Remote ethanol detectors

Abstract

Embodiments provide apparatus, modules, methods, etc. for detecting vaporous ethanol. The apparatus of some embodiments operate near fluorescent excitation / emission wavelength pairs for vaporous ethanol of 399 / 412 nanometers. Some embodiments provide vaporous ethanol detectors with range finding circuitry that interlocks the transmission of light when objects are too close to the detectors. Various embodiments transmit patterns of excitation light pulses and detect corresponding patterns of emission light returned from vaporous ethanol. Some embodiments provide detectors which use signal processing to recover weak fluorescent signals from potentially noisy environments.

Description

[0001] NON-PRO VISIONAL PATENT APPLICATION for

[0002] REMOTE ETHANOL DETECTORS

[0003] By: Robert L. Villhard

[0004] BACKGROUND

[0005] Drunk drivers kill thousands of innocent victims every year. As a result, law enforcement agencies patrol the streets and highways trying to detect and stop those intoxicated drivers before they cause an accident with resulting property damage, personal injuries, and / or death. Unfortunately, many of those intoxicated drivers escape detection for any of a number of reasons. Some are lucky. Others happen to be good enough at driving while under the influence to escape notice. Yet others take evasive routes on streets unlikely to be patrolled by the police. Constitutional protections prevent the police from stopping a vehicle unless they have at least a reasonable suspicion (or even probable cause) to do so. Plus, given the number of vehicles on the road, it would be prohibitive to stop every vehicle to determine the sobriety of the drivers. As a result, just in the United States alone, every year drunk drivers cause billions of dollars and kill and maim thousands.

[0006] Similar problems exist in industry. Many industries necessitate hazardous environments in order to provide their services and / or produce their products. For instance, the petrochemical industry handles many flammable and even explosive materials. Grain handling facilities produce explosive environments with the grain dust inherent in their operations. Farms employ heavy equipment with many exposed moving parts. Likewise, the automobile rental industry rents cars to drive some of whom might be intoxicated even though not visibly so. In the hospitality industry, waiters, bar tenders, and the like might “over serve” patrons thereby allowing those patrons to get behind the wheel of a car after over doing it.

[0007] Then there are teenage drinkers. These drinkers typically have little experience drinking, are new to driving, and immature. Their drinking concerns parents, guardians, and other family members to a great degree. Their immaturity, boosted by alcohol, increases the chances that they might become risky, reckless, promiscuous, and other behaviors fraught with peril and / or long range, expensive repercussions. Likewise, certain spouses might become problematic after drinking. The resultant abuse they inflict on their spouses and other loved ones represents a chronic situation in modern civilization. SUMMARY

[0008] To date remote detection of intoxication has not been possible. Current breathalyzers require the presence of alcohol (i.e., ethanol) at the sensing device. Heretofore available breathalyzers use either fuel cell or semiconductor technology to directly sense the presence of ethanol. Both types of breathalyzers rely on a chemical reaction AT (CAPS INTENTIONAL) either the fuel cell or at the surface of a semiconductor material. They sense the current / voltage change induced by those reactions and are entirely limited by the presence of ethanol AT the sensor. Even heretofore available passive alcohol sensors (PAS) rely on the presence of ethanol AT the sensor. More particularly, some of these PASs draw air (containing the ethanol) into themselves for a fuel cell or semiconductor material to react with the ethanol. Again, these reactions occur at the sensor regardless of whether the manufacture of such devices claim so-called remote alcohol detection. These devices typically require (or allow) the knowledge, consent, and cooperation of the subject. Thus, the subjects can evade them and / or refuse to cooperate or consent to the measurement of the BAC.

[0009] In sharp contrast to heretofore available breathalyzers and PASs, ethanol detectors of embodiments provided herein actually detect ethanol remotely. Remote, or long-range detection of ethanol (i.e., breath alcohol content) offers many unexpected benefits over previously available breathalyzers and PASs (hereinafter, breathalyzers). For instance, the subject of the detection might be completely unaware that their BAC (breath alcohol content) is being measured. They also need not consent much less cooperate with a remote reading of their BAC. Thus, police can monitor the cabins of passing vehicles for ethanol. Employers, managers, business owners, regulatory authorities, etc. can monitor workers without their knowledge, cooperation, or consent (as allowed by applicable laws, constitutional restrictions, regulations, union contracts, employment contracts, and the like). Moreover, parents can monitor their children (particularly teenagers) and even spouses for alcohol use. In such situations, the ability to do so can eliminate or at least minimize arguments, confrontations, and other unpleasant consequences of attempting to obtain a BAC reading with the subject’s knowledge, cooperation, consent, or combinations thereof.

[0010] More specifically, many embodiments provide vaporous ethanol fluorescent detection apparatus comprising a light source, a light sensor, and an indicator. The light sources are configured to transmit light at a vaporous ethanol excitation wavelength toward areas remote from the light sources and which potentially contain trace amounts of vaporous ethanol. The light sensors are co-located and aligned with the light sources and are configured to sense light at a vaporous ethanol emission wavelength wherein light at the vaporous ethanol excitation wavelength causes vaporous ethanol to fluoresce light at the vaporous ethanol emission wavelength. The indicators are in communication with the light sensors and are configured to indicate whether the light sensors sense light at the vaporous ethanol emission wavelength originating in the remote areas wherein the apparatus detects whether the trace amounts of vaporous ethanol are present in the remote areas.

[0011] In some embodiments the vaporous ethanol excitation wavelength is in an ultraviolet portion of the electromagnetic spectrum and more particularly at approximately 399 nanometers. Meanwhile the vaporous ethanol emission wavelength can be in the visible portion of the spectrum and can be approximately 412 nanometers. In various embodiments the apparatus also include pulse duration limiting circuits which are in communication with the light sources and are configured to limit the duration of a pulses of vaporous ethanol excitation light from the light sources. The apparatus, furthermore, can include cameras which are configured to capture images including the vaporous ethanol excitation light. The apparatus can also include memories configured to store the indications. In addition, or in the alternative, the apparatus can include circuits which are in communication with the memories and which time stamp and location stamp the indications. If desired, the apparatus can also include network interfaces to communicate the vaporous ethanol indications to other devices.

