ITMI20101007A1 - METHOD AND EQUIPMENT FOR THE DETERMINATION OF THE BODY TEMPERATURE OF AT LEAST ONE SUBJECT - Google Patents

Description

DESCRIPTION

Attached to a patent application for an INDUSTRIAL INVENTION PATENT entitled:

â € œMETHOD AND EQUIPMENT FOR DETERMINING THE BODY TEMPERATURE OF AT LEAST ONE SUBJECTâ €

The present invention relates to a method and an apparatus for determining the body temperature of at least one subject.

In particular, the present method and the present apparatus find particular application in determining the temperature of a plurality of subjects who are or are crossing a certain area, such as a transit area in an airport or a room in a hospital, or a € ™ other public area.

In a further aspect, the present method makes it possible to reliably detect the temperature of numerous subjects that are in a cold environment or that come from an environment whose temperature is not known.

As is known, in recent years, the need has become extremely felt to be able to measure the body temperature of a plurality of subjects very quickly and in a non-invasive way.

The spread of fears of pandemics (think of the â € œavianâ € flu or the â € œswineâ € flu) has made it necessary to more effective controls on subjects in transit, in particular on entry, in a specific country, area or place.

Think for example of airports, areas of intense passage of people from various countries that can lead to a very rapid spread of the infection.

In this situation, in the past years, controls have spread, particularly with reference to subjects coming from countries at risk, at the airports.

However, it is evident that the measurement of the body temperature of one subject at a time in areas of transit and passage for such a large number of people turns out to be impractical and an obstacle to an efficient and fluid operation of the airport.

For this reason, even the use of thermometers with non-invasive and sufficiently rapid temperature detection, in this situation, proved to be not ideal for preventing delays, queues and congestion in correspondence with the control areas, although performing very well the task of detecting subjects with fever.

In the light of the problems highlighted above, some studies have been carried out and, as a solution, thermal imaging cameras have been proposed, in particular infrared, capable of detecting the radiation coming from a specific area under control and, thanks to the intensity of the latter, to trace a temperature map of the area under control.

Moreover, the survey can be carried out continuously or dynamically in such a way as to be able to examine the passage of a flow of subjects in real time.

In other words, one or more thermal imagers control areas of forced access in which the subjects in transit must pass by estimating, in the light of the infrared radiation spectrum received, the temperature gradients in the area under control.

The thermal cameras highlighted above, while allowing a continuous and extremely rapid check on a plurality of subjects in transit, are however affected by some drawbacks and / or operating limits.

First of all, the thermal imaging cameras known today require the necessary presence of operators for the identification of subjects with fever.

In fact, today it is not possible to automate the decision process identifying the subject with fever, discerning him from the one without fever, without the help of one or more operators.

Typically, in fact, the temperature profile is rendered through colors ranging from dark (lower temperatures) to bright red or white (higher temperatures).

In some applications it is then possible by selecting a specific subject and in particular a point of the detected image, to automatically have, through a conversion software, the temperature detected of that point, or the maximum temperature inside the detection area. .

However, the maximum temperature in the detection area may not necessarily be traced back to the actual temperature of a subject, as it could instead be an object such as a cup of coffee or a mobile phone or a lit cigarette.

On the other hand, in systems in which the maximum temperature within the considered area is highlighted, it may happen that more subjects present fever, but the system would only highlight the one with the highest temperature while the others would be â € œignoredâ € €.

It should also be noted that using traditional contactless thermometers it is not possible today to reliably measure the temperature of subjects coming from areas with an unknown or uncontrollable temperature.

In fact, in such situations, the corrective parameter to be applied to the body surface temperature detected in order to obtain the internal temperature is not known (or not implemented in the architecture - memory - of the device).

Also the temperature of a subject that is in, or coming from, an area with low ambient temperature can also create problems in correct detection as the further the target surface temperature is from the internal temperature ( obviously the colder the external environment, the more this distance increases), the less reliable the correction of the detected temperature can be.

SUMMARY

According to a first aspect of the invention, a method for measuring temperature is provided, comprising the following steps: manually positioning a non-contact infrared thermometer at a predetermined distance from a target area of a patient whose internal temperature is to be known ; manually aim the target area so that an infrared radiation sensor of the thermometer receives infrared radiation coming from the target area; activate the non-contact infrared thermometer to measure the patient's internal temperature; to detect, through the infrared thermometer without contact and for a predetermined time interval, the intensity of an infrared radiation coming at least from the target area of the patient; the target area is a surface of the body of a human or animal patient chosen from the group comprising: the ethymoid sinus, the canthus or the eyelid.

