Ultrasonic probe

Abstract

Ultrasonic Probe This description concerns an ultrasonic probe (100) extending along a longitudinal direction (Z) along an axis (105), the ultrasonic probe comprising: - an interconnecting substrate (130) having a first face and a second face opposite the first face; - a plurality of ultrasonic transducers (110) arranged in a first region (101) of the ultrasonic probe and on the first face of the interconnecting substrate; - a plurality of control circuits (120) arranged in a second region (102) of the ultrasonic probe and on the second face of the interconnecting substrate, the second region being distinct from the first region. Figure for the abbreviation: Fig. 1

Description

Title of the invention: Ultrasonic probe technical field

[0001] This description relates generally to ultrasonic probes comprising ultrasonic transducers.

[0002] An example of the application of such an ultrasound probe relates to intravascular ultrasound diagnosis (pre-treatment or post-treatment diagnosis) or treatment, the ultrasound probe being, for example, integrated into a catheter. Prior art

[0003] It has already been proposed to integrate small ultrasound probes into a catheter intended for insertion into the body, for example into a blood vessel, of a human or animal patient, particularly for intravascular ultrasound (IVUS) imaging, for example for intravascular ultrasound diagnostic or treatment applications, or even for evaluating the effectiveness of a treatment (post-treatment diagnosis). An intravascular ultrasound imaging device, or IVUS device, generally comprising several ultrasound transducers, can be introduced into a blood vessel and guided to an area to be imaged. The ultrasound transducers emit ultrasound waves that are at least partially reflected by particular elements of the blood vessels.The reflected ultrasound waves are received by the ultrasound transducers which transmit them to a processing device which processes these reflected ultrasound waves to produce an image of the vessel in which the IVUS device is placed.

[0004] An example of an IVUS device comprises a sensing assembly with a substantially cylindrical external shape, which includes an array of ultrasonic transducers distributed around its circumference and control circuits, or controllers, mounted near the transducer array. The sensing assembly may correspond to an ultrasonic sensing device, or ultrasonic probe. The controllers select individual transducer elements, or groups of transducer elements, to transmit the ultrasonic waves and / or receive the reflected ultrasonic waves. The sensing assembly may be substantially tubular in shape, that is, include an internal cavity, which may be referred to as a "lumen" or "light." This internal cavity may be used, for example, to pass a guide wire.The IVUS device can be connected to the treatment device via electrical connections such as cables and / or an electrical connector.

[0005] It is becoming increasingly difficult to produce an ultrasound probe that can be integrated into a catheter and introduced into a vessel, or other anatomical space, of small cross-section or small diameter, and that includes an internal cavity of sufficient diameter to accommodate an element such as a guidewire; that is to say, an ultrasound probe with a minimized external diameter while having a sufficient internal cavity diameter, which can lead to an annular space with a reduced radial thickness. In particular, it can prove difficult to integrate the ultrasound transducers and controllers with their electrical interconnections into the ultrasound probe within a reduced annular space, for example, an annular space with a radial thickness of less than 1 mm, or even less than or equal to 0.5 µm.

[0006] It would be desirable to have an ultrasonic probe available, at least partially mitigating some of the disadvantages of known ultrasonic probes.

[0007] In particular, there is a need for an ultrasound probe, for example an intravascular ultrasound probe, whose external diameter is small enough to facilitate access to vessels, or other anatomical spaces, for example an external diameter of less than 5 mm, or even 3 mm, and which includes an internal cavity of sufficiently large diameter, for example greater than 1 mm, or even 1.3 mm, while maintaining efficient assembly, interconnection and operation of the ultrasound probe. Summary of the invention

[0008] One embodiment overcomes all or part of the disadvantages of known ultrasonic probes.

[0009] One embodiment provides for an ultrasonic probe extending in a longitudinal direction along an axis, the ultrasonic probe comprising: - an interconnection substrate comprising a first face and a second face opposite to the first face; - a plurality of ultrasonic transducers arranged in a first region of the ultrasonic probe and on the first face of the interconnecting substrate; - a plurality of control circuits arranged in a second region of the ultrasonic probe and on the second face of the interconnecting substrate, the second region being distinct from the first region.

[0010] According to one embodiment, the first face is an external face of the interconnecting substrate and the second face is an internal face of the interconnecting substrate.

[0011] According to one embodiment, the second region is axially offset with respect to the first region.

[0012] According to one embodiment, the first region comprises a first portion of the interconnecting substrate and the second region comprises a second portion of the interconnection substrate, the second portion being distinct from the first portion, for example axially offset with respect to the first portion.

[0013] According to one embodiment, the first portion of the interconnecting substrate has a first circular, oval, or polygonal section having a first number of sides, and the second portion has a second polygonal section having a second number of sides, the second number of sides being less than the first number of sides, for example at least five times less, or at least ten times less, or even at least twenty times less.

