Ultrasound imaging probe

Abstract

The present description relates to an ultrasound imaging probe (100) comprising a plurality of elementary ultrasound transducers (111) arranged in a matrix-array in rows and columns, in which the elementary transducers (111) are divided into multiple elementary groups (113) each comprising a plurality of transducers (111), the probe comprising, for each elementary group (113), an analogue micro-beamforming circuit (123) connected individually to each transducer (111) of the group (113), and designed to provide an analogue signal generated by delaying and summing analogue response signals from the elementary transducers (111) of the group (113), in which each elementary group (113) consists of a set of adjacent elementary transducers (111), said set having at least one dimension, in the direction of the rows, that differs from a dimension in the direction of the columns.

Description

DESCRIPTION TITLE: Ultrasound Imaging Probe This application is based on, and claims priority from, French patent application FR2302002 filed on March 3, 2023 and entitled "Ultrasonic Imaging Probe", which is considered to form an integral part of this description within the limits provided by law. technical field

[0001] This description relates to the field of ultrasound imaging, and more specifically to an ultrasound imaging probe intended to be connected to an external control and processing system via a cable, the probe integrating a plurality of ultrasound transducers and electronic circuits for controlling these transducers. Previous technique

[0002] Various architectures for ultrasound imaging probes have already been proposed.

[0003] It would be desirable to improve at least some aspects of known ultrasound imaging probes.

[0004] We are particularly interested here in the realization of an ultrasonic imaging probe including analog circuits adapted to implement micro-beam forming functions, for example for the implementation of ultrafast acquisition scenarios. Summary of the invention

[0005] One embodiment provides an ultrasound imaging probe comprising a plurality of elementary ultrasound transducers arranged in a matrix of rows and columns, the probe comprising, for each elementary ultrasonic transducer, a specific receiving circuit connected to an electrode of the transducer and adapted to amplify an electrical response signal generated by the elementary transducer during a reception phase of an ultrasonic wave, in which the elementary transducers are distributed into several elementary groups, each comprising a plurality of transducers, the probe comprising, for each elementary group, an analog micro-beamforming circuit individually connected to an output terminal of the receiving circuit of each transducer in the group, and adapted to provide an analog signal generated by delay and summation of analog output signals from the receiving circuits of the elementary transducers in the group, in which each elementary group consists of a set of adjacent elementary transducers, said set having at least one dimension, in the direction of the rows,different in dimension, in the direction of the columns, or in which the elementary transducers each have an elongated shape in the direction of the rows or columns, and each elementary group consists of a set of adjacent elementary transducers, said set having a general square shape.

[0006] According to one embodiment, each elementary group comprises a number of elementary transducers different from an integer raised to the square.

[0007] According to one embodiment, the elementary groups have nested forms.

[0008] According to one embodiment, the elementary groups have nested head-to-tail L-shaped forms, or nested head-to-tail F-shaped forms.

[0009] According to one embodiment, the elementary groups have interlocking cross shapes.

[0010] According to one embodiment, each elementary group consists solely of adj acent elementary transducers of the same row or column of the matrix of elementary transducers.

[0011] According to one embodiment, each column of elementary transducers of the matrix of elementary transducers comprises several elementary groups, each comprising a plurality of adj acent elementary transducers of the column, and / or each row of elementary transducers of the matrix of elementary transducers comprises several elementary groups, each comprising a plurality of adj acent elementary transducers of the row.

[0012] According to one embodiment, each elementary transducer belongs to only a first elementary group consisting solely of elementary transducers from the same row of the matrix of elementary transducers, and a second elementary group consisting solely of elementary transducers from the same column of the matrix of elementary transducers.

[0013] According to one embodiment, each elementary transducer belongs to a unique elementary group.

[0014] According to one embodiment, the probe includes, for each elementary transducer, a specific receiving circuit connected to an electrode of the transducer.

