Flexible ultrasound array

Patent metadata

Field	Value
Publication number	US-12220727-B2
Application number	US-202017438705-A
Country	US
Kind code	B2
Filing date	Mar 12, 2020
Priority date	Mar 14, 2019
Publication date	Feb 11, 2025
Grant date	Feb 11, 2025

Abstract

The present invention provides a flexible ultrasound transducer ( 1 ) for an ultrasound monitoring system for examining a curved object. The ultrasound transducer ( 1 ) comprises an integrated circuit structure ( 7 ) and a multi-layered structure ( 2 ), said multi-layered structure ( 2 ) comprising an array ( 3 ) of ultrasound transducing elements ( 3 a ) arranged in a first layer structure ( 4 ) and configured for generating ultrasonic energy propagating along a main transducer axis Z and an array ( 5 ) of control circuits ( 5 a ) arranged in a second layer structure ( 6 ), and wherein the array ( 5 ) of control circuits and the integrated circuit structure ( 7 ) are configured for operating the array ( 3 ) of ultrasound transducing elements in said first layer structure ( 4 ), Further, the multi-layered structure ( 2 ) comprises at least one flexible layer ( 8, 9 ) arranged so that the bending flexibility of the multi-layered structure ( 2 ) permits the ultrasound transducer ( 1 ) to form a continuous contact with said curved object during operation.

First claim

The invention claimed is:

1. A flexible ultrasound transducer for an ultrasound monitoring system for examining a curved object, wherein said flexible ultrasound transducer comprises an integrated circuit structure and a multi-layered structure, said multi-layered structure comprising:
an array of ultrasound transducing elements arranged in a first layer structure and configured for generating ultrasonic energy propagating along a main transducer axis Z; and
an array of control circuits arranged in a second layer structure,
wherein the array of control circuits and the integrated circuit structure are configured for operating the array of ultrasound transducing elements in said first layer structure;
at least one flexible layer arranged so that the bending flexibility of the multi-layered structure permits the flexible ultrasound transducer to form a continuous contact with said curved object during operation; and
an acoustic backing layer arranged axially below said first layer structure for reducing the acoustic transmission directed away from said curved object during operation,
wherein the acoustic backing layer is an acoustic damping layer or an acoustic reflection layer in the form of a Bragg stack, wherein said Bragg stack comprises multiple layers of alternating high and low acoustic impedance materials.

2. The flexible ultrasound transducer according to claim 1 , wherein each ultrasound transducing element in the array of ultrasound transducing elements of said first layer structure is connected with an individual control circuit of the array of control circuits of said second layer structure.

3. The flexible ultrasound transducer according to claim 1 , wherein the second layer structure is arranged axially above a backplane flexible layer of the at least one flexible layer.

4. The flexible ultrasound transducer according to claim 1 , wherein the integrated circuit structure comprises a plurality of Application Specific Integrated Circuits (ASIC), and wherein at least one ASIC supports a plurality of individual control circuits.

5. The flexible ultrasound transducer according to claim 3 , wherein the integrated circuit structure comprises a plurality of Application Specific Integrated Circuits (ASIC), and wherein at least one ASIC supports a plurality of individual control circuits, and wherein said plurality of Application Specific Integrated Circuits (ASIC) are mounted as discrete elements axially below said backplane flexible layer.

6. The flexible ultrasound transducer according to claim 1 , wherein the first layer structure comprises a frontplane flexible layer arranged between an array of piezoelements and a bulk layer, wherein said bulk layer comprises internal walls so as to define an array of cavities in the bulk layer, wherein an ultrasound transducing element in the array of ultrasound transducing elements is defined by one piezoelement of said array of piezoelements, a cavity of said array of cavities and a portion of the frontplane flexible layer that is arranged between the piezoelement and the cavity.

7. The flexible ultrasound transducer according to claim 1 , wherein the array of control circuits comprises an array of thin film transistors (TFT).

8. The flexible ultrasound transducer according to claim 1 , wherein the acoustic backing layer is arranged axially below said second layer structure.

9. The flexible ultrasound transducer according to claim 1 , further comprising a top flexible layer arranged as an outermost layer axially above the first layer structure.

10. The flexible ultrasound transducer according to claim 1 , wherein the multi-layered structure has a bending flexibility such that the flexible ultrasound transducer may be bent with a radius of curvature that is less than 5 cm.

11. A method for producing the flexible ultrasound transducer according to claim 1 , the method comprising:
a) arranging said second layer structure comprising the array of control circuits axially above a backplane flexible layer that is temporarily bonded to a first rigid substrate;
b) arranging said first layer structure comprising the array of ultrasound transducing elements;
c) forming the multi-layered structure of the flexible ultrasound transducer; and
d) removing said first rigid substrate.

12. The method according to claim 11 , wherein the first layer structure is built up on top of the second layer structure.

13. The method according to claim 11 , wherein the first layer structure is temporarily bonded to a second rigid substrate, and wherein the method comprises removing said second rigid substrate before forming the multi-layered structure of the flexible ultrasound transducer.

Assignees

• Imec Vzw
• Univ Leuven Kath

Inventors

• Cheyns David
• Jeong Yongbin
• Rottenberg Xavier

Classifications

• B06B2201/76

  Medical, dental · CPC title

• B06B1/0685

  on the back only of piezoelectric elements · CPC title

• B06B1/0207

  Driving circuits (specially adapted for particular applications, see the relevant subclass, e.g. G01; circuits for steering transducer arrays G10K11/34; basic circuits H03) · CPC title

• A61B8/4488

  the transducer being a phased array · CPC title

• B06B1/0629 Primary

  Square array · CPC title