[0014] According to one embodiment, the first portion of the interconnecting substrate has a cylindrical shape with a substantially circular or oval cross-section around the axis, said first portion including flat portions on which the ultrasonic transducers are positioned.

[0015] According to one embodiment, the second portion of the interconnecting substrate has a prismatic shape around the axis, said second portion including a plurality of facets, the control circuits being arranged against all or part of said facets.

[0016] According to one embodiment, the second portion of the interconnecting substrate includes rounded edges between the facets.

[0017] According to one embodiment, the interconnecting substrate comprises a third portion between the first portion and the second portion, the third portion being in a third region of the ultrasonic probe between the first region and the second region, the third portion forming a shape transition portion of the section of the interconnecting substrate.

[0018] According to one embodiment, the ultrasonic probe further includes stiffeners in the second region at the right of the control circuits, for example the interconnection substrate being between the control circuits and the stiffeners.

[0019] According to one embodiment, all or part of the stiffeners have an end oriented towards the first region, said end being adapted to constrain the interconnecting substrate to transform the first section into the second section, for example the stiffener extending into a third region of the ultrasonic probe between the first region and the second region.

[0020] According to one embodiment, the interconnecting substrate is in one piece in the longitudinal direction.

[0021] According to one embodiment, the ultrasonic probe further comprises electronic components arranged in the second region, on the second face of the interconnecting substrate and axially away from the control circuits.

[0022] According to one embodiment, the ultrasonic probe has an external cylindrical shape around the axis, the transducers being distributed, for example, regularly distributed around the axis in the first region and the control circuits being distributed, for example regularly distributed, around the axis in the second region.

[0023] According to one embodiment, the ultrasonic probe further comprises a support element around which the interconnecting substrate, the plurality of ultrasonic transducers and the plurality of control circuits are arranged, the support element comprising an internal cavity, for example adapted for the passage of a guiding element of the ultrasonic probe, such as a guide wire.

[0024] According to one embodiment, the ultrasonic probe further comprises an acoustic attenuation material between the support element and the interconnecting substrate in the first region.

[0025] According to one embodiment, the control circuits are between the support element and the interconnecting substrate in the second region, for example all or part of the control circuits being in contact with the support element.

[0026] According to one embodiment, the ultrasonic probe further comprises a fourth region extending the second region opposite the first region, and the interconnecting substrate comprising a fourth portion in the fourth region, said fourth portion comprising connecting strips of the interconnecting substrate, said connecting strips being for example connected to cables. Brief description of the drawings

[0027] 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:

[0028] [Fig.1] is a longitudinal view representing an ultrasonic probe 100 according to one embodiment;

[0029] [Fig.2] is a cross-sectional view of the ultrasonic probe 100 of [Fig.1];

[0030] [Fig. 3] is another cross-sectional view of the ultrasonic probe 100 of the [Fig.l];

[0031] [Fig. 4] is a top view partially representing the ultrasonic probe of [Fig. 1] before it is wound around its axis; and

[0032] [Fig.5] is a bottom view partially representing the ultrasonic probe of [Fig.1] before it is wound around its axis. Description of the implementation methods

[0033] 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.

[0034] 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 ultrasonic transducers of the described ultrasonic probes have not been detailed, as the described embodiments are compatible with all or most known ultrasonic transducer structures. Furthermore, the control circuits of the described ultrasonic probes have not been detailed, as the described embodiments are compatible with all or most common control circuits for ultrasonic transducers.

[0035] 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.

[0036] 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 or to an ultrasonic probe in a normal operating position.

[0037] Unless otherwise specified, the expressions "approximately", "about", "Sensibly" and "on the order of" mean to within 10% or 10°, preferably to within 5% or 5°.

[0038] In the following description, when referring to a longitudinal direction, it refers to a direction parallel to the axis of the ultrasonic probe. It can also be called an axial direction. The longitudinal direction corresponds to the Z direction shown in the figures. A transverse direction corresponds to a direction in a plane perpendicular to the longitudinal direction. The figures illustrate two transverse directions, X and Y. A section corresponds to a shape defined in a plane transverse to the longitudinal direction.

[0039] In the following description, when a transducer is referred to, unless otherwise specified, it refers to an ultrasonic transducer, and when a probe is referred to, unless otherwise specified, it refers to an ultrasonic probe.

[0040] Figure 1 is a longitudinal view representing an ultrasonic probe 100 according to one embodiment. Figure 2 is a cross-sectional view of the ultrasonic probe 100 of Figure 1. Figure 3 is another cross-sectional view of the ultrasonic probe 100 of Figure 1.

[0041] The cross-sectional view of [Fig. 2] is taken along the section plane AA identified in [Fig. 1]. Section AA is taken in a transducer region 101 described later. The cross-sectional view of [Fig. 3] is taken along the section plane BB identified in [Fig. 1]. Section BB is taken in a control region 102 described later.

