Apparatus for measuring oral and nasal respirations, and methods for controlling and assembling such a measuring apparatus

Abstract

A device for measuring a user's oral and nasal respirations, comprising a probe (2) internally delimiting three air passage channels with respective openings (22a, 22b, 23), the probe (2) comprising an electronic board (6) including a microcontroller (61) and a plurality of measurement circuits, each comprising an airflow measurement sensor (4a, 4b) arranged in the air passage channel, and an amplifier, the microcontroller (61) being further configured to: measure an amplified voltage at the output of the amplifier, calculate an amplitude of the amplified voltage measurement, modify a reference voltage supplied to the amplifier to maintain the amplitude constant, and estimate a quantity representative of the airflow. Figure for the abstract: Fig. 4

Description

Title of the invention: Apparatus for measuring oral and nasal respirations, and methods for controlling and assembling such a measuring apparatus. Technical field

[0001] The present invention relates to the general field of devices for measuring a user's oral and nasal respirations. The invention thus applies to a device for measuring a user's oral and nasal respirations, as well as to a method for controlling a measurement circuit of such a measuring device and to a method for assembling such a measuring device. STATE OF THE ART

[0002] In speech therapy, the assessment of breathing patterns, whether oral or nasal, plays a crucial role in identifying and treating orofacial dysfunctions, such as airway disorders or velopharyngeal insufficiency. Oral and nasal breathing measurement devices quantify airflow by analyzing, for example, the frequency, duration, and quality of a user's breathing. They provide valuable assistance in diagnosing abnormal breathing patterns, often linked to pathologies such as sleep apnea, nasal obstructions, or orofacial malformations, and thus facilitate the implementation of targeted rehabilitation interventions. Their use allows speech therapists to monitor the evolution of a user's breathing, such as that of a patient, and to adapt therapies accordingly, thereby improving the quality of life of affected individuals.

[0003] While invasive diagnostic methods such as nasoendoscopy exist, non-invasive devices such as the rhinomanometer, spirometer, or acoustic pharyngometer have also been developed, each enabling specific diagnoses. For example, the rhinomanometer allows for the assessment of nasal respiratory efficiency and the detection of potential obstructions by measuring the resistance to airflow in the nasal passages, while the spirometer allows for the assessment of respiratory capacity by measuring the volumes of air inhaled and exhaled by the lungs.

[0004] More recently, document WO 2016 / 128627 Al proposed a device to detect both mouth and nasal breathing of a patient, in order to simultaneously assess the functional capacities of the soft palate and detect respiratory abnormalities, and to analyze the effects of speech therapy or improvements following maxillary expansion, for example.

[0005] However, the proposed device detects airflow but does not provide sufficiently accurate measurements of the alternating airflow rate during patient respiration. Furthermore, there is a need to improve the reliability of such a device. Indeed, the measurement quality degrades rapidly as the device's operating time increases. Description of the invention

[0006] An object of the present invention is to provide a device for measuring a user's respiration with satisfactory accuracy while exhibiting better reliability of measurement over time.

[0007] To this end, the invention proposes, according to a first aspect, a device for measuring a user's oral and nasal respirations, comprising a probe internally delimiting

[0008] a first air passage channel comprising a first opening, the first opening being suitable for positioning under a first nostril of the user,

[0009] a second air passage channel comprising a second opening, the second opening being suitable for positioning under a second nostril of the user, and

[0010] a third air passage channel comprising a third opening, the third opening being suitable for positioning opposite the user's mouth,

[0011] the probe comprising

[0012] an electronic board comprising a microcontroller and a plurality of measuring circuits, each measuring circuit being specific to an associated air passage channel, the measuring device being notable in that each measuring circuit comprises

[0013] an airflow measurement sensor arranged in the associated air passage channel and comprising a metallic filament around which an airflow within the associated air passage channel is adapted to flow, each airflow measurement sensor being adapted to be powered by an electrical current when the user breathes through the device, and

[0014] an amplifier configured to provide at output an amplified voltage from a reference voltage and a voltage across the terminals of the metal filament of the powered airflow measurement sensor,

[0015] the microcontroller being further configured to: - measure the amplified voltage at the amplifier output, - calculate the amplitude of the amplified voltage measurement, - modify the reference voltage according to the amplified voltage measurement, so as to maintain a constant amplitude, and - estimate a quantity representative of the airflow flowing in the air passage channel associated with the airflow measurement sensor powered from the amplified voltage measurement.

[0016] Thus, the microcontroller is configured to dynamically modify the reference voltage at the amplifier input, thereby achieving servo control of the amplitude of the amplified voltage measurement. This ensures that the active sensor, subjected to a breathing airflow circulating in the air passage channel where it is located, exhibits constant sensitivity over time. In particular, this prevents drift in the measurement amplitude during variations in the physical properties of the heated filament of the sensor that is supplied with electrical current, typically its resistance.

[0017] The measuring device according to the invention is advantageously complemented by the following features, taken individually or in any of their technically possible combinations:

[0018] - the signal amplitude is calculated according to a cycle comprising one period, the period depending on the estimate of the representative quantity. This allows the value of the signal amplitude to be updated, in particular at each change of direction of the airflow corresponding to a moment when the airflow velocity is zero, between an inspiration and an expiration;

[0019] - each measuring circuit further includes a current source configured for to deliver an electric current to power the metal filament of the airflow measurement sensor, the delivered electric current having a constant intensity of less than 100mA. Typically, the current source is a current sink. This allows for low power consumption of the measuring device, and therefore better autonomy when the measuring device is powered by a battery;

[0020] - the microcontroller is further configured to control a preheating of the metallic filament of at least one airflow measurement sensor for a predetermined duration before measuring the amplified voltage. Preheating helps reduce variability in the estimation of the representative quantity of the flow due to the variation in the resistance of the metallic filament during the rapid temperature increase of the metallic filament at the beginning of its power supply;

[0021] - the microcontroller is further configured to modify a current intensity electrical output delivered from the amplified voltage measurement. This allows, in particular, calibration of the measuring device during preheating, and increases the reliability of the measurement;

[0022] - the probe further includes a temperature sensor configured to provide a temperature measurement at the microcontroller. This allows us to take into account the evolution of ambient temperature or airflow in the estimation of the quantity representing the airflow, and therefore the reliability of the measurement;

[0023] - the microcontroller further includes a clock configured to measure a The power supply duration of the metal filament of the powered airflow measurement sensor is monitored, and the microcontroller is configured to emit a maintenance signal when the measured power supply duration exceeds a maximum usage time. This prevents the use of the measuring device when the risk of obtaining a low-quality or unreliable measurement is significant;

[0024] - the airflow measurement sensors are assembled on a printed circuit board The modular design is connected to the electronic board in a removable manner. This allows for quick and easy replacement of the airflow measurement sensors when measurement quality is compromised due to wear of the metal filament.

[0025] According to a second aspect, the invention provides a method for controlling a measurement circuit of a measuring device as described above, implemented by a microcontroller, the measurement circuit comprising an amplifier configured to provide at output an amplified voltage from a reference voltage and a voltage across a metallic filament of an active sensor, the active sensor being arranged in an air passage channel, the control method comprising the steps of: - measurement of an amplified voltage at the amplifier output, - Calculation of signal amplitude from amplified voltage measurement, - modification of the reference voltage based on the voltage measurement amplified, so as to maintain a constant signal amplitude, - estimation of a quantity representative of an airflow flowing in the air passage channel from the amplified voltage measurement.

[0026] According to a third aspect, the invention proposes a method for assembling a measuring device as described above, comprising the following steps: - assembly of a plurality of incandescent bulbs on a printed circuit board, each incandescent bulb comprising a protective bulb covering a metallic filament, - removal of the protective bulb from each incandescent bulb in order to obtain a plurality of airflow measurement sensors, - optionally, folding of at least one airflow measurement sensor, and - integration of the printed circuit board carrying the plurality of airflow measurement sensors onto an electronic board of the probe.

