Apparatus and method for characterizing dental ultrasonic probes

Abstract

The present invention provides an apparatus and method for characterizing an ultrasonic probe having a closed acoustic chamber, the ultrasonic probe having an acoustic window and enclosing a transducer configured to emit an ultrasonic signal and receive the reflected ultrasonic signal through the acoustic window. The ultrasonic signal is emitted in multiple directions, and for each direction, the characteristics of the acoustic chamber are determined from the received ultrasonic signal after receiving the corresponding ultrasonic signal reflected by a portion of the acoustic chamber.

Description

Technical Field

[0001] The present invention relates to the field of oral measurement methods and devices for the healthcare industry. Specifically, the present invention relates to, but is not limited to only this, characterizing an ultrasonic probe, for example, to improve its calibration and / or to identify degradation of its performance.

Background Art

[0002] Ultrasonic imaging has been adapted for use in the oral cavity in a plurality of embodiments and has been found to be particularly useful for tasks such as measuring the depth of periodontal pockets. For example, conditions such as gingivitis can be detected by sensing the acoustic response of tissues.

[0003] Since ultrasonic imaging does not emit ionizing radiation, it is inherently safer than methods involving ionization and allows for repeated tests if necessary. Ultrasonic imaging can be used to replace or complement various types of X-ray imaging (cone beam computed tomography or CBCT, panoramic X-ray imaging or intraoral X-ray imaging), magnetic resonance imaging (MRI) or nuclear medicine.

[0004] In ultrasonic imaging, high-frequency sound waves, usually between 1 and 100 MHz, can be used. High frequencies attenuate more than low frequencies at a certain distance but have higher resolution at short distances, so high frequencies are mainly suitable for imaging surface structures, for example, in dermatological or dental imaging. For example, high-frequency sound waves may preferably be between 10 and 50 MHz for the examination of periodontal pockets. Conversely, low frequencies are suitable for imaging the deepest structures of the body. Furthermore, the resolution of the image also improves as the frequency of the wave increases.

[0005] An ultrasonic imaging device generally comprises one or more transducers that act as an ultrasonic beam emitter and / or ultrasonic beam receivers for receiving echoes from the emitted signal. In addition, the ultrasonic imaging device may include various processing and display units used to generate and present images from the acquired signal. The ultrasonic beam emitter generates an ultrasonic signal from an electrical signal, and conversely, the ultrasonic receiver generates an electrical pulse from a mechanical ultrasonic signal.

[0006] When an object lies within the path of the emitted ultrasonic signal, it returns a portion of the ultrasonic energy to the transducer, which generates an electrical signal indicating the detected structure. The transducer can be of various types, including single-element transducers or multi-element transducers (annular, linear, two-dimensional arrays, etc.). Furthermore, when multi-element transducers are used, the emission of the ultrasonic signal can be delayed to enable adaptive focusing. Electronically adaptive focusing allows for increased resolution depending on the depth of the body structure being imaged. This focusing also increases the sensitivity of the transducer, thereby improving the contrast of the image.

[0007] To explore various areas of a patient's mouth using a small ultrasound probe, the transducer may be movable within an acoustic chamber. Ultrasound signals are emitted in different directions and / or positions, using the transducer's reference position. By sampling the reflected ultrasound signals, an image representing the explored area of ​​the patient's mouth can be generated. The transducer's reference position is generally determined by a sensor, which may be associated with the transducer itself or a motor controlling the transducer's movement. Such sensors present disadvantages in terms of cost and system miniaturization.

[0008] In addition, using the sensor requires calibration, which aims to associate the acquisition window with a specified position on the transducer (or more generally, the motor that controls the movement of the transducer). However, calibration is time-consuming and may need to be performed many times during the product's lifespan. In fact, depending on the operating conditions (e.g., temperature and pressure), the system may experience positional discrepancies between the actual positions of the sensor and the transducer. Furthermore, mechanical assembly tolerances and the manufacturing of the transducer may result in misalignment between the active surface of the transducer and the transducer housing.

[0009] Therefore, there is a need for improvements to enhance calibration and identify probe degradation in detail. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] U.S. Patent Application Publication No. 2016 / 131746 [Patent Document 2] U.S. Patent Application Publication No. 2018 / 153517 [Patent Document 3] U.S. Patent Application Publication No. 2013 / 194891 [Patent Document 4] International Publication No. 2020 / 148406 [Overview of the Initiative] [Means for solving the problem]

[0011] This invention has been devised to address one or more of the aforementioned concerns.

[0012] In this regard, apparatus and methods for characterizing dental ultrasonic probes are provided.

[0013] According to one aspect of the present invention, a method for characterizing an ultrasonic probe comprising a closed acoustic chamber, wherein the acoustic chamber has an acoustic window and encloses a transducer configured to emit an ultrasonic signal and receive the reflected ultrasonic signal through the acoustic window, and the method is The process involves emitting ultrasonic signals in multiple directions and receiving the corresponding ultrasonic signals reflected by a portion of the acoustic chamber in each direction. Determining the characteristics of the acoustic chamber from the received ultrasonic signal and A method including this is provided.

[0014] The method according to the present invention makes it possible to obtain knowledge of the characteristics of an ultrasonic probe that can be used to improve the calibration of the ultrasonic probe and / or to identify the degradation of the performance of the ultrasonic probe.

