparatus of claim 1 wherein the gaseous mixture is a person'"'"'s breath.

3. The apparatus of claim 1 further comprising a temperature sensor connected to the gas induction tube, the temperature sensor electrically connected to the computing device, and the temperature sensor capable of producing an electrical temperature signal proportional to the temperature within the gas induction tube.

4. The apparatus of claim 1 further comprising a heating device connected to the fuel cell.

5. A sobriety interlock for a machine comprising:

(a) a breath induction tube for channeling a flow of human breath, the breath induction tube defining a breath flow channel, the breath induction tube further defining a breath flow exit;

(b) a pressure sensor connected to the breath induction tube, the pressure sensor capable of generating an electrical pressure signal in response to the pressure in the breath flow channel;

(c) a fuel cell connected to the breath induction tube, the fuel cell capable of producing an electrical alcohol volume signal proportional to the total volume of alcohol present in a breath sample;

(d) a valve having a closed position the valve disposed between the breath induction tube and the fuel cell, the valve capable, when in the closed position, of preventing flow between the breath flow channel and the fuel cell such that the entirety of the flow of breath flows through the breath flow exit;

(e) a computing device electrically connected to the pressure sensor and to the fuel cell, the computing device capable of generating an electrical valve open signal, further capable of determining the alcohol volume in the breath sample in response to the electrical alcohol volume signal, further capable of determining a breath sample volume in response to the electrical pressure signal, further capable of generating an electrical valve close signal when the breath sample volume exceeds a predetermined level ensuring that a predefined requisite volume of breath flow has passed thru the fuel cell, further capable of calculating the concentration of alcohol in the breath sample from the alcohol volume in the breath sample and the breath sample volume, and still further capable of generating an operations signal;

(f) a valve controller connected to the valve and to the computing device, the valve controller capable of opening the valve in response to the electrical valve open signal and capable of closing the valve in response to the electrical valve close signal; and

(g) an electronic circuit connected to the computing device, the electronic circuit capable of controlling the operation system of the machine in response to the operations signal.

6. The sobriety interlock of claim 5 wherein the operations signal comprises a signal generated in response to a determination that the concentration of alcohol in the breath sample is less than a predetermined level.

7. The sobriety interlock of claim 6 wherein the operations signal further comprises a signal generated in response to a determination that the temperature of the breath flow is within a predetermined range.

8. The sobriety interlock of claim 6 wherein the operations signal further comprises a signal generated in response to an oscillation in pressure within the breath induction tube.

9. The sobriety interlock of claim 6 wherein the operations signal further comprises a signal generated only when the electrical pressure signal exceeds a predetermined level.

10. The sobriety interlock of claim 5 wherein the operations signal comprises a signal generated in response to a determination that the concentration of alcohol in the breath sample is greater than a predetermined level.

11. A method of determining the sobriety of a person, comprising the steps of:

(a) receiving a flow of breath into a breath induction tube;

(b) determining the pressure of breath flow within the breath induction tube;

(c) providing a breath flow exit in the breath induction tube for allowing the breath flow to exit the breath induction tube;

(d) after a portion of the breath flow has exited the breath induction tube, opening a valve disposed between the breath induction tube and a fuel cell to permit a breath sample to flow through the fuel cell;

(e) generating an electrical alcohol volume signal corresponding to the volume of alcohol in the breath sample detected by the duel cell;

(f) calculating the volume of alcohol in the breath sample in response to the electrical alcohol volume signal;

(g) calculating a breath sample volume in response to the pressure in the breath induction tube;

(h) closing the valve when the breath sample volume exceeds a predetermined level thereby ensuring that a predefined requisite volume of breath flow has passed thru the fuel cell; and

(i) calculating the alcohol concentration within the person'"'"'s breath from the volume of alcohol in the breath sample and the breath sample volume.

12. The method of claim 11 further comprising the step of:

(i) preventing enablement of a machine unless the value of the alcohol concentration in the breath sample is less than a predetermined level.

13. The method of claim 11 further comprising the steps of:

(i) determining a value for the person'"'"'s blood alcohol concentration based upon the alcohol concentration of the breath sample; and

(j) generating an output in response to the person'"'"'s blood alcohol concentration.

14. The method of claim 13 wherein the step of generating an output comprises sending an enabling signal to a machine only if the person'"'"'s blood alcohol concentration is less than a predetermined level.

15. The method of claim 13 wherein the step of generating an output comprises displaying a numeric value of the blood alcohol concentration on a display screen.

16. The method of claim 13 wherein the step of generating an output comprises generating one response if the blood alcohol concentration is less than a predetermined level and generating a different response if the blood alcohol concentration is greater than or equal to the predetermined level.

17. The method of claim 13 wherein the step of generating an output comprises printing a message or data on a paper medium.

18. The method of claim 13 wherein the step of generating an output comprises illuminating a pass indicator light in response to a determination that the value for the person'"'"'s blood alcohol concentration is below a predetermined level.

19. The method of claim 13 wherein the step of generating an output comprises storing the blood alcohol concentration in a storage device.

20. The method of claim 11 further comprising the step of:

(i) disabling a machine unless the value of the alcohol concentration in the breath sample is less than a predetermined level.