[0027] Such a method allows for simple and rapid replacement of the airflow measurement sensors, limiting the risk of breakage of the metal filament when the measurement quality is compromised due to wear of the metal filament of one of the sensors airflow measurement. This also allows the use of readily available and inexpensive incandescent light bulbs as sensors. DESCRIPTION OF THE FIGURES

[0028] Other features, purposes and advantages of the invention will become apparent from the following description, which is purely illustrative and not limiting, and which should be read in conjunction with the accompanying drawings, given by way of non-limiting examples and on which:

[0029] Fig. 1 is a perspective view of a measuring device according to one embodiment.

[0030] Fig. 2 is a top view of the measuring device of Fig. 1.

[0031] The [Fig.3] is a section of the measuring device of the [Fig.1] in a facial plane.

[0032] Figure 4 is a perspective view of a cross-section in the facial plane of the device. measurement of [Fig.1].

[0033] The [Fig.5] is a section of the measuring device of the [Fig.1] in a lateral plane.

[0034] Figure 6 is a schematic representation of an airflow measurement sensor. the device.

[0035] Fig. 7 is a schematic representation of the measurement circuit of the electronic board of the measuring device.

[0036] Fig. 8 is a flowchart of the steps of a control method for a measurement circuit of the measuring device.

[0037] Fig. 9 is a schematic representation of a processing unit for analyzing respiration measurements from the measuring device.

[0038] The [Fig. 10] is a flowchart of the steps of a process for assembling the measuring circuit of the measuring device.

[0039] The [Fig. 11] is a perspective view of a modular printed circuit during a sensor assembly step of the assembly process.

[0040] Fig. 12 illustrates three perspective views of the modular printed circuit during a sensor cutting step of the assembly process.

[0041] Fig. 13 illustrates two perspective views of the modular printed circuit during a folding step of one of the sensors in the assembly process.

[0042] The [Fig. 14] is a perspective view of the modular printed circuit during a sensor protection step of the assembly process.

[0043] The [Fig. 15] is a perspective view of the probe of the device during an integration step of the modular printed circuit of the assembly process.

[0044] Fig. 16 illustrates three perspective views of the probe of the device during a sensor maintenance procedure.

[0045] Throughout the figures, similar elements bear identical references. DETAILED DESCRIPTION OF THE INVENTION

[0046] With reference to Figures 1 to 5, a measuring device 1 for the mouth and nasal breathing of a user is considered. The user may be a patient in the context of a medical diagnosis or the monitoring of rehabilitation, but the proposed measuring device may also be used in a non-medical context, for example for leisure or play.

[0047] Device structure

[0048] The respiration measuring device 1 as described includes a probe 2 adapted to be arranged in a measuring position opposite the user's face for measuring their respirations. The probe 2 forms a measuring unit comprising a plurality of respiration measurement sensors, as will be detailed later.

[0049] In this embodiment, the measuring device 1 includes a handle 3 for the user to grasp in order to position the probe 2 in the measuring position. Alternatively, the probe 2 may be integrated into a holder for the user, for example a helmet, or may be held in the measuring position by a retention system, for example straps or elastic bands.

[0050] With reference to [Fig. 1], the handle 3 is formed by an external wall 31 for gripping by the user's hand, whose nostrils are positioned opposite at least one opening 22a, 22b arranged in the upper part of the probe 2, preferably a first opening 22a and a second opening 22b, and whose mouth is positioned opposite a third opening 23, which is arranged in the lower part of the probe 2. The handle 3 extends along a longitudinal direction Z. The shape of the handle 3 is chosen to allow ergonomic one-handed gripping of the measuring device 1.

[0051] Preferably, the probe 2 is removably mounted on the handle 3. In other words, the probe 2 is reversibly attached to the handle 3. The probe 2 is thus fixed to the handle 3 in a reversible locking position, meaning that it can be mounted on or removed from the handle 3 by the user or an operator. This allows for easy maintenance in the event of a malfunction or failure of one of the respiration measurement sensors in the probe 2.

[0052] Preferably, the measuring device 1 comprises several removable probes 2, each of which can be mounted interchangeably in the locking position on the handle 3. This allows the use of probes 2 of different sizes to adapt to the morphology or age of the user. It also allows the use of a different probe 2 depending on the intended use of the measuring device 1, for example, a probe 2 for orthodontic diagnosis, a probe 2 for speech therapy diagnosis, or a probe 2 for recreational use.

[0053] This also ensures the compatibility of future probes and thus improves the measuring device 1 by replacing the probe 2 or the handle 3 with newer models.

[0054] The probe 2 includes an outer casing formed by a shell 21. In the embodiment shown, the shell 21 includes a first shell forming a front wall of the probe 2 of the measuring device 1, and a second shell forming a rear wall of the probe 2.

[0055] The shell 21 comprises an upper wall having at least one opening, preferably a first opening 22a and a second opening 22b. The opening, preferably each of the first opening 22a and the second opening 22b, comprises at least one orifice allowing air to flow through the shell 21 during nasal breathing. The opening, or the first opening 22a and the second opening 22b, are thus intended to be positioned below the user's nostrils, at least when the nasal breathing measurement is performed.

[0056] In the illustrated embodiment, the measuring device 1 comprises a first opening 22a and a second opening 22b, referred to as the upper openings, each corresponding to one of the user's nostrils when the measuring device 1 is positioned for measurement, i.e., against the user's face. In other words, the first opening 22a is designed to be positioned under the user's first nostril (here, the left nostril), and the second opening 22b is designed to be positioned under the user's second nostril (here, the right nostril). "Under" means that the opening is located opposite or directly across from the associated nostril and is sufficiently close to it so that the air exhaled through the nostril enters the probe 2 through the corresponding opening, namely the first opening 22a or the second opening 22b.

[0057] The probe 2 also includes a third opening 23, referred to as the mouth opening or lower opening, designed to be positioned opposite the user's mouth. More specifically, the casing 21 includes a front wall having the third opening 23. The third opening 23 includes at least one orifice allowing air to flow through the casing 21 during mouth breathing. In the measurement position, the third opening 23 is thus positioned in front of the user's mouth, and close enough so that the air exhaled from the mouth enters the probe 2 through the third opening 23.

[0058] Thus, the first opening 22a and the second opening 22b correspond to nasal expiratory air inlets and nasal inspiratory air outlets, and the third opening 23 corresponds to a mouth expiratory air inlet and a mouth inspiratory air outlet.

[0059] To improve user comfort, the shell 21 may include a notch 210 extending along the upper wall of the shell 21 from the front wall, between the first opening 22a and the second opening 22b. The notch 210 is ergonomically designed and shaped to accommodate the lower edge of the user's nose. In the measurement position, the user's nose rests against the upper wall of the shell 21, with each nostril coinciding with an associated opening 22a, 22b on either side of the notch 210.

[0060] Typically, the front wall of the shell 21 includes a forward-opening recess, allowing the user to comfortably position their mouth against the measuring device 1 in the measurement position. In the embodiment shown, the opening(s) of the third opening 23 are surrounded by a collar to allow for proper positioning of the upper and / or lower lip of the mouth at the level of the third opening 23. This also improves the reliability and quality of the measurement performed with the measuring device 1.

[0061] The probe 2 internally delimits a first air passage channel Ca comprising the first opening 22a, a second air passage channel Cb comprising the second opening 22b, and a third air passage channel Ce comprising the third opening 23. By "air passage", it is understood that a flow of breathing air can flow in each air passage channel Ca, Cb, Ce in a bidirectional manner.

[0062] The first air passage channel Ca and the second air passage channel Cb can be defined by the shell 21, i.e., integral with the shell 21, or obtained by assembling an added part, for example, a flexible hose. A seal between the first air passage channel Ca and the shell 21, or between the second air passage channel Cb and the shell 21, can be ensured by adding a sealing gasket. Similarly, the sensors of probe 2 are assembled in their respective air passage channels using a sealing gasket, described later, to ensure that no air circulating in an air passage channel Ca, Cb, or Ce escapes through any opening other than those provided for this purpose.

[0063] Preferably, the first air passage channel Ca and the second air passage channel Cb do not communicate with each other, i.e., they are fluidically separated. This allows the measuring device 1 to measure the breathing of each nostril of the user independently, and thus makes it possible to detect an asymmetry in nasal breathing.