[0015] In one embodiment, the ultrasonic signal is reflected by the inner surface of the acoustic chamber, the outer surface of the acoustic chamber, and / or by internal members of the acoustic chamber located between the inner and outer surfaces of the acoustic chamber or on one of the inner and outer surfaces of the acoustic chamber.

[0016] In one embodiment, the determined characteristics of the acoustic chamber include the characteristics of the acoustic window.

[0017] In one embodiment, the characteristics of the acoustic window portion are determined by at least one of the following: the thickness of the acoustic window portion being different from the thickness of the rest of the acoustic chamber; the acoustic impedance of the acoustic window portion being different from the acoustic impedance of the rest of the acoustic chamber; a predetermined covering of the acoustic window portion; the frame of the acoustic window portion; and / or a specific curvature of at least a portion of the acoustic window portion.

[0018] In one embodiment, the above method further includes determining the acquisition window portion among the acoustic window portions.

[0019] In one embodiment, the method further includes determining at least one of the length, width, and orientation of the acquisition window portion with respect to a reference position of the transducer.

[0020] In one embodiment, the determined characteristics of the acoustic window portion include the distance or signal time delay between the active surface of the transducer and a portion of the inner and / or outer surface of the acoustic chamber.

[0021] In one embodiment, the determined characteristics include those indicating that the material is heterogeneous between a portion of the inner surface of the acoustic chamber and the active surface of the transducer.

[0022] In one embodiment, the above method further includes determining whether an ultrasonic probe can be used based on the characteristics of the material heterogeneity.

[0023] In one embodiment, the above method is to estimate the intensity of the received reflected ultrasonic signal, wherein the reflected ultrasonic signal is reflected by the inner surface of the acoustic chamber or an internal member of the acoustic chamber, and further includes comparing the estimated intensity with a built-in reference intensity.

[0024] In one embodiment, the above method further includes comparing the difference between the intensities with a threshold value.

[0025] In one embodiment, the transducer is movable within the acoustic chamber.

[0026] In one embodiment, the transducer is a one-dimensional or two-dimensional array including a selectable set of transducers selected according to the determined characteristics of the acoustic window portion.

[0027] In one embodiment, the above method further includes modifying the settings of the ultrasonic probe according to the characteristics of the acoustic chamber.

[0028] In one embodiment, the above method further includes pre-warning the user or practitioner of the ultrasonic probe that the characteristics of the ultrasonic probe have deteriorated according to the characteristics of the acoustic chamber.

[0029] According to one aspect of the present invention, an ultrasonic probe is provided comprising a closed acoustic chamber, the acoustic chamber having an acoustic window portion and enclosing a transducer configured to emit an ultrasonic signal and receive the reflected ultrasonic signal through a portion of the acoustic window portion, and the ultrasonic probe further comprising a processing unit configured to perform each of the steps of the above-described method.

[0030] The ultrasonic probe according to the present invention makes it possible to obtain knowledge of the characteristics of an ultrasonic probe that can be used to improve the calibration of the ultrasonic probe and / or to identify degradation in the performance of the ultrasonic probe.

[0031] The ultrasonic probe may be a small intraoral ultrasonic probe, for example, a small intraoral ultrasonic probe used to measure the depth of periodontal pockets.

[0032] At least some parts of the method according to the present invention can be implemented within a processing unit. Accordingly, the present invention may take the form of a hardware embodiment as a whole, a software embodiment as a whole (including firmware, resident software, microcode, etc.), or an embodiment that combines software and hardware embodiments, all of which may generally be referred to herein as “circuit,” “module,” or “system.” Furthermore, the present invention may take the form of a computer program product materialized in any tangible medium of representation having computer-usable program code materialized in the medium.

[0033] Since the present invention can be implemented in software, it can be materialized as computer-readable code for supply to a programmable device on any suitable transmission medium. Tangible transmission media may include storage media such as floppy disks, CD-ROMs, DVDs, hard disk drives, magnetic tape devices, or solid-state memory devices. Temporary transmission media may include signals such as electrical signals, electronic signals, optical signals, acoustic signals, magnetic signals, or electromagnetic signals, such as microwave or radio wave signals.

[0034] Hereinafter, embodiments of the present invention will be described only as examples, with reference to the following drawings. [Brief explanation of the drawing]

[0035] [Figure 1] This is a perspective view of an example of a wireless, handheld intraoral ultrasonic device according to several embodiments of the present invention. [Figure 2] This is a schematic cross-sectional view of an acoustic chamber containing a vibrating transducer, perpendicular to the transducer's axis of rotation. [Figure 3] This is a diagram illustrating an example of transducer movement for estimating the characteristics of an ultrasonic probe. [Figure 4] This diagram shows an example of the steps in an automated diagnostic method for estimating the characteristics of an ultrasound probe. [Figure 5] This is an example of an image of a portion of the inner surface of the transducer housing, generated during an automated diagnostic process, which is used to determine the position of the acquisition window. [Figure 6] This is an example of an image of a portion of the inner surface of a transducer housing, generated during an automated diagnostic process used to determine anomalies in the acoustic path. [Figure 7] This is an example of an image of a portion of the inner surface of the transducer housing, generated during an automated diagnostic process, used to improve the settings of an ultrasound probe. [Figure 8]This figure shows an example of a reflected ultrasonic signal measured during an automated diagnostic procedure used to monitor the acoustic properties of the acoustic chamber of an ultrasonic probe. [Figure 9] This is a schematic block diagram of a processing device for carrying out one or more embodiments of the present invention. [Modes for carrying out the invention]

[0036] The following is a detailed description of specific embodiments of the present invention, with references to the drawings, where the same reference numerals identify the same elements of the structure in each of the figures.

