Ultrasound imaging apparatus

Abstract

The present specification relates to an ultrasound imaging device (200) comprising an ultrasound transducer group (101), an acoustic coupling layer (105) covering the ultrasound transducer group (101), and a suction system (203) adapted to apply a suction force, designed to press an object (111) to be imaged, arranged facing the acoustic coupling layer (105), against an upper surface of the coupling layer (105).

Description

[0001] The present application is based on French patent application FR2303100, entitled "Ultrasound imaging device", filed on March 30, 2023, and claiming priority from, which is considered as incorporated in the present description, within the limits set by the law. TECHNICAL FIELD

[0002] The present disclosure relates generally to the field of ultrasound imaging devices, and more specifically, to an ultrasound transducer-based device for acquiring skin relief and / or a microvascular imaging device. BACKGROUND

[0003] Ultrasound imaging devices generally comprise a plurality of ultrasound transducers and an electronic control circuit connected to the transducers. In operation, the set of transducers is positioned facing an object or a body from which an image is to be acquired. The electronic control circuit is configured to apply electrical excitation signals to the transducers so that they emit ultrasound waves toward the body to be analyzed. The ultrasound waves emitted by the transducers are reflected by the body to be analyzed (by its internal and / or surface structure) and then return to the transducers, which convert them back into electrical signals. These electrical response signals are read by the electronic control circuit and can be stored and analyzed to deduce information about the body being studied.

[0004] It is desirable to improve at least partially certain aspects of known ultrasound imaging devices. SUMMARY

[0005] To this end, one embodiment provides an ultrasound imaging device comprising a set of ultrasound transducers, an acoustic coupling layer coating the set of ultrasound transducers, and a (motorized) suction system adapted to apply a suction force tending to press an object to be imaged, arranged opposite the acoustic coupling layer, against an upper surface of the coupling layer.

[0006] According to one embodiment, the device comprises a protective enclosure comprising an upper plate located above the acoustic coupling layer, such that a cavity separates a lower surface of the upper plate of the enclosure from an upper surface of the acoustic coupling layer.

[0007] According to one embodiment, the upper plate has a through hole intended to be placed opposite the object to be imaged.

[0008] According to one embodiment, the through hole is positioned opposite the set of ultrasound transducers.

[0009] According to one embodiment, the suction system is connected to the cavity by a sealed conduit.

[0010] According to one embodiment, the suction system is configured to apply, during an ultrasound image acquisition phase, at least a partial vacuum in the cavity, so as to press the object to be imaged against the upper surface of the acoustic coupling layer.

[0011] According to an embodiment, the acoustically coupling layer is made of a polymer material.

[0012] According to an embodiment, the suction system comprises a vacuum pump.

[0013] One embodiment provides a use of an ultrasound imaging device as described above for acquiring biometric images.

[0014] One embodiment provides a use of an ultrasound imaging device as described above for acquiring medical images.

[0015] One embodiment provides a use of an ultrasound imaging device as described above for non-destructive ultrasonic testing applications. BRIEF DESCRIPTION OF DRAWINGS

[0016] In the following detailed description of specific embodiments, which is given by way of example and without limitation, the above features and advantages, as well as other features and advantages, will be described in detail with reference to the drawings, in which:

[0017] Figure 1 is a cross-sectional view schematically representing an example of an ultrasound imaging device; and

[0018] Figure 2A and 2B is a cross-sectional view schematically representing an example of an ultrasound imaging device according to an embodiment. DETAILED DESCRIPTION

[0019] In the various figures, identical features are denoted by identical reference numbers. In particular, structural and / or functional features common to the various embodiments can have identical reference numbers and can be provided with identical structural, dimensional and material properties.

[0020] For the sake of clarity, only the steps and elements useful for an understanding of the described embodiments are shown and described in detail. In particular, the construction of the ultrasound transducers and of the electronic control circuitry of the described devices is not described in detail, as the described embodiments are compatible with the usual construction of these elements. Moreover, the various applications of the described devices are not described in detail, as the described embodiments are compatible with all or most of the common applications of ultrasound imaging devices, in particular applications for imaging parts of the human or animal body.