[0064] In the embodiment shown, the side wall of the hull 21 comprises a first lateral opening 24a in fluid communication with the first opening 22a via the first air passage channel Ca, and a second lateral opening 24b in fluid communication with the second opening 22b via the second air passage channel Cb.

[0065] Each lateral opening 24a, 24b includes at least one orifice allowing air to flow through the shell 21, and in particular the air outlet when the user exhales through the nose through the opening 22a, 22b of the respective air passage channel Ca, Cb, and the air inlet when the user inhales through the nose through the opening 22a, 22b.

[0066] The shell 21 comprises a rear wall, opposite the front wall with respect to the probe 2, and having a rear opening 25 in fluid communication with the third opening 23 via the third air passage channel Ce. The rear opening 25 typically comprises a plurality of orifices opening onto the third air passage channel Ce. The third air passage channel Ce allows the circulation of a mouth airflow between the user's mouth and the exterior of the probe 2. The X direction here corresponds to a mouth flow direction. The third air passage channel Ce may be delimited by the shell 21, i.e., integral with the shell 21, or be obtained by assembling an added part.

[0067] Preferably, the third air passage channel Ce does not communicate with either the first air passage channel Ca or the second air passage channel Cb; that is, the third air passage channel Ce is fluidically separated from the first air passage channel Ca and the second air passage channel Cb. This allows the measuring device 1 to measure the user's mouth breathing independently of nasal breathing, and thus enables the detection of an asymmetry between nasal and mouth breathing.

[0068] The casing 21 delimits a compartment 26 in the probe 2 in which control elements of the measuring device 1, for example an electronic board 6, can be arranged. The casing 21 can form a sealed assembly. For example, the various airflow measurement sensors 4a, 4b, 4c and electronic components contained in the probe 2 are arranged in the compartment 26, which is separated from the outside in a sealed manner.

[0069] The measuring device 1 is designed to be sterilizable by a UV (ultraviolet radiation) method or by the use of disinfectant wipes. Preferably, the measuring device 1 is compatible with standard sterilization protocols such as autoclaving, vacuum sterilization with ethylene gas (EtO₂), or a hydrogen peroxide vapor diffusion sterilization process as offered by Sterrad (registered trademark).

[0070] Preferably, the measuring device 1 includes a removable hygiene piece intended to be fixed against the front wall of the housing 21. The hygiene piece is configured to filter oral or nasal airflow, and thus protect the sensors The probe 2 detects moisture or solid particles from the user's breath. In a medical setting, this also eliminates the need to sterilize the measuring device 1 between each user, thus saving the practitioner time and reducing the risk of respiratory disease transmission between successive patients. The removable hygiene component, corresponding to a protective mask, can be attached to the shell 21 via the protrusions at the first lateral opening 24a and the second lateral opening 24b.

[0071] The probe 2 includes an airflow measurement sensor 4a, 4b, 4c arranged in each air passage channel Ca, Cb, Ce, each airflow measurement sensor 4a, 4b, 4c being configured to measure a quantity representative of an airflow flowing in the air passage channel Ca, Cb, Ce in which it is arranged. The operation of the airflow measurement sensors 4a, 4b, 4c will be detailed later.

[0072] Breathing measurement sensors

[0073] The probe 2 is configured to provide a measurement of the user's oral and / or nasal breathing. Each airflow measurement sensor 4a, 4b, 4c is capable of providing at least one airflow presence measurement signal, i.e., is configured to provide a measurement signal enabling the estimation of a quantity representative of the airflow, for example the airflow velocity, its direction, or its flow rate.

[0074] With reference to the view in the facial plane (Y, Z) of [Fig.3], the probe 2 has an axis of symmetry parallel to the longitudinal direction Z passing through the notch 210. The longitudinal direction Z corresponds to a nasal flow direction.

[0075] The first air passage channel Ca comprises a first portion or primary portion extending from the first opening 22a towards the interior of the probe 2 in the Z direction, and a second portion extending from the lateral opening 24a towards the interior of the probe 2 in the Y direction. The two portions are separated by an elbow. Symmetrically, the second air passage channel Cb comprises two portions extending in two orthogonal directions and connected by an elbow.

[0076] The probe 2 comprises a first nasal airflow measurement sensor 4a and a second nasal airflow measurement sensor 4b. Each airflow measurement sensor 4a, 4b is disposed in a respective air passage channel Ca, Cb.

[0077] More specifically, the first airflow measurement sensor 4a is located at the elbow connecting the primary and second portions of the first air passage channel Ca. This ensures that the first airflow measurement sensor 4a is exposed to the airflow flowing from the first opening 22a during nasal expiration, or from the lateral opening 24a during nasal inhalation. Similarly, the second airflow measurement sensor 4b is arranged symmetrically in the bend of the second air passage channel Cb.

[0078] The probe 2 also includes an oral airflow measurement sensor 4c located in the third air passage channel Ce. The oral airflow measurement sensor 4c is configured to measure a quantity related to the oral airflow between the third opening 23 and the rear opening 25. The oral airflow measurement sensor 4c may be identical to the nasal airflow measurement sensors 4a, 4b. Their operation will be described in detail later.

[0079] Preferably, the probe 2 further comprises at least one microphone 5a, 5b, 5c configured to detect a pressure variation such as an overpressure in one of the air passage channels Ca, Cb, Ce linked to an airflow from the opening 22a, 22b, or 23 communicating with the air passage channel. This makes it easy to distinguish an inhalation phase from an exhalation phase, the overpressure activating the microphone 5a, 5b, 5c occurring only during the user's exhalation. The microphone 5a, 5b, 5c can pick up sound signals.

[0080] In the illustrated embodiment, the measuring device 1 advantageously comprises a first microphone 5a configured to detect an airflow from the first upper opening 22a, and a second microphone 5b configured to detect an airflow from the second upper opening 22b.

[0081] Each of the first microphone 5a and the second microphone 5b are typically arranged in a separate cavity in fluid communication with the respective air passage channel Ca, Cb. The first microphone 5a is oriented opposite the first opening 22a, and the second microphone 5b is oriented opposite the associated second opening 22b. More precisely, the separate cavity is arranged in line with the first portion of the air passage channel Ca, Cb, along the nasal expiration Z direction.

[0082] The probe 2 may also include a third microphone 5c or mouth microphone 5c configured to detect an airflow from the third opening 23. The third microphone 5c is arranged in a separate cavity in communication with the third air passage channel Ce, and typically oriented opposite, i.e., so as to face, the third opening 23. The third microphone 5c may be identical to the first microphone 5a and the second microphone 5b. The third microphone 5c is intended to be located near the user's mouth and is particularly useful for detecting phonemes.

[0083] Thus, each air passage channel Ca, Cb, Ce can be associated with a microphone 5a, 5b, 5c configured to detect a variation in air pressure in the channel of Air passage Ca, Cb, Ce associated. The first microphone 5a, the second microphone 5b, and the third microphone 5c can be of different types, for example, mechanical, electrostatic, EMC, or MEMS. Microphones 5a, 5b, and 5c have a high signal-to-noise ratio (SNR), typically greater than 60 dB(A). For example, a piezoelectric microphone is not sensitive enough to detect a change in air pressure.

[0084] Preferably, the probe 2 is further configured to be connected to a laryngeal vibration sensor. The laryngeal vibration sensor can be a generic external sensor or one embedded in another device, typically integrated into a smartwatch. The laryngeal vibration sensor can be of the vibration type (such as a piezoelectric sensor or an accelerometer), or, without limitation, a blood flow sensor. The housing 21 includes, for example, a connector, typically a jack port, connected to the electrical circuit 6 and intended to receive a jack cable connected to the laryngeal vibration sensor. Preferably, the laryngeal vibration sensor is configured to exchange information with the electronic board 6 wirelessly, for example via Bluetooth (registered trademark) or Wi-Fi (registered trademark). This increases user comfort and facilitates the use of the measuring device 1.

