WO2021224684A1

WO2021224684A1 - Non-contact fever screening system

Info

Publication number: WO2021224684A1
Application number: PCT/IB2021/000309
Authority: WO
Inventors: Michael Lende; Jason Elmaleh
Original assignee: Smrt Labs Inc.
Priority date: 2020-05-06
Filing date: 2021-05-05
Publication date: 2021-11-11
Also published as: CA3080548A1

Abstract

A noncontact fever detection system for determining presence of the elevated body temperature in a human subject is disclosed, including a frame assembly, an array of thermal sensors located on the frame assembly, a controller, and a user interface. The array of thermal sensors may perform a body temperature scan of the subject and may perform the scan at a rate greater than one scan per fifteen seconds. The controller may receive data from the array of thermal sensors and determines whether the human subject's body temperature is elevated. The user interface may provide a visual indication as to whether the body temperature of the subject is elevated.

Description

NON-CONTACT FEVER SCREENING SYSTEM

CROSS-REFERENCE

[0001] This application is related to Canadian Patent Application No. 3,080,548, filed on May 6, 2020, and U.S. Provisional Patent Application No. 63/044,261, filed on June 25, 2020, both of which are incorporated herein by reference in their entirety.

BACKGROUND

[0002] With the rapid spread of infectious diseases around the world, including COVID-19, effective screening techniques are required, particularly at high-traffic, public locations such as airports, schools, hospitals, sports stadiums, building lobbies and stores. Thermal scanning to detect elevated body temperature is a common method for detecting fever in symptomatic travelers. Handheld non-contact thermometers are commonly used to take a traveler’s temperature.

SUMMARY

[0003] A skilled operator may be required to properly use a handheld thermometer and to interpret the temperature readings the thermometer takes. Handheld units may also not be ideal in mass screening situations, such as at airports, where time may be lost by the person being screened having to stop and standstill while the operator aims the handheld unit at the traveler, takes a reading, and interprets the reading. Thermal imaging has also been used but thermal imaging cameras are sensitive to ambient temperature changes that may affect their accuracy. Most thermal imaging systems require a black body reference point.

[0004] Therefore, a high-throughput, automatic fever screening system may be desirable. The noncontact fever detection system described herein provides capabilities for high-throughput fever detection. The detection system may enable subjects to pass through without stopping, reducing testing delays. The detection system may also provide a high measurement rate, taking multiple readings per subject to minimize risk of detection failure. The detection system may include statistical data tracking of real-time data, as well as remote viewing of near real-time data. The noncontact fever detection system described may also improve temperature readings over using a thermometer because it may eliminate close contact between the operator of the thermometer and the people being tested.

[0005] The noncontact fever detection system may detect body temperature using touch less, infrared, thermal medical grade sensors. The noncontact fever detection system may perform by taking around 1,200 scans per second so that the subjects being scanned do not need to slow down or wait before passing through the body scanner. The fever detection system may be configured to enable minimal disruption of data collection while taking accurate thermal readings.

[0006] The disclosed fever detection system can capture thermal data using thermopiles instead of thermal imaging cameras, and thus may be more accurate than existing systems that use cameras.

[0007] In one aspect, the present disclosure provides a noncontact fever detection system for determining the presence of an elevated body temperature in a human subject, including a frame assembly, an array of thermal sensors located on the frame assembly, a controller, and a user interface. The array of thermal sensors performs a body temperature scan of the subject and may perform 1,200 scans per second. The controller receives data from the array of thermal sensors and may determine whether the human subject’s body temperature is elevated. The user interface may provide a visual indication as to whether the body temperature of the subject is elevated. [0008] Additional aspects and advantages of the present disclosure will become readily apparent to those skilled in this art from the following detailed description, wherein only illustrative embodiments of the present disclosure are shown and described. As will be realized, the present disclosure is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the disclosure. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.

INCORPORATION BY REFERENCE

[0009] All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference.

To the extent publications and patents or patent applications incorporated by reference contradict the disclosure contained in the specification, the specification is intended to supersede and/or take precedence over any such contradictory material.