[0042] The ultrasound probe 100 can be integrated into a catheter. The ultrasound probe 100 can be part of an ultrasound imaging device (not shown), for example, an intravascular ultrasound imaging device, or IVUS device, which generally includes a catheter, a guidewire, and / or a guide catheter, and which is adapted to be introduced into a lumen of a vessel or other anatomical space in a human or animal patient. The ultrasound probe can be positioned at a distal end of the imaging device. The imaging device can include a transmission line, for example, in the form of a cable bundle, extending to a proximal end of the imaging device.At its proximal end, the imaging device may include, or be connected to, a processing device adapted to control the ultrasound probe to produce emitted ultrasound waves, and to process ultrasound waves received by the ultrasound probe to produce a corresponding image.

[0043] In the following description, a distal end refers to an end through which the ultrasound probe, or imaging device, is introduced into the medium to be analyzed, and a proximal end refers to an end opposite the distal end. The proximal end generally corresponds to an electrical connection, or wiring, end of the ultrasound probe, or imaging device.

[0044] The ultrasonic probe 100 has a substantially cylindrical external shape about an axis 105. To allow it to be inserted into a space with a small cross-section or diameter, the external diameter DI of the ultrasonic probe can be less than 15 French (Fr), i.e., less than 5 millimeters (mm), or even less than 9 French, i.e., less than 3 mm. This can correspond to the external diameter of an imaging device in which the ultrasonic probe 100 is integrated.

[0045] The ultrasonic probe 100 comprises an array of ultrasonic transducer elements, designated ultrasonic transducers 110, adapted to emit and receive ultrasonic waves. The ultrasonic transducers 110 are distributed around the axis 105.

[0046] All or part of the ultrasonic waves emitted by the transducers may be reflected by particular elements of the medium into which the ultrasonic probe is introduced, for example, particular elements of a vessel. The reflected ultrasonic waves may be received by the ultrasonic transducers. These reflected ultrasonic waves may be processed by a processing device to produce an image of the environment in which the ultrasonic probe is placed, for example to visualize particular elements.

[0047] An ultrasonic transducer is a transducer adapted to convert an electrical signal into an ultrasonic wave, and conversely, to convert an ultrasonic wave into an electrical signal. Depending on the type of transducer, the electrical signal may correspond to a voltage, a current, or an electrical charge.

[0048] The transducer network may include any type of ultrasonic transducer, or even several types of ultrasonic transducers.

[0049] Ultrasonic transducers may consist of a layer of single-crystal or polycrystalline piezoelectric material, for example PZT (lead-zirconia titanium), or of a composite material comprising at least one piezoelectric material, for example a layer of PZT including polymer-filled grooves. A piezoelectric material is a material whose thickness can change when a voltage is applied to it.

[0050] Ultrasonic transducers can be microelectromechanical systems, or MEMS (Micro-Electro-Mechanical System), implementing microelectronic production technologies. A MEMS-type transducer generally consists of a deformable membrane suspended above a cavity. In one embodiment, the deformable membrane is displaced or deformed by capacitive force using an electrode attached to the membrane and an electrode separated by the cavity. This type of ultrasonic transducer is known by the acronym CMUT (Capacitive Micro-machined Ultrasonic Transducer), i.e., a micro-machined ultrasonic capacitive transducer, or membrane capacitive transducer. In another embodiment, the deformable membrane is displaced or deformed by piezoelectric force using a layer of piezoelectric material equipped with two electrodes attached to the membrane.This type of ultrasonic transducer is known by the acronym PMUT, from the English Piezoelectric Micro-machined Ultrasonic Transducer, i.e. a micro-machined ultrasonic piezoelectric transducer, or membrane piezoelectric transducer.

[0051] The ultrasonic transducers 110 extend along a first circumferential band of the ultrasonic probe, around the axis 105. The array of ultrasonic transducers 110, and the first circumferential band, extend longitudinally in a first region 101, or transducer region, of the ultrasonic probe 100.

[0052] The transducer network can include any number of ultrasonic transducers 110, for example between 10 and 200 transducers, or between 20 and 100 transducers, for example 40 transducers.

[0053] Ultrasonic transducers 110 are formed by several elements. Ultrasonic transducers include a layer of piezoelectric material, or piezoelectric layer, cut through its entire thickness to form several sectors 111 of the piezoelectric layer, or piezoelectric sectors 111. Instead of a piezoelectric layer, it may be a stack of piezoelectric layers.

[0054] The piezoelectric layer can be metallized on each of its inner and outer faces to form an outer metallic layer and an inner metallic layer, the cutting of the piezoelectric layer including the cutting of both the outer and inner metallic layers. Each piezoelectric sector 111 can thus comprise an outer electrode, corresponding to a sector of the cut outer metallic layer, and an inner electrode corresponding to a sector of the cut inner metallic layer.