[0012] Modules of embodiments are also provided. Such modules comprise light sources configured to transmit light at a vaporous ethanol excitation wavelength toward areas remote from the light sources and which potentially contain trace amounts of vaporous ethanol. Such modules also comprise light sensors which are co-located and aligned with the light sources. They are also configured to sense light at a vaporous ethanol emission wavelength wherein light at the vaporous ethanol excitation wavelength causes vaporous ethanol to fluoresce light at the vaporous ethanol emission wavelength. Such modules, moreover, also comprise outputs which are in communication with the light sensors and which are configured to output indications of whether the light sensors sense light at the vaporous ethanol emission wavelength in the remote areas. Thus, the indicators output indications of whether the modules detect whether the trace amount of vaporous ethanol are in the remote areas.

[0013] In some embodiments, the modules also include controllers which are in communication with the light sources and are configured to control the light sources. These controllers can control the light sources to transmit pulses of light one at a time or in patterns. If desired, the controllers can also detect patterns of light at the vaporous ethanol emission wavelength corresponding to the patterns of pulses of light transmitted by the light sources. In addition, or in the alternative, the controllers can control the light sources to transmit the pulses of light at a low power and can detect the arrival times of pulses of return light corresponding to the low power pulses whereby the controllers determine whether objects are at a close range to the modules.

[0014] In accordance with embodiments, methods of detecting trace amounts of vaporous ethanol remotely are also provided. Such methods comprise providing users light sources which are configured to transmit light at a vaporous ethanol excitation wavelength toward areas remote from the light sources which potentially contain trace amounts of vaporous ethanol. Such methods also include providing light sensors which are co-located and aligned with the light sources. These light sensors are configured to sense light at a vaporous ethanol emission wavelength. Furthermore, these methods include providing indicators which are in communication with the light sensors and which are configured to indicate whether the light sensors sense light at the vaporous ethanol emission wavelength originating from the remote areas. Additionally, these methods also include allowing the users to use the indicators to determine whether vaporous ethanol is present in the remote areas.

[0015] DESCRIPTION OF THE DRAWINGS

[0016] Fig. 1 illustrates a system of embodiments.

[0017] Fig. 2 illustrates a schematic diagram of a detector of some embodiments.

[0018] Fig. 3 illustrates a flowchart of a method in accordance with embodiments.

[0019] Fig. 4 shows a scene in accordance with embodiments.

[0020] Fig. 5 illustrates detectors of various embodiments.

[0021] Fig. 6 shows a timing diagram in accordance with embodiments.

[0022] Fig. 7 shows another timing diagram in accordance with embodiments.

[0023] Fig. 8 shows a cross-sectional diagram of detectors of various embodiments.

[0024] DETAILED DESCRIPTION

[0025] Fig. 1 illustrates a scene in which a remote alcohol detector of embodiments is in use. The detector works by transmitting light at an excitation wavelength at a subject vehicle and detects light emitted from alcohol (fumes) in the vehicle as a result of the fluorescence of the vapor alcohol.

[0026] More particularly, Fig. 1 illustrates the scene 100, a police car 102, a vehicle 104, a remote alcohol detector 106, alcohol fumes 108, a device 110, excitation light 112, emitted light 114, and a law enforcement Officer 116. For illustrative purposes, the criminal justice system is shown figuratively at 118. As is known to those skilled in the art, alcohol (or more specifically, ethanol) fluoresces when light of certain wavelengths encounters it. Thus the Officer 116 has positioned his car relative to the vehicle 104 so as to be able to shine light from the detector 106 on the vehicle 104. Figure 1, for illustrative purposes, shows the detector 106 external to the police car 102. Although it is understood that the detector 106 could be used in (or from) the police car without departing from the scope of the current embodiment.

[0027] In operation, the Officer 116 aims the detector 106 at the vehicle 104 and triggers a pulse of excitation light 112 at an excitation wavelength of alcohol. The excitation light 112 travels to the vehicle 104 and encounters the alcohol fumes 108 within the vehicle 104. Because the wavelength of the excitation light is one of the wavelengths at which alcohol fluoresces, the alcohol atoms in the fumes fluoresce causing the emitted light 114. In some embodiments, the wavelength of the transmitted light is 280 nanometers. Note that the wavelength of the current embodiment is in the deep UV-C (ultraviolet-C) band which is sometimes termed deep or “space UV.”

[0028] Air can attenuate space UV. Indeed, space UV from astronomical objects is known to be essentially extinguished by the time it traverses the depth of the atmosphere to reach ground level. Thus, in the current embodiment, digital signal processing (DSP) techniques are used to detect the emitted light signal coming from the subject vehicle. Appropriate techniques can be employed nonetheless to limit the amount, energy, or power of the UV excitation light. For instance, the transmitted light might be transmitted in short pulses; the transmitted light can be at a sufficiently low intensity; etc. The transmitted excitation light 112 can also be at another wavelength. For instance, certain visible wavelengths cause alcohol (ethanol) to fluoresce and can be used in accordance with embodiments. Thus, non-limiting excitation / emission wavelength pairs can be selected for use as follows in Table 1 (wavelengths are measured in nanometers and are approximate):

[0029] Table 1 : Excitation and Emission Wavelength Pairs

[0030] Excitation Wavelengths Emission Wavelengths Geometry

[0031] 400-520 450-600 Right-angled

[0032] 300-400 400-475 Right-angled

[0033] 320-520 400-600 Front-faced

[0034] 475 530 Right-angled

[0035] 350 450 Right-angled

[0036] 410 490 Front-faced The Inventor has found experimentally that vaporous ethanol fluoresces somewhat differently than liquid ethanol. While the foregoing wavelengths can detect liquid ethanol, vaporous ethanol can be detected at other wavelengths. Notably, the Inventor has found that vaporous ethanol fluoresces under the influence of excitation light in the range approximately between 385 and 405 nanometers. The corresponding emission light from vaporous ethanol occurs in the range approximately between 405 and 425 nanometers. Moreover, the Inventor has found that the fluorescence of ethanol vapor can vary over time within these approximate ranges.

[0037] With reference again to Fig. 1, a portion of the emitted light travels back to the detector 106 which detects that emitted light 114. The detector 106 then indicates through a light, sound, display, or other indication whether sufficient emitted light 114 has been detected to support a conclusion that alcohol fumes are present in the vehicle 104. The Officer 116 can therefore make a decision regarding whether he has enough evidence to support either a reasonable suspicion (or perhaps) probable cause to stop the subject vehicle and determine whether the driver is indeed driving under the influence of alcohol.

