1. Technical Field
The present disclosure pertains to monitoring systems utilizing radio frequency identification tags as well as motion and IR sensors and, more particularly, to a radio frequency transponder located in close proximity to the human body for use in a ceiling-mounted hand wash monitoring system.
2. Description of the Related Art
Studies have shown that up to one-half of all men and at least a quarter of all women fail to wash their hands after using restroom facilities, such as the toilet. Statistics are far worse for teenagers, children, and even young adults. Overall, approximately 97% of foodborne illnesses in the United States have been attributed to improper food handling in commercial and non-commercial environments. This means that over 70 million Americans contract a foodborne illness each year, resulting in 325,000 hospitalizations and 5,000 deaths. The Center for Disease Control (CDC) indicates that at least 25% of these cases are due to improper and inadequate hand washing. The annual cost to deal with food-borne illness was estimated to cost $35 billion in the U.S each year. This included medical charges, lost wages, lost business, lawyer fees, and legal claims.
The CDC advises that hand washing is the single most important means of preventing the spread of infection. Effective personal hygiene, especially hand washing, is critical at every stage of food production, preparation, and serving.
Under the law, commercial food handling requires compliance with certain requirements. It is important for companies to understand the risk imposed by these laws and the risk for failure to comply. Employees are required by state and federal law to wash their hands with soap and water after using the restroom. Statistics show that lawsuits are on the rise as are legal costs, settlement costs, and adverse judgments. In many states, the doctrines of strict liability and constructive knowledge expose the individual owners of these companies to liability, regardless of fault and knowledge.
Today, there are approximately 340,000 Quick Serve Restaurants (QSR) in the United States serving over 50 million Americans daily. It is estimated there are over one million QSRs worldwide.
Effective hand hygiene has been shown to be the most effective means for interrupting the transmission of viruses and bacteria. There is a need for a standard device to monitor employee compliance with a hand washing regime in the workplace and for tracking which employees are complaint and for generating statistics to enable management intervention when needed. Studies have shown that over 50% of food workers do not follow safe hygiene practices. The most common transmission of stomach virus and foodborne illnesses occurs through unwashed or inadequately washed hands. At least 1 in every 6 people in the United States will experience a foodborne illness from unclean hands each year.
Radio Frequency Identification (RFID) devices or “tags” have found their way into use in the monitoring of hygiene in various industries. RFID devices have also been used in inventory tracking and control as well as security to prevent or deter theft from shoplifting. The typical use is a tag attached with a cumbersome housing directly on the clothing that must be removed at the time of purchase. Such security applications can be undesirable where the attachment of the tag to the clothing damages the material or where the tag is forgotten and the purchaser either sets off the alarm or returns home to find the tag still attached to the clothing and unwearable. The use of RFID tags in association with clothing that is worn and then repeatedly laundered presents additional unique issues beside the problems discussed above with respect to the impact of the human body on tag performance. Attaching a tag to clothing that will be worn laundered with the tag attached requires a means of attachment that does not interfere with the comfort of the clothing, that is reliable and robust and will not fail during wear and cleaning, protects the tag while allowing for flexing and bending of the tag.
In operation, RFID devices act as transponders (generally referred to as “tags”), providing information stored in an associated semiconductor device in response to an interrogation signal received at the antenna from a reader or interrogator. The interrogation signal is usually in the form of a radio-frequency (RF) carrier wave signal without, or without, encoded information (e.g., modulated). The information stored on the tag may include a unique identifier of the RFID device, such as a unique serial number (e.g., alpha-numeric), or information (e.g., account, manufacturer, model, style, size, weight, price, color, etc.) about the item to which the RFID device is attached or otherwise associated or about a person who may be wearing the RFID device.
RFID devices that include a discrete power source, for example a battery, are commonly referred to as active devices. RFID devices that rely on an RF signal to derive power are commonly referred to as passive devices, which typically employ modulation backscatter techniques. Some RFID devices may employ both active and passive power sources.
Identification of passive RFID devices generally depends on RF energy produced by a reader or interrogator arriving at the RFID device, which backscatters modulated RF energy to the interrogator to convey the information stored in the RFID device or tag. In general, lower frequencies can penetrate objects better than higher frequencies, but higher frequencies can carry more data than lower frequencies. In addition, multiple protocols exist for use with RFID devices. These protocols may specify, among other things, particular frequencies, frequency ranges, modulation schemes, security schemes, and data formats. Conventional approaches employ multiple RFID devices, each RFID device using a frequency band and protocol suited to a particular application.