[0037] In the following drawings and text, similar components are designated by the same reference numerals, and similar descriptions of previously described components and their arrangement or interaction are omitted. The terms "first," "second," etc., when used, do not indicate any sequential or preferential relationship, and unless otherwise specified, may simply be used to more clearly distinguish one element from another.

[0038] In the context of this disclosure, the terms “operator” and “user” are considered equivalent and refer to a practicing physician, technician, or any other person operating an ultrasound probe.

[0039] In the context of this disclosure, the phrase “by signaling communication” indicates that two or more devices and / or components are capable of communicating with each other via signals traveling along some type of signaling path. The signaling communication may be wired or wireless. The signals may be communication, power, data, or energy signals. The signaling path may include physical, electrical, magnetic, electromagnetic, optical, wired, and / or wireless connections between a first device and / or component and a second device and / or component. The signaling path may include additional devices and / or components between the first device and / or component and the second device and / or component.

[0040] In the context of this disclosure, the term "internal component" refers to a phantom having specific acoustic properties, volume, dimensions, and geometry.

[0041] The term "subject" refers to the gums and other soft tissues in the oral cavity (and, in some cases, the surface of the teeth) of the patient being imaged.

[0042] According to some embodiments, images generated from data acquired by the transducer of an ultrasound probe during automated diagnostic procedures or when using an ultrasound probe are used to obtain characteristics of the ultrasound probe. These characteristics can be used to calibrate the ultrasound probe, adjust settings, and / or identify degradation of the ultrasound probe's performance. For example, such characteristics include: - The position or orientation of the acquisition window (e.g., angle, position, length, etc.) - The acoustic properties of the components of the acoustic chamber equipped with transducers (e.g., the position, dimensions, and / or geometry of a particular phantom inserted into the housing or placed on one of the inner and outer surfaces of the acoustic chamber, as well as the sensitivity, impedance, and / or attenuation of the acoustic chamber, etc.), - The presence of anomalies in the ultrasonic pathway (e.g., the presence of air bubbles in the liquid or gel used to fill the acoustic chamber), - Time delay (or distance) between the transducer and the housing and It includes.

[0043] The images used to obtain the characteristics of the ultrasound probe are obtained from data acquired, for example, while moving the transducer during automated diagnostic procedures or while acquiring soft tissue information (for example, by continuously measuring the inner surface of the acoustic chamber relative to the user). The transducer may move linearly along a predetermined path, rotate completely around an axis (without angular vibration, for example, with electrical connection provided by a current collector ring) or partially rotate (with angular vibration), or move in any other predetermined manner. Alternatively, a stationary arrangement of transducers may be used.

[0044] Figure 1 is a perspective view of an example of a wireless handheld intraoral ultrasound device 100, also referred to as an ultrasonic handpiece, handheld probe, ultrasonic probe, or probe, according to several embodiments of the present invention. As shown in the figure, the wireless handheld intraoral ultrasound device comprises a probe body 105 and a probe head 110, also called a transducer assembly.

[0045] In this example, the probe body 105 comprises a housing 115 capable of housing a battery and electronic components (not shown), for example, a processing device configured to perform the steps described with reference to Figures 4-8. In addition, the probe body 105 comprises an interface that allows the user to obtain information from the probe and to give commands to the probe. For example, the probe body 105 may comprise one or more buttons 120, a display 125, a color LED (light-emitting device) 130 (visible or visible through the housing when it is installed below the housing and illuminated), a buzzer, an inertial measurement unit (not shown), and / or a tactile feedback vibrator (not shown). The inertial measurement unit makes it possible to detect user actions such as taps or double taps that may be used to interact with the ultrasonic probe. Using the buttons 120 and short clicks, long clicks and / or repeated clicks, and / or the inertial measurement unit, the user can browse menus to obtain information from the probe and / or give commands to the probe. The probe body 105 also includes a mounting assembly 135 that allows the probe head to be attached to the probe body 105 (located under a cover which can be held in place by an elastic strap and is therefore invisible).

[0046] As shown in the figure, the probe head 110 has a mounting assembly 145 at one end (working with the mounting assembly 135 and therefore installed under the same cover), thereby allowing the probe head 110 to be mounted on the probe body, and a support arm 140 having a transducer chamber 150 at the other end (also referred to as an acoustic chamber or transducer housing). The transducer chamber 150 houses one or more transducers that are stationary or moving within the acoustic chamber, for example, vibrating, to emit ultrasound toward a target and measure echoes. The transducers are wirelessly connected to the electronic components of the probe body, or are connected to these electronic components by wires, for example, coaxially, but are not limited to this. In some embodiments, the transducers are mounted at one end of a shaft (not shown) that extends longitudinally through the support arm. A cam may be mounted at the other end of the shaft to control the movement of the transducers using a motor installed in the probe body. In addition, the shaft may be hollow to allow a coaxial cable connecting the transducer to the electronic components of the probe body to pass through.