According to a further aspect dependent on the previous one, the method comprises the step of correcting a temperature of the target area as a function of the intensity of infrared radiation detected to determine the internal temperature.

According to a further aspect dependent on any of the preceding ones, the method comprises the step of supporting the thermometer manually during all the positioning, aiming, activation and detection steps.

According to a further aspect dependent on any of the above, the method comprises the step of closing at least one eye and detecting the intensity of an infrared radiation coming from the closed upper eyelid, in particular the target area being the upper eyelid.

According to a further aspect dependent on any of the preceding ones, the method comprises the step of measuring an ambient temperature and a step of correcting the temperature of said target area or the internal temperature as a function of the measured ambient temperature.

According to a further aspect dependent on any of the above, the method comprises the step of checking the stability / correctness of the ambient temperature used to correct the temperature of the target area or the internal temperature.

According to a further aspect dependent on any of the preceding ones, the method comprises the step of manually activating the thermometer by pressing at least one button present thereon.

According to a further aspect dependent on any of the above, the method comprises, after activating the infrared thermometer, the use of a timer which starts a countdown, the detection of radiation is carried out for a predetermined time during the countdown. down and until the end of the countdown.

According to a further aspect dependent on any of the above, the patient is a non-human animal and the method is a veterinary method.

In this situation, the technical purpose underlying the invention is to solve the drawbacks highlighted above.

A first object of the invention is to provide a methodology and an apparatus that allow a more accurate identification of subjects suffering from fever than of healthy ones, possibly also allowing an automation of this process.

A further object of the invention is to allow more precise measurements by eliminating the systematic errors due to the main environmental effects.

A further objective of the invention is to make available an intelligent device that in fact has costs completely comparable with the thermal imaging cameras currently on the market, while guaranteeing much improved performance.

A further object of the invention is to improve the reliability of the internal temperature detection even in situations of potential uncertainty regarding the ambient temperature in which the subject has stabilized his own body temperature or in case the subject (s) are in particularly cold environments, for example before entering public places such as schools, hospitals, factories, etc.

These and other purposes are substantially achieved by a method and by a relative apparatus for determining the body temperature of at least one subject in accordance with the attached claims,

Further characteristics and advantages will become clearer from the detailed description of a preferred, but not exclusive, embodiment of a method and of an apparatus according to what is described below.

The description will be made hereafter with reference to the accompanying figures, provided for illustrative purposes only and therefore not limitative in which:

- Fig. 1 is a schematic view of an embodiment of an apparatus in accordance with the invention;

Fig. 2 shows an exemplary view of an image detected by means of a thermal imager in accordance with the present invention;

Fig. 3 illustrates a contactless infrared thermometer;

- Fig. 4 schematically shows a wave guide usable in the thermometer of figure 3; And

Fig. 5 shows a block diagram relating to a measurement method that uses the thermometer of figure 3.

With reference to the figures cited with 1, an apparatus for determining the body temperature of at least one subject S.

in particular, this equipment is normally called a thermal camera, or thermographic camera, and is a particular camera, sensitive to infrared radiation, capable of obtaining images or thermographic recordings. In other words, the device is able to acquire at least images in the infrared field and to display the irradiation measurement in two dimensions. In general, through the use of a thermal imager, non-destructive and non-invasive checks are carried out as the radiation in the infrared range of the electromagnetic spectrum is detected and correlated measurements are carried out with the emission of these radiations.

In particular, it is the instrument capable of detecting the temperatures of the bodies analyzed by measuring the infrared intensity emitted by the bodies under examination.

All objects at a temperature above absolute zero emit radiation in the infrared range and the relationship is numerically quantifiable thanks to Planck's law.

In general, thermography allows you to view absolute values and temperature variations of people or objects regardless of their illumination in the visible range.

The amount of radiation emitted increases proportionally to the fourth power of the absolute temperature of an object as clearly established by the Stefan-Boltzmann law which defines the correlation between radiation and temperature according to the following formula:

q = εσT4

Where σ is the Stefan-Boltzmann constant and ε is the emissivity of the emitting surface (variable between the theoretical limits of 0 and 1), while T is the absolute temperature.

Therefore, starting from the detected radiation, temperature maps of the exposed surfaces are obtained.

The image is generally built on a matrix of a certain number of pixels and a certain number of lines and the electronics of the instrument is able to quickly read the energy value stored by each single pixel and to generate a corresponding image, in black and white or in false colors, of the observed object.

The operating spectral range of thermal imaging cameras is, as mentioned, that of infrared and in general the most commonly used band suitable for measurements of values close to the environmental temperatures of interest is that of far infrared (LW).

Overall, a thermographic or IR system consists of a camera (thermal imager) 1 connected to (or including on board) an image processing and recording system.