[0055] Ultrasonic transducers 110 generally include an impedance matching layer around the piezoelectric layer. The impedance matching layer is cut, generally at the same time as the piezoelectric layer, to form several sectors 112 of the impedance matching layer, or impedance matching sectors 112. Each impedance matching sector 112 is positioned opposite a piezoelectric sector 111, and for example in contact with this piezoelectric sector 111, forming a stack.

[0056] A stack of an impedance matching sector 112 on a piezoelectric sector 111 makes it possible to form all or part of an ultrasonic transducer 110. The stacks of sectors 111, 112, and thus the ultrasonic transducers, are separated from each other by slots 113.

[0057] The transducers 110 can be surrounded by a protective sheath 108, which is preferably biocompatible.

[0058] The ultrasonic probe 100 further comprises a network of electronic control circuits 120, or control circuits. Each control circuit 120 may be a controller, a control integrated circuit, an application-specific integrated circuit, known by the acronym ASIC (Application-Specific Integrated Circuit), or any other electronic circuit suitable for controlling one or more transducers.

[0059] The control circuits 120 can be configured to select some of the transducers 110 to be used for the transmission / reception of ultrasonic waves, to transmit control signals to the selected transducers so that they generate and transmit ultrasonic waves, and / or to accept, or even amplify, return signals from the selected transducer elements when the latter receive reflected ultrasonic waves. More generally, several types of Signals, such as control, power and / or data signals, can be exchanged between the transducers 110 and the control circuits 120.

[0060] The control circuits 120 are arranged, or distributed, along a second circumferential band of the ultrasonic probe, around the axis 105. The network of control circuits 120, and the second circumferential band, extend longitudinally in a second region 102, or control region, of the ultrasonic probe 100. The second region 102 is positioned axially at a distance from the first region 101.

[0061] Each control circuit 120 can be configured to control several transducers, for example, to control between three and thirty transducers 110. In other words, there may be fewer control circuits than transducers. Four control circuits 120 are shown for forty transducers 110, which averages one control circuit for every ten transducers, but this is a non-limiting example.

[0062] A third region 103, or transition region, of the ultrasonic probe 100 may extend longitudinally between the first region 101 and the second region 102. In other words, the first region 101 and the second region 102 may not be contiguous.

[0063] The ultrasonic probe 100 may include a fourth region 104, or connector region, extending the control region 102 opposite the transition region 103, or the transducer region 101 when there is no transition region.

[0064] The transducer region 101 can be positioned at a distal end of the ultrasonic probe 100. The control region 102, or the connection region 104, can be positioned at a proximal end of the ultrasonic probe 100.

[0065] The ultrasonic probe 100 further comprises an interconnection substrate 130 around the axis 105. The interconnection substrate 130 comprises an external face 130A, or upper face, and an internal face 130B, or lower face.

[0066] The interconnecting substrate 130 has a distal end 130C, which is an end positioned at the level of the transducers 110, and a proximal end 130D which is opposite the distal end 130C.

[0067] The interconnecting substrate 130 is configured to provide an electrical connection between the ultrasonic transducers 110 and the control circuits 120, as well as with circuits, connectors and / or components external or internal to the ultrasonic probe 100. The interconnecting substrate 130 can also form a structural support for the ultrasonic transducers 110 and the control circuits 120.

[0068] The interconnecting substrate 130 generally comprises a set of conductive tracks 135 insulated from one another and arranged in and / or on an insulating support, or dielectric support 136. The dielectric support 136 and the interconnecting substrate 130 are flexible, so that the interconnecting substrate 130 can be wound around the axis 105. The dielectric support 136 is, for example, in the form of a film of polymer material, for example, polyimide. Several other materials can be suitable for a flexible dielectric support, for example, polyester, polyethylene polynaphthalate, or polyetherimide. The interconnecting substrate 130 can be a flexible printed circuit board. The interconnecting tracks 135 are, for example, metallic tracks, advantageously made of a malleable material, for example, gold or copper.

[0069] Some of these conductive tracks 135 can connect the transducers 110 to the control circuits 120, for example to carry control, power and / or data signals between the control circuits 120 and the transducers 110. Some of these conductive tracks 135 can be connected to electrodes of the transducers 110, for example internal electrodes, positioned between the piezoelectric layer and the conductive tracks 135. Other conductive tracks 135 can allow the control circuits 120 to be connected to circuits, connectors and / or components external or internal to the ultrasonic probe 100, for example to another interconnecting substrate, to a flexible or rigid printed circuit board, for example via cables.