[0085] The laryngeal vibration sensor is intended to be applied to the user's throat, at the level of the larynx. It is held in position by a suitable fastening means, for example, an adhesive or an elastic band. The laryngeal vibration sensor is typically a piezoelectric sensor configured to transform a force caused by the vibrations of the user's larynx into an electrical voltage transmitted to the electronic board 6. Such an external analysis channel is very useful in speech therapy, as it allows the detection of additional sounds and low-level breathing at the lung level. The pronunciation of the sound "A," for example, does not produce an airflow and can be detected by the laryngeal vibration sensor. The third microphone 5c can be advantageously used to detect sounds emitted by the user.

[0086] The probe 2 may include a language analysis module configured to detect spoken words and identify the user's language. Such a language analysis module may implement artificial intelligence. It may be implemented on the microcontroller 61 described below, or on an independent microcontroller connected to the electronic board 6 of the probe 2. Alternatively or complementarily, the language analysis module may be implemented in a processing unit 100 to which the measuring device 1 is connected.

[0087] Airflow measurement sensors

[0088] Hereafter, the term "airflow measurement sensor 4" will refer to any one of the airflow measurement sensors 4a, 4b nasal, and 4c oral. Thus, each of the airflow measurement sensors 4a, 4b nasal, and 4c oral can be implemented according to the airflow measurement sensor 4.

[0089] The airflow measurement sensor 4 is of the thermistor type. It is positioned in the respective air passage channel Ca, Cb, Ce to be exposed to the airflow coming from or going towards the associated opening 22a, 22b or 23.

[0090] With reference to [Fig. 6], the airflow measurement sensor 4 comprises a metal filament 41 which is a bare electrical conductor of an incandescent thermistor; that is, the electric current passing through the metal filament 41 induces an increase in the temperature of the metal filament 41, resulting in the emission of electromagnetic waves and heat. Since the electrical conductor is bare, combustion could occur through the introduction of oxygen, for example, from the oxygen contained in the air. The current intensity through the metal filament 41 is limited to prevent rapid consumption of the metal filament 41.

[0091] For example, the airflow measurement sensor 4 shown corresponds to a standard incandescent light bulb marketed by JKL Components Corporation under reference number 7373, from which the protective glass bulb 40 has been removed during an assembly process detailed later. This allows the metal filament 41 to be in direct contact with the airflow passing through the respective air passage channel Ca, Cb, Ce during the user's breathing. Typically, such a bulb is configured to be powered by a current of 100 mA and subjected to a voltage of 14 V.

[0092] The airflow measurement sensor 4 is preferably obtained from an incandescent bulb having an average life expectancy of 50,000 hours (under vacuum), which ensures a satisfactory service life of the measuring device 1. Moreover, as will be seen later, a defective sensor can be easily replaced.

[0093] The thickness of the metal filament 41 determines the current consumption of the airflow measurement sensor 4. Typically, the thickness of the metal filament 41 is between 50 pm and 200 pm.

[0094] The length of the metal filament 41 determines the voltage across the terminals of the airflow measuring sensor 4. Typically, the length of the metal filament 41 is greater than 50 cm, preferably greater than 1 m. Of course, as shown in [Fig. 6], such a metal filament 41, according to its initial arrangement in the bulb, can be at least partially coiled or at least partially helical, in order to reduce its size relative to its length. Such a metal filament 41 allows a much greater surface exchange, and therefore increased sensitivity and response amplitude.

[0095] The metal filament 41 has an electrical resistance between its two ends, which varies according to the temperature, and generates power by Joule effect depending on the airflow around the metal filament 41, typically passing through the turns of the wound metal filament 41.

[0096] The metal filament 41 can be made of a noble metal, for example gold, platinum, or a platinum-iridium alloy. The use of such a metal increases the resistance of the airflow measuring sensor 4 to corrosion and oxidation and increases the service life of the measuring device 1.

[0097] Preferably, the metal filament 41 can be made of tungsten or steel. Such metals are commonly used in incandescent light bulb filaments and are inexpensive. This makes the device 1 more accessible to practitioners. Preferably, the metal filament 41 is pre-oxidized, for example, by burning it on a test support before assembly on the electronic board 6. This allows it to be partially corroded and thus resistant to oxidation.

[0098] Preferably, the airflow measurement sensor 4 is of class C-2F so that the metal filament 41 is held in position in the respective airflow passage channel Ca, Cb, Ce by a double support 42. This prevents the metal filament 41 from deforming or breaking due to the flow of air in the airflow passage channel Ca, Cb, Ce in which it is arranged.

[0099] The airflow measurement sensor 4 also includes a sensor body 44 having two contacts 43, each connecting one end of the metal filament 41 to a respective electrode (or tab) 45. The metal filament 41 can be connected to the contacts 43 by welding or crimping.

[0100] The airflow measurement sensor 4 is intended to be connected to the electrical circuit of the electronic board 6 via the two electrodes 45, in order to pass an electric current through the metal filament 41. Thus, each airflow measurement sensor 4a, 4b, 4c is designed to be powered by an electric current when the user breathes through the measuring device 1. The structure of the airflow measurement sensors 4a, 4b, 4c and their assembly will be described in detail later.

[0101] The basic principle of the airflow measurement sensor 4 is that of a hot-wire anemometer evaluating the velocity of a fluid by measuring the power transferred by the metal wire 41 heated to lower its temperature. The heat transfer depends on the flow velocity of the airflow passing through it or flowing around the thermistor, according to King's law:

[0102] RxI2 = A + B^,

[0103] with R the resistance of the metal filament 41, I the current passing through the metallic filament 41, A and B are parameters that depend in particular on the temperature of the metal filament 41, and v the flow velocity of the airflow around the metal filament 41.

[0104] The electrical resistance of the metal filament 41 depends on several factors. Firstly, the electrical resistance of the metal filament 41 depends on its technical characteristics, particularly its composition, effective length, and contact resistance. It increases as the metal filament 41 ages, its diameter decreasing with wear. This increase is proportional to the length of the metal filament 41 and depends on the type of material chosen. It is particularly noticeable for steel or tungsten filaments.

[0105] On the other hand, the electrical resistance of the filament increases with the temperature of the filament according to a logarithmic law. The temperature of the metal filament 41 increases when a current passes through the metal filament 41 due to heat losses related to the Joule effect, and varies according to the ambient conditions and the airflow in the air passage channel Ca, Cb, Ce in which the airflow measurement sensor 4 is arranged (by conduction and convection phenomena).

[0106] These variations in resistance of the metal filament 41 must be taken into account to ensure the reliability of the measurement of the quantity representative of the airflow.

[0107] Conventionally, the resistance of the metal filament 41 can be measured by a measuring circuit comprising a Wheatstone bridge connected to the ends of the metal filament 4L. The Wheatstone bridge includes a galvanometer for measuring the variation in resistance of the metal filament 4L. However, this device requires prior adjustment of a variable resistance in the bridge. Due to the drift in the resistance of the metal filament 41 caused by wear and temperature variations, such a measuring circuit does not allow for reliable measurement over time.

[0108] Servoing the airflow measurement sensor 4

[0109] The proposed solution is to implement a control of the air flow measurement sensors 4a, 4b, 4c in order to obtain a reliable measurement of the resistance of the metal filament and therefore a reliable estimate of the quantity representative of the air flow flowing in each of the air passage channels Ca, Cb, Ce.

[0110] To achieve this, the electronic board 6 includes a microcontroller 61 and a plurality of measurement circuits, each measurement circuit being specific to an associated air passage channel Ca, Cb, Ce. Thus, each airflow measurement sensor 4 of the probe 2 is connected to the electrical circuit of the electronic board 6 by its own circuit of measure.

[0111] Subsequently, one of the measurement circuits of the electronic board 6 associated with the airflow measurement sensor 4 will be described.

[0112] Generally, the microcontroller 61 is configured to determine or estimate a quantity representative of the airflow, typically the flow velocity or flow rate, from input data including a voltage measurement. The electronic board 6 may include memory configured to store instructions or a control program for the measuring circuit implemented by the microcontroller 61, data measured during the use of the measuring device 1, and previously obtained data, for example, by calibration.