[0015] According to one embodiment, each transmit-receive circuit includes an amplifier and a time-adjustment gain circuit between said transducer electrode and an input terminal of the beam microforming circuit. Brief description of the drawings

[0016] 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 attached figures, among which:

[0017] Figure 1 schematically and partially represents an example of an ultrasound imaging probe;

[0018] Figure 2 schematically and partially represents an example of the arrangement of elementary transducers of an ultrasonic imaging probe according to one embodiment;

[0019] Figure 3 schematically and partially represents another example of the arrangement of elementary transducers of an ultrasonic imaging probe according to one embodiment;

[0020] Figure 4 schematically and partially represents another example of the arrangement of elementary transducers of an ultrasonic imaging probe according to one embodiment;

[0021] Figure 5 schematically and partially represents another example of the arrangement of elementary transducers of an ultrasonic imaging probe according to one embodiment;

[0022] Figure 6 schematically and partially represents another example of the arrangement of elementary transducers of an ultrasonic imaging probe according to one embodiment;

[0023] Figure 7 schematically and partially represents another example of the arrangement of elementary transducers of an ultrasonic imaging probe according to one embodiment;

[0024] Figure 8 schematically and partially represents another example of the arrangement of elementary transducers of an ultrasonic imaging probe according to one embodiment;

[0025] Figure 9 schematically and partially represents another example of the realization of an ultrasonic imaging probe according to one embodiment;

[0026] Figure 10 schematically and partially represents another example of the realization of an ultrasonic imaging probe according to one embodiment;

[0027] Figure 11 schematically and partially represents another example of the arrangement of elementary transducers of an ultrasound imaging probe according to one embodiment; and

[0028] Figure 12 schematically and partially represents another example of the arrangement of elementary transducers of an ultrasonic imaging probe according to one embodiment; Description of the implementation methods

[0029] The same elements have been designated by the same reference numerals in the different figures. In particular, 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.

[0030] For the sake of clarity, only the steps and elements necessary for understanding the described embodiments have been shown and detailed. In particular, the various applications of the described ultrasound probes and imaging systems have not been detailed, as the described embodiments are compatible with the usual applications of ultrasound imaging probes. Furthermore, the properties (frequencies, shapes, amplitudes, etc.) of the electrical excitation signals applied to the ultrasonic transducers have not been detailed, as the described embodiments are compatible with the excitation signals commonly used in ultrasonic imaging systems. These signals can be chosen according to the application and, in particular, the nature of the body to be analyzed, for example, based on the physiology of the tissues to be analyzed, and the type of information one seeks to acquire. Similarly, the various processing steps applied to the electrical signals provided by the ultrasonic transducers and read by the control circuit to extract useful information about the body to be analyzed have not been detailed, as the described embodiments are compatible with the processing commonly used in ultrasonic imaging systems.Furthermore, the fabrication of the ultrasonic transducers and the electronic control circuits of the transducers has not been described in detail, the detailed fabrication of these elements being within the reach of a person skilled in the art from the indications of this description, using known techniques for the fabrication of ultrasonic transducers and electronic circuits.

[0031] Unless otherwise specified, when referring to two connected elements, this means directly connected without any intermediate elements other than electrical conductors, and when referring to two coupled elements, this means that these two elements can be connected or linked through one or more other elements.

[0032] In the description that follows, when referring to absolute positional qualifiers, such as the terms "front", "back", "top", "bottom", "left", "right", etc., or relative terms such as "above", "below", "superior", "inferior", etc., or orientation qualifiers such as "horizontal", "vertical", etc., refers, unless otherwise specified, to the orientation of the figures.

[0033] Unless otherwise specified, the expressions "approximately", "roughly", and "on the order of" mean within 10%, preferably within 5%.

[0034] Figure 1 is an exploded view schematically and partially representing an example of an ultrasonic imaging probe 100.

[0035] The probe 100 comprises a plurality of elementary ultrasonic transducers 111, and electronic circuits for controlling the transducers.