[0070] The interconnecting substrate 130 can be extended by connecting tabs, blades, or strips 137. The connecting strips 137 can be part of the interconnecting substrate 130 and be positioned at the proximal end 130D of the interconnecting substrate 130, i.e., the end furthest from the transducers 110. The connecting strips 137 can be connected to cables 140 to couple the interconnecting substrate 130 to circuits, connectors, and / or components external or internal to the ultrasonic probe 100.

[0071] Preferably, the interconnecting substrate 130 extends in the longitudinal direction Z in one piece, that is to say in one piece.

[0072] The interconnecting substrate 130 may comprise several portions along the longitudinal direction Z: - a first portion 131 which is substantially at the same axial level as the region of transducers 101; - a second portion 132 which is substantially at the same axial level as the control region 102; - a third portion 133, or transitional portion, between the first portion 131 and the second portion 132; and - a fourth portion 134, or connecting portion, the second portion 132 being between the third portion 133 and the fourth portion 134.

[0073] The third portion 133 can be positioned axially at the level of the third region 103. The fourth portion 134 can be positioned axially at the level of the fourth region 104.

[0074] The connecting strips 137 can be arranged at the level of the fourth portion 134 of the interconnecting substrate 130.

[0075] The connecting strips 137 and the cables 140 can be arranged in the connection area 104.

[0076] As illustrated in Figures 2 and 3, the transducers 110 are positioned on the outer face 130A of the first portion 131 of the interconnecting substrate 130, and the control circuits 120 are positioned on the inner face 130B of the second portion 132 of the interconnecting substrate 130. More generally, the transducers 110 and the control circuits 120 are axially spaced and positioned on two different faces, preferably two opposite faces, of the interconnecting substrate 130. In other words, the transducers 110 and the control circuits 120 are positioned in two axial portions and on two different faces, preferably opposite faces, of the interconnecting substrate 130.

[0077] Furthermore, as illustrated in Figures 2 and 3, the first portion 131 of the interconnecting substrate 130 has a cylindrical shape whose cross-section (first section) is substantially circular. By cylindrical shape, a broad definition of a cylinder is to be understood, namely a shape defined by a surface consisting of parallel lines connecting two parallel planes, the cross-section of the cylinder corresponding to the surface of one or the other of the planes.

[0078] Preferably, the substantially circular cross-section of the first portion 131 of the interconnecting substrate 130 has flat sections beneath the transducers 110, the flat sections being connected by rounded or arc-shaped sections. Thus, the cross-section of the first portion 131 can be likened to a polygonal section with at least N sides, which are by definition flat, N being the number of transducers, preferably with rounded sections between the sides. The first portion 131 of the interconnecting substrate 130 can therefore comprise N facets.

[0079] The second portion 132 of the interconnecting substrate 130 has a prismatic cross-section (second section) that is substantially polygonal with several sides, at least M sides, where M is the number of control circuits, for example, at least four sides. Preferably, the substantially polygonal cross-section of the second portion 132 has rounded (arc-shaped) portions between the sides, which are by definition flat. In other words, the second portion 132 of the interconnecting substrate 130 has a multifaceted prismatic shape 139, of Preference is given to facets with rounded edges between the 139 facets. The second portion 132 comprises M facets. Four facets 139 are shown in [Fig. 3], but this is not exhaustive, as indicated later.

[0080] The first and second portions have the same axis, corresponding substantially to axis 105.

[0081] The third portion 133 of the interconnecting substrate 130 is a shape transition portion.

[0082] The third portion 133 has a form adapted for transforming: - a substantially circular section into a substantially polygonal section, and vice versa; or - a substantially polygonal section with N sides into a substantially polygonal section with M sides, where N is greater than M.

[0083] According to one embodiment, the number of facets N of the first portion 131 is greater than or equal to three times the number of facets M of the second portion 132, or greater than or equal to ten times the number of facets M of the second portion 132, or even greater than or equal to twenty times the number of facets M of the second portion 132.

[0084] In each of the first and second portions of the interconnecting substrate, the rounded portions between the sides, and thus the rounded edges between the facets, can form folding regions of the interconnecting substrate when it passes from a flat shape to a cylindrical or prismatic shape.

[0085] The control circuits 120 are positioned on the inner faces of the facets 139 of the second portion 132 of the interconnecting substrate 130. The transducers 110 are positioned on the cylindrical outer face of the first portion 131 of the interconnecting substrate 130, for example on flat portions of the first portion 131.

[0086] The ultrasonic probe may include electronic components 125, for example passive components, in the control region 102. The electronic components 125 may be arranged axially at a distance from the control circuits 120, for example between the control circuits 120 and the connection region 104 of the ultrasonic probe 100. The electronic components 125 may advantageously be positioned on the second portion 132 and on the inner face 130B of the interconnecting substrate 130, for example on the inner face of one or more facets 139. Electronic components 125 are shown in [Fig. 3] on the four facets 139, with a single electronic component on each of the four facets, but there could be an electronic component on only some of the four facets and / or several electronic components on the same facet, more generally one or more electronic components on one or more facets.