[0113] Each measuring circuit further includes an amplifier 62. The amplifier 62 is configured to provide an amplified output voltage Vo from a reference voltage Vref and a voltage across the metal filament 41 of the airflow measuring sensor 4, when the measuring circuit and therefore the airflow measuring sensor is powered.

[0114] In other words, the amplifier 62 is configured to amplify the voltage at one terminal of the metal filament 4L. More precisely, a first input at potential V of the amplifier 62 is connected to the metal filament 4L. The amplifier 62 is selected for its high temperature stability. Typically, the amplifier 62 is of the zero-drift type, with an input offset drift on the order of nanovolts per degree Celsius, and a very low voltage offset, preferably less than a millivolt. The microcontroller 61 comprises various functional modules schematically separated in [Fig. 7] into a digital-to-analog converter (DAC), an analog-to-digital converter (ADC), and a control unit (CTL).

[0115] The digital / analog converter DAC is configured to provide the reference voltage Vref to the amplifier 62. It is connected to a second input of the amplifier 62 at the potential Vref, typically to the terminal V+ in the illustrated embodiment.

[0116] The analog-to-digital converter (ADC) is configured to convert the output voltage of amplifier 62 into a digital value. It is connected to the output of amplifier 62.

[0117] In the illustrated embodiment, the measuring circuit further includes a current source 63 (also called a current limiter, current sink or "current sink" in Anglo-Saxon terminology), a voltage generator 64 and a switch 65. The voltage generator 64 is connected to the metal filament 41 via the switch 65.

[0118] The current source 63 is configured to power the measuring circuit, and to limit the current passing through the metal filament 4L. II is connected to the voltage reference GND (or ground) and to the metal filament 4L. The current source 63 is selected to generate very little heat intrinsically and therefore not lead to significant heat loss.

[0119] The CTL control unit is connected to the switch 65 and configured to actuate the switch 65 so as to heat the metal filament 41 and adjust the current through it, by a control signal from the microcontroller 61, with a duty cycle d. According to Kirchhoff's voltage law at point S, we have Vw = dx Vin - Vs.

[0120] In the illustrated embodiment, the amplifier 62 is a non-inverting amplifier, so the measuring circuit includes a first resistor RI connecting the V- terminal of the amplifier 62 to the metal filament 41, and a second resistor R2 connecting the output of the amplifier 62 to the V- terminal. When the amplifier 62 operates in linear mode, the output voltage Vo satisfies 101211

[0122] with the ratio of the resistances defining the gain of amplifier 62, and Vs the potential at point S, corresponding to the voltage of the current source 63 (connected to ground GND).

[0123] The method of controlling a measurement circuit of the measuring device 1, implemented by the microcontroller 61, will now be described with reference to [Fig.8].

[0124] The metal filament 41 of the air flow measurement sensor 4 is supplied with current I by the current source 63. The voltage Vw across the metal filament 41 varies as a function of the resistance Rw across it, at constant current iw, according to Ohm's law (Vw = Rw x iw).

[0125] During a Sel step, the microcontroller 61 measures the amplified voltage Vo at the output of the amplifier 62 received by the analog / digital converter ADC.

[0126] During a step Sc2, the microcontroller 61 calculates an amplitude of the amplified voltage measurement Vo. By "amplitude," it is understood that the microcontroller 61 determines a voltage value corresponding to a local maximum over a defined range. As will be illustrated later, the calculated amplitude may correspond to a voltage peak measured between an inhalation and an exhalation by the user in the air passage channel where the airflow measurement sensor 4 is located.

[0127] During a step Sc3, the microcontroller 61 modifies the reference voltage Vref according to the amplified voltage measurement Vo, so as to maintain the amplitude of the local maximum constant. In other words, the microcontroller 61 controls the previously calculated amplitude. The microcontroller 61 is further configured to vary the reference voltage Vref according to the temperature, calibration parameters, and the amplified voltage measurement Vo. The microcontroller 61 cyclically controls the reference voltage Vref of the amplification signal supplied by the digital-to-analog converter (DAC) to the amplifier 62.

[0128] In particular, the microcontroller 61 is configured to fix Vref so that the inequality 0 < Vo < Vin is always verified, regardless of the conditions, and in particular (1- / 0 Vw + VREF < Vin and ( 1 _ ^ ) rj» + Vref < y with Rw the resistance of the filament heated without the presence of airflow.

[0129] Since the detection threshold of the measuring circuit depends on the reference voltage Vref, the resistance measurement remains reliable over time. Indeed, this allows for the correction of voltage measurement drift observed when the temperature of the metal filament 41 varies, thus resulting in a more reliable measuring circuit and therefore a more reliable measuring device 1.

[0130] For example, [Fig. 9] shows voltage values ​​measured by the microcontroller 61 during three user breathing cycles of varying intensity. Before each exhalation, a local maximum is observed in the measurement. The microcontroller 61 is configured to regulate the reference voltage Vref so as to maintain a constant amplitude of the amplified voltage Vo measured at the output of the amplifier 62 over time. In other words, the microcontroller 61 drives the digital-to-analog converter (DAC) so that the local maximum has the same value over time. Thus, the measurement circuit has a constant sensitivity over time.

[0131] During a step Sc4, the microcontroller 61 estimates a quantity representative of the airflow in the air passage channel Ca, Cb, Ce associated with the airflow measurement sensor 4a, 4b, 4c, which is powered by the amplified voltage measurement Vo. From the amplified voltage measurement Vo and the electric current intensity iw known to the microcontroller 61, the microcontroller 61 can calculate the resistance of the metal filament and the dissipated power Rw x iw². The estimation of the representative quantity, for example the flow velocity, can be carried out, for example, from tables or laws stored in the microcontroller's memory. Typically, the representative quantity is estimated from a law relating a resistance of the metal filament 41 of the active sensor to a temperature value, the law having been obtained by prior calibration of the measurement circuit.

[0132] The microcontroller 61 can perform measurements cyclically during the operation of the probe 2. By "cyclically," it is understood to be according to a periodic pattern repeating itself over time according to a period. The period can be fixed, for example 1 s, or depend on the user's breathing rate.

[0133] Preferably, the microcontroller 61 calculates a signal amplitude. The signal amplitude is calculated according to a cycle comprising a period that depends on the estimate of the representative quantity obtained in step Sc4. Typically, the period can correspond to the duration of an expiration or an inspiration, or to the duration of a cycle Expiratory-inspiratory. Estimating the representative quantity, typically the velocity, allows us to detect these respiratory variations.

[0134] Alternatively or complementarily, the period can depend on the measurement signals from the microphone 5a, 5b, 5c detecting the pressure variation in the air passage channel Ca, Cb, Ce associated with the airflow measurement sensor 4 of the measurement circuit under consideration. This allows for a more precise determination of the signal amplitude value by identifying the local voltage maximum observed between inspiration and expiration in the relevant airway.

[0135] The microcontroller 61 can modify the reference voltage Vref according to a cycle having the same period. Indeed, depending on whether the metal filament 41 is in an inhaled or exhaled airflow, the temperature of the airflow varies, which can impact the measurement.

[0136] The operation of the measuring circuit will now be described, with reference to [Fig.8].

[0137] Preferably, the current source 63 delivers an electric current such as to supply the metal filament 41 of the airflow measurement sensor 4 with a constant intensity. According to Kirchhoff's current law at point S, we have iw ~ is because little current enters the amplifier 62. The current source 63 acts as a current sink.

[0138] The microcontroller 61, here via the CTL control unit, can actuate the switch 65 between an open and a closed position. When it is in the closed position, the potential imposed by the voltage generator 64 at one end of the metal filament 41 is Vin. Thus, the metal filament 41 is traversed by current pulses (pumps) whose frequency varies according to the control signal, and in particular according to the duty cycle d of the switch 65.

[0139] The average current flowing through the metal filament 41 is therefore controlled by the microcontroller 61. Preferably, the microcontroller 61 is also configured to modify the intensity of the electric current delivered from the amplified voltage measurement Vo. This makes it possible to increase the electric current iw when the resistance of the metal filament 41 increases, due to wear or temperature, and thus to ensure that the voltage across the metal filament 41, at the input of the amplifier 62, is sufficiently high. This modification can take place, in particular, during the preheating described below.