[0038] If desired, the detector 106 can communicate evidence of the detected alcohol fumes 108 to the device 110 for storage, re-transmission, display, etc. That evidence can be photographic, video, a measurement of the intensity of the emitted light, or otherwise. Moreover, that evidence can then be used in proceedings within the context of the criminal justice system 118. Indeed, depending on other observations that the Officer 116 might have made of the vehicle and / or its driver (or occupants), reasonable suspicion might exist sufficient to stop the vehicle 104 and question the occupant(s). In the alternative, or in addition, the Officer 116 might chose to follow the vehicle 104 or otherwise place it under continued surveillance until such time that at least a reasonable suspicion to support a stop does exist.

[0039] Figure 2 illustrates a schematic diagram of a remote alcohol detector 200 of embodiments. As shown, the detector 200 includes a housing 202, a pulse shaper 203, a source 204, a receiver 206, detector electronics 208, a memory 210, a processor 212, an application 213 (with or without a graphical user interface or GUI), a network interface 214, a geolocation device 215 (such as GPS), an antenna 216, a network 218, a radar gun 220, an onboard computer 222, and other onboard electronics 224. Using the application 213 resident on the processor 212, a user can control the operation of the detector 200 of the current embodiment. Manual and / or hardware controls such as a trigger can be included in detector 200.

[0040] Thus, the user can trigger the pulse shaper 203 to create a pulse of light to be transmitted from the source 204. The source 204 and receiver 206 can be mechanically registered and / or optically aligned with each other such that the two devices point in the same direction. In some embodiments the source 204 and receiver 206 are coaxial. Thus, the receiver 206 can receive emitted light from the subject at which the detector 200 is pointed. The light received by the receiver 206 can be detected by the electronics 208. Moreover, the application 213 can be configured to monitor the detector electronics 208. Of course, if desired, the application 213 can only monitor the detector electronics 208 at times during which the source 204 is active (transmitting light) and / or for a time thereafter corresponding to the time it takes light to travel to and from the subject and / or for the alcohol to fluoresce so as to minimize false positives from extraneous sources.

[0041] Note that the memory 210 can store information created by the detector 200. For instance, images and (see Fig. 4) other information can be stored in the memory 210. Moreover, using the geolocation device 215, the detector 200 can time stamp and / or geo stamp such information. Furthermore, that information can be transmitted to other devices (on other police cars, at a police station, etc.) via the network interface 214 and / or (RF) antenna 216. Geo-location information from the geolocation device 215 can also be used to correlate the readings the detector makes with information local to the detector. For instance, online services can be accessed via the network interface 214 to determine the local elevation and / or weather conditions (relative humidity, barometric pressure, temperature, time of day (light levels), cloud cover percentage, etc.) which can be used to adjust such readings for local conditions if desired. Using the network 218 on the police car, information from other devices such as a radar gun 220 can be combined with the information created by the detector 200 and stored in the memory 210 in the onboard computer 222, and / or on other onboard electronics 224.

[0042] In some embodiments, two or more remote alcohol detectors cooperate to capture images of subject vehicles and / or the alcohol fumes therein. More particularly, these detectors can be networked via Wifi, Bluetooth, other RF techniques, optical techniques, hardwired connections, etc. One or more of the detectors can be configured to transmit the excitation light with the other detectors being configured to detect emitted light from the subject. Thus, the detectors can be positioned and oriented in right-faced, front-faced, and / or 0 to 180 degrees transmitting configurations (about a selected position through which the subject vehicle(s) will travel). Moreover, a radar gun can be included in such setups and be configured to detect when a vehicle is present to trigger the operation of the transmitting detector(s) and receiving detector(s).

[0043] With continued reference to Fig. 2, more information regarding detector electronics 208 might be of interest. For instance, detector electronics 208 could include a graphics processing unit (GPU), a field programmable gate array (FPGA) device, an application specific integrated circuit (ASIC), other components, or could even be included in the processor 212. In some embodiments, detector electronics 208 includes a GPU and an FPGA. The GPU of such embodiments processes images captured by the receiver 206 which includes a camera. The FPGA conducts digital signal processing techniques on the image for various purposes including recovering low-level signals at the emission wavelength(s). In some embodiments, the transmitted light is driven with a sine wave with the detector electronics being configured as a lock-in amplifier that uses phase-sensitive techniques to recover the fluorescent signal. Other techniques such as phase lock loops, wavelet analysis, synchronous detection, spectrum analyzers, etc. can be configured into detector electronics 208 as desired. Detector electronics 208 can, in the alternative or in addition, be configured to detect leading and / or trailing edges of the emitted light corresponding to those edges of the transmitted light (adjusted in time for the distance the light must travel to / from the subject.). Band pass filters and other analog devices could also be included in detector electronics 208.

[0044] In other embodiments, the selected wavelengths correspond to the fluorescence of other intoxicating substances. For instance, it might be the case that cannabis (i . e. , marijuana), cocaine, methamphetamine, fentanyl, and other intoxicating substances might contain fluorescent materials and / or might produce the same when consumed, smoked, mixed with liquids / gases, etc. Detectors can thus be configured to detect the presence of these other intoxicating fluorescent materials (by configuring the sources and detectors to operate at the corresponding wavelength pairs).

[0045] Figure 3 illustrates a flowchart of a method in accordance with embodiments. The method can begin with calibrating a remote alcohol detector (or “gun”). That calibration can include aiming a detector 200 at a specimen configured to contain a known concentration of alcohol fumes, at a selected distance, and under selected lighting and / or other pertinent conditions. The gun can be triggered and the emitted light can be measured via the gun. If the measured emitted light is within a selected intensity range the gun can pass calibration. If not, the gun can be adjusted until it detects the emitted light and does so within the selected range.

[0046] Method 300 can continue with the gun being used on the street(s) or elsewhere. It can be aimed and triggered to illuminate a subject with transmitted light at a frequency known to cause alcohol to fluoresce. See 304. The resulting emitted light, if any, can be detected and used to determine whether fluorescence consistent with the presence of ethanol has been detected at 306. That emitted light signal can be analyzed and / or processed as desired. For instance, should a background signal of light at the emitted light wavelength be present, the detection of the emitted light signal can be timed to correspond with the triggering of the transmitted light to eliminate false positives. In addition, or in the alternative, a corresponding increase in light at the emitted wavelength can be detected. In accordance with other embodiments, digital signal processing techniques can be used to recover / detect the light emitted from the alcohol fumes. For instance, wavelet analysis can be used to recover weak emitted light signals and / or those emitted light signals with large noise sources present. Such processing can continue until the emitted light signal is detected or for some selected amount of time. See 308.

