Methods and systems for shape changing invasively deployable devices

Abstract

The present invention provides various methods and systems for deployable invasive devices. In one example, the deployable invasive device has a transducer having a plurality of transducer arrays connected by at least one shape memory material, the at least one shape memory material being configured to cause the transducer to transition between a first folded shape and a second unfolded shape in response to one or more stimuli. When in the second unfolded shape, the active area of ​​the transducer is increased relative to the first folded shape.

Description

Technical Field

[0001] Embodiments of the subject matter disclosed herein relate to deployable catheters. Background Art

[0002] Invasive devices can be used to obtain information about tissues, organs, and other anatomical regions that may be difficult to collect via external scanning or imaging techniques. The invasive device may be a deployable catheter that can be inserted intravenously into a patient. In one example, the device can be used for intracardiac echocardiography (ICE) imaging, where the device is introduced into the heart via, for example, the aorta, inferior vena cava, or jugular vein. The device may include an ultrasound probe having a hole size consistent with a size that enables the device to fit through an artery or vein. Therefore, the resolution and penetration of the ultrasound probe may be determined by the maximum allowable diameter of the invasive device. Summary of the invention

[0003] In one embodiment, a deployable invasive device includes: a transducer having a plurality of transducer arrays connected by at least one shape memory material, the at least one shape memory material being configured to cause the transducer to transition between a first folded shape and a second expanded shape in response to one or more stimuli, wherein in the second expanded shape, the plurality of transducer arrays are arranged adjacent to each other without any other transducer components positioned in an area between each of the plurality of transducer arrays, the area being defined by inner edges of the plurality of transducer arrays and edges of the plurality of transducer arrays perpendicular to the azimuthal direction, and the active area of ​​the transducer is increased relative to the first folded shape. The transducer size can thereby be reduced to allow the transducer to pass through an intravenous channel, and the transducer size can be increased when necessary to obtain high resolution data at an increased acquisition speed.

[0004] It should be understood that the above brief description is provided to introduce in a simplified form selected concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is solely defined by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The present invention will be better understood by reading the following description of non-limiting embodiments with reference to the accompanying drawings, in which:

[0006] Figure 1 A block diagram of an exemplary imaging system including a deployable catheter is shown.

[0007] Figure 2 Shown in more detail Figure 1 Deployable catheters, including for Figure 1 An exemplary imaging catheter tip and transducer of the system is shown.

[0008] Figure 3 shows that it may be included in Figure 2 A first cross-sectional view of an exemplary imaging catheter tip within a deployable catheter of FIG.

[0009] Figure 4 yes Figure 2 Schematic diagram of a second cross-sectional view of a deployable catheter.

[0010] Figure 5 is a first diagram illustrating the two-way shape memory effect of a transducer incorporating a shape memory material.

[0011] Fig. 6A A first example of a transducer in a folded configuration adapted with a shape memory material is shown.

[0012] Figure 6B Shown in the deployed configuration Fig. 6A A first example of a transducer.

[0013] Fig. 7A A second example of a transducer in a folded configuration adapted with a shape memory material is shown.

[0014] Figure 7B Shown in the deployed configuration Fig. 7A A second example of a transducer.

[0015] Fig. 8A A perspective view of a third example of a transducer in a folded configuration adapted with a shape memory material is shown.

[0016] Figure 8B Shows Fig. 8A An end view of a third example of a transducer.

[0017] Figure 8C Shown in a transformed configuration Fig. 8A A perspective view of a third example of a transducer.

[0018] Fig.8D Shown in the deployed configuration Fig. 8A A perspective view of a third example of a transducer.

[0019] Fig. 9A A perspective view of a fourth example of a transducer in a folded configuration adapted with a shape memory material is shown.

[0020] Fig. 9B Shows Fig. 9A An end view of a fourth example of a transducer.

[0021] Fig. 9C Shown in a transformed configuration Fig. 9A A perspective view of a fourth example of a transducer.