The infrared detectors have the task of identifying the consistency of the radiation that strikes them and to analyze the radiant surface point by point, to arrive at the definition of the heat map.

From the structural point of view, the apparatus 1 for determining the body temperature of at least one subject S comprises an acquisition system 2 of an image relating to at least one predefined area 3 within which there is at least one and preferably a plurality of subjects S are found (or pass through it) whose body temperature is to be known.

The apparatus obviously comprises suitable optical means 5 to allow focusing and image acquisition; these means 5 are constituted by standard lenses and telephoto lenses and chosen according to the specific application to which the thermal imager will be destined as better explained below. The apparatus then comprises an infrared sensor 6 which may be by way of example only, and not limitative, a sensor of the flat matrix, single matrix or dot matrix microbolometric type.

The sensors 6 can be either uncooled or cooled (generally with peltier cells or stretch pump).

The material that makes up the sensor affects the thermal sensitivity of the thermal imager, which is the smallest difference in temperature detectable by a thermal imager.

It is evident that a high thermal sensitivity identifies the most imperceptible temperature differences and therefore the lower its value, the higher the measurement resolution of the thermal imager and the higher the image quality.

By way of example, thermal imaging cameras with thermal sensitivity lower than at least 80 mK can be used.

Obviously, the temperature measurement range of the apparatus for determining body temperature in accordance with the invention must be centered in the range of the normal human body temperature, i.e. between 30 and 45 degrees centigrade with the best performance confined around the temperature of 37 °.

Since the equipment in accordance with the invention will generally be destined to acquire images of moving subjects or in any case be able to perform this type of scans as well, the acquisition frequency is a fundamental parameter for the use of the camera.

The measurement of the temperature of a moving object must be carried out with good acquisition frequencies to avoid the phenomenon of â € œsmearingâ € on the image, which prevents an accurate temperature measurement. In general, acquisition frequencies higher than 60 Hertz are preferred.

Therefore the instrument also includes a processing unit 7 capable of acquiring, with the appropriate frequencies, the electrical signal emitted by the infrared sensor 6 following the acquisition of the image or heat map.

The same processing unit 7 is able to process the received signal and to show the detected thermal image on a suitable display 8 present in the equipment (or in an external system - a computer for example).

In particular, it is possible to appropriately select the (false) display colors linked to the different temperatures with the desired degree of precision.

In other words, it is possible to display with different colors variations in temperatures from 32 to 43 degrees, for example, with colder colors for the lowest temperatures up to warmer colors for the highest temperatures.

Through the device it is possible to measure the temperature of each single point of the image; In fact, the instrument (or in any case in the post-processing software) contains a module 9 capable of correlating irradiation with temperature by means of the aforementioned Stefan-Boltzmann law.

It should be noted, however, that the device also comprises a real image sensor 10 capable of acquiring a real image relating to the same predefined area 3 which contains the subjects whose body temperature is to be known.

In other words, the thermal imaging camera object of the invention also includes a common sensor 10 currently used in cameras or video cameras on the market capable of acquiring the image in the visible spectrum (visible light).

The detected signal is acquired by the same processing unit 7 and can be shown on the aforementioned display 8 either as an alternative to the thermographic image, or jointly with it in superimposition.

In particular, a real digital image is automatically recorded for each infrared image detected.

In this way, the system always has two corresponding and simultaneous images available.

Optionally, the equipment can include suitable integrated LEDs or other lighting systems 11 which guarantee excellent visibility in the 3 image acquisition zones.

Advantageously, the processing unit 7 is able to analyze the image acquired through an appropriate recognition module 12 to identify at least one area of interest 13 of the subject S.

In detail, the instrument is therefore able to acquire the image coming from the predefined area 3 and to carry out on this last acquired image a predetermined number of calculations capable of carrying out the aforementioned recognition of the area of interest 13 of the subject S.

In particular, it is preliminarily advantageous to be able to identify one or more chosen areas of each of the subjects of interest (for example) between the forehead, eyes, temples, neck, auricle, etc.

Note that the recognition operation can be performed alternatively on the infrared image acquired in detail by the sensor 6 (in this case the real image sensor 10 in the visible light spectrum could be totally optional) or even carry out the recognition directly on the € ™ real image acquired by the second sensor 10,

This second option is now commercially more advantageous as there are methods available that already operate the recognition of the face of a subject implemented in cameras and camcorders, including amateur ones. In general, the teachings of, for example, one or more of the American patents US 6940545, US 7218759 or US 2009/0190803 can be used, which allow an analysis of the image to identify the areas of interest in it.