[0140] As mentioned previously, the microcontroller 61 is configured to take into account the variation in electrical resistance of the metal filament 41 in the estimation of the representative quantity during step Sc4.

[0141] Preferably, the microcontroller 61 incorporates compensation for resistance variations due to temperature via prior calibration of the measurement circuit. In other words, a calibration of the measurement circuit is performed by an operator before the electronic board 6 is assembled onto the measuring device 1. For example, resistance measurements of the metal filament 41 and the amplified voltage Vo are taken for known airflow rates and ambient temperatures, and for a known current intensity iw in the metal filament 41. This allows the impact of the temperature change of the metal filament 41 on the resistance to be taken into account when estimating the airflow velocity from the amplified voltage measurement. In particular, the resistance across the metal filament 41 in the presence of airflow is lower than the resistance R in the absence of airflow. Similarly, it is observed *YH' ' During each expiration, the amplified voltage measurement reaches a plateau with a progressively lower average value. Preferably, the microcontroller 61 is configured to control the reference voltage Vref and / or the duty cycle d of the switch 65 so as to maintain the average voltage value during a stationary or constant expiration. This also prevents measurement drift and improves the reliability of the measuring device 1.

[0142] Preferably, the microcontroller 61, via a standby signal emitted by the CTL control unit, opens the switch 65 when the measuring device 1 is not in use. The microcontroller 61 can then open the switch 65 of each measuring circuit simultaneously. This advantageously prevents current from flowing through the metal filament 41 and thus avoids contributing to its unnecessary wear. This allows the measuring device 1 to be put into standby mode quickly and also avoids consuming the power available in the battery, if present, and thus preserves the autonomy of the measuring device 1.

[0143] Preferably, the microcontroller 61 can independently control the respective switches of each measuring circuit. For example, when the measuring device 1 is used to measure only the user's mouth breathing, the microcontroller 61 can open the switches of the measuring circuits associated with the first airflow measuring sensor 4a and the second airflow measuring sensor 4b. This prevents unnecessary consumption of the metal filaments 41 of the airflow measuring sensors 4a and 4b.

[0144] Preferably, the microcontroller 61 is further configured to control a preheating of the metal filament 41 of at least one airflow measurement sensor 4a, 4b, 4c for a predetermined duration before measuring the amplified voltage Vo. As before, the microcontroller 61 can control the preheating at the level of all measurement circuits, or selectively, depending on the use of the measuring device 1.

[0145] The measuring circuit does not include any significant losses other than those induced by the metal filament 41, despite the presence of resistors R1 and R2 and internal resistances in the current source 63. The measuring circuit exhibits good responsiveness, i.e., a good dynamic response. This is due to the nature of the metal filament, particularly its length and winding. The predetermined heating time for the metal filament 41 can be short, for example, 5 seconds every minute, or 1 second every 5 seconds, or, as another example, 5 seconds every 25 seconds. The preheating time can be stored in memory. It can be determined during the preliminary calibration.

[0146] Typically, the microcontroller 61 periodically preheats the metal filament 41 before starting the amplified voltage measurements. This stabilizes the filament resistance and limits variations during the measurement, thus reducing the uncertainty in estimating the velocity or flow rate of the airflow.

[0147] For example, the microcontroller 61 can receive an activation signal indicating that the measuring device 1 is going to be used, and control the switch 65 to the closed position upon receiving this activation signal. The activation signal can come from an external system, for example, an interface or an application to which the measuring device 1 can connect via Bluetooth (trademark). The activation signal can come directly from the user, for example, via a button arranged on the casing 21 or via motion sensors integrated into the measuring device 1. Typically, the activation signal can be emitted 10 s before the start of a game.

[0148] Alternatively, the microcontroller 61 may include an internal clock configured to emit the preheating signal for the metal filament 41 according to a predefined cycle.

[0149] Preferably, during the preheating phase, the microcontroller 61 adjusts the current I flowing through the metal filament 41 to precisely calibrate the resistance of the metal filament 4L. In other words, the microcontroller 61 is configured to modify the current delivered by the current source 63 and / or to modify the actuation frequency of the switch 65 so that the amplified voltage Vo reaches a target value during the preheating phase. This increases the accuracy of the voltage measurement, and therefore the estimation of the characteristic quantity.

[0150] Preferably, the microcontroller 61 further includes an internal clock configured to measure the energization time of the metal filament 41 of the powered airflow measurement sensor 4. The microcontroller 61 can store a counter associated with each airflow measurement sensor 4a, 4b, 4c, which increments when the corresponding measurement circuit is energized.

[0151] The microcontroller 61 can then emit a maintenance signal when the measured power supply time exceeds a maximum usage time. Thus, the microcontroller 61 can transmit information to the user to schedule a replacement of the airflow measurement sensor 4 during a maintenance operation, based on the measured usage time. Typically, the microcontroller 61 can transmit, via the interface of the processing unit 100 to which the measuring device 1 is connected, an alert message when the usage time of the airflow measurement sensor 4 exceeds a limit, for example, 1000 h. This prevents the use of the measuring device 1 when the reliability of the measurement is compromised, and therefore avoids producing an inconsistent speech therapy diagnosis, for example.

[0152] Preferably, the voltage generated by the voltage generator 64 is low, for example less than 5 V, typically between 3 V and 4 V, for example 3.3 V. The current generated or limited by the current source 63 is low, for example less than 150 mA. Preferably, the current is less than 100 mA, typically 50 mA (on average). This reduces the power dissipated by the metal filament 41 and consumed by the measuring circuit. Matching the delivered current to the measured voltage Vo preserves the sensitivity of the measuring circuit and reduces the power consumption of the measuring device 1, thus increasing its operating time.

[0153] Preferably, the probe 2 further includes a temperature sensor 66 configured to provide a temperature measurement to the microcontroller 61. Preferably, each measurement circuit of the electronic board 6 includes a temperature sensor 66 connected to the microcontroller 61. This allows the microcontroller 61 to determine and measure the temperature variation of the metal filament 41, and to estimate the representative value of the airflow in the associated air passage channel Ca, Cb, Ce by taking this information into account.

[0154] For example, the temperature sensor 66 is a flip-chip platinum sensor that can be mounted on the circuit board 6 by soldering or gluing. Such a sensor can operate over a wide temperature range, typically between -50°C and 150°C. It has the advantage of being very compact and exhibits a very fast response time and high stability over time. According to another example, the temperature sensor 66 is a thin-film linear nickel thermistor. Such a temperature sensor 66 has a similar operating range and little variability with temperature changes, which allows for stable measurement. According to yet another example, the temperature sensor 66 is a wire-based platinum sensor that can be soldered onto the circuit board 6. Such a temperature sensor 66 has a greater operating range, typically up to 600°C, and also high stability over time (error less than 0.04% after 1000 h at maximum operating temperature).

[0155] In this embodiment, the microcontroller 61 is further configured to measure the temperature cyclically via the temperature sensor 66. This makes it possible to take into account the impact of the ambient temperature or the temperature of the airflow, which varies between inspiration and expiration, on the estimation of the representative quantity.

[0156] Preferably, the airflow measurement sensors 4 are configured to perform self-calibration, so that the measuring device 1 can perform user breathing measurements without prior calibration.

[0157] The measurement circuit shown schematically comprises a single metal filament 41. Since the electronic board 6 is connected to the three airflow measurement sensors 4a, 4b, 4c, it will be understood that the measurement circuit shown is duplicated so that each of the respective metal filaments 41 of the airflow measurement sensors 4a, 4b, 4c is integrated into a measurement circuit.

[0158] Preferably, the microcontroller 61 drives each of the airflow measurement sensors 4a, 4b, 4c independently. Each airflow measurement sensor 4a, 4b, 4c can be integrated into an independent measurement circuit, so that the microcontroller 61 receives an amplified voltage measurement for each of the airflow measurement sensors 4a, 4b, 4c from probe 2. The microcontroller 61 is configured to calculate or estimate the representative value of a nasal or oral airflow from the measurement signal, depending on the source of the measurement signal.