[0047] As described above, the acoustic chamber may house one or more transducers. These transducers may have different properties. For example, one or more transducers may be stationary or movable, the transducers may be in a linear one-dimensional or two-dimensional array of transducers or in a ring-shaped array of transducers, or the transducers may use the same transducer to emit and receive ultrasonic signals, or different transducers may be used for emitting and receiving ultrasonic signals, etc. For clarity, in the following description, one or more transducers will be collectively referred to as transducers.

[0048] In the illustrated example, the probe head 110 is a closed probe head having a transducer immersed in a sealed acoustic chamber filled with an internal acoustic coupling material such as a liquid or gel. In addition, the acoustic chamber may include a solid coupling material that can be used, for example, to control the acoustic gradient of the acoustic chamber.

[0049] The ultrasonic probe 100 may be used for clinical applications in periodontology, implantology, restorative dentistry, oral dermatology, and other fields.

[0050] In particular, the ultrasound probe 100 makes it possible to receive signals that allow images of the oral soft tissue to be obtained, and these images and / or signals allow for the acquisition of images of the oral soft tissue. - To detect morphological abnormalities such as gingival abscesses or cancer, and / or - Perform oral measurements such as measuring the depth of periodontal pockets, the amount of gingival margin around the periodontal area, the level of adhesion in the periodontal area, the width of abscesses, and the distance between anatomical markers. This makes it possible to perform, for example, one or more of the works described in International Publication No. 2020 / 148406, which is incorporated herein by reference in its entirety.

[0051] It has been observed that these tasks can be performed either in real time during the acquisition process, or during post-test work once the image dataset and / or raw data have been acquired.

[0052] According to some embodiments, imaging a portion of the inner surface of a transducer housing (or acoustic chamber) having one or more acoustic windows, and identifying the acoustic windows in the generated image, is used to determine the acquisition window among the acoustic windows, thereby identifying a precise reference position of the transducer relative to the acoustic windows and enabling reliable measurements. The acoustic windows are observed to be part of a transducer housing designed to allow ultrasonic signals to pass through (i.e., reflection of ultrasonic signals at the acoustic windows is reduced as much as possible). For an acoustic window to be detectable, its thickness may differ from the thickness of the rest of the housing, for example, one-fifth the thickness of the housing. In addition, or alternatively, the acoustic impedance of the acoustic window may differ from the acoustic impedance of the rest of the housing (e.g., different material). Furthermore, or alternatively, the acoustic window may be detectable according to a specific curvature of the acoustic window or its frame. A detectable frame or specific covering surrounding the acoustic window may also be used. Alternatively, the material used to form the acoustic chamber may be embedded with a predetermined acoustically detectable element that can be used as a reference for position and / or as a reference for measuring the intensity of the reflected ultrasonic signal. Such an acoustically detectable element behaves like a phantom used to calibrate an ultrasonic probe.

[0053] By measuring the ultrasonic signal reflected off the inner surface of the acoustic chamber, the outer surface of the acoustic chamber, and / or the acoustically detectable elements of the acoustic chamber (preferably by holding the probe away from any reflective surfaces), it is possible to identify the acoustic window, determine the distance (or time delay) between the acoustic window and the active surface of the transducer, and determine the quality of acoustic transmission of the material between the acoustic window and the active surface of the transducer. These findings can be used to determine several properties of the ultrasonic probe. Such properties may also be used to calibrate the ultrasonic probe (e.g., define the acquisition window and identify the position of the transducer corresponding to the boundary of the acquisition window), identify any degradation of its performance, adjust several parameters of the ultrasonic probe mechanically or non-mechanically, for example, by adjusting the gain of the acoustic probe to compensate for the acoustic attenuation of worn gel, or by calibrating a set of ultrasonic probes to ensure that the ultrasonic probes share the same properties.

[0054] Figure 2 schematically shows a cross-sectional view of an acoustic chamber containing a vibrating transducer, which is perpendicular to the transducer's axis of rotation (which may be parallel to the longitudinal axis of the ultrasonic probe).

[0055] For clarity, only the housing 200 of the acoustic chamber is shown. In the illustrated example, the acoustic chamber includes one acoustic window 205 whose acoustic properties differ from those of the rest of the housing, for example, having a thickness less than that of the rest of the housing.

[0056] A transducer (not shown) can vibrate around the axis 210 within an angular sector 215 defined by angles A and B (for example, at the center, -38° to 38° with respect to the axis 220 which is perpendicular to the acoustic window), emitting an ultrasonic signal and receiving a corresponding reflected ultrasonic signal. Such vibrational motion may be caused by a rotating mechanical crank having an eccentric or crankpin cooperating with a cam groove of a cam firmly fastened to the transducer, as shown in Figure 3b.

[0057] To improve the accuracy of measurements performed by the ultrasound probe when examining a patient, and to reduce the complexity of processing the acquired data, it has been observed that the sector 215 is swept twice, as shown in Figure 3a, and the reflected ultrasound signal is measured in only one direction. However, according to some embodiments of the present invention, the sector 215 is swept twice, and the reflected ultrasound signal is measured in both directions, as shown in Figures 5, 6, and 7. Furthermore, according to some specific embodiments, the sector 215 is swept twice, and the reflected ultrasound signal is measured in both directions, with the measurement obtained in one direction used for calibration or setting purposes, and the measurement obtained in the other direction used to image the patient's soft tissue.