In any case, a recognition operation carried out by means of the thermal imager directly, ie without the use of the real image captured in the visible, but vice versa, by exploiting the thermal image, it allows to exploit hardware already present in the device without requiring any further.

The recognition methods may be different according to the needs and possibly the place of specific application of the thermal imager.

Merely by way of example, it will be possible to distinguish first of all an oval of the face (generally warmer) compared to the background (environment usually at a temperature below 37 degrees). Furthermore, it will be possible to recognize the positioning of the eyes inside the oval, and possibly also of the lips and / or nose.

In any case, once some significant portions of the face have been identified with a thermographic method, it is possible to establish with reasonable precision and in a very short time (as well as automatically) the position of the area where the infrared radiation is to be taken for reliable temperature measurement.

Moreover, in case of fever, cold or flu, some portions of the face are warmer and therefore not only the temperature changes, but also the relative distribution of the different temperatures on the face.

The clinical situation of the subject could therefore also be determined by not detecting the temperature of the portion of interest, but also the extent of a warmer area and / or temperature delta between different portions of the face above or below a predetermined threshold. (e.g. temperature differences between nasal septum and forehead greater than a standard value)

Obviously the interest for the present invention is to identify not so much the face of a subject, but the specific areas of interest highlighted above which are the best for the subsequent thermal analysis. In fact, once the specific area of interest 13 has been identified, the analysis of infrared radiation is carried out on the latter.

The determination of the subject's body temperature takes place in fact as a function of the infrared radiation detected coming from the area of interest. In general, with specific reference to the area of interest (for example the forehead), the determination of the maximum intensity radiation coming from the aforementioned area is determined and then the determination of the body temperature as a function of this maximum radiation detected.

The importance of determining the actual area of interest is linked to the possibility of improving the accuracy of the measurements and also to the possibility of automating the calculation of the temperature of a subject avoiding errors. In fact, the recognition of the zone whose temperature is to be measured makes it possible to prevent the software from being misled by calculating and reporting temperatures outside the predetermined ranges linked to heat sources not of interest (see zone 4 in figure 2).

Consider, for example, hot drinks carried by subjects, electronic equipment that heat, or even a simple cigarette, which would involve the detection of high temperatures, but of elements of no interest for the detection.

Vice versa, the identification of the precise area 13 where to carry out the measurement thanks to the recognition software allows first of all to eliminate the problems mentioned above.

Furthermore, the methodology according to the invention also provides for a correction phase of the detected temperature to determine the actual body temperature. First of all, the correction phase will be (or could be) according to the area of interest of origin of the infrared radiation.

It is in fact evident that the origin of the infrared radiation from the forehead, rather than from the neck (jugular artery) or from the temples, may require a different corrective parameter.

In fact, it should be noted that in general the external temperature of the various portions of the body not only differs from the internal temperature, but differs significantly differently depending on the point of detection (the temperature of the forehead is generally lower than that of the temple and so on).

It should also be noted that this correction can be carried out, alternatively, with corrective functions or even with parametric tables with fixed correction data, also obtained experimentally.

A second correction, opportune or necessary, is vice versa a function of the ambient temperature in which the subjects whose temperature is to be measured are located.

In fact, a subject with the same internal temperature who is in an environment with low temperatures will have a lower surface body temperature than the same subject with the same internal temperature who is in a warm environment.

Therefore, a first corrective parameter could be linked to the ambient temperature of the environment in which the subject is at the time of detection or also to the ambient temperature (different from that in the detection area) in which the subject was found for a predetermined time interval such as to substantially influence and stabilize the temperature of interest immediately before detection.

For example, think of subjects whose temperature is detected at the entrance to an air-conditioned area and coming from an area with a different temperature.

A subject who is outside at low temperatures and therefore enters an entrance and the temperature is immediately detected, will obviously have his own surface temperature stabilized with reference to the external temperature and not with reference to that of the place of measurement.

In this case the ambient temperature as a corrective reference could be the external one.

Furthermore, a corrective phase may also take into account a predetermined predetermined detection temperature for a majority of the plurality of subjects. In other words, without intervening with corrections linked to environmental parameters or to the detection zone 13, the thermal detection is carried out on a plurality of subjects who are expected to be on average in good health (temperature of about 37 °). In this case, the temperature detected for this plurality of subjects will be corrected in such a way as to assume the value of 37 ° as the internal temperature of most of the subjects that have the same thermal radiation emitted by the corresponding area of interest and the differences will then be evaluated. compared to subjects with a higher temperature.

In other words, it is assumed that most of the subjects whose temperature is measured have a normal value and therefore, if the temperature detected for these subjects were, for example, 35 °, it would be corrected to 37 °, also automatically correcting all other temperatures.