Currently, there are passive RFID tags with single or multiple antennas that receive interrogation signals from a reader or interrogator via the antenna(s). The RF voltage developed on the antennas is converted to DC voltage, thereby generating enough power for the RFID tag to power up and transmit a response. Transmitting the response takes the form of backscattering modulated interrogation signals via the antenna(s). Most tag antennas are designed for a specific application, generally referred to in the art as “tuned” to the environment in which it is used. Tags that are brought into contact with the human body or near to the human body will “detune” and not receive interrogation signals due to a coupling effect with the human body.
When a tag is used on or near the human body, its receptive characteristics are diminished due to signal absorption caused by the conductivity of the human body. In other words, because of the size of the human body and its electrostatic characteristics, such as tissue texture, high permittivity, and power absorption, the gain of the tag's antenna will be lowered, reducing its receptivity to interrogation signals and its effective range.
Various approaches have been taken to designing a tag that is “tuned” to receive interrogation signals. In UHF RFID Tag Antenna Design for On-Body Applications by Ziai and Batchelor (2010 Loughborough Antennas *& Propagation Conference, 8-9 Nov. 2010), proposes a slot antenna design on a PET substrate using etched copper, although this design is for 867 Mhz operations. In UHF RFID PIFA Array Tag Antenna for Human Body Applications by Tsai, Li, Chiu, and Wang, an involves a structure consisting of 4 symmetrical small patch antenna arrays formed of planar inverted-F antennas (PIFA's) built on an FR4 substrate. This design relies on grounded vias to enhance directive gain. U.S. Patent Application Publication No. 2006/0054710 (“Forster et al.”) proposed an RFID tag using a self-compensating antenna and conductive shield. Forster et al. utilize an antenna design that has compensation elements, such as impedance matching between the antenna and a chip or components that change the effective length of the antenna elements, so the antenna stays in or near a resonant condition. U.S. Pat. No. 7,323,994 (Yamagajo et al.”) describes an RFID tag formed of two superimposed RFID tags having 13.56 Mhz overlapping coiled stacked resonator loops. W02011005550A2 (“Isabell”) proposes an RFID device for tracking clothing in which a conductive thread is used as a radiating structure to enhance the read range of the tag formed in a button. U.S. Pat. No. 7,999,683 (“Fein”) provides an RFID card style tag that may accept a lanyard.
It is therefore desirable to have a passive or partially passive RFID device and method for backscattering modulated signals via one or more antennas that is tuned to operate in close proximity to the human body, such as on a name tag applied to clothing or on a tag integrally formed with clothing, to ensure the RFID tag receives sufficient power to continue functioning with maximum range.
The present disclosure is directed to an RFID system and monitoring method designed for use in close proximity to the human body, preferably in the context of monitoring and tracking hand washing. The present disclosure is also applicable to point of purchase security, inventory control, and other applications where the RFID transponder or tag is worn on the exterior of the clothing or is integrally formed with fabric, such as clothing, and when worn in near proximity to the human body, the antenna is tuned to respond to interrogation signals.
In accordance with one aspect of the present disclosure, a system for monitoring hand washing at a hand washing station having a sink and a soap dispenser is provided that includes an interrogator located in a ceiling in proximity to the hand washing station and configured to transmit interrogation signals and to receive responsive backscattered signals and to transmit data signals to the processor and the memory; a first sensor located in the ceiling above the soap dispenser and structured to detect the presence of the user's hands in close proximity to the soap dispenser; a second sensor located in the ceiling above the sink and structured to detect the presence of the user's hands in close proximity to the sink; a high intensity LED spotlight located in the ceiling above the sink and structured to visibly illuminate the sink for an interval of time in response to detection of the user by the second sensor; an RFID tag configured to be worn on or in close proximity to a user's body, the tag including: a radio frequency circuit configured to receive and modulate an interrogation signal for backscatter transmission; and an antenna configured to resonate in response to the interrogation signal when in close proximity to the human body. The system further includes a computer processor coupled to the interrogator and configured to receive the data signals from the interrogator to determine a presence of the user and to process the same and generate reports pertaining to use of the hand washing station by users, the computer processor further coupled to the LED light and configured to control the interval of time the LED light illuminates the sink.
