Ultrasound imaging device

Abstract

Ultrasonic Imaging Device This description relates to an ultrasonic imaging device (200) comprising an array of ultrasonic transducers (101), an acoustic coupling layer (105) covering said array of ultrasonic transducers (101), and a suction system (203) adapted to exert a suction force tending to press an object to be imaged (111) positioned opposite the acoustic coupling layer (105) against an upper surface of the coupling layer (105). Figure for the abbreviation: Fig. 2B

Description

Title of the invention: Ultrasonic imaging device technical field

[0001] This description relates to the field of ultrasound imaging devices, and more particularly to skin impression acquisition devices and / or microvascular imaging devices based on ultrasound transducers. Prior art

[0002] An ultrasound imaging device typically comprises 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 body whose image is to be acquired. The electronic control circuit is configured to apply electrical excitation signals to the transducers, causing them to emit ultrasound waves towards 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.

[0003] It would be desirable to improve at least in part certain aspects of known ultrasonic imaging devices. Summary of the invention

[0004] For this purpose, an embodiment provides an ultrasonic imaging device comprising an array of ultrasonic transducers, an acoustic coupling layer covering the array of ultrasonic transducers, and a suction system adapted to exert a suction force tending to press against an upper surface of the coupling layer an object to be imaged arranged opposite the acoustic coupling layer.

[0005] According to one embodiment, the device includes a protective housing comprising a top plate located above the acoustic coupling layer, such that a cavity separates a lower face of the top plate of the housing from the upper face of the acoustic coupling layer.

[0006] According to one embodiment, the upper plate has a through opening intended to be placed opposite the object to be imaged.

[0007] According to one embodiment, the through opening is located opposite the assembly of ultrasonic transducers.

[0008] According to one embodiment, the suction system is connected to said cavity by a airtight conduit.

[0009] According to one embodiment, the suction system is configured to apply at least a partial vacuum in the cavity during an ultrasonic image acquisition phase, so as to press the object to be imaged against the upper face of the acoustic coupling layer.

[0010] According to one embodiment, the acoustic coupling layer is made of a polymer material.

[0011] According to one embodiment, the suction system includes a vacuum pump.

[0012] One embodiment provides for the use of an ultrasonic imaging device as defined above, for the acquisition of biometric images.

[0013] One embodiment provides for the use of an ultrasonic imaging device as defined above, for the acquisition of medical images.

[0014] One embodiment provides for the use of an ultrasonic imaging device as defined above, for ultrasonic non-destructive testing applications. Brief description of the drawings

[0015] These features and advantages, as well as others, will be described in detail in the following description of particular embodiments, given by way of non-limiting example, in relation to the accompanying figures, among which:

[0016] [Fig.1] is a cross-sectional view schematically representing an example of an ultrasound imaging device;

[0017] Figures 2A and 2B are cross-sectional views schematically representing an example of an ultrasound imaging device according to one embodiment. Description of embodiments

[0018] The same elements have been designated by the same reference numerals in the different figures. In particular, the structural and / or functional elements common to the different embodiments may have the same reference numerals and may have identical structural, dimensional and material properties.

[0019] For the sake of clarity, only the steps and elements necessary for understanding the described embodiments have been shown and are detailed. In particular, the implementation of the ultrasonic transducers and the electronic control circuits of the described devices has not been detailed, as the described embodiments are compatible with common embodiments of these components. Furthermore, the various applications of the described devices have not been detailed, as the described embodiments are compatible with all or most common applications of ultrasonic imaging devices, and in particular, applications for imaging parts of the human or animal body.

[0020] Unless otherwise specified, when referring to two elements connected between them, this means directly connected without intermediate elements other than conductors, and when referring to two elements connected (in English "coupled") to each other, this means that these two elements can be connected or linked via one or more other elements.

[0021] In the following description, when reference is made to absolute position qualifiers, such as the terms "front", "back", "top", "bottom", "left", "right", etc., or relative position qualifiers, such as the terms "above", "below", "superior", "inferior", etc., or to orientation qualifiers, such as the terms "horizontal", "vertical", etc., reference is made, unless otherwise specified, to the orientation of the figures.

[0022] Unless otherwise specified, the expressions "approximately", "roughly", and "in the order of" mean within 10%, preferably within 5%.

[0023] Fig. 1 is a cross-sectional view schematically representing an example of an ultrasonic imaging device 100, for example for biometric applications.

[0024] The device 100 of [Fig. 1] comprises an assembly 101 of ultrasonic transducers (not detailed in the figure), for example arranged in a matrix, in a strip, or in any other arrangement. The transducers of the assembly 101 are, for example, CMUT type transducers (capacitive ultrasonic membrane transducers), PMUT type transducers (piezoelectric membrane transducers), crystal transducers, or any other type of ultrasonic transducer, for example piezoelectric or piezocomposite transducers, or single crystal transducers.