[0036] In operation, the probe's array of ultrasonic transducers is positioned facing the object whose image is to be acquired. The electronic control circuits are configured to apply electrical excitation signals to the transducers, causing them to emit ultrasonic waves towards the object being analyzed. The ultrasonic waves emitted by the transducers are reflected by the object (through 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 circuits and then transmitted to an external processing device (EXT, not detailed in the figure), such as a computer, via a connecting cable (not shown). These signals can be stored and analyzed by the external device to deduce information about the object being studied.Figure 1 shows the transmission circuits, adapted to apply signals. electrical excitation to the transducers, have not been shown.

[0037] The 100 probe, for example, is a portable probe designed to be positioned and, possibly moved, manually on a patient's body.

[0038] In the example in Figure 1, the probe 100 comprises a plurality of elementary ultrasonic transducers 111 arranged in a matrix of rows and columns. The elementary transducers 111 are, for example, all identical except for manufacturing variations. Figure 1 shows a 9x9 matrix of elementary transducers 111. In practice, the matrix can contain several thousand to several tens of thousands of individually addressable elementary transducers 111.

[0039] Each elementary transducer 111 comprises two electrodes (not detailed in the figure) for applying an electrical excitation signal to the transducer and for reading an electrical response signal from the transducer.

[0040] Elementary transducers 111 are for example CMUT type transducers (micro-machined capacitive ultrasonic transducers), for example PMUT type transducers (piezoelectric micro-machined ultrasonic transducer), piezoelectric crystal or ceramic transducers, or any other type of ultrasonic transducer.

[0041] As an example, the inter-transducer pitch is on the order of a few tens to a few hundred micrometers in both the row and column directions. However, the described embodiments are not limited to this particular case. In the example of Figure 1, the elementary transducers 111 have a square shape, with the orthogonal sides of the squares being parallel. respectively to the direction of the rows and to the direction of the columns, and the inter-transducer pitch being identical in the direction of the rows and in the direction of the columns.

[0042] In the example in Figure 1, the elementary transducers 111 of the probe 100 are distributed into elementary groups 113, each containing a square submatrix of n*n adjacent transducers. In the example shown, n is equal to 3. As an example, each elementary transducer 111 belongs to one and only one elementary group 113.

[0043] The probe 100 also includes an analog transmit-receive circuit 120, only partially shown in Figure 1. The analog transmit-receive circuit 120 includes, for each elementary transducer 111, an elementary receiving circuit 121. The analog transmit-receive circuit 120 may further include, for each elementary transducer, an elementary transmitting circuit (not shown), and a transmit-receive switch (not shown).

[0044] As an example, the elementary transmission circuit is adapted to apply an electrical excitation signal to the elementary transducer 111 during an emission phase of an ultrasonic wave. The elementary reception circuit 121 is adapted to condition and amplify an electrical response signal generated by the transducer 111 during the reception phase of an ultrasonic wave. The transmit-receive switch allows an electrode of the elementary transducer 111 to be connected either to an output terminal of the elementary transmitting circuit (during the transmission phase of an ultrasonic wave), or to an input terminal of the elementary receiving circuit (during the reception phase of an ultrasonic wave).

[0045] The transmission circuit includes, for example, a pulse generator having an input terminal for receiving a control logic signal, and an output terminal connected, for example, to the output terminal of the transmission circuit. The input terminal of the pulse generator can be connected, for example, to an output node of a control logic circuit (not shown) of the probe. When the logic signal applied to the input terminal of the pulse generator is in a first state, the pulse generator provides a high-level voltage at its output terminal, and when the logic signal applied to the input terminal of the pulse generator is in a second state, the pulse generator provides a low-level voltage at its output terminal. The output signal of the pulse generator corresponds to an excitation signal for the transducer 111, which can be applied directly to the transducer electrode.