In accordance with another aspect of the present disclosure, the computer processor is configured to provide audio or visual feedback to the user indicating compliance with hand washing procedures in response to input from the first and second sensors.
In accordance with another aspect of the present disclosure, a system is provided for monitoring hand washing compliance, the system including a plurality of sensors installed in a space to detect the presence of or proximity of personnel to key areas; and a controller operatively coupled to the sensors, the controller being programmed to analyze sensor inputs to determine if personnel are washing their hands in a manner compliant with a set of requirements, and a networked data storage and reporting system operatively coupled to the controller and configured to provide reports of hand washing compliance.
In accordance with one aspect of the present disclosure, an RFID transponder is provided that includes an antenna configured to resonate in response to an interrogation signal when in close proximity to the human body. Ideally the RFID transponder is associated with a name plate or other device worn on clothing that is attached with a metal pin.
In accordance with another aspect of the present disclosure, an RFID transponder is provided that is configured to respond to an interrogation signal when attached to a name plate or other device having an attachment pin for wearing near the human body. Ideally the transponder antenna is tuned to respond to an interrogation signal when the transponder antenna is RF coupled to the pin and the pin is in close proximity to the human body.
In accordance with yet a further aspect of the present disclosure, an RFID system is provided that utilizes an RFID tag with an antenna configured to be tuned for reception of an interrogation signal when integrally formed on clothing worn in close proximity to the human body. In one embodiment, the system is implemented in a hand washing monitoring station.
In accordance with yet another aspect of the present disclosure, a hand washing monitoring system is provided that includes an RFID system having a tag with an antenna tuned for reception of an interrogation signal when worn on a name tag attached to clothing on the human body.
In accordance with another aspect of the present disclosure, the foregoing hand washing station is configured to generate statistics for each individual who is required to utilize a hand washing station. Preferably, the present disclosure is implemented as a web application utilizing RFID technology to assist employees in compliance with public health regulations and to assist employers in managing employee compliance. Employees receive feedback on hand washing duration and the use of soap or disinfectant, and they can receive feedback in the form of a history of compliance and non-compliance.
In accordance with one aspect of the present disclosure, the method includes sensing the presence of a radio-frequency identification device, such as a tag, when worn in close proximity to the human body and within in a defined area around the hand washing station; identifying an individual associated with the RFID tag; detecting soap dispenser activity; initiating a first audible alert in response to a timer; initiating a second audible alert in response to expiration of a timer.
In accordance with another aspect of the present disclosure, the method includes storing data identifying the individual associated with the RFID tag, and generating and storing data regarding employee identification, location of wash station, compliance rate, wash time, average wash time, and compliance status.
In accordance with a further aspect of the present disclosure, a system is provided that includes an RFID tag configured to be worn on clothing or integrally formed with the clothing and having an antenna configured to be RF coupled to the skin of the employee, at least one reader configured to detect the presence of the RFID tag when RF coupled to the skin of the employee, at least one activation device configured to activate the RFID device when the RFID device is within an activation area, a skin disinfectant medium dispenser configured to dispense the disinfectant medium and to transmit a dispensing signal in response to dispensing the disinfectant medium, and a remote processor and associated memory with user interface coupled to the at least one reader, the at least one activation device, and the dispenser and configured to store data related to employee identification, location of wash station, compliance rate, wash time, average wash time, and compliance status, and to process the data to enable employer management of employee hand washing.
In accordance with a still yet another aspect of the present disclosure, a system is provided that includes an RFID tag configured to be worn on clothing or integrally formed with the clothing and having an antenna configured to be RF coupled to the skin of the employee, at least one reader or interrogator configured to detect the presence of the RFID tag when RF coupled to the skin of the employee and to activate the RFID tag when the RFID tag is within an activation area, a skin disinfectant medium dispenser configured to dispense the disinfectant medium and to transmit a dispensing signal in response to dispensing the disinfectant medium, and a remote processor and associated memory with user interface coupled to the at least one reader, the at least one activation device, and the dispenser and configured to store data related to employee identification, location of wash station, compliance rate, wash time, average wash time, and compliance status, and to process the data to enable employer management of employee hand washing.