[0087] The second portion 132 of the interconnecting substrate 130 is represented in [Fig. 3] in the form of a four-faceted prism, that is to say a prism with a cross-section square, with rounded edges between the facets, but this is not limiting. For example, the second portion 132 could be a prism with more than four facets or with three facets, or even have another cross-section, and / or be an irregular prism.

[0088] Furthermore, [Fig. 2] shows the first portion 131 of the interconnecting substrate 130 as a cylinder with a substantially circular cross-section, preferably with flat portions, but this is not limiting. For example, the first portion 131 may be in the form of a cylinder having another cross-section, for example oval, or, as indicated above, in the form of a prism having more facets than the prism of the second portion, for example at least ten facets or at least fifty facets.

[0089] The ultrasonic probe 100 may further include stiffeners 122 in the control region 102. The stiffeners 122 are preferably distributed radially along the control circuits 120, with the interconnecting substrate 130 located between the stiffeners 122 and the control circuits 120. The stiffeners 122 serve, in particular, to protect the control circuits 120. For example, the stiffeners have a thickness of approximately 50 micrometers (µm). For example, the stiffeners 122 are made of a polymer, such as polyimide.

[0090] The stiffeners 122 can each have an end 122A (visible in [Fig.4]) facing the transition region 103, or the transducer region 101. Each of these ends 122A can have a pointed or arrow-shaped form, or any other shape suitable for constraining the interconnecting substrate 130 to change its cross-sectional shape in the transition portion 133. For example, each stiffener 122 can constrain the interconnecting substrate 130 to flatten in the second portion 132 so as to obtain the flat portions to support the control circuits 120, or to widen the flat portions of the first portion 131 to form the wider flat portions in the second portion 132.

[0091] The stiffeners 122 can extend into the transition region 103.

[0092] The ultrasonic probe 100 may further include a support element 106 around which the interconnecting substrate 130 is positioned.

[0093] Preferably, the interconnecting substrate 130 is not in contact with the support element 106, at least not along the entire length of the interconnecting substrate 130. Indeed, the space between the support element 106 and the interconnecting substrate 130 is at least partly occupied by elements, these elements being different depending on whether one is in the transducer region 101 or in the control region 102, or even in the transition region 103.

[0094] In the transducer region 101, the space between the support element 106 and the interconnecting substrate 130 can advantageously be filled, at least partially, by an acoustic attenuation material 107, which may be known under the English term "backing". The acoustic attenuation material 107 may have the advantage of attenuating the ultrasonic waves emitted by the transducers.

[0095] The space between the support element 106 and the interconnecting substrate 130 in the transition region 103 can also be at least partially filled by the acoustic attenuation material 107. This can have the advantage of protecting the attachment, for example the gluing, of the transducers 110 on the interconnecting substrate 130 at the edge of the transition region 103.

[0096] In the control region 102, the control circuits 120, and possibly the electronic components 125, occupy at least part of the space between the support element 106 and the interconnecting substrate 130, i.e. the space between the support element 106 and the second portion 132 of the interconnecting substrate 130. All or part of the control circuits 120 may be in contact with the support element 106.

[0097] The support element 106 may be made of a metallic material, for example stainless steel, or of a non-metallic material, for example a polymer or a plastic. The material of the support element 106 may be, for example, a biocompatible material. A layer 109 of a biocompatible material may coat the inner face of the support element 106. Preferably, the support element 106 is made of a material that ensures or improves the mechanical strength of the ultrasonic probe 100.

[0098] The support element 106 shown is a cylindrical tube with a circular cross-section whose axis corresponds substantially to Taxe 105 of the ultrasonic probe 100. The interior of the tubular support element 106 defines an internal cavity 107. Other forms of support element can be considered, in particular polygonal, oval, symmetrical or asymmetrical, geometric or non-geometric cross-sectional profiles, the support element preferably being hollow.

[0099] The internal cavity 107 can be adapted to accommodate a guide wire, or another flexible element such as a tube ending in an inflatable balloon, or a sheath ending in a tool. The diameter D2 of the cavity is, for example, greater than 0.5 mm, for example greater than or equal to 1.3 mm. A larger cavity diameter can be considered, but this may require increasing the outer diameter DI of the ultrasonic probe 100.

[0100] The second region 102 of the ultrasonic probe 100 can be covered by a protective sheath 108. The sheath 108 is preferably made of a biocompatible material. The sheath 108 notably protects the control circuits 120. The protective sheath 108 of the second region 102 is preferably an extension of the protective sheath 108 of the first region 101, and can thus also cover the first 101 and third 103 regions of the ultrasonic probe 100. The protective sheath 108 can also extend at least into part of the fourth region 104.