[0022] Fig.9D Shown in the deployed configuration Fig. 9A A perspective view of a fourth example of a transducer.

[0023] Fig.10 A fifth example of a transducer adapted with a shape memory material forming an acoustic layer of the transducer is shown.

[0024] Fig.11 A sixth example of a transducer adapted with a shape memory material forming an acoustic layer of the transducer is shown.

[0025] Fig.12 is a diagram showing the shape transition mode variation of a shape memory material implemented in a transducer.

[0026] Figures 1 to 4 and 6A to 9D They are drawn approximately to scale, although other relative dimensions may be used. DETAILED DESCRIPTION

[0027] The following description relates to various embodiments of a deployable invasive device. The deployable invasive device may be a deployable catheter in an imaging system and configured to be inserted into a patient's body to obtain information about internal tissues and organs. An example of an imaging system equipped with a deployable catheter is shown in FIG. Figure 1 Shown in. Figure 2 A side view of a deployable catheter is depicted in FIG. Figure 3 The internal components of the deployable catheter are shown in a first cross-sectional view of the deployable catheter. Figure 4 A second cross-sectional view of a deployable catheter is shown in schematic form in FIG. The transducer adapted to the shape memory material transitions between the first shape and the second shape. Figure 5 As shown in FIG, the shape memory material may be included in a deployable catheter. Examples of transducers incorporating shape memory materials in multiple locations relative to the active area of ​​the transducer and the transducers in different configurations are shown in FIG. FIG. 6A to FIG. 11 For example, Fig. 6A As shown in FIG. 7B , the shape memory material may be arranged between the transducer arrays, such as 8A to 9D As shown, it can be arranged outside the effective area, or as Figure 10 to Figure 11 As shown, it can be arranged as an acoustic layer incorporated into the transducer. Additional modes of shape transformation of shape memory materials are Fig.12 As shown in , the additional mode includes contraction of the shape memory material along at least one dimension.

[0028] Figures 1 to 12 An example configuration with relative positioning of various parts is shown. In at least one example, if shown as directly contacting or directly coupling each other, such elements may be referred to as directly contacting or directly coupling, respectively. Similarly, in at least one example, elements adjacent to or adjacent to each other may be adjacent to or adjacent to each other, respectively. For example, parts arranged to coplanarly contact each other may be referred to as coplanar contact. For another example, in at least one example, elements positioned to be spaced apart from each other and having only space therebetween without other parts may be described and cited as such. For another example, elements shown as being located above / below each other, located on opposite sides of each other, or located between the left / right sides of each other may be described and cited as such relative to each other. In addition, as shown in the figure, in at least one example, the topmost element or point of an element may be referred to as the "top" of a part, and the bottommost element or point of an element may be referred to as the "bottom" of a part. As used herein, top / bottom, upper / lower, upper / lower may be relative to the vertical axis of the figure, and may be used to describe the positioning of elements relative to each other in the figure. Therefore, in one example, an element shown as being located above other elements is vertically positioned above other elements. As another example, the shapes of elements shown in the figures may be referred to as having these shapes (e.g., such as being rounded, straight, planar, curved, rounded, chamfered, angled, etc.). In addition, in at least one example, elements shown as intersecting each other may be referred to as intersecting elements or intersecting each other. In addition, in one example, elements shown as being within another element or shown as being outside another element may be described and referred to as such.

[0029] Medical imaging techniques such as ultrasound imaging can be used to obtain real-time data about a patient's tissue, organ, blood flow, etc. However, it may be difficult to obtain high-resolution data of the inner cavity of tissues and organs via external scanning of the patient. In such cases, a deployable catheter equipped with a probe can be inserted intravenously into the patient's body and guided to the target site. The deployable catheter can travel through narrow passages (such as veins or arteries) and can therefore have a similar diameter. However, the narrow diameter of the deployable catheter can limit the size of the probe, which in turn can constrain the data quality and acquisition speed provided by the probe. For example, when the probe is an ultrasound probe, the resolution and penetration of the ultrasound probe can be determined by the size of the transducer of the probe. In order to improve the quality of the image generated by the ultrasound probe, a larger transducer than the transducer that can be enclosed in the housing of the deployable catheter may be required.