[0021] Unless otherwise stated, when referring to two elements connected together, this means a direct connection without any intermediate element other than a conductor, and when referring to two elements coupled together, this means that the two elements can be connected or they can be coupled via one or more other elements.

[0022] In the following disclosure, unless otherwise stated, when referring to absolute position qualifiers (such as the terms "front", "back", "up", "down", "left", "right", etc.), or relative position qualifiers (such as the terms "above", "below", "higher", "lower", etc.), or orientation qualifiers (such as "horizontal", "vertical", etc.), reference is made to the orientation shown in the drawings.

[0023] Unless otherwise stated, the expressions "about", "approximately", "substantially" and "around" mean within 10%, preferably within 5%.

[0024] Figure 1 is a cross-sectional view schematically representing an example of an ultrasound imaging device 100, for example for biometric applications.

[0025] Figure 1 The device 100 in comprises an ultrasound transducer group 101 (not shown in detail in the figures), for example arranged in a matrix, in a bar or in any other arrangement. The transducers in the group 101 are for example CMUT type transducers (Capacitive Micromachined Ultrasonic Transducers), PMUT type transducers (Piezoelectric Micromachined Ultrasonic Transducers), crystal transducers or any other type of ultrasound transducer, for example piezoelectric or piezocomposite transducers or single crystal transducers.

[0026] For example, the transducers of the group 101 are integrated into a monolithic chip, for example formed in or on a semiconductor substrate, for example a silicon substrate, or alternatively in and on an insulating substrate, for example a glass substrate (not shown in the figures).

[0027] In the example shown, the transducer group 101 is mounted on a printed circuit board 103. The printed circuit board 103 comprises a support, for example made of an electrically insulating material, such as plastic, and a set of metal interconnection pads and tracks (not shown in the figures) formed on at least one surface of the support. In this example, the ultrasound transducer group 101 is fixed and electrically connected to the upper surface of the printed circuit board 103.

[0028] Figure 1 The device 100 of can also comprise one or more electronic circuits (not shown) for powering and controlling the ultrasound transducer group 101. For example, the electronic power and control circuit is fixed and electrically connected to one surface of the printed circuit board 103.

[0029] The electronic power and control circuit comprises, for example, a transmitting circuit adapted to supply an electric excitation signal to the ultrasound transducers in order to cause the transducers to emit ultrasound waves, and a receiving circuit adapted to read the electric response signals generated by the ultrasound transducers of the group 101 under the action of the ultrasound waves received from the object to be imaged.

[0030] Figure 1 The device 100 also includes a coupling layer 105 coated on the upper surface of the ultrasonic transducer assembly 101, for example made of a polymer material, such as electrically insulating. For example, the layer 105 is disposed on and in contact with the upper surface of the ultrasonic transducer assembly 101. Alternatively, the layer 105 is fixed to the upper surface of the transducer assembly 101 by an adhesive layer (not shown).

[0031] For example, the coupling layer 105 extends continuously over the entire upper surface of the ultrasonic transducer assembly 101. In the example shown, the coupling layer also extends laterally beyond the edge of the transducer assembly 101, thus also covering the sides of the assembly 101.

[0032] The thickness of the coupling layer 105 is, for example, between 100µm and 10mm, or between 500µm and 2mm.

[0033] The upper surface of layer 105 defines a contact surface on which the object to be imaged is placed, such as one or more of the user's fingers, the user's palm, or any other part of the human or animal body to be imaged.

[0034] Layer 105 provides ultrasonic coupling between the transducer of group 101 and the object to be imaged. Specifically, layer 105 is preferably relatively flexible and deformable to avoid an air gap between the transducer of group 101 and the object to be imaged. Furthermore, layer 105 preferably has an acoustic impedance adapted to the acoustic impedance of the object to be imaged, for example, an acoustic impedance substantially equal to that of skin. Therefore, layer 105 allows for maximizing the transmission of acoustic energy between the ultrasonic transducer and the object to be analyzed.

[0035] Layer 105 may also provide protection for the equipment, particularly for the ultrasonic transducer of group 101. In particular, layer 105 preferably has relatively high mechanical strength so that it will not deteriorate over time and in contact with the object to be imaged.