[0101] Compared to a configuration in which the transducers are positioned radially around the control circuits, the configuration shown in Figures 1 to 3 allows for a reduction in the diameter of the ultrasonic probe. This can also allow for maintaining an annular space between the interconnecting substrate and the support element in the transducer region, for example, to insert an acoustic attenuation material.Furthermore, compared to a configuration in which the transducers and control circuits are axially spaced but positioned on the same face of the interconnect circuit, the configuration shown in Figures 1 to 3 allows the annular space between the interconnect substrate and the support element to be used to position the control circuits in the control region. The annular space between the interconnect substrate and the support element in the transducer region can advantageously be filled with an acoustic damping material. Moreover, the configuration of Figures 1 to 3 is particularly advantageous because it allows the interconnect substrate 130 to be contained within a cylindrical envelope whose diameter remains constant along portions 131, 132, and 133.In other words, the unrolled interconnect substrate has the same width along its entire length, and for example does not require any adjustments (folds or partial cutting for example).

[0102] Fig. 4 is a top view partially showing the ultrasonic probe 100 of Fig. 1 before it is wound around its axis 105. The top view of Fig. 4 is a view of the side of the outer face 130A of the interconnecting substrate 130. Fig. 5 is a bottom view partially showing the ultrasonic probe 100 of Fig. 1 before it is wound around its axis 105. The top view of Fig. 5 is a view of the side of the inner face 130B of the interconnecting substrate 130.

[0103] The ultrasonic probe of Figures 4 and 5 is similar to the ultrasonic probe 100 of Figures 1 to 3, Figures 4 and 5 showing other aspects of the ultrasonic probe which are not described in relation to Figures 1 to 3.

[0104] In particular, [Fig. 4] shows the stiffeners 122, and their ends 122A, in the control region 102, opposite the control circuits 120 (visible in [Fig. 5]), the interconnecting substrate 130 being between the stiffeners 122 and the control circuits 120. [Fig. 4] also shows the outer face 130A of the interconnecting substrate 130, which extends into the connecting strips 137, whose outer faces, or upper faces, 137A are also visible. The upper faces 137A of the connecting strips 137 can form tracks or planes for the mass.

[0105] Figure 4 shows the various ultrasonic transducers 110 in the transducer region 101, and Figure 5 shows the various control circuits 120, as well as the electronic components 125, in the control region 120. Figure 5 also shows the inner face 130B of the interconnecting substrate 130, which extends into the connecting strips 137, the inner faces, or lower faces, 137B of which are also shown. The connecting strips 137 have various tracks 138 on their lower faces 137B, which can form electrical signal conduction tracks.

[0106] Figures 4 and 5 also show conductive tracks 135 of the interconnecting substrate 130 which are arranged on and / or in the dielectric support 136. Some conductive tracks 135 arranged on the outer face 130A can be connected to other conductive tracks arranged, for example, on the inner face 130B by means of a vertical connection, known as a "via", passing through the dielectric support 136. Advantageously, areas of the interconnecting substrate 130 which include the conductive tracks 135 on the outer face 130A can be metallized on the inner face 130B so as to locally form an electromagnetic shield.

[0107] The ultrasonic probe 100 can be manufactured by assembling the ultrasonic transducers 110 on the outer face 130A of the first portion 131 of the interconnecting substrate 130, and by assembling the control circuits 120, and optionally the electronic components 125, on the inner face 130B of the second portion 132 of the interconnecting substrate 130. The stiffeners 122 can be assembled on the outer face 130A of the second portion 132 of the interconnecting substrate 130 opposite the control circuits 120. Then, the interconnecting substrate 130 assembled with the transducers 110 and the control circuits 120 can be wound around the support element 106. An acoustic attenuation material 107 can then be inserted, for example in liquid form before solidifying, into the annular space between the support element 106 and the first portion 131 of the interconnecting substrate 130.

[0108] Optionally, the protective sheath 108 can be placed all around the ultrasonic probe, before or after winding.

[0109] According to one embodiment, as described above, the ultrasonic transducers 110 can be formed by a layer of piezoelectric material, and an impedance matching layer can be formed on the piezoelectric material layer and then cut out along with the piezoelectric material layer, so as to form the piezoelectric sectors 111 and the impedance matching sectors 112. The impedance matching layer can then be wound at the same time as the piezoelectric material layer and the interconnecting substrate.

[0110] The ultrasound probe according to the embodiments can find applications in the field of diagnostics (pre-treatment or post-treatment diagnosis), or intravascular ultrasound treatment, the ultrasound probe being able for example to be integrated into a catheter.

[0111] Various embodiments and variations have been described. A person 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 a person skilled in the art.