In this sense, it could also be possible to simply highlight those subjects who have a temperature in the area of interest higher, in addition to a certain threshold, than the average of the subjects whose temperature was measured over the time interval.

In other words, instead of determining a precise body temperature to establish the presence of subjects with fever, it is considered that most of the subjects whose temperature is measured do not have febrile phenomena and only those subjects who have a higher temperature are reported. .

The above obviously always referring to surveys linked to the identified area of interest, the same for all subjects, in such a way as to be reliable and automatable.

It should be noted that the methodology described above is particularly suitable for temperature measurements in high traffic areas, such as airports, factories, schools, museums, hospitals (in the latter case with particular reference to visitors).

One or more thermal imaging cameras positioned in correspondence with compulsory accesses, for example of passengers entering the country, allows to measure the internal temperature of a plurality of subjects in a reliable way and to report in real time those potentially suffering from febrile diseases.

The device can also be associated with an automatic access control system, for example consisting of a gate or a turnstile that locks automatically to prevent the passage of the â € œsuspectâ € subject.

By operating as described, the equipment is able to eliminate false positives linked to high temperatures not of the subjects of interest, and also to carry out precise measurements thanks to the correction steps highlighted above. Obviously, a further possible application of the thermal imaging camera is in hospitals or in any public place to detect the temperature of visitors and / or passers-by.

For example, the thermal imaging camera can be positioned in correspondence with accesses to hospital wards with critically ill patients in such a way as to be able to selectively deny entry to visitors with fever.

In a further advantageous, albeit secondary, aspect of the invention, a phase of recognition of a face and / or another bodily characteristic of a given subject can also be envisaged in such a way that with the comparison with faces and / or other corresponding and pre-memorized bodily characteristics, it is also possible to identify the subject.

In this way it is not only possible to detect a certain temperature, but also to associate it with a specific identified subject / patient.

A possible application of this methodology would be extremely advantageous in hospitals or health facilities.

In fact, it is possible to memorize faces or in any case identification parameters of certain patients that can subsequently be recognized and / or identified by the thermal imaging camera.

A thermal imager positioned in correspondence with a hospital room could be able to detect not only the temperature of a subject, but also, for example, his face by recognizing the patient's identity and therefore automatically memorizing the patient's temperature. If the device is placed on the bed, it may continuously detect the subject's temperature.

In these cases, these devices may be able to automatically sound an alarm by signaling the patient (s) with fever at the very moment in which the fever occurs, i.e. when the body temperature exceeds a certain control threshold. This threshold can also be of low temperature, for example in the case of a deceased patient.

The system can also be associated with the traditional control systems used by the personnel assigned to security checks such as controls using â € œmetal detectorsâ €, X-ray detectors or equivalent systems in airports, courts, etc.

In these cases, a person who shows a â € œsuspiciousâ € temperature alerts the relative alarm signal and is invited to a special area where medical personnel can carry out the necessary medical checks.

In a simpler and alternative embodiment to the one described above, it is envisaged to provide a fixed (or substantially fixed) structure or panel to which each person requested must approach.

By observing the panel directly and frontally at a predetermined distance (for example about 50 cm) the infrared radiation coming from the area of interest is received (for example, but not limited to, the forehead) and the body temperature of the subject is calculated from this.

In particular, the correct distance can be signaled by the device itself by means of signaling (for example an acoustic â € œbipâ €); by way of example, ultrasound can be used to establish whether the subject has reached the optimal position for measurement.

When the subject is at the right distance, the sensor mounted on the panel detects the radiation coming from the subject and then a control unit calculates the body temperature according to the detected radiation and the ambient temperature. In other words, the real internal temperature will be obtained by correcting the temperature detected on the forehead (or other area of interest) on the basis of the stored or detected ambient temperature.

In case of presence of temperature above a certain threshold (for example suspected fever) an alarm is issued (for example audible and / or visual).

The use of an eventual parabolic wave guide to bring the infrared radiation to the sensor can allow, if necessary, to reduce the sensor field of view and make the measurement more accurate.

In a further aspect of the invention there is also provided a method for measuring the temperature in which it is possible to use a thermometer also realized as follows.

With reference to Figure 1, an infrared thermometer 100 is shown as a whole in accordance with a further aspect of the present invention. Conventionally, the infrared thermometer comprises a main containment body 102 which defines a gripping area 103 for a user. The handle can carry conventional control means 104 such as keyboards and the like, as well as one or more displays 105 for the possible reading of the temperature and / or other information.

At one end of the main body, infrared radiation detector means 106 are provided which comprise an infrared radiation intensity sensor member 107 and at least one wave guide 108 operatively associated with the sensor member to appropriately convey towards the latter the radiations emitted by the target zone or area 109 of the body whose thermal level is to be measured.