[0047] If fluoresce is detected at 306, method 300 can continue with a signal being generated to alert the user of the detection. See 312. As discussed elsewhere herein, the user can follow the subject to collect and secure additional evidence (see 310 and 314). At some point, the user can determine whether enough evidence exists to support a reasonable suspicion for a stop / questioning and / or to support probable cause for an arrest. See 316. If not, method 300 can repeat with another subject being selected at 318. If sufficient evidence exists, method 300 can continue with a stop and / or arrest being made at 320.

[0048] Figure 4 illustrates a scene and an image of the scene captured in accordance with embodiments. More particularly, Fig. 4 illustrates the scene 400, a subject 404, a spot illumination 406, a fume cloud 408, breath 410, a container 412, an image 420, a fluorescent spot 426, a fluorescent cloud 428, a concentration 429, fluorescent breath 430, and a fluorescent liquid 432. The scene can be within a vehicle or elsewhere and can include the subject 404, the subject’s breath 410 (which might contain ethanol fumes), and the resulting fume cloud 408. The scene 400 might also include the container 412 which might or might not contain an alcoholic liquid.

[0049] If the scene 400 is illuminated with a spot beam of transmitted light the corresponding fluorescent spot 426 might appear and be detected by a remote alcohol detector of embodiments. If a broader beam of transmitted light illuminates the scene 400, the image 420 captured by a camera (selected to capture images at the emitted wavelength) might contain more information than a single indicative, fluorescent spot 426. For instance, it might reveal the contours of the fume cloud as shown by fluorescent could 428. Concentrations 429 within the fume cloud 429 could also be captured. Likewise, the subject’s breath 410 could be revealed as containing alcohol fumes / droplets as indicated by fluorescent breath 430. Note that body heat from the subject 404 could preferentially cause alcohol in the subject’s mouth, lungs, etc. to partially vaporize enabling such capture. Fig. 4 also illustrates that the alcohol containing liquid in the container 412 could produce a corresponding image (see fluorescent liquid 432).

[0050] In certain circumstances, some other vapors, objects, materials, etc. might fluoresce with the same excitation and emission wavelength pairs as one of the pairs for ethanol. In such cases, excitation light can be transmitted from two (or more) sources with wavelengths at differing excitation wavelengths of ethanol. The detector(s) can be configured to detect light at the corresponding differing wavelengths. One excitation wavelength could be in the UV, visible, or infrared (IR) bandwidths with corresponding emission wavelengths. Because these pairs can be selected so as to avoid causing the other vapor, object, material, etc. to fluoresce at all excitation wavelengths, only those subjects fluorescing at all transmitted wavelengths can be considered as “positive” signals. Subjects fluorescing at less than all of the transmitted wavelengths can be considered “negative” signals and disregarded.

[0051] Fig. 5 illustrates remote alcohol detectors of various embodiments. In these embodiments, the detectors 500 generally resemble heretofore available radar guns such that various law enforcement Officers will find their use familiar. They therefore include housings 502 handles 504, triggers 506, sources / receivers 508, displays 510, in positions corresponding to such radar-related components on radar guns.

[0052] Fig. 6 illustrates a timing diagram in accordance with embodiments. More particularly, it might be desirable to time the detection of the emitted light relative to the transmission of the excitation light. Thus, a timing window can be utilized such that the detectors of the current embodiment exclude measurements of light at the emission wavelength which fall outside of that window. Moreover, such detectors only consider detected light at the emission wavelength that falls within that window. The detection window can begin once the transmitted light has had time to travel to the subject and once the emitted light has time to travel back to the detector. That window, can remain open for a length of time corresponding to the fluorescent life time of alcohol or multiples or fractions thereof.

[0053] Fluorescent lifetimes typically range between 0.5 and 20 nano seconds. Therefore the detection window can remain open for some multiple of the fluorescent lifetime of ethanol (or some other subject intoxicant). Moreover, the beginning of the detection window can be set to the time it takes for light to travel from the detector to the subject, and back. Note also that, if desired, multiple pulses of excitation light can be transmitted. In such embodiments, multiple detection windows can be opened corresponding to the pulses of excitation light.

[0054] Fig. 7 illustrates another timing diagram in accordance with embodiments. More specifically, Fig.7 shows a series of pulses with a selected time-distribution and shape. It also shows the resulting return signal of emitted light and a comparatively high noise signal (environment). Detectors of the current embodiment recover the return signal using DSP and / or other signal recovery techniques.

[0055] As further described herein, embodiments have been provided which allow law enforcement officials to remotely detect drivers potentially under the influence of alcohol (or other intoxicants). For instance, a detector can be aimed at a vehicle, triggered, and then its display can be examined to determine if alcohol fumes are present in the subject vehicle. The Officer can then quickly check the next car and repeat the process until a vehicle containing sufficiently high levels of alcohol fumes is identified. Subsequently, such vehicles can be stopped and arrests made as circumstances suggest. Thus, instead of following vehicles one-by-one for extended times, detectors of embodiments allow law enforcement to check many cars quickly. Moreover, these checks can be performed non- intrusively. Nor do remote alcohol detectors of embodiments require setting up and maintaining a traffic checkpoint while adhering to pertinent constitutional and / or legal constraints. Indeed, occupants of subject vehicles might be unlikely to even realize that their vehicle is being checked. Thus, novel and non-obvious remote alcohol detectors have been provided.

[0056] Fig. 8 shows a cross-sectional diagram of detectors of various embodiments. More specifically, Fig. 8 illustrates a detector 800, a housing 802, a source 804, an optical sensor 806, electronics 808, a chamber 810, an excitation light 812, an emission light 814, an ethanol fumes 828, a slider 830, an aperture 832, a vent tube 834, a sample tube 836, an aperture 838, a vent path 840, and a range adaptor 860 including a housing 862, lens 864, filters 866, and optical coatings 868. Fig. 8 also illustrates the detector 800 in two positions (a “breathalyzer” or closed position and a “remote” or open position). The two positions are defined in part by the position of the slider 830. Thus, the detector 800 of the current embodiment can be used in a manner similar to a conventional breathalyzer and in a new and non-obvious “remote” manner. Note that even in the breathalyzer mode, the detectors of the current embodiment do not require the presence of ethanol at the optical sensor 806.