[0046] In this example, the receiving circuit 121 includes a receiving amplifier 121a, preferably a low-noise amplifier (LNA), having an input terminal connected, for example, to the input terminal of the receiving circuit. The amplifier 121a is, for example, a linear amplifier. Furthermore, in this example, the receiving circuit 121 includes a time-dependent gain adjustment (TGC) circuit 121b having an input terminal connected, for example, to an output terminal of the receiving amplifier 121a, and an output terminal connected, for example, to an output terminal of the receiving circuit 121. The circuit 121b is configured to apply a time-varying analog gain to the transducer response signal during a receiving phase.More specifically, during a phase of reception of a return ultrasonic wave by the transducer 111, the gain applied by the circuit 121b to the response signal of the transducer gradually increases. The gain adjustment function depends on time, and therefore on the depth of the scanned area, in order to compensate for the attenuation of the ultrasonic signal by the scanned medium. As an alternative (not shown), the time-dependent gain adjustment circuit 121b can be placed upstream of the amplifier 121a, between the input terminal of the receiver circuit 121 and the input terminal of the amplifier 121a. In this case, circuit 121b applies a gradual attenuation to homogenize the signal amplitude according to the scanning depth before amplification by circuit 121a. In another alternative, the gain adjustment function is implemented by the amplifier circuit 121a itself (non-linear amplification).

[0047] The analog transmit-receive circuit 120 further includes, for each elementary group 113 of ultrasonic transducers 111, an analog micro-beamforming circuit 123 individually connected to each transducer in the group, and adapted to provide an analog signal corresponding to a sum of analog response signals from the elementary transducers 111 in the group.

[0048] More specifically, in this example, each microbeamforming circuit 123 comprises, for each elementary transducer 111 of group 113, a delay circuit 123a, i.e., n*n delay circuits 123a per circuit 123. Each delay circuit 123a has an input terminal connected, for example, to the output terminal of the receiver circuit 121 of the associated elementary transducer 111, and an output terminal. Each circuit 123a is adapted to provide at its output terminal an analog signal corresponding to the analog signal applied at its input terminal, delayed by a predetermined, fixed, or adjustable delay. The delays introduced by the circuits 123a can be identical for all the elementary transducers 111 of the elementary group 113, or differentiated individually for each transducer.

[0049] Each micro-beamforming circuit 123 further includes an analog summation circuit 123b having a specific input terminal for each elementary transducer 111 of the associated elementary group 113, i.e., n*n individual input terminals in this example, and a single output terminal. The input terminals of the analog summation circuit 123b are connected, for example, individually and respectively to the output terminals of the n*n elementary receiving circuits 121 associated with the n*n elementary transducers 111 of the elementary group 113. The circuit 123b is adapted to provide, at its output terminal, an analog signal representing the sum or superposition of the analog signals applied to its n*n input terminals.

[0050] The output signal from each beamforming microcircuit 123 can be transmitted to the external control and processing device (EXT) in analog form via a single conductor. Alternatively, the probe may include a dedicated analog-to-digital converter (not shown) at the output of each summing circuit 123b, with the output signals from the beamforming microcircuits 123 then being transmitted outside the probe in digital form.

[0051] As illustrated in Figure 1, the electronic transmit-receive circuit 120 includes one or more input terminals adapted to receive power and control signals P. The power and control signals P are, for example, transmitted from the external device via one or more conductive wires of the connecting cable electrically linking the probe 100 to the external device.

[0052] Predicting the analog beamforming microcircuits 123 in the probe 100 advantageously limits (divides by n*n) in the example of Figure 1, the number of response signals to be transmitted at the output of the analog transmit-receive circuit 120 during a phase of receiving an ultrasound wave. All the response signals generated by the beamforming microcircuits 123 can be transmitted outside the probe (before or after digitization), for example, to implement ultrafast imaging methods.

[0053] Ultrafast ultrasound imaging differs from so-called conventional ultrasound imaging.