[0058] These measurements allow for the estimation of the characteristics of the ultrasonic probe, which are used to calibrate the ultrasonic probe, update settings, and / or identify degradation in the performance of the ultrasonic probe. According to some embodiments, calibration aims to determine the reference position of the transducer and / or estimate the position of the acquisition window. For example, the acquisition window 225 (shown by thick curves), defined by angular positions A' and B', may be determined within a sector 215 where measurements can be taken, and the acquisition window represents a trade-off between measurement range and measurement quality.

[0059] According to other embodiments, the transducer is either translationally movable or stationary and is configured to emit and receive ultrasonic signals through the surface of the acoustic window, preferably the entire surface of the acoustic window.

[0060] Figure 3 shows an example of transducer movement for estimating the characteristics of an ultrasonic probe.

[0061] As shown in Figure 3a, the transducer moves from angular position A to angular position B (phase 300) while performing a high-resolution measurement, then moves faster from angular position B to angular position A (phase 305) while performing a low-resolution measurement or without performing any measurement, then moves again slower from angular position A to angular position B (phase 310) while performing a high-resolution measurement, and finally moves faster from angular position B to angular position A (phase 315) while performing a low-resolution measurement or without performing any measurement. No measurements are performed between phases 305 and 315, when the ultrasound probe is used to examine the patient, although it is preferable that measurements are performed between these phases during the automated diagnostic procedure. It is also possible to perform high-resolution measurements between phases 300 and 310 to examine the patient, and low-resolution measurements between phases 305 and 315 for calibration or setting purposes. In such cases, the measurements performed between phases 305 and / or 315 are not visible to the user. In addition, measurements taken during phases 305 and / or 315 can be used to improve the accuracy of measurements taken during phases 300 and / or 310 by mechanically adjusting several parameters of the probe.

[0062] Figure 3b shows the angular position of the transducer relative to the angular position of the motor's output shaft. When the motor's output shaft rotates, the transducer vibrates. The angular position of the transducer is shown on the vertical axis (y-axis), while the angular position of the motor is provided on the horizontal axis (x-axis).

[0063] One aspect of the automated diagnostic method is to identify the angular position of the transducer relative to the acquisition window (e.g., to identify the angular position of the transducer corresponding to angular positions A' and / or B'), which can be easily specified (e.g., using a stepping motor, i.e., a motor whose position can be controlled to move and hold one of several steps without any position sensors for feedback).

[0064] Figure 4 shows an example of the steps in an automated diagnostic method for estimating the characteristics of an ultrasound probe.

[0065] As illustrated, the first step of this method is to start the movement of the transducer (step 400), for example, by starting a motor that vibrates the transducer between two angular positions such as angular positions A and B in Figures 2 and 3.

[0066] Next, an ultrasonic (US) signal is emitted (step 405), and the reflected ultrasonic signal is received and sampled (step 410). Raw data representing the time it takes for the emitted signal to reflect and be received can be calculated and filtered (step 415). For example, filtering the raw data may include ignoring raw data related to ultrasonic signals with emission-to-reception times that are below a first threshold and / or above a second threshold according to the transient window in question, i.e., raw data representing reflecting surfaces that are too close and / or too far from the active surface of the transducer. According to some embodiments, raw data related to ultrasonic signals with emission-to-reception times that are above a second threshold (i.e., raw data representing reflecting surfaces that are too far from the active surface of the transducer) is ignored. For example, the second threshold can be set in the form of a distance of 1 cm between the active surface of the transducer and the reflecting surface.

[0067] In parallel, the position of the transducer or the output shaft of the motor that vibrates the transducer when emitting and receiving ultrasonic signals is obtained (step 420).

[0068] This position and (possibly filtered) raw data are stored (step 425).

[0069] Next, a test is performed to determine whether the angular sector to be swept has been swept as required, for example, twice in a given direction (step 425). Steps 405-425 are repeated until all measurements have been taken.

[0070] Once all measurements are complete, an image is generated from the stored raw data, for example, using a known method (step 435). An example of a generated image is shown in Figure 5.

[0071] Next, the generated images and / or raw data are analyzed (step 440) to determine several characteristics of the ultrasonic probe, such as anomalies in the acoustic path between the acoustic window and the transducer and its housing.

[0072] The analysis of images generated to detect and pinpoint the acquisition window is described with reference to Figure 5. The analysis of images generated to detect the presence of anomalies such as bubbles in the acoustic path is described with reference to Figure 6, and the analysis of images generated to improve the settings of the ultrasonic probe is described with reference to Figure 7. The analysis of ultrasonic signals to monitor acoustic properties is described with reference to Figure 8.

[0073] After analyzing the generated images and / or raw data, the calibration of the ultrasound probe parameters can be set or updated (step 445). For example, the relative position of the transducer in the acquisition window or the output shaft of the motor that vibrates the transducer can be set or updated. In addition, several instructions can be given to the user or practitioner to warn them in advance about the need to replace ultrasound probe components such as the probe head if, for example, the liquid or gel filling the acoustic chamber is no longer effective.