[0057] With continuing reference to Fig. 8, the housing defines the chamber 810. The sample (or breath) tube 836 communicates with the chamber 810 which in turn communicates with the vent tube 834. The tubes penetrate the housing 802 wall so that air can flow from outside of the housing 802 through the sample tube, through the chamber 810, and then exit through the vent tube 834. The chamber 810 and tubes are sized relative to one another such that the air (or other fluid) flowing through the detector 200 dwells or resides in the chamber 810 for a time sufficient for the detector 800 to detect any ethanol that might be therein.

[0058] Additionally, a check valve can be included in that flow path (for instance in one of the tubes) to prevent air being drawn in from the vent tube 834. Note also that all components in communication with the flow path (the tubes and the chamber 810 walls) as well as the source 804, the optical sensor 806, the slider 830, etc. can be made from material that can be cleaned and / or sanitized. Some or all of these components can also be heated to prevent condensation of water (and other vapors) that might be present therein or in the air flowing through the detector 800. In some embodiments, the housing 802 is generally cylindrical although the housing 802 can be generally rectangular (i.e. a rectangular prism), oval or have other cross-sections / shapes. Indeed, the housing 802 can be configured ergonomically to allow the user to grasp and operate the detector 800. A trigger, a display, and other controls (not shown) can be positioned on the housing 802. With continuing reference to Fig. 1, the source 804 provides excitation light to cause alcohol fumes (i.e. the ethanol molecules therein) to fluoresce. In some embodiments the source transmits light at 399 nm although other wavelengths are within the scope of the current embodiment. Wavelengths between 385 and 405 nm have been observed causing vaporous ethanol fluorescence and such sources are also within the scope of the current embodiment. LEDs, super-bright LEDs, fluorescent lights, laser diodes and the like can be used as sources 804 and can be used in groups or in conjunction with one another.

[0059] Still with reference to Fig. 8, the optical receivers 206 detect the light emitted by vaporous ethanol when excited by the light provided by the source(s) 804. As such, the wavelengths at which the sensors operate can be chosen in conjunction with choosing the operating wavelength of the source 804. Since real-world, commercially available sources 804 and 806 operate over respective wavelength ranges it can be the case that optimal combinations of sources and detectors can be selected together by trading off their individual performances, optical power delivery / sensitivity, accuracy, etc. along with detector 800 level considerations such as component costs, form factors, availability, lead- times, etc.

[0060] In general, the Inventor has found experimentally that the emission wavelength tends to increase with increasing excitation wavelength. Some variability in the excitation wavelength (which causes the peak emission activity) has been observed as well as variability in the peak emission activity with a given excitation wavelength. For a given application, therefore, practitioners seeking to optimize a system can build statistical databases of this variability to guide their choice of sources 804, optical sensors 806, the supporting electronics 808, etc. During experimentation the Inventor found that a source 804 operating at approximately 399 nm paired with an optical sensor operating at 412 nm can provide indications that vaporous ethanol is present. It is noted here that commercially available sources 804 and optical sensors 806 1) operate over respective ranges and 2) those ranges peak at some distance from the desired wavelengths. Users can therefore trade off the detector and optical sensor ranges and peaks along with the ranges of various optical coatings, filters, etc. in designing detectors 800 for various applications.

[0061] Note also that while Figure 8 shows the source 804 and optical sensor 806 at one end of the chamber 810, other configurations are within the scope of embodiments. Likewise, the source 804 and optical sensor 806 need not be coaxial as illustrated in the current embodiment. Locating them coaxial though can increase the ability to align one with the other as well as the aperture 838.

[0062] The electronics 808 of the current embodiment include the circuitry and components which support the source 804, the optical sensor 806, and user controls and displays (not shown) of the detector 800. For operation in the breathalyzer mode, those electronics can be relatively simple and include power supplies; temperature stabilization circuitry; signal conditioning circuitry; circuitry to convert the output of the optical sensor 806 to a scale suitable for display to the user; etc. Memory, GPS, processing, networking and other functionality can be included in the electronics 808 as the user desires. To support operation in the remote mode, electronics 808 can include additional circuitry / components. For instance, a position sensor can sense the position of the slider 808 and communicate that information to the electronics so that the electronics can adjust operation according to the slider 830 position.

[0063] For detectors 800 intended for short ranges (on the order of inches) between the detector 800 and potential locations of ethanol fumes, little or no additional electronics might be necessary. As the intended range increases, additional electronics might be helpful. For instance, range finding circuitry can be included in electronics 808 to find the range to the nearest object along the line of sight of the detector 800. Such range finding electronics 808 could control the source 804 to emit one or more low power pulses and could monitor the output of the optical sensor 806 to detect the arrival of reflected pulses (at the wavelength of the source 804). Those electronics could then determine the time between the transmitted and reflected pulses (and given the speed of light) further determine the distance to that nearest object. If that object is too close for operations given the power output by the source 804, the electronics 808 can interlock or prohibit further operations until the object moves away.

[0064] With increasing intended range, the detector could include a “reference” with which to determine the actual output power of the source 804. The reference of such embodiments might be a mirror in the path of the transmitted light configured and oriented to reflect a predetermined portion of the transmitted light back to the optical sensor 806 for measurement. Electronics 808 can be configured to make that measurement at a time corresponding to the time it takes for the transmitted light to travel from the source 804, to the reference, and back to ensure that the reference is being measured and not external light (as adjusted for ambient light at the transmitted wavelength). Thus, the electronics 808 can determine the power output by the source 804 for use in determining the relative strength of returning emitted light (from the ethanol fumes 828). Other references are within the scope of the current embodiment. For instance, a photodiode can be positioned to measure the transmitted light and in a feedback loop with the electronics control the intensity of the transmitted light. In other embodiments intended for longer range operation, electronics 808 can include means to modulate the source 804 according to one or more predetermined patterns. Electronics 808 could also be configured to watch for a corresponding pattern in the emitted light as detected by the optical sensors 806. See Fig, 7. Still with reference to Fig, 8, the chamber 810 defines a volume in which the detector can capture and hold a sample of air (for instance, the user’s breath) for the source 804, optical sensor 806, and electronics 808 to determine the alcohol content thereof. As such, the source 804 and optical sensor can be located at one end of the chamber 810 and oriented to point along the length of the chamber 810. The wall of the housing 802 at the other end of the chamber and / or the slider 830 can include an area of material with a high capacity to absorb light at the transmitted wavelength. Thus, once the source 804 transmits a pulse of light, that light can rapidly be absorbed by that material enabling the optical sensor 806 to operate with lessened interference from the transmitted light.