[0054] Conventional imaging is based on focusing ultrasonic waves by applying delay laws to elementary ultrasonic transducers at the transmitter. The same process is applied at the receiver to reconstruct the acoustic image received by the array of ultrasonic transducers. In other words, delay and summation processing is applied to achieve the desired focus at both the transmitter and receiver.

[0055] Ultrafast imaging, on the other hand, involves insonifying (acoustically exciting) the entire medium using multiple unfocused acoustic waves (for example, plane or divergent waves). The system records the electrical response signals generated by all the elementary transducers during an acquisition time window, and then, from these signals, reconstructs the resulting image for a large number of focal points until sufficient information about the object being studied is obtained.

[0056] Ultrafast ultrasound imaging allows the observation of very rapid phenomena (typically 1000 images / second) at the cost of numerous calculations. It is complementary to conventional imaging, which allows for equivalent image quality with much less calculation but also a slower image rate (typically 50 images / sec).

[0057] Microbeam shaping reduces the number of response signals to be processed and is based on conventional imaging delay-summation algorithms applied at the scale of elementary groups 113 of transducers, also called sub-apertures. The electrical signals generated by the elementary transducers 111 of each elementary group or sub-aperture 113 are delayed and summed by the group's analog elementary microbeam shaping circuit 123, which is integrated into the probe. This summation allows for a single output data transmission conductor between each elementary group 113 and the imaging system. The system can then reconstruct the image seen by the probe by applying further delay-summation processing to the signals produced by the microbeam shaping circuits 123, i.e., to macro-elements, each corresponding to an elementary group 113.In other words, unlike a so-called fully populated probe (that is, one in which the set of individual response signals from the elementary transducers is transmitted to the system), in a micro-beamforming probe of the type described in relation to Figure 1, the delay and summation processing is carried out in two stages, a first stage in the probe and a second stage outside the probe.

[0058] In the example in Figure 1, the elementary transducers 111 have a square shape, and the sub-openings or elementary groups 113 also have a square shape.

[0059] The inventors identified that, depending on the type of images one seeks to acquire, it can be advantageous to plan micro-beam forming circuits coupled to elementary groups of ultrasonic transducers of different geometries.

[0060] We can distinguish in particular the cases where we seek to acquire a two-dimensional image of the body to be analyzed (2D imaging), from the cases where we seek to acquire a three-dimensional image of the body studied (3D imaging).

[0061] In 3D imaging, it is preferable that the distribution of elementary groups be as isotropic as possible, that is to say that the inter-elementary group spacing 113 is the same or substantially the same in the direction of the rows and in the direction of the columns of the matrix of elementary transducers 111.

[0062] In this regard, the choice of a square submatrix of n*n elementary transducers as described in relation to Figure 1 is an interesting solution.

[0063] However, in some cases, the miniaturization capabilities of the electronics embedded in the probe may allow for the creation of micro-beamforming circuits 123 capable of addressing a number of receiving channels other than a square number. In this case, it may be advantageous, in order to utilize all the channels of each micro-beamforming circuit, to define non-square elementary groups 113 or non-square elementary transducers 111.

[0064] Thus, according to one aspect of an embodiment, an ultrasonic probe is provided, incorporating micro-beam forming electronic circuits of the type described in relation to Figure 1, differing from the probe of Figure 1 by the geometric construction of the elementary groups 113 of ultrasonic transducers 111.

[0065] Non-limiting examples of patterns of the elementary groups 113 of such a probe are illustrated in figures 2, 3, 4 and 5.

[0066] In figures 2, 3, 4 and 5, the direction of the rows of the matrix of elementary transducers 111 has been represented by an R axis and the direction of the columns of the matrix of elementary transducers 111 has been represented by an C axis.

[0067] In each of Figures 2, 3, 4, and 5, only a set of 2*2 elementary groups 113, respectively referenced 113(1), 113(2), 113(3), and 113(4), has been represented. In practice, the illustrated pattern can be repeated identically across the entire matrix of elementary transducers 111.