The foregoing and other features and advantages of the present disclosure will be more readily appreciated as the same become better understood from the following detailed description when taken in conjunction with the accompanying drawings, wherein:
In the following description, certain specific details are set forth in order to provide a thorough understanding of various disclosed embodiments. However, one skilled in the relevant art will recognize that embodiments may be practiced without one or more of these specific details, or with other methods, components, materials, etc. In other instances, well-known structures or components or both associated with RFID readers, passive power supply circuits, front-ends, memories, packaging, interrogators, sensors, dispensers, computers and computer processors have not been shown or described in order to avoid unnecessarily obscuring descriptions of the embodiments.
Unless the context requires otherwise, throughout the specification and claims that follow, the word “comprise” and variations thereof, such as “comprises” and “comprising” are to be construed in an open inclusive sense, that is, as “including, but not limited to.” The foregoing applies equally to the words “including” and “having.”
Reference throughout this description to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearance of the phrases “in one embodiment” or “in an embodiment” in various places throughout the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
As stated, the interrogator 24 may take the form of an RFID reader or interrogator that is readily commercially available in the automatic data collection field (ADC), and these are typically employed for reading from or writing to RFID tags. The interrogator 24 may transmit the carrier waves 26 as un-modulated carrier waves, or may transmit the carrier waves 26 as un-modulated carrier waves interspersed with modulated carrier waves.
The RFID tag 22 has at least one antenna 30 and an RFID circuit 32 carried by a substrate 34 as shown more clearly in
The antenna 30 may be shaped and otherwise configured to receive and transmit at or within a frequency range emitted by the interrogator 24. For example, the antenna 30 may have a serpentine shape, crenulated shape, coil or volute shape, or a dipole T-shape or dipole opposing L-shape. The antenna 30 may include more than one antenna elements, for example one or more active antenna elements or one or more passive or parasitic antenna elements. Although numerous suitable antenna shapes and structures are known in the RFID art, they suffer from the inability to stay tuned to the interrogator frequency when near the human body.
In passive antenna designs, a radio frequency (RF) voltage is produced across the leads of the respective antenna 30 upon receipt of the carrier waves 26. The RFID circuit includes a passive power supply circuit 36. As used herein and in the claims, the term “passive power supply circuit” and variations of such mean a circuit that derives power via incident electromagnetic energy, such as energy from the radio frequency or microwave portions of the electromagnetic spectrum. The passive power supply circuit 36 may take the form of one or more integrated circuits or chips. Integrated circuits or chips suitable for use in some RFID applications are commercially available.
The passive power supply circuit 36 may include one or more front ends coupled to the antenna 30. For example, the passive power supply circuit 32 may include a respective front end for each antenna 30. As is well known in the RFID arts, the front end is configured to rectify the RF voltage produced across the leads of the respective antenna 30 to provide power to the RFID tag 22. The front end is configured to modulate the carrier wave responses 28, for example via load modulation for near field applications or varying the impedance of the respective antenna 30 for far field applications such as when providing the carrier wave responses 28 via backscattering.
The antenna 30 shown in
In accordance with the present disclosure an antenna design is provided for use with a name tag worn on clothing associated with the human body. Shown schematically in
Because of the presence of the metal pin 52 and pin clasp 54, as well as the near proximity of the human body 58 when the tag 40 is worn on the clothing 56, the antenna 44 must be designed to receive the interrogation signal 62.
Because the name tag 50 is typically worn on the user's clothing on the front of the body, generally adjacent the chest, the antenna 44 design is configured to accommodate signal reception at this location. The substrate 46 can be used in a flip-chip configuration or the name tag can utilize a strap insertion. The antenna will cooperate with the skin or flesh of the user to obtain and respond to an interrogation signal.
In accordance with another aspect of the present disclosure, an alternative antenna design is provided for use on clothing, preferably in the form of a sewn-on or iron-on patch.
In a preferred embodiment, the antenna 100 is formed of metal inlay of about 5.0 mm in width throughout the entire antenna structure. It is to be understood that the antenna 100 can be made threaded metal or weaved metal thread. The main body 102 has a width of about 33.0 mm from each of the exterior lower corners, leaving the top width 23.0 mm. Each arm 108, 110 has a width along the top side of 33.0 mm, leaving the bottom side to have a width of 23.0 mm. Each side leg 112, 114 has an overall outside length of 20.0 mm and inside length of 15 mm. As will be appreciated from the foregoing and the accompanying illustration in
In this embodiment, impedance matching was done with an NXP chip UCode 7, with approximately 12 +j167 impedance. The read range for this tag is about 4 meters. If used with shorter adults, children, or even animals, the tag may have a reduced range. Because the system is designed to a 10 dB margin, items such as jewelry or a cell phone should not affect the tag's range or operational characteristics.