[0025] The transducers of the assembly 101 are for example integrated into a monolithic chip, for example formed in and on a semiconductor substrate, for example a silicon substrate, or in and on an insulating substrate, for example a glass substrate (not detailed in the figure).

[0026] In the example shown, the transducer assembly 101 is mounted on a printed circuit board 103. The printed circuit board 103 comprises, for example, a substrate made of an electrically insulating material, for example plastic, and a set of metallic interconnecting pads and tracks (not detailed in the figure) formed on at least one face of the substrate. In this example, the ultrasonic transducer assembly 101 is fixed and electrically connected to the top face of the printed circuit board 103.

[0027] The device 100 of [Fig. 1] may further include one or more electronic circuits (not shown) for powering and controlling the assembly 101 of ultrasonic transducers. The electronic power and control circuits are, for example, fixed and electrically connected to one side of the printed circuit board 103.

[0028] Electronic power supply and control circuits include, for example, transmission circuits adapted to provide electrical excitation signals to the ultrasonic transducers so as to cause the emission of ultrasonic waves by the transducers, and reception circuits adapted to read electrical response signals generated by the ultrasonic transducers of assembly 101 under the effect of an ultrasonic wave received from the object to be imaged.

[0029] The device 100 of [Fig. 1] further comprises a coupling layer 105, for example made of a polymer material, for example electrically insulating, coating the upper surface of the ultrasonic transducer assembly 101. By way of 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 means of an adhesive layer, not shown.

[0030] By way of 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 edges of the elementary transducer assembly 101, and thus also covers the sides of the assembly 101.

[0031] The thickness of the coupling layer 105 is for example between 100 pm and 10 mm, for example between 500 pm and 2 mm.

[0032] The upper face of layer 105 defines a contact surface on which an object to be imaged is placed, for example one or more fingers of a user, the palm of a user, or any other part of the human or animal body that one wishes to image.

[0033] Layer 105 provides ultrasonic coupling between the transducers of assembly 101 and the object to be imaged. In particular, layer 105 is preferably relatively flexible and deformable to avoid the presence of air gaps between the transducers of assembly 101 and the object to be imaged. Furthermore, layer 105 preferably has an acoustic impedance matched to that of the object to be imaged, for example, an acoustic impedance substantially equal to the acoustic impedance of skin. Thus, layer 105 maximizes the transfer of acoustic energy between the ultrasonic transducers and the object to be analyzed.

[0034] The layer 105 can also have a function of protecting the device and in particular the ultrasonic transducers of the assembly 101. In particular, the layer 105 preferably has a relatively high mechanical strength so as not to degrade over time and in contact with the objects to be imaged.

[0035] In the example of [Fig. 1], the acoustic coupling layer 105 and the transducer assembly 101 are encapsulated in a protective housing 107, for example made of a rigid material, for example a metallic material or an electrically plastic-type insulation. The protective housing 107 includes a through opening or window 109 opposite the assembly of ultrasonic transducers, allowing free access to the upper face of the acoustic coupling layer 105.

[0036] In operation, the object to be imaged is placed in contact with the upper face of the acoustic coupling layer 105 opposite the opening 109.

[0037] In the example shown in [Fig.1], the object to be imaged is a finger 111. The opening 109 has, for example, substantially the same dimensions as those of a portion of the finger, for example an end of the finger, which we seek to image.

[0038] In practice, to avoid the presence of an air gap between the surface of the finger and the coupling layer 105, and to limit the risks of finger movements, users tend to apply relatively high pressure on the coupling layer 105 with their finger throughout the entire duration of an ultrasound image acquisition phase.

[0039] Experiments carried out by the inventors have shown that, for certain applications, for example for microvascular imaging applications, the quality of the acquired images can be degraded due to pressure exerted by the user during acquisition. For example, imaging weak blood flow and microscopic vessels 113 located at the tips of the fingers and toes is difficult because these vessels can be compressed, and therefore have a reduction in blood flow.

[0040] Figures 2A and 2B are cross-sectional views schematically representing an example of an ultrasonic imaging device 200 according to one embodiment.

[0041] Device 200 includes elements common to device 100 of [Fig. 1]. These elements will not be detailed again. Only the differences with device 100 of [Fig. 1] will be detailed below.

[0042] Device 200 differs from device 100 in [Fig. 1] primarily in that it includes a motorized suction system adapted to exert a suction force tending to press the object to be imaged against the upper surface of the coupling layer 105. Thus, the user does not have to manually apply pressure to press the object to be imaged against the surface of the coupling layer 105. This limits the risk of excessive compression of the object, which can degrade the quality of the acquired ultrasound images. In particular, for microvascular imaging applications, this prevents undesirable compression of the vessels being imaged.

[0043] In the example of Figures 2A and 2B, the protective housing 107 comprises a top plate 107a disposed above the upper face 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 face from the acoustic coupling layer. 105 of the lower face of the upper plate 107a of the housing.

[0044] 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.