[0030] In one example, the above problems can be at least partially solved by incorporating a shape memory material into a deployable catheter. The shape memory material can be a shape memory polymer (SMP) configured to alternate between at least two different shapes. When the SMP is coupled to the transducer, the footprint of the transducer of the deployable catheter can be selectively increased or decreased. The shape changing behavior of the SMP allows the transducer to have, for example, a first shape within the deployable catheter housing, the first shape having a first set of dimensions so that the transducer array can be easily inserted into the patient's body. In response to exposure to a stimulus, the SMP can be adjusted to a second shape having a second set of dimensions, which increases the size of the transducer.

[0031] The SMP can be coupled to the transducer via more than one configuration, thereby allowing flexibility in the design of the transducer to accommodate available packaging space and enhance the performance of the transducer. For example, the positioning of the SMP relative to the active area of ​​the transducer can be changed and / or the SMP can be configured to change shape via more than one mode. In this way, the imaging probe can be placed in a conformation that is more conducive to intravenous passage within the patient's body and then zoomed in to obtain high-resolution data when deployed in the target anatomical area. By utilizing the SMP to induce shape transformation, the cost of the deployable catheter can be kept low while allowing a wide range of deformation.

[0032] Now go to Figure 1 , a block diagram of an exemplary system 10 for medical imaging is shown. It should be understood that although described herein as an ultrasound imaging system, system 10 is a non-limiting example of an imaging system that can utilize a deployable device to obtain medical images. Other examples may include incorporation of other types of invasive probes, such as endoscopes, laparoscopes, surgical probes, intracavitary probes, etc. System 10 may be configured to facilitate acquisition of ultrasound image data from patient 12 via an imaging catheter 14. For example, imaging catheter 14 may be configured to acquire ultrasound image data representing an area of ​​interest within patient 12, such as a heart or lung area. In one example, imaging catheter 14 may be configured to be used as an invasive probe. Reference numeral 16 indicates a portion of imaging catheter 14 disposed within patient 12, such as inserted into a vein. Reference numeral 18 indicates Figure 2 A portion of the imaging catheter 14 is depicted in more detail in FIG.

[0033] The system 10 may also include an ultrasound imaging system 20 that is operably associated with the imaging catheter 14 and is configured to facilitate the acquisition of ultrasound image data. It should be noted that while the exemplary embodiments shown below are described in the context of a medical imaging system (such as an ultrasound imaging system), other imaging systems and applications are also contemplated (e.g., industrial applications such as non-destructive testing, borescopes, and other applications where ultrasound imaging may be used within confined spaces). In addition, the ultrasound imaging system 20 may be configured to display an image representing the current position of the imaging catheter tip within the patient 12. Figure 1 As shown, the ultrasound imaging system 20 may include a display area 22 and a user interface area 24. In some examples, the display area 22 of the ultrasound imaging system 20 may be configured to display a two-dimensional image or a three-dimensional image generated by the ultrasound imaging system 20 based on image data collected via the imaging catheter 14. For example, the display area 22 may be a suitable CRT or LCD display on which ultrasound images can be viewed. The user interface area 24 may include an operator interface device that is configured to help an operator identify a region of interest to be imaged. The operator interface may include a keyboard, a mouse, a trackball, a joystick, a touch screen, or any other suitable interface device.

[0034] Figure 2 The imaging catheter 14 is shown Figure 1 An enlarged view of the portion 18 is shown. Figure 2 As shown, the imaging catheter 14 may include a tip 26 on the distal end of a flexible shaft 28. The catheter tip 26 may house a transducer and a motor assembly. The transducer may include one or more transducer arrays, each transducer array including one or more transducer elements. The imaging catheter 14 may also include a handle 30, which is configured to facilitate manipulation of the flexible shaft 28 by an operator.