BRIEF DESCRIPTION OF THE DRAWINGS [0010] The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings (also “Figure” and “FIG.” herein), of which: [0011] FIG. 1 schematically illustrates a view of a fever detection system comprising a set of extrusions, in accordance with embodiments of the present disclosure;

[0012] FIG. 2 schematically illustrates a set of corner brackets to strengthen comers of a “U” component of the fever detection system, in accordance with embodiments of the present disclosure;

[0013] FIG. 3 schematically illustrates a bracket for holding the fever detection system’s “T” component and “U” component together, in accordance with some embodiments of the present disclosure.

[0014] FIG. 4 schematically illustrates a noncontact fever detection system, in accordance with some embodiments of the present disclosure;

[0015] FIG. 5 illustrates embodiments of the fever detection system; in accordance with some embodiments of the present disclosure;

[0016] FIG. 6 illustrates a method for noncontact fever detection using the noncontact fever detection system in accordance with some embodiments of the present disclosure; and [0017] FIG. 7 schematically illustrates a user interface for the fever detection system.

DETAILED DESCRIPTION

[0018] While various embodiments of the invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions may occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed.

[0019] Whenever the term “at least,” “greater than,” or “greater than or equal to” precedes the first numerical value in a series of two or more numerical values, the term “at least,” “greater than” or “greater than or equal to” applies to each of the numerical values in that series of numerical values. For example, greater than or equal to 1, 2, or 3 is equivalent to greater than or equal to 1, greater than or equal to 2, or greater than or equal to 3.

[0020] Whenever the term “no more than,” “less than,” or “less than or equal to” precedes the first numerical value in a series of two or more numerical values, the term “no more than,” “less than,” or “less than or equal to” applies to each of the numerical values in that series of numerical values. For example, less than or equal to 3, 2, or 1 is equivalent to less than or equal to 3, less than or equal to 2, or less than or equal to 1.

[0021] Throughout this specification the word “comprise,” or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

[0022] Disclosed is a system for noncontact fever detection. The disclosed system may include a frame assembly fitted with thermal sensors. The frame assembly may be rectangular in shape (e g., similar to a door frame), with the thermal sensors placed along the frame at particular distances from one another. The frame may include a top cross member, two side members, and a base, with the base comprising two perpendicular members. The top cross member and two side members may comprise a “U” component of the fever detection system, while the bases and side members together may comprise “T” components. The perpendicular members may include wheels for eased transportation of the noncontact fever detection system. The cross member may include an electronics block with batteries for powering the detection system and a controller for collecting and processing sensor data.

[0023] The frame assembly may be configured to capture thermal data of a human subject passing through an entryway in the frame. The thermal sensors may scan the subject moving through the entryway at least about 2, 3, 4, 5, 10, 15, 20, 25, 30, 40, 50, 60, 70, 80 or more times per second. The thermal data may be used to determine a human body temperature of the subject. The controller may compare the temperature to a threshold to determine whether the subject has a fever.

[0024] The controller can provide thermal information over a network (e g., a cellular network) to remote computing systems for data analysis. The remote computing systems may determine fever incidence rates of subjects passing through the system over particular time periods, for example, or may measure the prevalence of a virus by calculating average temperatures of subjects.

[0025] In one embodiment, the present disclosure relates to a noncontact fever detection system including a square horseshoe-shaped metal frame assembly as 102 of FIG. 1. In other embodiments, other suitable materials may be used for the frame assembly. The frame assembly may include two base members “T” on castors “K” or leveling feet “F”, two upright members “B” and a cross member “A”. The two upright “B” members and the “A” cross member form a “U” component of the frame. The frame may have at least about 1, 2, 3, 4, 5, 10, 12, 15, 16, 20, 24, 25, 28, 32, 36, 40, 44, 48, 50, 52, 56, 60, 64 or more thermal sensors. In one embodiment, an array of twenty four thermal sensors may be located on the frame with a series of twelve thermal sensors located along the “U” component staggered between the left and right sides at a spacing of about 80 mm between the thermal sensors. The bottom most thermal sensor on the upright members may be about 1 m above the floor surface. In one embodiment, the 24 sensors (12 on each side) on the upright members “B” may be designed to accommodate differences in height among humans passing through the frame assembly. A plurality of thermal sensors may increase the probability that at least one of the thermal sensors makes an accurate temperature measurement. In other embodiments, the number of thermal sensors, the spacing of the thermal sensors, and their heights above the floor can be varied.