[0065] On the other hand, the remainder of the chamber 810 walls can be coated with reflective material (at least at the emitted wavelength) such that most of the emitted light eventually reflects to the optical sensor 806 when the detector is in breathalyzer mode. In other words, at the beginning of a breathalyzer detection cycle, the source 804 transmits a pulse of light which traverses the length of the chamber 810. As it passes through the chamber 810 it excites any ethanol fumes it might encounter before being absorbed by the absorbing material at the far end of the chamber 810 (or on the slider 830). Meanwhile, those ethanol molecules excited by the transmitted light vibrate until they emit photons of light. The emitted light travels through the chamber 810 in random directions until it either encounters the chamber 810 walls or the optical sensor 806. The light which strikes the chamber walls reflects again and again until ultimately reaching the optical sensor 806. As that emitted light (whether direct or reflected) reaches the optical sensor 806, the sensor absorbs it and produces a corresponding signal (which the electronics 808 receive).

[0066] However, in remote mode, the light behaves somewhat differently. More particularly, with the slider 830 in the remote position, it exposes the chamber 810 to the aperture 838 formed through the slider. Note that the corresponding area of the chamber wall can include an optically transparent (at both the transmitted and emitted wavelengths) covering. Thus, the pulse of light transmitted by the source 804 traverses the chamber 810 and then passes through the aperture 838. Once through the aperture 838, it continues traveling to an area in which ethanol containing air might be. If it encounters ethanol, it excites that ethanol to fluoresce. In turn, the ethanol emits light at the emission light and in more or less random directions. Even though the emitted light thus spreads out, a portion does travel back to the aperture 838, across the chamber 810, and strikes the optical sensor 806. Note that the detector 800 can be configured to determine the time from the pulse transmission to the receipt of the emitted light (if any) and derive (from that time) an approximate distance to the object emitting the emitted light (that is, any ethanol that might be present). Still with reference to Fig. 8, a discussion of the flow path through the detector 800 might also be helpful. Air, or the user’s breath, can flow through the sample tube 836 and into the chamber 810. Since the volume of the chamber 810 is large compared to the sample tube 836 the air slows considerably once entering the chamber 810. As air enters the chamber 810 from the sample tube 836, it displaces air already there, forcing it out of the vent tube 834. All surfaces in contact with the flowing air can be made of easily cleanable material such as stainless steel, plastics of various types, glass, etc. Heaters, not shown, can maintain these same surfaces above body temperature (98.6F) to prevent undue condensation. As noted elsewhere herein, the chamber 810 can be lined with a reflective coating or the material of the housing 802 can be made of reflective material. The reflectivity allows emitted light to reflect around the chamber until encountering the optical sensor 806 where it is absorbed (and converted into a signal). Such embodiments therefore provide an optical “gain” for the emitted light improving accuracy, repeatability, etc.

[0067] Note also that the reflectivity can be at both the excitation (transmission) wavelength as well as the emission wavelength if desired. Such embodiments allow the transmitted light to reflect about the chamber until inherent losses at the surfaces diminish the transmitted light. This “gain” provided to the transmitted light can be traded off against other factors (such as a settling time between the end of the light pulse and the beginning of measurement sampling by the optical sensor 806 and electronics 808) in the design of detectors 800 for various applications. For instance, if the user desires higher accuracy, a more reflective surface (for the transmitted light) can be provided with allowance of a longer settling time for the transmitted light to die away. This trade-off can be determined by experimentation.

[0068] Again, with reference to Fig. 8, a discussion of the slider 830 might be helpful. The slider 830 allows the user to switch the detector 800 between breathalyzer and remote modes. It can be spring loaded into one or the other positions and can include mechanical stops, detents, etc. to hold it in either position. It can also have a position switch built into it or nearby which communicates with the electronics 808 to allow the electronics to change gains, timing, etc. to account for the selected operating mode. Of course, use of a slider per se is not limiting and other configurations are within the scope of various embodiments. For instance, a shutter or rotary device could be used in lieu of slider 830.

[0069] In the current embodiment, the slider 830 is a solid rod or bar defining the aperture 832 and a portion of the vent path 840. The aperture 838 and vent path 840 are located and orientated on the slider 830 to align with corresponding features in the housing 802. In the case of the aperture 832, in remote position, it aligns with its corresponding housing 802 features to allow the transmitted light to pass from the chamber out to the environment and allows the emitted light to pass from the environment and into the chamber 810. When in the breathalyzer position, the aperture 832 is spaced apart from those corresponding housing features with an opaque position of the slider 830 blocking light from passing / to from the chamber 810. That opaque portion of the slider 830 can be reflective or light absorbing at the transmitting and / or emitting frequencies as the user might desire.

[0070] The vent path 840 aligns with corresponding housing 802 features when in breathalyzer position. It thereby allows the air from the chamber 810 to vent to the environment thereby allowing air from the sample tube 836 to flow into the chamber 810. In the remote position, the vent path 840 is spaced apart from those corresponding housing 802 portions to maintain the air in the chamber in a stable configuration. Although, some embodiments do provide a vent path 840 even in remote mode to allow clearing of the chamber with air unadulterated by the presence of ethanol (and / or other vapors that might fluoresce at the excitation / emission wavelength pairs of ethanol).

[0071] In breathalyzer mode, detectors 800 of embodiments operate as follows. First, the user places the slider 830 in the breathalyzer position if it is not already there. That action aligns the vent path 840 with the corresponding features of the housing 802 opening a flow path from the sample tube 836 through the chamber 810 and out to the environment. It also causes the slider 830 to block the aperture 838. The user can then trigger the detector 800 causing the electronics 808 and take an initial reading to ensure that the chamber 810 is clear of ethanol. If it is not, the user can then clear the detector 800 by blowing into the sample tube 836 and testing the detector 800 until obtaining a clear reading. The detector 800 can also include an air pump (whether manually or electrically activated) if desired for clearing the chamber. Once the user is satisfied that the chamber 810 is clear, they can then begin operations.