[0035] Figure 2 An example of a catheter tip 26 is shown in FIG. Figure 3 A set of reference axes 301 indicating the y-axis, x-axis, and z-axis are provided. The catheter tip 26 may have a housing 302 surrounding a transducer 304 that may include at least one transducer array 306, a capacitor 308, and a catheter cable 310. Figure 3 Other components not shown in the drawings may also be enclosed within the housing 302, such as, for example, a motor, a motor holder, a thermistor, and an optional lens. Additionally, in some examples, the catheter tip 26 may include a system for filling the tip with a fluid, such as an acoustic coupling fluid.

[0036] The transducer array 306 has several layers stacked along the y-axis and extending along the xz plane. One or more layers of the transducer array 306 can be layers of transducer elements 312. In one example, the transducer elements 312 can be piezoelectric elements, where each piezoelectric element can be a block formed of a natural material (such as quartz) or a synthetic material (such as lead zirconate titanate) that deforms and vibrates when a voltage is applied by, for example, a transmitter. In some examples, the piezoelectric element can be a single crystal with a crystal axis, such as lithium niobate and PMN-PT (Pb (Mg 1 / 3 Nb 2 / 3 )O3-PbTiO3). The vibration of the piezoelectric element generates an ultrasonic signal formed by ultrasonic waves emitted from the catheter tip 26. The piezoelectric element can also receive ultrasonic waves (such as ultrasonic waves reflected from a target object) and convert the ultrasonic waves into voltage. The voltage can be transmitted to a receiver of an imaging system and processed into an image.

[0037] The acoustic matching layer 314 may be positioned above the transducer element 312. The acoustic matching layer 314 may be a material positioned between the transducer element 312 and the target object to be imaged. By arranging the acoustic matching layer 314 therebetween, the ultrasonic wave may first pass through the acoustic matching layer 314 and be emitted from the acoustic matching layer 314 in phase, thereby reducing the possibility of reflection at the target object. The acoustic matching layer 314 may shorten the pulse length of the ultrasonic signal, thereby increasing the axial resolution of the signal.

[0038] The layer formed by the acoustic matching layer 314 and the transducer elements 312 may be cut along at least one of the yx plane and the yz plane to form individual acoustic stacks 316. Each of the acoustic stacks 316 may be electrically isolated from adjacent transducers, but may all be coupled to a common layer positioned below or above the transducer element relative to the y-axis.

[0039] The circuit 318 can be layered below the transducer elements 312 relative to the y-axis. In one example, the circuit can be at least one application specific integrated circuit (ASIC) 318 that is directly in contact with each of the acoustic stacks 316. Each ASIC 318 can be coupled to one or more flexible circuits 317 that can extend continuously between the transducer array 306 and the catheter cable 310. The flexible circuit 317 can be electrically coupled to the catheter cable 310 to enable communication between the transducer array 306 and an imaging system (e.g., Figure 1 The electrical signal can be tuned by capacitor 308 during transmission.

[0040] The acoustic backing layer 320 can be disposed below the ASIC 318 relative to the z-axis. Figure 3As shown, the backing layer 320 can be a continuous material layer extending along the xz plane. The backing layer 320 can be configured to absorb and attenuate backscattered waves from the transducer element 312. The bandwidth and axial resolution of the acoustic signal generated by the transducer element 312 can be increased by the backing layer 320.

[0041] As described above, the transducer 304, capacitor 308, and catheter cable 310 may be enclosed within the housing 302. Thus, the size (e.g., diameter or width) of the components may be determined by the inner diameter of the housing 302. The inner diameter of the housing 302, in turn, may be determined by the outer diameter of the housing 302 and the desired thickness. The outer diameter of the housing 302 may be constrained by the area of ​​the patient's body into which the imaging catheter is inserted. For example, the imaging catheter may be an intracardiac echocardiography (ICE) catheter used to obtain images of cardiac structures and blood flow within the patient's heart.