Both embodiments of the fabric tag can be worn in close proximity to the human body, such as on clothing or outer apparel worn over clothing. The RFID fabric tags are detuned when they are not in close proximity to the human body. For maximum performance and read range, the RFID fabric tags are incorporated into the clothing to be worn over the chest or in the collar adjacent the neck or upper back. In the latter case, a reader would be located above the user, such as in a ceiling, door frame, light fixture, or other elevated location in a structure.
In accordance with another aspect of the present disclosure, an RFID tag is configured to be worn on the user's clothing or integrally formed with the user's clothing and includes an antenna configured to be RF coupled to the user's skin. A corresponding interrogator or reader is configured to detect the presence of the RFID tag when RF coupled to the skin of the user and to activate the RFID tag when the RFID tag is within an activation area.
As will be appreciated from the foregoing, the novel RFID tag can be used in a monitoring system that includes an RFID tag configured to be worn on clothing or integrally formed with the clothing and having an antenna configured to be RF coupled to the skin of the employee. The system also includes at least one reader or interrogator configured to detect the presence of the RFID tag when RF coupled to the skin of the employee and to activate the RFID tag when the RFID tag is within an activation area. Preferably, the system further includes a skin disinfectant medium dispenser configured to dispense the disinfectant medium and to transmit a dispensing signal in response to dispensing the disinfectant medium, and a remote processor and associated memory with user interface coupled to the at least one reader, the at least one activation device, and the dispenser and configured to store data related to employee identification, location of wash station, compliance rate, wash time, average wash time, and compliance status, and to process the data to enable employer management of employee hand washing. A detail description of a representative embodiment of such a system is provided below.
The tag 202 is configured in accordance with the tags described herein, either as the RFID name tag 40 shown in
Once the interrogator 208 receives the responsive signal 222, it processes it for transmission to the computer processing system 214, which can include a microprocessor 224 and associated memory 226. The tag 202 in this application would include information about the identity of the user 206, such as the name, employee number, and badge number (if applicable) or clothing ID number (if applicable). This data is transmitted via the backscattered signal 222 to the interrogator 208 by the tag 202 in response to the interrogation signal 220. The interrogator 208 in turns provides this information to the computer processing system 214 along with additional date. This additional data can include without limitation one or more of the following: date, time, hand washing station location, duration of hand washing, duration of stay, whether soap was dispensed, hand drying time, and water turn on and turn off times or water use duration.
Proximity or presence can be determined through an analysis by a computer processor coupled to the interrogator 208 of a signal strength or RF phase characteristic of the backscatter signal from the RFID tag.
The sensing of soap dispensing, water use time, and hand drying time can be accomplished with conventional sensors associated with a soap dispenser, water faucet, and electric hand dryer. These sensors can be hard wired to the interrogator 208 for collection of the afore-mentioned data. Because this sensing is within the level of one of skill in this art, no further detailed explanation is deemed necessary.
Currently there is no monitoring program that records washing time suggested by the FDA and the CDC by RFID. In accordance with a further aspect of the present disclosure, a hand scan program is provided that has a 20 second software-timed monitoring of hand washing. The time recording software starts when an employee steps up to the sink to start washing his/her hands. Once the employee steps up to the sink to wash their hands, a twenty second alert will start. After twenty seconds wash is completed a temporal alert will be provided, such as a light, a sound, or a display or any combination of the foregoing will be broadcasted, thus alerting the employee that his or her hands have been washed the proper length of time. The alert may be a digital time display on a LED sign, counting down from 20 seconds and or a LED projected on the sink mirror. A sound tone or voice could also be used.
The computer processing system 214 utilizes the data received from the interrogator 208 to provide reports for management and users. More particularly, the microprocessor 224 stores the received data in the memory 226 and prepares various reports as requested by system users. By way of example,
Ideally a ceiling antenna 284 coupled to the interrogator 208 is located out of sight above the ceiling 282 as shown. The ceiling antenna works above ceiling tile, drywall, concrete, tile, and most building products. The ceiling antenna comes in lengths of three feet, five feet, and seven feet. These antennas can be coupled together to extend over seven feet if needed. A seven foot ceiling antenna can cover a counter with 4 sinks 212. In a referred application, an eight inch wide antenna strip is utilized. When ceiling tile is in place, the ceiling antenna 284 will not be seen by others. Preferably the antenna 284 is a NeWave™ antenna is commercially available from Synergy RFID, Inc. in the United States. This antenna uniquely creates a cylindrical pattern illuminating uniformly the entire length of the antenna, filling the entire volume of the surrounding space as defined by the user. This design reads all RFID tags in the targeted zone while not reading extraneous tags outside the zone.