[0072] Again, the user can confirm that the slider 830 is in the breathalyzer position as shown in the upper portion of Fig. 8. This action ensures that the vent path 840 is open and that the chamber 810 (or rather aperture 832) is closed optically. The user then blows into the sample tube 836 allowing their breath to push air already in the chamber 810 out and filling the chamber 810 with their breath. Note that the detector 800 can include a flow meter to measure the amount of breath / air flowing therethrough. And, if so, the electronics 808 can read the corresponding signal and indicate when sufficient air / breath has flown through the detector 800 to adequately fill the chamber 810.

[0073] The user can then trigger the detector 800. Responsive thereto, the electronics 808 controls the source 802 to transmit a pulse of light at the excitation wavelength of ethanol (for instance, at a wavelength near 399 nm). The excitation light 812 traverses the chamber 810 in a matter of micro (or many nano) seconds depending on the length of the chamber 810. It then encounters the exposed portion of the slider 830 (instead of passing through the aperture 838 which is spaced apart therefrom in breathalyzer position). If the detector in use has an absorbing material at that location on the slider 830, the transmitted light is largely absorbed by that portion. Accordingly, little excitation light 812 remains in the chamber 810 after it is absorbed. Meanwhile, any ethanol molecules floating in the chamber 810 that the excitation light 812 excited have temporarily absorb energy from that light. In accordance with their fluorescent quantum yield and lifetimes, the excited ethanol molecules begin emitting light at the emission wavelength.

[0074] The emission light 814 initially spreads out in 3 dimensions in the chamber 810. However, it encounters the reflective coating 868 on the chamber walls and reflects back into the chamber 810. Eventually, perhaps after repeated reflections from those walls, the emission light 814 encounters the optical sensor 806 and is absorbed thereby. In accordance with its operating nature, the optical sensor 806 produces a signal corresponding to the amount of emission light 814 it absorbs. Thus, if the optical sensor 806 is a photoresistor, its resistance changes. If it is a photodiode, PIN photodiode, avalanche photodiode, or (BJT, FET, MOSFET, etc.) phototransistor, charge coupled device (CCD), etc. its output current / voltage will change accordingly. The electronics 808 sense that change and convert it into a reading for display to the user.

[0075] Note that because of the fluorescent lifetime of ethanol, the ethanol will continue to emit the emission light 814 after the source 804 stops producing the excitation light 812. The excitation light 812, of course, will eventually be diminished to such an extent that the emission light 814 in the chamber predominates. The electronics 808 can therefore be configured to begin reading the optical sensor 806 signal at (or after the source 804 stops transmitting) to avoid interference from the excitation light 812 if desired. Of course, if interference from the excitation light 812 is not a concern, the electronics 808 can begin taking readings immediately. In either case, the electronics 808 convert the signal from the optical sensor 806 to a reading in terms of breath alcohol content (BAC). Note here that fluorescence is proportional to the concentration of the fluorescent material. Accordingly, the signal (emission light) received by the optical sensor 806 will be proportional to the concentration of ethanol in the chamber 810 (and hence the users breath).

[0076] With reference still to Fig. 8, the user can also operate the detector 800 in remote mode. To do so, the user can clear the detector 800 of r (or other gas / vapors) that might be in chamber 810 and / or check for a null reading. With the slider 830 in the remote position, the source 804, optical sensor 806, and aperture 838 align to provide the detector 800 a line of sight allowing it to be pointed at a target area in which a cloud of air / ethanol vapor is suspected of being. For instance, a parent can point it toward the breath plume of a child, a police Officer can point it at the breath plume of a driver, etc. The user can then trigger the detector 800.

[0077] The electronics 808 can control the source 806 to emit a low power pulse of light to determine the range to the nearest object. If an object is too close to the detector 800, the electronics 808 can disable further transmissions. If no object is within that close range, the electronics 808 can then cause the source 804 to transmit a pulse of excitation light 812 out from the aperture 838 toward the subject area. The electronics 808 can also begin a timer which it will use to determine the range to the cloud of ethanol fumes 828 that might be present in the subject area. The excitation light 812 travels to the subject area and excites vaporous ethanol molecules therein. They, in turn, fluoresce thereby generating emission light 814. Emission light 814 spreads from the area spherically with some of the emission light entering the aperture 838 of the detector.

[0078] The electronics 808 meanwhile can be monitoring the optical sensor 806 for the leading edge of the emission light 814. When the excitation light 812 arrives at the fumes, the fluorescent signal will begin increasing due to the transmission light encountering the near edge of the ethanol fumes 828. The electronics 808 can detect that leading edge and use the timer to determine the range to the ethanol fumes 828 by subtracting a constant to account for the rise-time in the fluorescent signal and dividing the remaining time by the speed of light. As the excited ethanol molecules near the edge begin emissions, the excitation light 812 will of course continue penetrating the ethanol fumes 828 and exciting additional ethanol molecules along its path. Those particular ethanol molecules within the ethanol fumes 828 add their emissions to the earlier emissions thereby strengthening the return signal. Thus, the fluorescent signal (as carried by the emission light 814) will peak at some intensity when the pulse of excitation light has illuminated the breadth (or depth) of the ethanol fumes 828.

[0079] The trailing edge of the pulse of excitation light then reaches the near edge of the ethanol fumes 828 and begins traversing the same. As it does so, the fluorescent signal in the emission light 814 will begin to decrease as more of the ethanol molecules along the path of the excitation light lose illumination. Thus, the fluorescent signal emitted from the ethanol fumes 828 will begin to decrease thereby exhibiting a trailing edge. The electronics 808 can also determine the time at which the trailing edge of the fluorescent signal arrives. Using the time between the leading edge and trailing edge of the fluorescent signal, the electronics 808 can determine the depth of the ethanol fumes 828. Given the peak intensity of the fluorescent signal, the range to the ethanol fumes, and the depth of the ethanol fumes 828, the electronics 808 can determine the loss attributable to the spherical spreading of the emission light 814 and the additive effect from the depth of the ethanol fumes to produce an average measure of the ethanol concentration in the ethanol fumes 828. The electronics 808 then display this measure for the user. Note that the foregoing discussion assumes that the excitation light 812 pulse is long enough to illuminate the depth of the alcohol fumes 828 and much longer than the fluorescent lifetime of vaporous ethanol. Other scenarios are possible of course. And those skilled in the art will understand how to adapt the timing discussed with regard to this scenario to other arrangements.