[0042] The imaging catheter may be introduced into the heart through the aorta, inferior vena cava, or jugular vein. In some cases, the imaging catheter may be fed through areas with narrower diameters, such as the coronary sinus, tricuspid valve, and pulmonary artery. Thus, the outer diameter of the imaging catheter may be no greater than 10 Fr or 3.33 mm. The outer diameter of the imaging catheter housing and the corresponding inner diameter are in the range of Figure 4 China-Israel Figure 3 A cross-section 400 of the housing 302 of the catheter tip 26 taken along line AA′ is shown.

[0043] like Figure 4 As shown, the outer surface 402 of the housing 302 of the imaging catheter can be spaced apart from the inner surface 404 of the housing 302 by the thickness 406 of the housing 302. The thickness 406 of the housing 302 can be optimized to provide a target degree of structural stability (e.g., resistance to deformation) for the housing 302, which is balanced with flexibility (e.g., the ability to bend when a force is applied). In one example, the outer diameter 408 of the housing 302 can be 3.33 mm, the thickness 406 can be 0.71 mm, and the inner diameter 410 of the housing 302 can be 2.62 mm. In other examples, the outer diameter of the housing can be between 2 mm-5 mm, the thickness can be between 0.24 mm-1 mm, and the inner diameter can be between 1 mm-4 mm. In other examples, the imaging catheter can have a variety of sizes depending on the application. For example, an endoscope can have an outer diameter of 10 mm-12 mm. It should be understood that the imaging catheter can have various diameters and sizes without departing from the scope of the present disclosure.

[0044] The inner surface 404 of the housing 302 may include circular protrusions 412 that protrude into the inner volume or lumen 414 of the housing 302. The circular protrusions 412 may be semicircular protrusions, each of which encloses a separate lumen 416 for accommodating a steering wire of an imaging catheter. The placement of the transducer 304 of the imaging catheter within the lumen 414 of the housing 302 is indicated by the dashed rectangle. The maximum height hole 418 of the transducer 304 may be determined based on the inner diameter 410 of the housing 302, and the height 420 of the transducer 304 may be configured to fit between the circular protrusions 412 of the housing 302. In one example, the height hole 418 may be a maximum of 2.5 mm, and the height 420 may be a maximum of 1 mm.

[0045] As described above, the size of the transducer 304 can be determined by the inner diameter 410, thickness 406, and outer diameter 408 of the housing 302, which in turn can be determined based on the specific region of the patient's anatomy in which the imaging catheter is inserted. The constraints imposed on the size of the transducer 304 and the diameter 422 of the catheter cable 310 can affect the resolution, penetration, and manufacturing of the transducer 304. Each of the resolution, penetration, and manufacturing convenience can be enhanced by increasing the size of the transducer 304, but the geometry of the transducer 304, and therefore the performance, is limited by the size of the catheter housing 302 so that the catheter can be deployed intravenously through the patient.

[0046] In one example, the transducer can be amplified by adapting the transducer with a shape memory material when deployed at the target site. The shape memory material can be a shape memory polymer (SMP) configured to mechanically respond to one or more stimuli. The example of SMP includes linear block copolymers, such as polyurethane, polyethylene terephthalate, polyethylene oxide and other thermoplastic polymers (such as polynorbornene). In one example, SMP can be a powder mixture of silicone and tungsten in acrylic resin. SMP can be stimulated by physical stimuli (such as temperature, moisture, light, magnetic energy, electricity, etc.), chemical stimuli (such as chemicals, pH level, etc.) and biological stimuli (such as the presence of glucose and enzymes). When applied to the imaging catheter, the transducer can be combined with SMP so that the shape of the transducer can be changed when exposed to at least one stimulus. SMP can have the physical properties provided in Table 1 below, which can provide more ideal properties than other types of shape memory materials (such as shape memory alloys). For example, SMP can have higher elastic deformation capacity, lower cost, lower density, and greater biocompatibility and biodegradability. In particular, the lower cost of SMPs may be desirable for use in disposable deployable catheters.