[0074] The steps shown in Figure 4 can be performed on demand, for example, on the basis of a user's request, a remote device's request (for example, a request received from the supplier / manufacturer of the ultrasonic probe (or other appropriate party)), or automatically, for example, when starting or activating the ultrasonic probe.

[0075] According to some embodiments, the ultrasonic probe is equipped with a position sensor such that whenever the ultrasonic probe is detected to be in a specific position, or periodically when the ultrasonic probe is detected to be in a specific position, the steps shown in Figure 4 can be performed only at a specific position of the probe, for example, head-up (so that, for example, bubbles can be detected if they are present on the probe head).

[0076] Figure 5 shows an example of a partial image of the inner surface of the transducer housing, generated during an automated diagnostic process used to determine the position of the acquisition window.

[0077] As shown in the diagram, the vertical axis (y-axis) represents the time delay between the emission of an ultrasonic signal and the reception of the corresponding reflected ultrasonic signal, corresponding to the distance between the transducer and the resonating surface, i.e., the distance between the active surface of the transducer and the resonating surface. The horizontal axis (x-axis) represents the time at which the reflected ultrasonic signal, shown on the horizontal axis as a time delay for the corresponding emitted ultrasonic signal, represents the position of the transducer (or the output shaft of the motor that vibrates the transducer).

[0078] Image 500, denoted by reference numeral 500, shows the shape of a portion of the inner surface of the transducer housing (shown four times because the transducer was swept twice). Part 505 of Image 500 shows measurements performed between angular position A and angular position B, while part 510 shows measurements performed between angular position B and angular position A. As is evident from the widths of parts 505 and 510, the transducer moves slower from angular position A to angular position B than from angular position B to angular position A (to improve the angular resolution between angular position A and angular position B).

[0079] For example, by analyzing image 500 using a pattern analysis algorithm applied to the sum of pixel values ​​along the y-axis, it becomes possible to identify a specific pattern representing a particular part of the inner surface of the transducer housing.

[0080] For example, to define the boundary of the acoustic window, it is possible to create a strong acoustic signal shift by utilizing the cover / housing design. In fact, for reflection to occur, acoustic ultrasound needs to strike a flat or slightly inclined surface. Therefore, as soon as the surface inclination becomes too high, the ultrasonic signal will no longer be reflected towards the transducer. Thus, it is possible to adapt the design of the acoustic window to the transducer assembly so that the acoustic window can be easily detected.

[0081] In the case of a single-element transducer or an annular multi-element transducer rotating or vibrating around an axis of rotation, the radius of curvature of the acoustic window can be aligned with the center of the transducer's axis of rotation. In the case of a stationary one-dimensional or two-dimensional linear array of transducers, the acoustic window may conform to the three-dimensional shape of the transducer array (for example, it is planar in the case of a planar transducer array). In the case of a one-dimensional or two-dimensional linear array of transducers rotating or vibrating around an axis of rotation, the radius of curvature of the acoustic window can be aligned with the center of the transducer's axis of rotation in order to obtain a three-dimensional acoustic space.

[0082] For example, the acoustic window can be identified by the shifts in strong acoustic signals, which are denoted by the reference symbols 515, 520, 525, and 530. By combining the shape of the expressed signal (e.g., flat areas) and the width of several specific shapes between these shifts in strong acoustic signals (e.g., the width of the flat areas), an acquisition window 535 located between the shifts in strong acoustic signals 515 and 520, corresponding to a large, substantially flat area, can be defined. By identifying the portion 535 in image 500, the boundaries A' and B' of the acquisition window and their horizontal coordinates can be determined. Using the position of the transducer (or motor that vibrates the transducer) and the horizontal coordinates corresponding to boundaries A' and B' saved in step 420 of Figure 4, the position of the transducer (or motor) where the transducer will begin measuring and the position where the transducer will end measuring can be determined. These angular positions where the measurement begins and ends can be saved as calibration data to be used as acquisition windows when examining a patient.

[0083] Here, if the boundary of the acoustic window area may be defined by a steep slope or corner of the head cover (to utilize the shift or reflection properties of the acoustic beam), it is observed that other solutions exist, such as adding a marker (e.g., a groove), a phantom, or a marker, or modifying the acoustic properties of the acquired window area relative to other parts of the transducer housing, for example, by using a specific structural element, material, or coating.

[0084] If the transducer is a stationary array of transducers, the acquisition window allows you to determine which transducers in the array will become active.

[0085] Figure 6 shows an example of an image of a portion of the inner surface of the transducer housing, generated during an automated diagnostic process used to determine anomalies in the acoustic path.

[0086] Image 600 is similar to Image 500. Image 600 shows the shape of a portion of the inner surface of the transducer housing, corresponding to two sweeps (forward and backward). It is used to detect the presence of defects such as air bubbles, surface damage, wear or deterioration of the internal binder in the acoustic chamber, suspended particles, etc.

[0087] As is evident from the measurements taken between angular positions A' and B' (and between angular positions B' and A'), the bubble is located in the center of the acquisition window, as exemplified by reference numerals 605, 610, 615, and 620.