The ceiling antenna 284 is positioned to run parallel with the sink counter. Ideally one ceiling antenna will detect an individual wearing the ID tag 202 walking into a restroom or approaching the sink station 210. For example, the system will be configured to detect the identity of an individual (employee) 206 wearing an RFID tag 202 when the individual enters the area.
In most cases when an employee enters a restroom, they will proceed to a toilet area. The ceiling antenna 284 range is limited to the area around the station 210 or around the entrance exit door or both the station 210 and the entrance and exit door. Once an employee proceeds to the toilet area, the antenna 284 will stop detecting or reading the RFID tag 202. When the employee 206 walks toward the station 210 or the exit door, the ceiling antenna 284 interrogates or reads the employee's RFID tag 202 within three to four feet in front of the station 210 or the sink 212.
When the interrogator 208 detects the RFID tag 202, it will activate or energize a soap dispensing sensor 228 and a hand wash unit that includes a hand wash motion sensor 231 and LED spotlight 233. Thus, when an employee 206 walks into the ceiling antenna zone, the sensors 228 and 231 as well as the LED spotlight 233 on the ceiling will be ready to activate.
When the employee 206 reaches out for a soap dispenser 286, the motion or infrared sensor 228 will sense or detect the employee's movement and the system will record soap dispenser usage. At the same time the employee's RFID tag serial number will be recorded. The system will match the name of employee 206 with a number of the tag 202 and record this in a database.
When the employee's hands are placed in sink, the sink sensor 231 located on the ceiling will start recording hand washing. The system or the sink sensor 231 will initiate activation of a red or cool white high intensity LED spotlight 233 projecting down on the sink 212 and the user's hands as they are being washed. The LED spotlight 233 will continue to beam a narrow (8-12 inch beam) down into the sink 212 an amount of time specified by the manager of the system, such as a restaurant owner. Proper hand wash compliance established by the CDC and FDA is 20 seconds.
If the employee 206 does not use soap or does not wash their hands with soap for the required time management has set, for example 20 seconds, the system software is designed to record noncompliance. The amount of time, date, hour and minute of hand washing is recorded and made available to management through a screen display, paper report, or other notification means. Hand wash compliance will be completed when soap is applied and a 20 second (or such time interval that management has established) water wash is completed. The system is configured to enable the management of the system to alter the time interval to be more or less than 20 seconds.
Two kinds of sensors 228, 231 to read hand washing and soap dispenser usage can be used, either a digital pyroelectric infrared (PIR) motion detector or an infrared optical range sensor. A proximity sonar sensor could be used, but it is the least functional for this described use. A digital pyroelectric infrared motion detector module designed to detect infrared radiation (IR) from a moving human or animal both in daylight and at night is preferred. It will only respond to a moving source of infrared radiation. It will not detect a static IR source. Preferably a module is used that includes a digital pyroelectric infrared sensor, a microprocessor and a relay driver. An on-board voltage regulator powers the circuits and accepts a 4 to 15.5 volt DC power supply voltage.
The high intensity LED spotlight 233 is preferably a custom made 1 watt, 85-100 Lumens, LED mounted in a lightweight aluminum housing obtained from the Oznium company in Colorado. The front face of the housing is concave with the LED light emitter positioned at the bottom center of the face. The beam angle of the lens can have a range from 5 degrees to 25 degrees. Alternatively, an adjustable lens that is able to achieve an 8 inch spot at six feet could be used, although the dimensions of the housing would be much taller, requiring a larger housing. Either a red or cool white LED light can be used that is narrowly directed as shown in
In one aspect of the present disclosure, the hand washing sensor 231 and the LED spotlight 233 are mounted in the same housing that is in turn mounted on the ceiling over the sink 212.
From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the present disclosure. Accordingly, the disclosure is not limited except as by the appended claims and the equivalents thereof.
Number | Date | Country | |
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61914754 | Dec 2013 | US |