[0047] Table 1. Physical properties of shape memory polymers

[0048]

[0049] In one example, the SMP may have a two-way shape memory, such that the SMP can be adjusted between two shapes without reprogramming or applying external forces. For example, the SMP may transform into a temporary shape in response to a first stimulus, and return to a permanent shape in response to a second stimulus. The first stimulus and the second stimulus may be of the same or different types, for example, the first stimulus may be a high temperature and the second stimulus may be a low temperature, or the first stimulus may be a humidity level and the second stimulus may be a threshold temperature. The two-way shape memory behavior is neither mechanically nor structurally constrained, allowing the SMP to switch between a temporary shape and a permanent shape without applying external forces.

[0050] For example, the transition of the transducer 502 between the first shape and the second shape is Figure 5 500. The transducer 502 includes a first transducer array 504 and a second transducer array 506, wherein the second transducer array 506 is aligned with the first transducer array 504 along the z-axis and is spaced apart from the first transducer array 504. In other words, the transducer 502 has an overall planar shape, wherein the first transducer array 504 and the second transducer array 506 are coplanar with each other along a common plane (e.g., an xz plane). The first step 501 of the first illustration 500 depicts a backing layer 510 in which an SMP 508 is coupled to each of the first transducer array 504 and the second transducer array 506. The SMP 508, which is configured as a bidirectional memory SMP, is arranged between the transducer arrays along the z-axis and may be fixedly attached to an edge of the backing layer 510 and arranged coplanar with the backing layer 510. For example, the backing layer 510 and the SMP 508 arranged therebetween may form a continuous planar unit. The transducer elements 512 are laminated to the backing layer 510 of the first transducer array 504 and the second transducer array 506 .

[0051] In some examples, SMP 508 may form a continuous layer that completely spans transducer 502. For example, SMP 508 may be an acoustic layer of transducer 502, such as a matching layer or a backing layer. By incorporating SMP 508 as an acoustic layer, the assembly and number of components of the transducer may be simplified without adversely affecting the reduction in size of the transducer footprint. Figure 10 to Figure 11 The implementation of SMP as the acoustic layer of the transducer is discussed.

[0052] The transducer 502 is exposed to a first temperature T1, and at a second step 503, the SMP 508 changes shape in response to T1. The SMP 508 can bend into a semicircular shape, thereby causing the second transducer array 506 to pivot substantially through 180 degrees in a first rotational direction (e.g., clockwise) indicated by arrow 520. As described herein, bending can be any transition of a planar structure to a non-planar conformation. Therefore, various deformations of a structure from a configuration aligned with a plane can be considered bending.

[0053] When the SMP 508 bends, the transducer 502 may also bend accordingly. Although the SMP can bend through a range of angles, the bending of the SMP so that two regions of the transducer 502 become stacked on top of each other and substantially parallel to each other is referred to herein as a fold. In some examples, the SMP may not bend to the extent that the transducer is folded. However, the folding of the transducer may provide the most compact configuration of the transducer to enable the deployable catheter to pass through an intravenous passage.

[0054] Due to the folding of the transducer 502, the second transducer array 506 is positioned in a folded shape relative to the y-axis below the first transducer array 504. When the transducer 502 is viewed along the y-axis, the overall surface area of ​​the transducer elements 512 (including the transducer elements 512 of both the first transducer array 504 and the second transducer array 506) is reduced at the second step 503 compared to the first step 501.

[0055] The transducer 502 is exposed to a second temperature T2, and in response, the SMP 508 returns to the planar geometry of the first step 501 at a third step 505 of the first illustration 500. The second transducer array 506 is pivoted substantially through 180 degrees in a second rotational direction (e.g., counterclockwise) opposite to the first rotational direction. The second temperature T2 may be a temperature higher or lower than T1. Subjecting the transducer 502 to T1 again forces the SMP 508 to bend, thereby folding the transducer 502, such that the second transducer array 506 is pivoted 180 degrees at a fourth step 507.