[0036] exist Figure 1 In the example shown, the acoustic coupling layer 105 and the transducer assembly 101 are encapsulated in a protective housing 107, made of a rigid material, such as a metal or an electrically insulating material of the plastic type. The protective housing 107 includes a through-hole or window 109 opposite the ultrasonic transducer assembly, thereby allowing free access to the upper surface of the acoustic coupling layer 105.

[0037] During operation, the object to be imaged is placed in contact with the upper surface of the acoustic coupling layer 105 opposite the opening 109.

[0038] exist Figure 1In the illustrated example, the object to be imaged is a finger 111. The opening 109 has a size that is substantially the same as the size of a portion of the finger to be imaged, for example the tip of the finger.

[0039] In practice, in order to avoid the presence of an air gap between the surface of the finger and the coupling layer 105 and to limit the risk of finger movement, the user tends to exert a relatively high pressure on the coupling layer 105 with their finger for the entire duration of the ultrasound image acquisition phase.

[0040] Experiments carried out by the inventors have shown that, for certain applications such as microvascular imaging applications, the quality of the acquired images can be reduced due to the pressure exerted by the user during acquisition. For example, the imaging of low blood flow and microvessels 113 located at the tip of the fingers and toes is difficult to achieve because these blood vessels can be compressed, resulting in a reduction in blood flow.

[0041] Figure 2A And 2B is a cross-sectional view schematically representing an example of an ultrasound imaging device 200 according to an embodiment.

[0042] The device 200 comprises elements common to the device 100 of Figure 1 These elements will not be described in detail again. Only the differences with the device 100 of Figure 1 will be described in detail below.

[0043] The device 200 differs from the device 100 in Figure 1 mainly in that it comprises an electrically powered suction system adapted to exert a suction force pressing the object to be imaged against the upper surface of the coupling layer 105. Thus, the user him / herself does not have to exert a manual pressure to press the object to be imaged against the surface of the coupling layer 105. This allows to limit the risk of excessive compression of the object, which can reduce the quality of the acquired ultrasound images. In particular, for microvascular imaging applications, this allows to prevent unnecessary compression of the blood vessels to be imaged.

[0044] In the example of Figure 2A and 2B the protective housing 107 comprises an upper plate 107a disposed above the upper surface of the acoustic coupling layer 105. In this example, the housing 107 is arranged so that an air gap or cavity 201 separates the upper surface of the acoustic coupling layer 105 from the lower surface of the upper plate 107a of the housing.

[0045] The air gap or cavity 201 can have a relatively small thickness, for example between 0.1 mm and 10 mm, for example between 0.5 mm and 5 mm.

[0046] When the user places his / her finger on the device, the finger rests on and is in contact with the upper surface of the plate 107a. The central part of the finger, corresponding to the part to be imaged, encloses the opening 109 and is therefore opposite the upper surface of the coupling layer 105, separated from it only by the cavity 201.

[0047] The air gap or cavity 201 is connected to a suction system 203 (not shown in the figures) via a sealed conduit (not shown in the figures). For example, the air gap or cavity 201 is connected to the atmosphere outside the housing 107 only via the opening 109 and the suction system 203.

[0048] The suction system 203 is for example a vacuum pump or any other electrically powered suction system. The provision of an air gap of relatively small thickness advantageously allows the space required by the suction system to be limited.

[0049] Figure 2A A configuration is shown in which the electrically powered suction system 203 is in an inactive state. In this case, the finger rests on the upper plate 107a of the protective housing, the part of the finger to be imaged completely or partially closing the opening 109. It should be noted that in this configuration, the part of the finger to be imaged is not in contact with the upper surface of the acoustically coupling layer 105, but is separated from it by the air gap 201. This configuration is not conducive to the acquisition of an ultrasound image, since there is an air gap between the finger and the acoustically coupling layer 105.

[0050] Figure 2B A configuration is shown in which the electrically powered suction system 203 is in an active state. In this case, at least a partial vacuum is created in the cavity 201, such that the part of the finger to be imaged is sucked inside the cavity. Under the action of the suction, the part of the finger to be imaged is pressed against the upper surface of the acoustically coupling layer 105. An ultrasound image of the finger can then be acquired.

[0051] The suction applied during the acquisition phase has several advantages.