In greater detail (fig. 4) the wave guide 108 has a first end 108a, facing the body whose temperature is to be known, and a second end 108b facing the sensor member 107.

As can be seen from the accompanying drawings, the waveguide is structured in the form of a tubular body having a specular internal surface 110, which defines a passage capable of putting in optical communication a first and a second opening 111 and 112 of the opposed tubular body.

The internal surface 110 of the waveguide has a convergent trend towards the second opening 112, i.e. it has an internal diameter which gradually decreases as one proceeds from the first opening 111 of the waveguide 108 towards the second opening where The sensor organ 107 is substantially located.

More precisely, in accordance with the present invention, it should be noted that the convergence of the wave guide 108 is more and more accentuated as one proceeds towards the second opening 112 of the tubular body.

In other words, the wave guide according to the present invention can have two or more sections, axially consecutive to each other, presenting a respective convergence which is constant in each section and progressively more accentuated passing from one section to the next section in direction and towards the second opening 112 of the tubular body defining the wave guide.

In practice, in the case just described, at least the converging portion of the waveguide will appear as a succession of truncated cone surfaces with increasingly accentuated conicity as one approaches the second opening 112.

Alternatively, to replace two or preferably a plurality of consecutive sections with ever greater convergence, a wave guide can be provided in which the internal surface is curved and converging progressively and continuously, in a more and more marked way, man as you proceed from the first opening towards the second opening.

In any case, the wave guide in accordance with the invention is made in such a way that, with the same axial advancement approaching the second opening, there is an ever greater diameter reduction as one proceeds from the first to the same second. opening.

In the exemplary waveguide illustrated in the accompanying drawings, where longitudinal sections of the same are represented, it is noted that the internal surface 110 of the waveguide is defined by arcuate lines 113, 114 and, preferably, by conic arcs with axis coinciding with the longitudinal axis of symmetry of the wave guide as well as with concavity facing the first opening 111.

As can be seen, the convergence of these parabola arcs is always greater as one proceeds towards the second aperture 112.

The internal surface 110 has specular characteristics in order to be able to reflect the radiations incident on it.

Advantageously, the waveguide, in correspondence with the first opening, can preferably have no protection mask such as those typically provided on traditional waveguides for these uses and must therefore be subjected to periodic cleaning by users in order to to be able to guarantee the necessary performance.

It should be noted that the possible absence of a protective mask is extremely advantageous since it avoids an unnecessary loss of signal in the radiation entering the wave guide.

In the case of a paraboloid-shaped wave guide, the sensor can be substantially placed in correspondence with the focus of the parabolic surface, in order to efficiently collect in particular the radiations coming from directions parallel or slightly inclined with respect to the longitudinal axis of the guide. wave itself.

It should be noted that, beyond the structure given to the waveguide, the latter as well as the sensor member operatively associated with it, are typically housed inside an auxiliary tubular body 120 made of metallic material, preferably made of copper or zamak, visible in particular in Figure 4.

It should be noted that the infrared thermometer in question, in addition to the components described above, comprises a processing unit (not shown) capable of processing the output signal from the infrared radiation sensor organ and, through suitable algorithms, of generating the thermal reading which is transferred to the display or shown to the user through other display systems, for example projection systems, such as those described in application PCT / IT98 / 00379 in the name of the same applicant.

The infrared thermometer according to the present invention can also be equipped with control means operatively associated with the containment body and cooperating with the processing unit; these control means are designed to determine a condition of correct positioning of the sensor member 107 at a predetermined distance D from the detection area, a distance of correct positioning which is considered optimal for carrying out an accurate reading and for delimiting reading area exclusively to the area of interest.

It is evident that in addition to the particular shape of the waveguide described above in accordance with the invention, a correct positioning at an adequate distance D between the sensor member and the sensing surface contributes to obtaining an extremely precise thermal reading.

At the implementation level, the control means can consist of various technical solutions that can be used alone or in combination with each other.

In particular, the use of light emitters or pointing lights 121 may be envisaged (see Figure 1). In particular, two or three light rays can be provided, visible, preferably not coplanar with each other and converging. In greater detail, it is envisaged that these non-coplanar light rays converge towards a point on the target area in order to determine a figure (for example a spot or other) when the sensor organ is positioned at the correct distance D from the area of detection,

Alternatively, the use of control means consisting of an emitter of a light beam intended to affect the detection surface and to be reflected by the latter to generate a return signal perceptible by a detection member which is able to calculate the inclination between the incident ray and the reflected ray. In particular, one or two detectors of the aforementioned incident ray angle-reflected ray can be provided, positioned in symmetrically opposed positions and cooperating with the processing unit to obtain the inclination of the reflected ray and therefore be able from this last to trace the real distance of the sensor organ from the sensing surface.