[0159] Preferably, the airflow measurement sensors 4a, 4b, 4c have high sensitivity, so that the microcontroller 61 can estimate an airflow rate over an amplitude range greater than ±15 l / s, with an accuracy of less than ±5% error, preferably less than ±1% error. Advantageously, the flow rate range measurable by the airflow measurement sensors is ±250 sim (standard liters per minute). The resolution of the airflow measurement sensors 4a, 4b, 4c is preferably less than 0.1 sim, preferably even less than 0.01 sim.

[0160] The measurement signals from the airflow sensors 4a, 4b, 4c can enable the microcontroller 61 to calculate a plurality of representative quantities to assist the practitioner in their diagnosis. For example, the microcontroller 61 can be configured to calculate, from the measurement signals, a maximum ventilation per minute (MW), a peak expiratory flow rate (PEF), and an exhaled or inspired air volume.

[0161] At least one of the airflow measurement sensors 4a, 4b, 4c can be configured to implement TrueFlow spirometry technology (registered trademark). A Another example of an airflow measurement sensor 4a, 4b, 4c is marketed by Sensirion (registered trademark) and based on CMOSens® technology.

[0162] Industrial assembly of airflow measurement sensors 4a, 4b, 4c

[0163] In order to use the incandescent bulbs described above as airflow measurement sensors 4a, 4b, 4c in the measurement circuit, an assembly method is proposed. Indeed, the metal filament 41 of the airflow measurement sensor 4a, 4b, 4c is very fragile.

[0164] Preferably, the airflow measurement sensor 4 is mounted on a modular printed circuit board 46 attached to the electronic board 6. This allows for the safe assembly of the airflow measurement sensors 4a, 4b, 4c in the measuring device 1, as well as easy replacement of the airflow measurement sensors 4a, 4b, 4c in case of failure, or when a maximum service life of the sensors is exceeded. The reliability of the measuring device 1 is thus improved.

[0165] Preferably, all the airflow measurement sensors 4a, 4b, 4c are assembled on the modular printed circuit board 46 removably connected to the electronic board 6.

[0166] The assembly method of the measuring device 1 in the three-sensor embodiment is illustrated in Figures 10 to 15.

[0167] With reference to [Fig. 11], during an assembly step Sal, a plurality of incandescent bulbs are assembled on the printed circuit board 46. Each incandescent bulb includes the protective bulb 40 covering the metal filament 41, which is intended to become the sensing element of the flux measurement sensor 4a, 4b, 4c. In other words, the incandescent bulbs are mounted on the modular printed circuit board 46. The glass protective bulb 40 is designed to protect the metal filament 41 and optionally contain a suitable gas.

[0168] The printed circuit board 46 includes, for each airflow measurement sensor 4a, 4b, 4c, two through-holes configured for the passage of the electrodes 45 of the airflow measurement sensor 4a, 4b, 4c. Soldering or bonding can be performed to ensure the electrical connection between the electrodes 45 and the printed circuit board 46.

[0169] Preferably, the airflow measurement sensor 4a, 4b can be mounted on the printed circuit board 46 using a sealing gasket 47. Such a sealing gasket 47 prevents coupling problems and air leakage outside the air passage channel Ca, Cb, Ce where the airflow measurement sensor is located. The sealing gasket 47 also raises the sensor body 44 and ensures that the metal filament 41 of the airflow measurement sensor 4a, 4b is correctly positioned in the corresponding air passage channel Ca, Cb.

[0170] With reference to [Fig. 12], during a removal step Sa2, the protective bulb 40 of each incandescent bulb is removed so as to obtain the plurality of airflow measurement sensors 4a, 4b, 4c.

[0171] Preferably, all the protective bulbs are cut simultaneously by a device 9. The device 9 comprises two members 91, 92 having a shape complementary to the assembled airflow measuring sensors 4a, 4b, 4c, so as to remove, after cutting, each protective bulb 40 without risk of shattering. After cutting, the metal filaments 41a, 41b, 41c of the airflow measuring sensors 4a, 4b, 4c are free and can be traversed by an airflow to allow estimation of the representative quantity.

[0172] With reference to [Fig. 13], during an optional folding step Sa3, an airflow measurement sensor 4c is folded. In the embodiment of the measuring device 1 shown, the oral airflow measurement sensor 4c is folded. Indeed, the third air passage channel Ce extends along the oral flow direction X, substantially orthogonal to the nasal flow direction Z. Thus, the folding allows the oral airflow measurement sensor 4c to be oriented so that its metal filament 41c is traversed by the oral airflow after assembly of the printed circuit board 46 onto the electronic board 6 of the probe 2.

[0173] With reference to [Fig. 14], the assembly process includes an optional protection step Sa4, during which a removable cover 48 is placed on each air flow measurement sensor 4a, 4b, 4c, so as to protect their metal filament 41. This allows the printed circuit board 46 obtained after folding, therefore ready to be assembled on the electronic board 6 of the probe 2, to be stored or moved without risk of damaging the metal filament 41, and thus preserving the integrity of the air flow measurement sensor 4a, 4b, 4c.

[0174] With reference to [Fig. 15], the printed circuit board 46 carrying the plurality of airflow measurement sensors 4a, 4b, 4c can be integrated onto the electronic board 6 of the probe 2 during an integration step Sa5.

[0175] In the illustrated embodiment, the printed circuit board 46 includes mounting holes for receiving mounting studs 82 of the shell 21, so as to hold the printed circuit board securely after integration. The shell 21 defines circular openings leading to the nasal air passage channels Ca, Cb, at which the nasal airflow measurement sensors 4a, 4b are inserted. The shell 21 defines an opening leading to the third air passage channel Ce, at which the oral airflow measurement sensor 40 is inserted.

[0176] The printed circuit board 46 includes a lower face, opposite the face on which the airflow measurement sensors 4 are assembled. The pins 45 of the airflow measurement sensors 4a, 4b open onto the lower face. The lower face features connectors to ensure the electrical connection of the printed circuit 46 to the electronic board 6.

[0177] Method for maintaining airflow measurement sensors 4

[0178] With reference to [Fig. 16] is illustrated a method for maintaining the probe 2. The shell 21 is here formed of a front wall having the third opening 23 and the lateral openings 24a, 24b, and a rear wall having the rear opening 25. The two walls of the shell 21 are removable and are fixed to each other by a screw 81 inserted into a fixing hole 8 of the shell 21. After disassembly of the screw 81, the rear wall can be tilted about an axis of rotation extending in the Y direction, the front wall and the rear wall being connected to each other by hinges.

[0179] The defective modular printed circuit board 46 can then be removed from the shell 21 by sliding it along the mounting studs 82 of the shell 21. A reverse process can be followed to integrate a new printed circuit board 46 into the probe 2.

[0180] The present invention is not limited by the fixing and assembly means described, alternatives such as clipping or screwing may be envisaged.

[0181] The handle 3 may include an indicator light whose illumination is controlled by the microcontroller 61. This allows communication with the user of the measuring device 1, for example to indicate that the battery level is low, or that the maximum operating time of the airflow measuring sensors 4 has been reached, so that the user is prompted to recharge the measuring device 1 or to carry out a maintenance operation according to the procedure detailed above.

[0182] Assembling the measuring device 1

[0183] The removable probe 2 can be assembled onto one end of the handle 3, for example by means of cooperating fastening means, typically a screw or clip system. The fastening means are reversible to allow the removable probe 2 to be removed from the handle 3.

[0184] In one embodiment, the measuring device 1 is electrically powered via the processing unit 100 located outside the measuring device 1 by means of a power cable. Preferably, the handle 3 includes a battery for powering the airflow measurement sensors 4a, 4b, 4c, the microphones 5a, 5b, 5c, and the electronic board 6. Typically, the battery can be a lithium-ion battery. Preferably, the battery is rechargeable and can perform fast charging cycles. The battery can have a capacity greater than 1000 mAh to provide sufficient autonomy for the measuring device 1.

[0185] Thus, the probe 2 includes a first connector 7 and the handle 3 includes a second connector configured to be electrically connected to the first connector 7, when the probe 2 is assembled on the handle 3. The first connector 7 is, for example, of the male type, and the second connector of the female type.