[0112] 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 probe (100) extending in a longitudinal direction (Z) along an axis (105), the ultrasonic probe comprising: - an interconnecting substrate (130) comprising a first face (130A) and a second face (130B) opposite the first face; - a plurality of ultrasonic transducers (110) arranged in a first region (101) of the ultrasonic probe and on the first face of the interconnecting substrate; - a plurality of control circuits (120) arranged in a second region (102) of the ultrasonic probe and on the second face of the interconnecting substrate, the second region being distinct from the first region.

2. Ultrasonic probe (100) according to claim 1, wherein the first face (130A) is an external face of the interconnecting substrate and the second face (130B) is an internal face of the interconnecting substrate.

3. Ultrasonic probe (100) according to claim 1 or 2, wherein the second region (102) is axially offset with respect to the first region (101).

4. Ultrasonic probe (100) according to any one of claims 1 to 3, wherein the first region (101) comprises a first portion (131) of the interconnecting substrate (130) and the second region (102) comprises a second portion (132) of the interconnecting substrate, the second portion being distinct from the first portion, for example axially offset from the first portion.

5. Ultrasonic probe (100) according to claim 4, wherein the first portion (131) of the interconnecting substrate (130) has a first circular, oval, or polygonal section having a first number (N) of sides, and the second portion (132) has a second polygonal section having a second number (M) of sides, the second number of sides being less than the first number of sides, for example at least five times less, or at least ten times less, or even at least twenty times less.

6. Ultrasonic probe (100) according to claim 5, wherein the first portion (131) of the interconnecting substrate (130) presents a cylindrical shape with a substantially circular or oval cross-section around the axis (105), said first portion including flat portions on which the ultrasonic transducers (110) are positioned.

7. Ultrasonic probe (100) according to claim 5 or 6, wherein the second portion (132) of the interconnecting substrate (130) has a prismatic shape around the axis (105), said second portion including a plurality of facets (139), the control circuits (120) being arranged against all or part of said facets.

8. Ultrasonic probe (100) according to claim 7, wherein the second portion (132) of the interconnecting substrate (130) includes rounded edges between the facets (139).

9. Ultrasonic probe (100) according to any one of claims 5 to 8, wherein the interconnecting substrate (130) comprises a third portion (133) between the first portion (131) and the second portion (132), the third portion being in a third region (103) of the ultrasonic probe between the first region (101) and the second region (102), the third portion forming a shape transition portion of the section of the interconnecting substrate.

10. Ultrasonic probe (100) according to any one of claims 1 to 9, the ultrasonic probe further comprising stiffeners (122) in the second region (102) at the right of the control circuits (120), for example the interconnecting substrate (130) being between the control circuits and the stiffeners.

11. Ultrasonic probe (100) according to any one of claims 5 to 9 in combination with claim 10, wherein all or part of the stiffeners (122) has an end (122A) oriented towards the first region (101), said end being adapted to constrain the interconnecting substrate to transform the first section into the second section, for example the stiffener extending into a third region (103) of the ultrasonic probe between the first region (101) and the second region (102).

12. Ultrasonic probe (100) according to any one of claims 1 to 11, wherein the interconnecting substrate (130) is a single piece in the longitudinal direction (Z).

13. Ultrasonic probe (100) according to any one of claims 1 to 12, the ultrasonic probe further comprising components electronics (125) arranged in the second region (102), on the second face (132) of the interconnecting substrate (130) and axially away from the control circuits (120).

14. Ultrasonic probe (100) according to any one of claims 1 to 13, the ultrasonic probe having an external cylindrical shape around the axis (105), the transducers (110) being distributed, for example regularly distributed, around the axis in the first region (101) and the control circuits being distributed, for example regularly distributed, around the axis in the second region (102).

15. Ultrasonic probe (100) according to any one of claims 1 to 14, the ultrasonic probe further comprising a support element (106) around which the interconnecting substrate (130), the plurality of ultrasonic transducers (110) and the plurality of control circuits (120) are arranged, the support element comprising an internal cavity (107), for example adapted for the passage of a guiding element of the ultrasonic probe, such as a guide wire.

16. Ultrasonic probe (100) according to claim 15, the ultrasonic probe further comprising an acoustic attenuation material (107) between the support element (106) and the interconnecting substrate (130) in the first region (101).

17. Ultrasonic probe (100) according to claim 15 or 16, wherein the control circuits (120) are between the support element (106) and the interconnecting substrate (130) in the second region (102), for example all or part of the control circuits being in contact with the support element.

18. Ultrasonic probe (100) according to any one of claims 1 to 17, the ultrasonic probe further comprising a fourth region (104) extending from the second region (102) opposite the first region (101), and the interconnecting substrate (130) comprising a fourth portion (134) in the fourth region, said fourth portion comprising connecting strips (137) of the interconnecting substrate, said connecting strips being for example connected to cables (140).

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