[0080] In some applications, it might be that the distance to the ethanol fumes 828 is too large (due to the spherical spreading of the emission light) for the optical sensor 806 to readily detect a measurable signal. For such applications a range adaptor 860 and / or additional signal processing by the electronics 808 can be employed to recover the signal. See Fig. 8. The range adaptor 860 releasably attaches to the detector 800 of the current embodiment. It also fits over and aligns with the aperture 838. Thus, when attached to the detector 800, the range adaptor aligns the source 806, the optical sensor 806, the aperture 838, and itself along the line of sight of the detector 800.

[0081] The range adaptor 860 of the current embodiment also includes a long, hollow, housing 662, the lens 864, and one or more filters 866. The lens 864 is positioned at the far end of the range adaptor 860 and has a larger area than the aperture 838. Thus, it gathers more emission light 814 than the aperture 838 acting alone and helps amplify the fluorescent signal emanating from the ethanol fumes 828. The filters 866 can be a combination of high pass, low pass, and / or band pass filters configured together to allow only light at the excitation and emission wavelengths to pass. In some applications one of the filters 866 can be a thin film monochromatic (or band pass filter) selected to allow both the excitation light 812 and emission light 814 to pass through the range adaptor 860. In this manner, much extraneous light can be excluded from the view of the optical sensor 806 thereby increasing its sensitivity.

[0082] Note that the elongated housing 862 can also limit the amount of ambient and / or extraneous or “noisy” light from the field of view of the optical sensor 806 thereby increasing its accuracy while decrease external noise being mistaken for the fluorescent signal. In addition, or in the alternative, the interior surface of the elongated housing 862 can be coated with an optical coating 868. That optical coating 868 can be selected to absorb light outside of the excitation / emission range of wavelengths so as to limit the amount of extraneous light from reaching the optical sensor 806. In the alternative, the optical coating 868 can be selected to reflect light at the emission wavelength toward the optical sensor 806 thereby increasing the sensitivity of the detector 800 to the fluorescent signal. It is also worth noting that the lens 864 and or filters 866 can be placed over the source 804 and / or optical sensor 806 if their affects are wanted only for one or the other device or it is otherwise found to be convenient.

Claims

CLAIMS1. A vaporous ethanol fluorescent detection apparatus comprising: a light source configured to transmit light at a vaporous ethanol excitation wavelength toward an area remote from the light source and potentially containing a trace amount of vaporous ethanol; a light sensor co-located and aligned with the light source and configured to sense light at a vaporous ethanol emission wavelength wherein light at the vaporous ethanol excitation wavelength causes vaporous ethanol to fluoresce light at the vaporous ethanol emission wavelength; and an indicator in communication with the light sensor and configured to indicate whether the light sensor sensed light at the vaporous ethanol emission wavelength in the remote area wherein the apparatus detects whether the trace amount of vaporous ethanol is in the remote area.2 The apparatus of claim 1 wherein the vaporous ethanol excitation wavelength is in an ultraviolet portion of the electromagnetic spectrum.3 The apparatus of claim 2 wherein the vaporous ethanol excitation wavelength is approximately 399 nanometers.4 The apparatus of claim 1 wherein the vaporous ethanol emission wavelength is approximately 412 nanometers.5 The apparatus of claim 1 wherein the vaporous ethanol excitation wavelength is in a visible portion of the electromagnetic spectrum.6 The apparatus of claim 1 further comprising a pulse duration limiting circuit in communication with the light source and configured to limit a duration of a pulse of vaporous ethanol excitation light from the light source.7 The apparatus of claim 1 further comprising a camera configured to capture an image including the vaporous ethanol excitation light.8 The apparatus of claim 1 further comprising a memory configured to store the indication.

9. The apparatus of claim 8 further comprising a circuit in communication with the memory and configured to time stamp and location stamp the indication.

10. The apparatus of claim 1 further comprising a network interface in communication with the light detector and configured to communicate the indication.

11. A module comprising: a light source configured to transmit light at a vaporous ethanol excitation wavelength toward an area remote from the light source and potentially containing a trace amount of vaporous ethanol; a light sensor co-located and aligned with the light source and configured to sense light at a vaporous ethanol emission wavelength wherein light at the vaporous ethanol excitation wavelength causes vaporous ethanol to fluoresce light at the vaporous ethanol emission wavelength; and an output in communication with the light sensor and configured to output and indication of whether the light sensor sensed light at the vaporous ethanol emission wavelength in the remote area wherein the module outputs an indication of whether the module detects whether the trace amount of vaporous ethanol is in the remote area.

12. The module of claim 11 wherein the vaporous ethanol excitation wavelength is approximately 399 nanometers and wherein the vaporous ethanol emission wavelength is approximately 412 nanometers.

13. The module of claim 11 further comprising a light source controller in communication with the light source and configured to control the light source.

14. The module of claim 13 wherein the light source controller is configured to control the light source to transmit a pulse of light.

15. The module of claim 13 wherein the light source controller if further configured to control the light source to transmit a pattern of pulses of light.

16. The module of claim 15 wherein the light source controller is further configured to detect a pattern of light at the vaporous ethanol emission wavelength corresponding to the pattern of pulses of light transmitted by the light source.

17. The module of claim 13 wherein the light source controller is further configured to control the light source to transmit the pulse of light at a low power.

18. The module of claim 17 wherein the light source controller is further configured to detect the arrival time of a pulse of return light corresponding to the low power pulse whereby the controller determines whether an object is at a close range to the module.

19. A method of detecting trace amounts of vaporous ethanol remotely, the method comprising: providing a user a light source configured to transmit light at a vaporous ethanol excitation wavelength toward an area remote from the light source and potentially containing a trace amount of vaporous ethanol; providing a light sensor co-located and aligned with the light source and configured to sense light at a vaporous ethanol emission wavelength wherein light at the vaporous ethanol excitation wavelength causes vaporous ethanol to fluoresce light at the vaporous ethanol emission wavelength; providing an indicator in communication with the light sensor and configured to indicate whether the light sensor sensed light at the vaporous ethanol emission wavelength in the remote area wherein the apparatus detects whether the trace amount of vaporous ethanol is in the remote area; and allowing the user to use the indicator to determine whether vaporous ethanol is in the remote area.

20. The method of claim 19 wherein the vaporous ethanol excitation wavelength is approximately 399 nanometers and the vaporous excitation wavelength is approximately 412 nanometers.