[0026] In one embodiment, the thermal sensors 4 are oriented at about a 45° degree angle relative to the vertical plane 6 of the frame. In one embodiment, the thermal sensors are infrared sensors. In another embodiment, the thermal sensor may have a 5° field of view 8. In another embodiment, the thermal sensors may determine a body temperature with an accuracy within +/- 0.2°C inside a limited temperature range for fever.

[0027] In another embodiment, the thermal sensor may be an infrared thermometer. In another embodiment, the infrared thermometer may include an infrared sensitive detector chip. In another embodiment, the infrared thermometer may have a temperature range with a resolution of 0.02°C. In another embodiment, the thermal sensors may be positioned such that at least one of the sensors detects a temperature from the surface of the skin between the eyebrows of a human passing through the frame assembly. In another embodiment, the thermal sensors are connected to a computer bus.

[0028] In another embodiment, up to 120 thermal sensors may be connected using a single computer bus. In one embodiment, the thermal sensors can communicate through a Controller Area Network (CAN) bus where the thermal sensors are connected to a controller board in clusters of 4. These clusters may include a dedicated temperature microcontroller, 4 IR sensors and a temperature comparator 16. In another embodiment, each thermal sensor may be programmed with a unique IP address which enables the system to identify which thermal sensor detected a temperature above a pre-set threshold. In another embodiment, the output of the thermal sensors can be configured to be pulse width modulated (PWM) to reduce power consumption.

[0029] In operation, when a person passes through the device, the thermal sensors can take temperature readings. The temperature readings may be sent to temperature processing equipment. The fever threshold generator may generate a fever threshold temperature and a temperature comparator may compare the temperature readings from the thermal sensors to the fever threshold temperature. If a temperature reading from at least one of the thermal sensors is above the fever threshold temperature, an indicator may be triggered to provide an alert that a fever temperature reading has been taken. The indicator can be a light, an audible alarm or the like. [0030] In some embodiments, the metal frame assembly may be made of metal extrusions with cavities. The cavities may contain wiring for the thermal sensors. The cavities may cause the metal frame assembly to be lightweight and portable.

[0031] FIG. 2 schematically illustrates a set of corner brackets to strengthen comers of a “U” component of the fever detection system, in accordance with embodiments of the present disclosure. Illustrated are brackets that fit the left and right corners of the “U” component. The brackets may include a rectangular member and a curved member welded or otherwise attached to form an “L” shape. The bracket may have holes in which screws, bolts, or nails may be inserted to adhere the bracket to the frame.

[0032] FIG. 3 schematically illustrates a bracket for holding the fever detection system’s “T” component and “U” component together, in accordance with some embodiments of the present disclosure. The bracket may itself be a rectangular piece which may include holes for adhering itself to both the “U” and “T” members.

[0033] FIG. 4 schematically illustrates a noncontact fever detection system 400, in accordance with an embodiment. The noncontact fever detection system 400 may include a frame assembly 410, an array of thermal sensors 420, a system controller 430, a fever threshold generator, a threshold comparator, and one or more indicators 440. The fever detection system may be configured to run continuously on battery power for more than 50 hours. The fever detection system 400 may be weather-proof and may be implemented inside or outside, and operated in temperatures of -20°C to 50°C. The fever detection system 400 may be made of a metal such as black anodized aluminum, plastic, PVC to ensure that it is weatherproof. The fever detection system 400 may be configured to run on battery power or wall power. The fever detection system may be configured to weigh less than about 100 pounds, 50 pounds, 25 pounds, or less. [0034] The frame assembly 410 enables high-throughput, non-invasive remote scanning of subjects as they transit through its portal. In accordance with an embodiment, the frame assembly 410 may include a base with two horizontal members that rest on the ground, two side (left and right) members, and an upper cross member 412. In other embodiments, the base members may include wheels to transport the frame assembly 410. The frame assembly 410 may be foldable to enable portability. The frame assembly 410 may be increased or decreased in size to enable easy passage of strollers and wheelchairs. In the embodiment of FIG. 4, the frame assembly 410 is rectangular in shape, but does not need to be limited to being of rectangular shape. The frame assembly 410 may be round, oval, or arch-shaped, may consist of a single bar placed across an existing door frame, or may be a bar hanging from or mounted to a ceiling, for example. The frame assembly may include a device for counting human subjects. The device may perform a scan using an infrared beam, which may emit a beam of wavelength between 700 and 1000 nm periodically. The period may be 0.1, 0.5, 1, 2, or 10 seconds. Other counter measures might be included (ex: laser, proximity sensor).