[0088] Similar to the determination of the acquisition window area, identifying such bubbles may be based on pattern recognition and / or by comparing the actual pattern with a predicted pattern. For example, bubbles can be identified by identifying holes in the image (i.e., since the air in a bubble does not reflect sound waves). The size of the bubble can be determined by measuring the size of the hole. Such a size can be compared to one or more thresholds to determine whether the bubble is negligible, acceptable, or should be considered a significant problem.

[0089] Figure 7 shows an example of a partial image of the inner surface of the transducer housing, generated during an automated diagnostic process, which is used to improve the settings of the ultrasound probe.

[0090] Image 700 is similar to, or identical to, Image 500. Image 700 represents the shape of a portion of the inner surface of the transducer housing, corresponding to two sweeps (forward and backward). It is used to perform several measurements, such as determining the distance or time delay between the active surface of the transducer and the inner and / or outer surface of the transducer housing, as indicated by reference numeral 705. By determining such distances, which may differ between one ultrasound probe and another due to manufacturing reasons or imprecision, it is possible to determine the time delay to be set between exciting the transducer and sampling the reflected signal, thereby avoiding imaging the transducer housing and harmonizing the manufacturing of the transducer (e.g., setting the same view within soft tissue for all probes of a set of probes).

[0091] Figure 8 shows an example of a reflected ultrasonic signal generated during an automated diagnostic procedure used to monitor the acoustic properties of the acoustic chamber of an ultrasonic probe.

[0092] As described above, it is possible to monitor the time-dependent evolution of signals reflected by the inner surface of the transducer housing while imaging the inner surface of the housing itself.

[0093] According to some embodiments, the intensity of the ultrasonic signal reflected by the inner surface of the transducer housing is measured and stored at the time of manufacturing (or at another time) the ultrasonic probe. This intensity may be stored in the memory of the ultrasonic probe and / or in the memory of a nearby local computer / device or a remote server or other data storage device. Then, each time the ultrasonic probe is powered on (or on demand or based on other criteria, e.g., once a month), the intensity of the signal reflected by the inner surface of the transducer housing is measured and compared with the intensity of the reflected signal stored at the time of manufacturing (or at another time) the ultrasonic probe.

[0094] Figure 8 shows a graph of the intensity (y-axis) of the reflected ultrasonic signal over time (x-axis). For example, the reflected ultrasonic signal may have a first peak 805 of intensity corresponding to a first surface of reflection (e.g., the inner surface of the acoustic chamber) and a second peak 810 of intensity corresponding to a second surface of reflection (e.g., the outer surface of the acoustic chamber).

[0095] According to some embodiments, the intensity of the signal reflected by the inner surface of the transducer housing at the time the ultrasonic probe is being tested, and the intensity of the signal reflected by the inner surface of the transducer housing at the time the ultrasonic probe is being manufactured (or at another time), are compared to a threshold.

[0096] Probe head degradation is detected when the absolute difference between the signal intensity reflected by the inner surface of the transducer housing at the time of testing the ultrasonic probe and the signal intensity reflected by the inner surface of the transducer housing at the time of manufacturing the ultrasonic probe (or at another time) exceeds a threshold. Such degradation can be notified to the user of the ultrasonic probe or the person responsible for maintaining the ultrasonic probe, for example, to request the replacement of the probe head.

[0097] For example, such degradation may be due to the wear and tear of internal binders that contribute to the absorption of ultrasonic signals (e.g., liquids or gels used to fill the acoustic chambers), and / or a decrease in the performance of the transducer (a decrease in the intensity of the emitted ultrasonic signal leads to a decrease in the intensity of the reflected signal sampled by the transducer).

[0098] Figure 9 is a schematic block diagram of a processing device for characterizing an ultrasonic probe, specifically described with reference to Figures 4-8, for carrying out one or more embodiments of the present invention.

[0099] Processing device 900 is, - A central processing unit 905, such as a microprocessor, labeled as CPU. - A random access memory 910, which is designated as RAM for storing executable code for the method of an embodiment of the present invention, and registers adapted to record variables and parameters necessary for carrying out a method for training and / or running an automated dental record keeping system according to an embodiment of the present invention, the storage capacity of which the registers can be expanded by an optional RAM connected to an expansion port. - A read-only memory 915 labeled ROM for storing a computer program for carrying out embodiments of the present invention, - A user interface and / or input / output interface 930 that can be used to receive input from the user, display information to the user, and / or receive / transmit data to / from an external device, - A network interface 920 typically connected to a communication network capable of transmitting or receiving digital data to receive / send data to / from a remote device, which may consist of a single network interface or a set of different network interfaces (e.g., wired and wireless interfaces, or various types of wired or wireless interfaces), and under the control of a software application running on the CPU 905, data packets are written to the network interface for transmission or read from the network interface for reception. It is equipped with a communication bus that is connected to it.

[0100] Optionally, the communication bus of computing device 900 can be connected to a hard disk 925, designated as HD, which is used as a hardware accelerator (e.g., an artificial intelligence accelerator module) and / or a mass storage device.

[0101] The executable code can be stored in read-only memory 915, hard disk 925, or a removable digital medium such as a disk. According to a modified example, the code of an embodiment of the program can be received via a communication network through a network interface 920 before execution, in order to be stored in one of the storage means of the computing device 200, such as the hard disk 925.