[0052] In particular, it allows the finger, or more generally any object or organ to be imaged, to be held in position opposite the ultrasound transducer group 101, in contact with the upper surface of the coupling layer 105, via a suction force calibrated and controlled automatically by the electrically powered system.

[0053] For example, this allows the sensor to be held in place autonomously during acquisition, without the need to provide a specific manual or mechanical holding system.

[0054] This also allows to prevent the slight movements of the area to be imaged, which can degrade the quality of the image acquired.

[0055] Furthermore, this allows for protection against the risk of excessive manual pressure applied by the user, which could cause the object to be imaged to deform or compress, thereby reducing the quality of the acquired image.

[0056] In microvascular imaging applications, one advantage is that it prevents compression of the acquired image quality from potentially damaging the blood vessels in the area of ​​the finger to be imaged. Conversely, suction can cause localized dilation of the area of ​​the finger to be imaged, thereby improving image quality.

[0057] and Figure 1 Compared to device 100, the proposed solution also allows for an increase in the contact surface between the finger and the acoustic coupling layer 105.

[0058] Various embodiments and variations have been described. Those skilled in the art will understand that certain features of these various embodiments and variations can be combined, and other variations will be apparent to those skilled in the art. In particular, the described embodiments are not limited to… Figure 2A and 2B An example of the arrangement of the suction system 203 and the protective housing 107 of the illustrated device. More generally, those skilled in the art will know how to adjust the arrangement of the suction system 203 and the protective housing 107 according to the application discussed and the type of object to be imaged.

[0059] Furthermore, the described embodiments are not limited to the examples applied to microvascular imaging devices described above. As a variation, the proposed aspiration system can be applied to fingerprint acquisition devices to facilitate finger positioning and retention during acquisition.

[0060] Furthermore, the described embodiments are not limited to biometric applications, but can be applied to any ultrasound imaging system used for parts of the human or animal body, such as for medical applications.

[0061] Furthermore, the described embodiments can be applied to ultrasound imaging devices for non-living objects, such as for non-destructive ultrasound testing applications. The provision of a motorized suction system then facilitates the positioning and holding of the acquisition device relative to the object to be imaged.

[0062] Finally, based on the functional descriptions provided above, the actual implementation of the embodiments and variations described herein is within the capabilities of those skilled in the art.

Claims

1. An ultrasonic imaging device (200) comprising an ultrasonic transducer assembly (101), an acoustic coupling layer (105) coated thereon, and an electric suction system (203) adapted to apply suction, the suction tending to press an object (111) to be imaged, which is positioned opposite the acoustic coupling layer (105), against the upper surface of the coupling layer (105).

2. The ultrasonic imaging device (200) according to claim 1, comprising a protective housing (107) including an upper plate (107a) located above the acoustic coupling layer (105) such that a cavity (201) separates the lower surface of the upper plate (107a) of the housing (107) from the upper surface of the acoustic coupling layer (105).

3. The ultrasonic imaging device (200) according to claim 2, wherein, The upper plate (107a) has a through hole (109) which is intended to be positioned opposite the object (111) to be imaged.

4. The ultrasound imaging device (200) according to claim 3, wherein, The through hole (109) is positioned opposite the ultrasonic transducer assembly (101).

5. The ultrasound imaging device (200) according to any one of claims 2 to 4, wherein, The suction system (203) is connected to the cavity (201) by a sealed conduit.

6. The ultrasound imaging device (200) according to any one of claims 2 to 5, wherein, The suction system (203) is configured to apply at least a partial vacuum in the cavity during the ultrasound image acquisition phase in order to press the object to be imaged (111) against the upper surface of the acoustic coupling layer (105).

7. The ultrasound imaging device (200) according to any one of claims 1 to 6, wherein, The acoustic coupling layer (105) is made of polymer material.

8. The ultrasound imaging device (200) according to any one of claims 1 to 7, wherein, The suction system includes a vacuum pump.

9. Use of an ultrasound imaging device (200) according to any one of claims 1 to 8 for acquiring biometric images.

10. Use of an ultrasound imaging device (200) according to any one of claims 1 to 8 for acquiring medical images.

11. Use of the ultrasonic imaging apparatus (200) according to any one of claims 1 to 8 for non-destructive ultrasonic testing applications.

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