[0068] In the examples in Figures 2, 3, 4 and 5, the number of adjacent elementary transducers 111 per elementary group 113 is equal to 18. The embodiments described are of course not limited to this particular case.

[0069] The elementary groups 113, for example, exhibit forms that are nested in the direction of the rows and / or in the direction of the columns, for example as illustrated in relation to figures 2, 3 and 4.

[0070] By nested forms in the direction of the rows, we mean that at least a subset of first and second elementary groups 113 adjacent in the direction of the rows comprises at least one column with elementary transducers 111 belonging to the first elementary group and transducers 111 belonging to the second elementary group.

[0071] By nested forms in the column direction, we mean that at least a subset of first and second elementary groups 113 adjacent in the column direction comprises at least one row containing elementary transducers 111 belonging to the first elementary group and transducers 111 belonging to the second elementary group.

[0072] Two elementary groups 113 adj acents for example have symmetrical forms with respect to an axis parallel to the direction of the rows or parallel to the direction of the columns.

[0073] As an example, each elementary group 113 of ultrasonic transducers has at least one dimension in the row direction, different from one dimension in the column direction.

[0074] Figure 2 illustrates a first example of an embodiment in which the elementary groups 113 have head-to-tail L-shaped forms, nested in the direction of the rows.

[0075] Figure 3 illustrates a second example of realization in which the elementary groups 113 have head-to-tail F shapes, nested in the direction of the rows.

[0076] Figure 4 illustrates a third example of realization in which the elementary groups 113 have interlocking cross shapes, whose main branches are respectively parallel to the direction of the rows and the direction of the columns.

[0077] As an alternative, the elementary groups 113 have a square shape, and the elementary transducers 111 each have an elongated shape in the direction of the rows or columns, for example a rectangular shape.

[0078] Figure 5 illustrates an example of an embodiment in which the elementary transducers 111 each have a general rectangular shape, the longer side of the rectangle (length) being parallel to the direction of the columns and the the smallest side (width) of the rectangle being parallel to the direction of the rows. In this example, each elementary group 113 comprises a submatrix of n*m elementary transducers 111, n being the number of rows of the submatrix and m being the number of columns of the submatrix, n and m being chosen so that the elementary group 113 has a general shape substantially square.

[0079] More specifically, in the example in Figure 5, each elementary transducer has a length approximately equal to twice its width, and m is equal to twice n (n = 3 and m = 6 in the example shown), so that the elementary group 113 has a generally square shape.

[0080] Ultrafast 2D imaging can consist of reconstructing a single plane after insonating the entire medium. The image can be optimized by using, at the emission stage, a delay law that concentrates the energy in the plane to be imaged. For example, a divergent or planar delay law is used for the plane to be imaged, focused perpendicularly to this plane, such as a saddle-shaped delay law. At the reception stage, only the plane to be imaged is reconstructed. The return wave is focused perpendicularly to the plane to be imaged. An example of such an imaging mode is described in the document entitled "3D ultrafast echocardiography: toward a quantitative imaging of the myocardium" - Victor Finel - Sorbonne Paris Cité University, 2018, specifically in section 2.3.1.1 of this document.

[0081] In this case, it is advantageous for the elementary intergroup step to be as close as possible to that of a linear probe in the direction of the plane to be imaged.

[0082] Thus, according to one aspect of an embodiment, each elementary group 113 consists of adjacent elementary transducers 111 of the same and unique row or column of the matrix of elementary transducers.

[0083] Figures 6, 7, and 8 schematically illustrate examples of 2D ultrasonic imaging probes according to this embodiment. In these examples, the probe is particularly well-suited for imaging one or more planes parallel to the direction of the matrix rows.

[0084] In the examples in Figures 6 and 7, the elementary transducers 111 each have a square shape.

[0085] In the example in Figure 6, each column of the matrix of elementary transducers 111 defines an elementary group 113. In other words, each elementary group 113 consists of the set of elementary transducers 111 from the same column of the matrix.