[0102] The central processing unit 905 is adapted to control and manage the execution of instructions or portions of software code of one or more programs according to embodiments of the present invention, and the instructions are stored in one of the aforementioned storage means. After power is turned on, the CPU 905 is capable of executing instructions from the main RAM memory 910 relating to a software application after the instructions have been loaded, for example, from the ROM 915 or the hard disk 925. When such a software application is executed by the CPU 905, it causes the steps of the algorithm disclosed herein to be performed.

[0103] Any step of the algorithms disclosed herein may be implemented in software by executing a set of instructions or programs on a programmable computing machine such as a PC ("Personal Computer"), laptop computer, tablet computer, smartphone or similar device, DSP ("Digital Signal Processor") or microcontroller, or alternatively in hardware by a machine or dedicated component such as an FPGA ("Field-Programmable Gate Array") or ASIC ("Application-Specific Integrated Circuit").

[0104] Although this disclosure has been described above with reference to several specific embodiments, the present invention is not limited to these specific embodiments, and modifications within the scope of the invention will be obvious to those skilled in the art.

[0105] Many further modifications and variations are described for illustrative purposes only and are not intended to limit the scope of the invention, and will be suggested to those skilled in the art by referring to the exemplary embodiments described herein, defined solely by the appended claims. In particular, different features arising from different embodiments may be interchangeable with each other where appropriate.

[0106] In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude the plural. The mere fact that different features are described in different dependent claims does not mean that combinations of these features cannot be used to their advantage.

Claims

1. A method for characterizing an ultrasonic probe (100) having a closed acoustic chamber, wherein the acoustic chamber has an acoustic window and encloses a transducer configured to emit an ultrasonic signal and receive the reflected ultrasonic signal through the acoustic window, and the method is The system emits ultrasonic signals in multiple directions and receives the corresponding ultrasonic signals reflected by a portion of the acoustic chamber in each direction. The characteristics of the acoustic chamber are determined from the received ultrasonic signal. A method characterized by including the following.

2. A method according to claim 1, characterized in that the ultrasonic signal is reflected by the inner surface of the acoustic chamber, the outer surface of the acoustic chamber, and / or by an internal member of the acoustic chamber located between the inner surface and the outer surface of the acoustic chamber, or installed on one of the inner surface and the outer surface of the acoustic chamber.

3. A method according to claim 1 or 2, characterized in that the determined characteristics of the acoustic chamber include the characteristics of the acoustic window.

4. A method according to claim 3, wherein the characteristics of the acoustic window portion are determined by at least one of the following: the thickness of the acoustic window portion which is different from the thickness of the other portion of the acoustic chamber; the acoustic impedance of the acoustic window portion which is different from the acoustic impedance of the other portion of the acoustic chamber; a predetermined covering of the acoustic window portion; the frame of the acoustic window portion; and / or a specific curvature of at least a part of the acoustic window portion.

5. A method according to claim 3 or 4, further comprising determining the acquisition window portion among the acoustic window portions.

6. A method according to claim 5, further comprising determining at least one of the length, width, and orientation of the acquisition window with respect to a reference position of the transducer.

7. A method according to claim 3 or any one of claims 4 to 6 relating to claim 3, wherein the determined characteristics of the acoustic window portion include a distance or signal time delay between the active surface of the transducer and a portion of the inner and / or outer surface of the acoustic chamber.

8. A method according to any one of claims 1 to 7, wherein the determined characteristics include indicating that the material is heterogeneous between the portion of the inner surface of the acoustic chamber and the active surface of the transducer.

9. A method according to claim 8, further comprising determining whether or not the ultrasonic probe can be used based on the heterogeneity characteristics of the material.

10. A method according to claim 2 or any one of claims 3 to 9 that references claim 2, further comprising estimating the intensity of the received reflected ultrasonic signal, wherein the reflected ultrasonic signal is reflected by the inner surface of the acoustic chamber or the internal members of the acoustic chamber, and comparing the estimated intensity with a built-in reference intensity.

11. A method according to claim 10, further comprising comparing the difference between intensities with a threshold.

12. A method according to any one of claims 1 to 10, characterized in that the transducer is movable within the acoustic chamber.

13. A method according to any one of claims 1 to 11, wherein the transducer is a one-dimensional or two-dimensional transducer array comprising a selectable set of transducers, and the transducer is selected according to the determined characteristics of the acoustic window portion.

14. A method according to any one of claims 1 to 13, further comprising modifying the settings of the ultrasonic probe according to the characteristics of the acoustic chamber.

15. A method according to any one of claims 1 to 14, further comprising providing prior warning to the user of the ultrasound probe or the practicing physician that the characteristics of the ultrasound probe have deteriorated in accordance with the characteristics of the acoustic chamber.

16. A computer program product for a programmable device, wherein the computer program product includes a series of instructions for performing each of the steps of the method according to any one of claims 1 to 15, when loaded into the programmable device and executed by the programmable device.

17. An ultrasonic probe comprising an acoustic window and a closed acoustic chamber, wherein the acoustic chamber encloses a transducer configured to emit an ultrasonic signal and receive the reflected ultrasonic signal through the acoustic window, and the ultrasonic probe further comprises a processing unit configured to perform each of the steps of the method according to any one of claims 1 to 15.

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