[0035] The array of thermal sensors 420 detect temperatures of people passing through the frame assembly 410. The thermal sensors 420 may be arranged on the assembly to account for different heights of passengers, including those that may be seated when entering the fever detection system, those who do not traverse through the very center of the fever detection system, or those who otherwise travel through the fever detection system in atypical ways. The sensors may be located on the vertical or horizontal members. The sensors may be thermometers, thermopiles, or other temperature-measuring devices. The thermal sensors 420 may be able to measure temperature with a high degree of accuracy and precision. For example, the thermal sensors 420 may be able to measure temperature accurate to within 0.2°C for a range of 36°C to 38°C. The thermal sensors may be precise enough to measure temperature variations of 0.1°C, 0.05°C, 0.02°C, or 0.01°C. The thermal sensors 420 may be configured to capture thermal data from one or more subjects at a time, at a high capture rate (e.g., 50 scans per second per sensor). The thermal sensors 420 may collect multiple readings for a particular subject that walks through the body scanner and select a best or most actionable reading for detection. The thermal sensors may be able to detect radiation at wavelengths of 5.5 to 14 micrometers.

[0036] In the embodiment of FIG.4, the sensors may be placed in particular arrangements on daisy-chain cables. Sensors may be arranged in groups of four on each side members 414s for a total of 24 thermal sensors 420. The system controller 430 may be a computing device that directs the components of the fever detection system to collect data from subjects and determine whether the subjects are likely to have fever. The system controller 430 may receive data from the thermal sensors 420 and process the data to determine whether the data received is indicative of a fever. For example, the system controller 430 may offset the received temperature data with respect to an ambient temperature. The system controller 430 may also weigh readings taken from different positions on the subjects’ bodies. The system controller 430 may direct positioning of the sensors in order to determine a configuration of sensors that improves data collection. The system controller 430 may include software capabilities for performing statistical data tracking. For example, the system may count traffic through the body scanner and may produce statistics based on the counted traffic. The system may determine times of day with high and low amounts of traffic. The system may track the number of alerts produced within particular time periods (e.g., hours, days, or weeks) in order to monitor the number of potentially virus-positive subjects attempting to enter a location. The system may anonymize the data and provide it to remote devices through internet or Bluetooth for real-time tracking and data analysis.

[0037] The controller 430 may enable users of the fever detection system to program sensor identifiers. Users may then view information captured by particular sensors, in order to determine which sensors produced the most actionable temperature readings.

[0038] The controller 430 may include a fever threshold generator. The fever threshold generator determines at which received temperature a subject is predicted to have a fever. For example, the fever threshold generator may select a body temperature of 38°C or 100°F as a threshold for fever. The threshold may be configured to maximize specificity or sensitivity depending on the goals of the system. For example, system operators may decide that detecting false positives is less dangerous than detecting excess false negatives, as the former may result in fewer people spreading a virus.

[0039] The controller 430 may also include a fever threshold comparator. The temperature comparator may be a device that outputs a signal indicating whether the temperature exceeds a threshold value (e g., for fever in a human being). The comparator may operate on data that has been normalized for ambient temperature or has been error-corrected.