[0045] When the user places their finger on the device, the latter comes into contact with and supports the upper face of the plate 107a. A central part of the finger, corresponding to the part to be imaged, closes the opening 109 and is thus opposite the upper face of the coupling layer 105, separated from the upper face of the layer 105 only by the cavity 201.

[0046] The air gap or cavity 201 is connected to a suction system 203 (not detailed in the figure) via a sealed duct (not detailed in the figure). By way of example, the air gap or cavity 201 is connected to the outside atmosphere of the housing 107 solely via the opening 109 and the suction system 203.

[0047] The suction system 203 is, for example, a vacuum pump, or any other motorized suction system. Providing a relatively thin air gap advantageously limits the overall size of the suction system.

[0048] Figure 2A illustrates a configuration in which the motorized suction system 203 is inactive. In this case, the finger rests on the upper plate 107a of the protective housing, with the portion of the finger to be imaged completely or partially obstructing the opening 109. It should be noted that, in this configuration, the portion of the finger to be imaged is not in contact with the upper surface of the acoustic coupling layer 105 but is separated from it by the air gap 201. Due to the presence of an air gap between the finger and the acoustic coupling layer 105, this configuration is not favorable for acquiring an ultrasonic image.

[0049] Figure 2B illustrates a configuration in which the motorized suction system 203 is active. In this case, at least a partial vacuum is created in the cavity 201, leading to the suction of the portion of the finger to be imaged into the cavity. Under the effect of the suction, the portion of the finger to be imaged is pressed against the upper surface of the acoustic coupling layer 105. An ultrasonic image of the finger can then be acquired.

[0050] The aspiration applied during the acquisition phase has several advantages.

[0051] In particular, it allows the finger, or, more generally, any object or organ to be imaged, to be held in position opposite the assembly 101 of ultrasonic transducers, in contact with the upper face of the coupling layer 105, via a suction force calibrated and automatically controlled via a motorized system.

[0052] This allows, for example, the sensor to be kept in place autonomously during acquisition, without having to provide a specific holding system, human or mechanical.

[0053] This also helps to avoid micromovements of the area to be imaged, which could degrade the quality of the images acquired.

[0054] This also avoids the risk of the user applying excessive manual pressure, which could lead to deforming or compressing the object to be imaged and thus degrading the quality of the acquired image.

[0055] In the case of a microvascular imaging application, one advantage is to avoid compression of the blood vessels in the portion of the finger being imaged, which could impair the quality of the acquired image. Conversely, suction can cause localized dilation in the portion of the finger being imaged, improving image quality.

[0056] Compared to device 100 of [Fig. 1], the proposed solution also makes it possible to increase the contact area between the finger and the acoustic coupling layer 105.

[0057] Various embodiments and variations have been described. Those skilled in the art will understand that certain features of these various embodiments and variations could be combined, and other variations will become apparent to them. In particular, the embodiments described are not limited to the example of the arrangement of the suction system 203 and the protective housing 107 of the device shown in Figures 2A and 2B. More generally, those skilled in the art will be able to adapt the arrangement of the suction system 203 and the protective housing 107 according to the application under consideration and the type of object to be imaged.

[0058] Furthermore, the described embodiments are not limited to the application example mentioned above for microvascular imaging devices. As an alternative, the proposed suction system can be applied to fingerprint acquisition devices to facilitate the placement and maintenance of the finger during acquisition.

[0059] Moreover, the embodiments described are not limited to biometric applications but can be adapted to any ultrasound imaging system of portions of the human or animal body, for example for medical applications.

[0060] Furthermore, the described embodiments can be applied to ultrasonic imaging devices for non-living objects, for example, for non-destructive ultrasonic testing applications. The provision of the motorized suction system then facilitates the placement and maintenance of the acquisition device in position relative to the object to be imaged.

[0061] Finally, the practical implementation of the embodiments and variants described is within the reach of a person skilled in the art, based on the functional indications given above.

Claims

Demands

1. Ultrasonic imaging device (200) comprising an array of ultrasonic transducers (101), an acoustic coupling layer (105) covering said array of ultrasonic transducers (101), and a motorized suction system (203) adapted to exert a suction force tending to press against an upper surface of the coupling layer (105) an object to be imaged (111) disposed opposite the acoustic coupling layer (105).

2. 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 a lower face of the upper plate (107a) of the housing (107) from the upper face of the acoustic coupling layer (105).

3. Ultrasonic imaging device (200) according to claim 2, wherein said upper plate (107a) has a through opening (109) intended to be placed opposite the object (111) to be imaged.

4. Ultrasonic imaging device (200) according to claim 3, wherein said through aperture (109) is located opposite the assembly (101) of ultrasonic transducers.

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

6. Ultrasonic 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 an ultrasonic image acquisition phase, so as to press the object to be imaged (111) against the upper face of the acoustic coupling layer (105).

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

8. Ultrasonic imaging device (200) according to any one of claims 1 to 7, wherein the suction system comprises a vacuum pump.

9. Use of an ultrasound imaging device (200) according to any one of claims 1 to 8, for the acquisition of bio- images metrics.

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

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

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