[0186] In one embodiment, the interface between the handle 3 and the probe 2 is digital (and not analog). This allows for an almost unlimited number of different types of sensors to be connected to the probe 2. The digital interface also offers the advantage of being immune to ambient noise (particularly electromagnetic noise). The connector of the digital interface is, for example, a snap-in type software component that allows for hot-swapping. Such an interface is protected against electrostatic (transient) phenomena and has no voltage across the connectors when the probe 2 and the handle 3 are separated.

[0187] The cooperation of the connectors with each other can contribute to locking the probe 2 on the handle 3 in the operating position of the measuring device 1.

[0188] Use of measuring device 1 for measuring respirations

[0189] The electronic board of the measuring device 1 can be connected to the unit of processing 100 of the measurement signal. For example, the handle 3 includes, at one lower end, an interface for connection to the processing unit 100. The interface is, for example, a USB or USB-C type port, so as to connect a USB or USB-C cable connected to the processing unit 100.

[0190] Preferably, the measuring device 1 includes wireless communication means for communicating with the processing unit 100. For example, the electronic board 6 includes a Bluetooth module configured to exchange information via Bluetooth (trademark) with the processing unit 100. Alternatively or complementarily, the measuring device 1 includes a Wi-Fi module (trademark) configured to exchange information via Wi-Fi (trademark) with the processing unit 100.

[0191] The processing unit 100 advantageously includes a human-machine interface, for example a screen 101. The screen 101 may be touch-sensitive. The processing unit 100 may include buttons or sliders 102 for selecting the signals to be displayed or for changing the display on the screen 101. This allows visualization of the time evolution of the measurement signals from the airflow measurement sensors 4a, 4b, 4c and the microphones 5a, 5b, 5c, as illustrated in [Fig. 8].

[0192] The measuring device 1 according to the invention thus allows the practitioner to perform a simultaneous and comparative study of nasal and / or oral airflow. In particular, it allows for a clinical assessment of upper air ventilation and the functional capacities of the soft palate. The analysis of the measurement signals 104 from the airflow measurement sensors 4a, 4b, 4c, and the measurement signals 105 from the microphones 5a, 5b, 5c allows the practitioner to evaluate velar insufficiency and assess nasal leaks, and to propose respiratory and phonation rehabilitation methods adapted to the user, such as a patient.

[0193] Observation by the practitioner (e.g., orthodontist or speech therapist) of the time curves of the measurement signals on the processing unit 100 allows for a diagnosis of the user's breathing. The measuring device 1 also allows for the analysis of the user's mouth and / or nasal breathing when speaking. The detection by the measuring device 1 of nasal airflow during the repetition of phonemes, words, or phrases spoken by the user objectively demonstrates the phenomenon of nasal air leakage and quantifies its severity.

[0194] Thanks to the sensitivity of the nasal airflow measurement sensors 4a, 4b, the opening and closing movements of the velopharyngeal sphincter are clearly visible on the curves displayed on the processing unit 100, objectifying the muscular potential of the sphincter and allowing verification of its rigidity, its possibilities of complete opening and closing, its speed of execution of opening and closing movements, or its stability.

[0195] The present invention is not limited to the embodiments shown. The embodiments and examples described may be combined with each other in any technically feasible combination or selected independently of each other.

Claims

1. Demands A device (1) for measuring the oral and nasal respirations of a user, comprising a probe (2) internally delimiting a first air passage channel (Ca) including a first opening (22a), the first opening (22a) being suitable for positioning under a first nostril of the user, a second air passage channel (Cb) including a second opening (22b), the second opening (22b) being suitable for positioning under a second nostril of the user, and a third air passage channel (Ce) including a third opening (23), the third opening (23) being suitable for positioning opposite the user's mouth, the probe (2) including an electronic board (6) including a microcontroller (61) and a plurality of measurement circuits, each measurement circuit being suitable for an associated air passage channel (Ca, Cb, Ce),the measuring device (1) being characterized in that each measuring circuit comprises an airflow measuring sensor (4a, 4b, 4c) arranged in the associated air passage channel (Ca, Cb, Ce) and comprising a metallic filament (41a), around which an airflow is suitable for flowing in the associated air passage channel (Ca, Cb, Ce), each airflow measuring sensor (4a, 4b, 4c) being suitable for being powered by an electric current when the user breathes through the device (1), and an amplifier (62) configured to provide at output an amplified voltage (Vo) from a reference voltage (Vref) and a voltage across the metallic filament (41) of the powered airflow measuring sensor (4a, 4b, 4c), the microcontroller (61) being further configured to:, - measure the amplified voltage (Vo) at the output of the amplifier (62), - calculate the amplitude of the amplified voltage measurement (Vo), - modify the reference voltage (Vref) according to the amplified voltage measurement (Vo), so as to maintain a constant amplitude, and - estimate a quantity representative of the airflow flowing in the air passage channel (Ca, Cb, Ce) associated with the airflow measurement sensor (4a, 4b, 4c) powered from the amplified voltage measurement (Vo).

2. Measuring device (1) according to claim 1, wherein the signal amplitude is calculated according to a cycle comprising one period, the period depending on the estimate of the representative quantity.

3. Measuring device (1) according to any one of claims 1 and 2, wherein each measuring circuit further comprises a current source (63) configured to deliver an electric current so as to power the metal filament (41a, 41b, 41c) of the airflow measuring sensor (4a, 4b, 4c), the delivered electric current having a constant intensity of less than 100mA.

4. Measuring device (1) according to claim 3, wherein the microcontroller (61) is further configured to modify an intensity of the electric current delivered from the amplified voltage measurement (Vo).

5. Measuring device (1) according to any one of claims 1 to 4, wherein the microcontroller (61) is further configured to control a preheating of the metal filament (41) of at least one airflow measurement sensor (4a, 4b, 4c) for a predetermined time before measuring the amplified voltage (Vo).

6. Measuring device (1) according to any one of claims 1 to 5, wherein the probe (2) further comprises a temperature sensor (66) configured to provide a temperature measurement to the microcontroller (61).

7. Measuring device (1) according to any one of claims 1 to 6, wherein the microcontroller (61) further comprises a clock configured to measure a power-up time of the metal filament (41) of the powered airflow measuring sensor (4a, 4b, 4c), and wherein the microcontroller (61) is configured to emit a maintenance signal when the measured power-up time exceeds a maximum usage time.

8. Measuring apparatus (1) according to any one of claims 1 to 7, wherein the airflow measuring sensors (4a, 4b, 4c) are

9.

10. assembled on a modular printed circuit board (46) connected to the electronic board (6) in a removable manner. A method for controlling a measurement circuit of a measuring device (1) according to any one of claims 1 to 8, implemented by a microcontroller (61), the measurement circuit comprising an amplifier (62) configured to provide an amplified output voltage (Vo) from a reference voltage (Vref) and a voltage across a metallic filament (41) of an active sensor (4), the active sensor (4) being arranged in an air passage channel (Ca, Cb, Ce), the control method comprising the steps of: - measurement of an amplified voltage (Vo) at the output of the amplifier (62), - Calculation of a signal amplitude from the amplified voltage measurement (Vo), - modification of the reference voltage (Vref) according to the amplified voltage measurement (Vo), so as to maintain a constant signal amplitude, - estimation of a quantity representative of an air flow in the air passage channel (Ca, Cb, Ce) from the measurement of amplified voltage (Vo). Method for assembling a measuring device (1) according to any one of claims 1 to 8, comprising the following steps: - assembly (Sal) of a plurality of incandescent bulbs on a printed circuit board (46), each incandescent bulb comprising a protective bulb (40) covering a metallic filament (41), - removal (Sa2) of the protective bulb (40) of each incandescent bulb so as to obtain a plurality of airflow measurement sensors (4a, 4b, 4c), - optionally, folding (Sa3) at least one airflow measurement sensor (4c), and - integration (Sa5) of the printed circuit (46) carrying the plurality of air flow measurement sensors (4a, 4b, 4c) on an electronic card (6) of the probe (2).

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