[0086] In the example in Figure 7, each column of the matrix of elementary transducers 111 comprises several elementary groups 113, two elementary groups 113 referenced respectively as 113(1) and 113(2) in the example shown. Each elementary group 113 consists of a set of adjacent elementary transducers 111 from the same column of the matrix.

[0087] The example in Figure 8 is similar to the example in Figure 6, except that, in the example in Figure 8, the elementary transducers 111 each have an elongated direction in the direction of the columns, for example a rectangular shape, for example of the type described in relation to Figure 5.

[0088] The embodiment shown in Figure 8 can of course be combined with the embodiment shown in Figure 7.

[0089] Figure 9 schematically and partially represents another example of the realization of an ultrasonic imaging probe according to one embodiment.

[0090] In this example, the probe is adapted to image one or more planes parallel to the direction of the matrix rows, and one or more planes parallel to the direction of the matrix columns.

[0091] This example schematically represents elementary groups 113 of 3 elementary transducers 111 each. The embodiments described are, of course, not limited to this particular case.

[0092] In the example in Figure 9, each elementary transducer belongs to two and only two elementary groups 113(C) and 113(R). The first elementary group 113(C) consists of a set of adjacent elementary transducers in the same column of the elementary transducer matrix 111, and the second elementary group 113(R) consists of a set of adjacent elementary transducers in the same row of the matrix.

[0093] As an example, each first elementary group 113 (1) consists of the set of elementary transducers 111 in the corresponding column, as described in relation to Figure 6. Alternatively, each first elementary group 113 (1) consists of a subset of adjacent elementary transducers 111 in the corresponding column, as described in relation to Figure 7. Similarly, each second elementary group 113 (2) can consist of the set of elementary transducers 111 in the corresponding row, or of a subset of adjacent elementary transducers 111 in the corresponding row.

[0094] Figure 9 also schematically represents, for each elementary group 113, a dedicated micro-beamforming (pBF) circuit 123 connected to the elementary transducers of the group. For the sake of simplicity, the receiving circuits 121 (Figure 1) connected to the elementary transducers 111 have not been detailed in Figure 9.

[0095] Thus, in the example in Figure 9, each elementary transducer 111 is connected to two and only two micro-beam-forming circuits 123.

[0096] Figure 10 schematically and partially represents another example of the realization of an ultrasonic imaging probe according to one embodiment.

[0097] The example in Figure 10 differs from the example in Figure 9 essentially in that, in the example in Figure 10, the same micro-beam-forming circuits 123 are pooled and shared by the elementary groups 113 (R) and by the elementary groups 113 (C).

[0098] More specifically, in this example, each micro-beam-forming circuit 123 is shared by one and only one elementary group 113 (R) and one and only one elementary group 113 (C) elementary 113 (R).

[0099] For this purpose, a MUX multiplexing circuit allows to connect to the input terminals of the circuit 123 either the elementary transducers 111 of the associated elementary group 113 (R), or the elementary transducers 111 of the associated elementary group 113 (C).

[0100] Thus, the number of micro-beam-forming circuits is divided by two compared to the example in Figure 9.

[0101] Figures 11 and 12 represent further examples of arrangements of elementary transducers of an ultrasonic imaging probe according to one embodiment.

[0102] The examples in Figures 11 and 12 concern two-dimensional (2D) imaging probes. The probes in Figures 11 and 12 are more specifically so-called 1.75D type probes, that is to say matrix probes whose inter-transducer pitch in elevation, i.e. in the direction of the columns, is equal to several times the central wavelength X of the emitted ultrasonic waves, while the inter-transducer pitch in azimuth, i.e. in the direction of the rows, is between X and X / 2.

[0103] The transition from a 1D probe (linear array of elementary transducers) to a 1.75D probe notably improves its imaging capabilities in terms of: variation of the size of the aperture and elevating acoustic apodization; - dynamic focusing in transmission and reception; - beam deflection outside the imaging plane to better discretize reflectors.