When this distance corresponds to the correct positioning distance D, optical / acoustic means may be provided to signal the achievement of this condition to the user.

Still as an alternative to the two solutions outlined above or simultaneously with them, the control means can comprise a generator of a primary light beam operating so as to focus a primary figure when the sensor member 107 is at the correct positioning distance D.

It should be noted that it is possible to provide for the use of an optical matrix selector, for example of the liquid crystal type, capable of varying the shape of the primary figure which can be focused on the detection surface. In greater detail, the matrix optical selector is managed by the central processing unit which is preferably able to vary the shape of the primary figure as a function of the detected temperature.

Note that the primary light beam can also be combined with a secondary light beam which is also variable with the use of an optical matrix selector, preferably of the liquid crystal type, manageable by the CPU. The second secondary light beam can also be controlled in order to compose a secondary figure when the sensor is at the correct distance D from the sensing surface.

The secondary figure can also be focused directly on the detection surface and can be composed with the primary figure and / or delimit the reading area from which it is reasonably presumed that the sensor organ is detecting the radiations and therefore is obtaining the thermal information. .

As a further variant, possibly also combinable with the three solutions described above, the control means can finally comprise an emitter of an incident wave signal (sound and / or electromagnetic) which determines a return signal following reflection on the detection surface. The central processing unit coordinates the emission and reception of the wave signal by calculating a time difference between these two signals. It is evident that the time difference will be proportional to the distance of the thermometer and therefore of the emitter from the surface of the body whose thermal level is to be known. In this way it is possible to know when the sensor organ is at the correct distance D from the detection surface, a situation that the CPU signals to the user by means of signaling, for example optical or acoustic.

inspect the oral cavity of the patients and then detect the presence of any pathologies.

Preferably, it is noted that the containment body of the infrared thermometer in question has an elongated structure and provides that the detection portion and therefore the means for conveying the infrared radiation to the sensor member are placed at a first end 102a of said containment body . After what has been described in a predominantly structural sense, the general operating operation of the waveguide and of the infrared thermometer in accordance with the invention is as follows.

Thanks to the shape of the internal surface of the waveguide which is progressively and increasingly converging towards the sensor member, the following effects are substantially obtained; the radiations directed parallel to the longitudinal axis of the wave guide or slightly inclined with respect to the latter are conveyed by the wave guide and substantially focused on the sensor organ, regardless of the area in which they come into contact with the internal surface of the guide d wave itself.

Conversely, the rays having an excessive inclination which come from an area of the patient's surface not of interest, which can distort the thermal detection, can either be sent back towards the input opening of the waveguide as a result of multiple reflections ( in practice, at each reflection there is an increase in the inclination of the beam up to exceeding 90 with respect to the axis of the wave guide).

In general, thanks to the conformation of the internal surface of the waveguide, the rays with greater inclination with respect to the longitudinal axis of the waveguide cannot reach the second opening of the waveguide itself which they can reach o rays with low inclination (which will hit the sensing organ) o rays which, depending on the inclination, may break on the internal or external walls of the body containing the sensing organ. However, it is evident that, thanks to the conformation given to the waveguide and to the detection portion, a considerable reduction and above all a precise definition of the effective target area of radiation detection on the surface of the body to be measured are obtained, in fact, the guide wave exerts a sort of optical filter of the radiations coming in excessively inclined directions with respect to the longitudinal axis of the guide itself.

In addition to skimming the excessively inclined rays, the waveguide in question is nevertheless able to focus substantially in a better way most of the rays coming from the reading area of actual interest, overall obtaining a signal sufficient to allow the thermal reading without radiation coming from areas not of interest and without an excessive reduction of the signal / noise ratio.

Given the above, the thermometer of figure 3 is particularly suitable for temperature measurements according to the method schematically shown in figure 5.

The method first of all comprises a step of manual positioning of the non-contact infrared thermometer 100 at a predetermined distance D from a target area 109 of a patient whose internal temperature is to be known.

In particular, the thermometer will be held by the hand at a gripping portion 103, for example directly by an operator.

As mentioned, the thermometer appears to be without contact with the patient, i.e. not only the infrared sensor 107 is located at a predetermined distance from the area whose temperature is to be measured, but no part of the instrument is in contact with the patient. itself during the measurement phases.

The operator points the thermometer in the direction of the target area 109 whose temperature is to be measured, in particular making sure that the infrared radiation coming from the target area can enter the waveguide 108 and be conveyed on the infrared sensor itself 107.

