EP-4070051-B1 - METHODS AND SYSTEMS FOR A MULTI-FREQUENCY TRANSDUCER ARRAY

Inventors

• DACRUZ, EDOUARD
• DALOZ, Flavien
• BARRETT, JASON

Dates

Publication Date

20260513

Application Date

20201123

Claims (5)

1. A multi-frequency acoustic stack, comprising: a first comb structure (1100) coupled to a second comb structure (1300), the first comb structure having at least one first element of a first type of element with a first resonance frequency and the second comb structure having at least one second element of a second type of element with a second resonance frequency, wherein the width of the first type of element is greater than the width of the second type of element; and a plurality of electrical circuits, each circuit (208) including at least one of the first elements and the second elements and configured to vary in frequency bandwidth to provide frequency apodization along at least one of an azimuth (101) and an elevation (103) direction; wherein the first comb structure has a geometry complementary to a geometry of the second comb structure and coupling of the first and second comb structure forms an interdigitated structure; and wherein each electrical circuit is coupled to a matching layer (1002) and a dematching layer (1006).
2. The multi-frequency acoustic stack of claim 1, wherein each electrical circuit of the plurality of electrical circuits includes one or more additional elements of an additional type of element in addition to at least one of the first and second elements, the additional types of elements having different resonance frequencies than the first or second types of elements.
3. The multi-frequency acoustic stack of claim 1, wherein each electrical circuit is coupled to a backing layer (126).
4. The multi-frequency acoustic stack of claim 1, wherein each element of the plurality of elements is separated from adjacent elements by kerfs (2503) filled with one of a non-conductive material and air.
5. The multi-frequency acoustic stack of claim 1, wherein each element is electrically coupled to positive and ground connections to form individual integrated circuits.

Description

FIELD Embodiments of the subject matter disclosed herein relate to a transducer for a medical device. BACKGROUND Transducer probes are used in a variety of applications to convert energy from a physical form to an electrical form. For example, a transducer probe may include piezoelectric materials which generate electrical voltage from a mechanical stress or strain exerted on the materials. Piezoelectric transducer probes are configured to be highly sensitive to provide large signal amplitudes, broad bandwidth for use across a wide range of frequencies, and short-duration impulse for high axial resolution. Such properties are desirable for medical applications such as imaging, non-destructive evaluation, fluid flow sensing, etc. Furthermore, frequency apodization of the transducer probe may mitigate loss of signal resolution due to signal attenuation and dispersion as the signal travels away from its source. WO 2009/078208 A1 describes that an ultrasonic probe transmits a first ultrasonic signal into an examinee and receives a second ultrasonic signal based on the first ultrasonic signal and coming from the examinee. The ultrasonic probe includes a plurality of first piezoelectric elements each formed of a piezoelectric material and capable of using a piezoelectric phenomenon to perform conversion between an electric signal and an ultrasonic signal. Each of the first piezoelectric elements is divided into a plurality of areas. A plurality of second piezoelectric elements having different resonance frequencies are arranged in the respective areas. US 2017/136495 A1 describes that in some examples, a CMUT array may include a plurality of elements, and each element may include a plurality of sub-elements. For instance, a first sub-element and a second sub-element may be disposed on opposite sides of a third sub-element. In some cases, the third sub-element may be configured to transmit ultrasonic energy at a higher center frequency than at least one of the first sub-element or the second sub-element. Further, in some instances, the sub-elements may have a plurality of regions in which different regions are configured to transmit ultrasonic energy at different resonant frequencies. For instance, the resonant frequencies of a plurality of CMUT cells in each sub-element may decrease in an elevation direction from a center of each element toward the edges of the CMUT array. US 2002/188200 A1 describes that an ultrasonic probe is provided for medical applications which can be used both in high resolution imaging and therapy or other high intensity applications. The probe includes a primary ultrasonic transducer array operating at first resonant frequency and formed by a plurality of elements arranged linearly along a coordinate axis, and a secondary ultrasonic transducer array operating at second resonant frequency and comprising a plurality of elements arranged linearly along the coordinate axis and being interdigitated with the elements of the primary ultrasonic transducer array. In one embodiment, separate transducer units are joined to form the probe while in a further embodiment, the two arrays are produced from a common piezoelectric member. US 2004/227429 A1 describes a method for making a composite, such as a piezoelectric composite, having a predetermined volume ratio. Initially, a pair of base slabs are diced to form slot having uniform pitch spacing such that a material portion of one diced base slab may be received within the slots of another diced base slab. The diced base slabs are interdigitated and joined to form a first piezoelectric composite that can subsequently be diced to form slots having a uniform pitch spacing that are spaced from the first slots. Two diced first piezoelectric composites are interdigitated and joined to form a second piezoelectric composite of reduced volume ratio and finer pitch. US 6,726,631 B2 describes that a method and apparatus for apodization is exemplified in an ultrasound transducer used, for example, in medical applications. The described method and apparatus provides an ultrasonic transducer with frequency and amplitude apodization. Described is the making of composite cuts into piezoelectric material according to a predetermined pattern which generally varies the concentration of piezoelectric material across the surface of the transducer. Concentration of piezoelectric material can be varied across the surface of the piezoelectric transducer by varying the spacing between the cuts in the piezoelectric material, or by varying the width of the cuts in the piezoelectric material, or a combination of both. US 2009/085440 A1 discloses an ultrasonic probe comprising sub-element being formed of different types of piezoelectric material and interdigitated comb structures. US 2018/175278 A1 discloses an ultrasound transducer with interdigitated comb structures and dematching layer. BRIEF DESCRIPTION It should be understood that the brief description above is provided to