[0104] In the examples in Figures 11 and 12, the probe comprises four elementary transducers per column, and 64 columns. However, the embodiments described are not limited to this particular case.

[0105] In the examples in Figures 11 and 12, the number of adjacent elementary transducers 111 per elementary group 113 is equal to 16. Again, the embodiments described are not limited to this particular case.

[0106] In the example in Figure 11, each elementary group 113 consists of the set of elementary transducers 111 from four adjacent columns of elementary transducers. Thus, in this example, the elementary transducers of the same column are connected to the same and unique micro-beam forming circuit 123.

[0107] In the example in Figure 12, each elementary group 113 consists of all the elementary transducers in a submatrix of 2 adjacent rows by 8 adjacent columns of elementary transducers. Thus, in this example, each column comprises two adjacent transducers connected to a first beamforming microcircuit 123 and two adjacent transducers connected to a second beamforming microcircuit 123.

[0108] 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 specific examples of arrangement of the elementary groups 113 described in relation to Figures 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0109] Finally, the practical implementation of the described methods and variants is within the reach of the person in the trade, based on the functional indications given above.

Claims

CLAIMS 1. Ultrasound imaging probe (100) comprising a plurality of elementary ultrasonic transducers (111) arranged in a matrix in rows and columns, the probe comprising, for each elementary ultrasonic transducer (111), a specific reception circuit (121) connected to an electrode of the transducer and adapted to amplify an electrical response signal generated by the elementary transducer (111) during a reception phase of an ultrasonic wave, in which the elementary transducers (111) are distributed into several elementary groups (113) each comprising a plurality of transducers (111), the probe comprising, for each elementary group (113), an analog micro-beamforming circuit (123) individually connected to an output terminal of the reception circuit (121) of each transducer (111) of the group (113),and adapted to provide an analog signal generated by delay and summation of analog output signals from the reception circuits (121) of the elementary transducers (111) of the group (113), in which each elementary group (113) consists of a set of adjacent elementary transducers (111), said set having at least one dimension, in the direction of the rows, different from a dimension, in the direction of the columns, or in which the elementary transducers (111) each have an elongated shape in the direction of the lines or columns, and each elementary group (113) consists of a set of adjacent elementary transducers (111), said set having a generally square shape., 2. Probe (100) according to claim 1, in which each elementary group (113) comprises a number of elementary transducers (111) different from an integer squared.

3. Probe (100) according to claim 1 or 2, in which the elementary groups (113) have nested shapes.

4. Probe (100) according to claim 3, in which the elementary groups (113) have nested head-to-tail L shapes, or nested head-to-tail F shapes.

5. Probe (100) according to claim 3, in which the elementary groups (113) have nested cross shapes.

6. Probe (100) according to claim 1 or 2, in which each elementary group (113) is made up solely of adjacent elementary transducers (111) of the same row or of the same column of the matrix of elementary transducers.

7. Probe according to claim 6, in which each column of elementary transducers (111) of the matrix of elementary transducers comprises several elementary groups (113) each comprising a plurality of adjacent elementary transducers (111) of the column, and / or each row of elementary transducers (111) of the matrix of elementary transducers comprises several elementary groups (113) each comprising a plurality of adjacent elementary transducers (111) of the row.

8. Probe (100) according to claim 6 or 7, in which each elementary transducer (111) belongs to only a first elementary group (113 (R)) consisting only of elementary transducers (111) of the same row of the matrix of elementary transducers, and a second elementary group (113 (C)) consisting only of elementary transducers (111) of the same column of the matrix of elementary transducers.

9. Probe (100) according to any one of claims 1 to 7, in which each elementary transducer (111) belongs to a single elementary group (113).

10. Probe (100) according to any one of claims 1 to 9, wherein each transceiver circuit comprises an amplifier (121a) and a gain time adjustment circuit (121b) between said transducer electrode and an input terminal of the microbeamforming circuit (123).

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