Once the correct distance D from the target area has been determined (note that this distance can be determined by way of example with optical methods such as non-planar converging rays, but also with the determination of the time from sending and receiving a signal reflected from the target area such as ultrasound or with the other methods described above) the infrared thermometer is activated to measure the patient's internal temperature.

It should be noted that the activation of the infrared thermometer will generally be manual and will take place by pressing an appropriate button 122 present, for example on a grip portion 103 of the thermometer.

However, in particular situations or with more advanced instruments, the activation of the temperature measurement can take place automatically and this activation can, optionally, be generated by reaching the correct distance.

In other words, once a control unit has determined the correct positioning distance D of the thermometer, it automatically starts detecting the infrared signal.

Once the thermometer is activated, infrared radiation is detected coming from the target area 109 of the patient for a predetermined time interval; by means of the intensity of infrared radiation detected it is possible to calculate the temperature of the target area or, equivalently, the internal temperature of the patient.

Advantageously, the target area 109 used is chosen in a group that includes the ethmoidal sinus, the canthus or the eyelid of a subject.

In particular, in the case in which the target area is the eyelid, the upper eyelid is chosen and the method generally provides that before the detection the patient is asked to close at least one eye to detect the temperature of the closed upper eyelid itself. .

It is evident that the upper eyelid, being when the eyes are open, protected and in contact with the eye sockets, is less affected by changes in external temperature and is more stabilized with reference to the patient's internal temperature.

Alternatively, the area of skin corresponding to the ethymoid sinus can be used as the target area, that is the portion of the body located between each eye and the nasal septum.

This portion is more perfused (through the internal carotid artery) and is therefore less affected by variations in the ambient temperature, having a temperature closer to the internal one and more stable than other portions of the human body.

Finally also the canthus, or that portion of the eye next to the nasal septum (the small recess also called "internal canthus" is formed between the two eyelids and is partly occupied by a small, red eminence, the "caruncula lachrymalis") It turned out to have a sufficiently stable temperature close to the internal one to allow more reliable measurements, particularly in cold external conditions or not at a known / stable temperature.

Finally, it is noted that when the thermometer is activated, the detection of infrared radiation for the aforementioned predetermined time interval is determined by means of a countdown by means of a timer.

In other words, once the thermometer has been activated, the infrared sensor that receives radiation from the target area 109 transmits the intensity received to the control unit which starts the calculation of the patient's internal temperature.

The quantity of infrared radiation is received and processed until the aforementioned predetermined time interval has elapsed.

The additional radiation received after this interval is not considered for the purposes of the calculation.

The invention achieves important advantages.

The identification of specific target areas that allow a distance measurement of temperature with contactless thermometers and which nevertheless possess characteristics such as to maintain a more stabilized temperature even in harsh environmental conditions improves the internal temperature reading and significantly increases the operating range of the thermometers known.

Claims (9)

CLAIMS 1. Method for measuring temperature comprising the following steps: - manually position a non-contact infrared thermometer at a predetermined distance from a target area of a patient whose internal temperature is to be known; - manually aim the target area so that an infrared radiation sensor of the thermometer receives infrared radiation coming from the target area; - activate the non-contact infrared thermometer to measure the patient's internal temperature; - detect, through the infrared thermometer without contact and for a predetermined time interval, the intensity of an infrared radiation coming at least from the target area of the patient; characterized by the fact that said target area is a surface of the body of a human or animal patient chosen from the group comprising: the etymoid sinus, the canthus or the eyelid. 2. Method according to claim 1, comprising the step of correcting a temperature of the target area as a function of the intensity of infrared radiation detected to determine the internal temperature. Method according to any one of the preceding claims, comprising the step of supporting the thermometer manually during all the positioning, aiming, activation and detection steps. 4. Method according to any one of the preceding claims, comprising the step of closing at least one eye and detecting the intensity of an infrared radiation coming from the closed upper eyelid, in particular the target area being the upper eyelid. Method according to any one of the preceding claims, comprising the step of measuring an ambient temperature and a step of correcting the temperature of said target area or the internal temperature as a function of the measured ambient temperature. The method according to claim 5, comprising the step of checking the stability / correctness of the ambient temperature used to correct the temperature of the target area or the internal temperature. Method according to any one of the preceding claims, in which the step of activating the contactless infrared thermometer is a step of manually activating the thermometer by pressing at least one button on it. Method according to any one of the preceding claims, wherein after activating the infrared thermometer, a timer starts a countdown, the radiation detection being carried out for a predetermined time during the countdown and until the end of the countdown. reverses. Method according to any one of the preceding claims wherein said patient is a non-human animal, the method being a veterinary method.