[0040] The indicators 440 may provide information as to whether the subject has a fever. The indicator may be a message (e.g., text, pictorial, audio, or video) on a display or may be a light or sound indicator. For example, light-emitting diodes arranged on the frame may light up to indicate that a subject has an elevated temperature. An indicator may be a user interface (e.g. a computer display) which may display a warning image or text to operators of the fever detection system that a subj ect may have a fever.

[0041] FIG. 5 illustrates embodiments of the fever detection system 500 and 550. Both embodiments 500 and 550 have side members of length 84” and abase of dimensions 41.34” by 36”, with sensors spaced 5.91” apart on the cross member 412 and 7.87” apart on the side members. But the pro model has a taller base with bigger wheels. Both models may include upper electrical boxes affixed to the upper cross members to hold batteries to power the thermal sensors 420 and computing units.

[0042] FIG. 6 illustrates a method for noncontact fever detection using the noncontact fever detection system 400 of FIG. 4.

[0043] In a first operation 610, thermal sensors 420 collect information about the subject’s temperature. The temperature sensors may take multiple readings while the subject walks through the frame assembly 410. For example, if a subject walks or moves through the frame assembly 410 over a period of one second, the thermal sensors 420 may provide 20 temperature readings. The thermal readings may be taken from many exposed areas of the person’s body (e g., the forehead, arms, legs).

[0044] In a second operation 620, the temperature information is directed by the controller to the comparator, which determines whether the temperature exceeds a threshold value for fever detection. The temperature may be a highest recorded temperature for a subject or an average of temperatures recorded (e.g., an arithmetic mean, geometric mean, median, or mode temperature). The threshold value may be updated daily, based on ambient conditions. This may lead to a determination as to whether the subject may have contracted a fever. The temperature information may be collected and anonymized for processing by a third-party device. The data may be communicated remotely to the third-party device, e.g., over a cellular network or internet.

[0045] In a third operation 630, the system provides an indication as to whether the subject has contracted fever. The indication may be provided by light or sound indicators 440. For example, the indicators may be flashing LEDs.

[0046] FIG. 7 schematically illustrates a user interface 700 for the fever detection system. The user interface 700 may be displayed on a computing device of an operator of the fever detection system. The user interface may display information regarding fever detection and system statistics in real time or substantially in real time. The user interface may display settings such as time, date, and current temperature threshold. The user interface may display hourly, daily, weekly, or otherwise periodically statistics, including traffic count, time passed, and number of alerts. The user interface may display scan activity information, including a last scan time, a last scan temperature, a last alert time, and a last alert temperature.

[0047] While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. It is not intended that the invention be limited by the specific examples provided within the specification. While the invention has been described with reference to the aforementioned specification, the descriptions and illustrations of the embodiments herein are not meant to be construed in a limiting sense. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. Furthermore, it shall be understood that all aspects of the invention are not limited to the specific depictions, configurations or relative proportions set forth herein which depend upon a variety of conditions and variables. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is therefore contemplated that the invention shall also cover any such alternatives, modifications, variations or equivalents. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.

Claims

WHAT IS CLAIMED IS:

1. A system for determining whether a body temperature of a subject is elevated, comprising: a frame assembly configured to permit said subject to pass through said frame assembly; an array of thermal sensors disposed on said frame assembly, wherein said array of thermal sensors is configured to perform a body temperature scan of said subject, and wherein said array of thermal sensors is configured to perform body temperature scans at a rate of greater than fifty scans per second per sensor; a controller configured to receive data from said array of thermal sensors and determine whether said body temperature of said subject is elevated based on said data; and a user interface configured to provide a visual indication if said body temperature of said subject is elevated.

2. The method of claim 1, wherein said thermal sensors are not thermal cameras.

3. The method of claim 1, wherein said indicator provides audible and visual indication for said elevated body temperature above a threshold.

5. The method of claim 1, wherein said array of thermal sensors enables minimal or no pausing between scans.

6. The method of claim 1, wherein said array comprises at least 24 thermal sensors.

7. The method of claim 1, wherein said thermal sensors are programmable.

8. The method of claim 1, wherein said thermal sensors provide accuracies of +0.2°C in a range of 36°C to 38°C.