[0056] As described above, the transducer 502 may be enclosed in a housing at the distal end of a deployable catheter (such as that shown in FIGS. 3 and 4 ). Figure 4In order to accommodate the deployment of the transducer 502 to a planar geometry, the housing may be formed of a flexible elastic material that stretches and deforms as the transducer 502 changes shape. For example, the deployable catheter may be a balloon catheter, and the housing at the end of the catheter may be an inflatable balloon. The balloon may be formed of materials such as polyester, polyurethane, silicone, etc., and may be inflated by filling the balloon with a fluid or gas. Before the transducer 502 is adjusted to a planar geometry, the balloon may be inflated to allow the transducer 502 to transform unimpeded. When the transducer 502 is adjusted to a folded configuration, the balloon may be deflated by exhausting gas or exhausting fluid.

[0057] The steps shown in the first diagram 500 may be repeated multiple times. Figure 5 Before an imaging catheter adapted to the transducer 502 is inserted into a patient, the transducer 502 may be initially exposed to T1 to fold and reduce the size of the transducer 502. The folded transducer 502 may be assembled within the housing of the imaging catheter and inserted intravenously into the patient. When the transducer 502 reaches the target site in the patient, the transducer 502 may be unfolded and enlarged by subjecting the array to T2. When the transducer 502 is unfolded and increased in size, an image may be obtained. For example, unfolding the transducer 502 may increase the height aperture of the transducer 502.

[0058] When the scan is complete, the transducer 502 can be exposed to T1 again, causing the transducer 502 to collapse and reduce in size. The imaging catheter can then be withdrawn from the site and removed from the patient or deployed to another site for imaging in the patient. Thus, the shape and size of the transducer 502 can be adjusted between a flat configuration and a collapsed configuration multiple times during an imaging session.

[0059] It should be understood that Figure 5 The configurations of the transducer 502 shown are non-limiting examples of shapes that the transducer can transition between. Other examples may include the transducer 502 being in a non-planar geometry (such as a slightly bent or curved shape) at a first step 501, becoming more bent or curved at a second step 503, and alternating between a less bent / curved shape and a more bent / curved shape when exposed to one or more stimuli. Additionally, the transducer 502 may be folded such that the first transducer array 504 and the second transducer array 506 are not parallel to each other. In other examples, the first transducer array 504 and the second transducer array 506 may be different sizes.

[0060] In addition, when the SMP 508 forms an entire layer across the transducer 502 rather than forming a segment between the backing layer 510 of the first transducer array 504 and the second transducer array 506, the SMP 508 may be adapted to change shape only in the area between the transducer arrays. In one example, the SMP 508 may be able to change shape via more than one type of transition. For example, the SMP 508 may bend when exposed to one type of stimulus and contract when exposed to another type of stimulus. In another example, the SMP 508 may include more than one type of shape memory material. For example, the SMP 508 may be formed of a first type of material configured to bend and a second type of material configured to contract. Other variations in shape transitions, material combinations, and positioning of the SMP 508 within the transducer have been contemplated.

[0061] Although temperature changes are described as being used to induce Figure 5 The first illustration 500 of the SMP shape change stimulus is shown, but it should be understood that the first illustration 500 is a non-limiting example of how to trigger the deformation of the SMP. Other types of stimuli such as humidity, pH, UV light, etc. can be used to induce mechanical changes in the SMP. More than one type of stimulus can be applied to the SMP to achieve similar or different shape modifications. In addition, the deformation of the SMP can include other shape change modes besides bending. For example, the SMP can be curled into a core configuration or contracted along at least one dimension. The details of the mechanical deformation are further described below.

[0062] In some examples, such as Figure 5 As shown, the transducer of the deployable catheter may include two segments or two transducer arrays. Each transducer array may include one or more acoustic stacks, including as described above with reference to Figure 2 The matching layers, elements and backing layers described above. An ASIC may be coupled to each transducer array. A first example of a transducer 602 incorporating an SMP to enable modification of the active area of ​​the transducer 602 is Fig. 6A and Figure 6B The transducer 602 is shown in Fig. 6A 600 and is shown in a first folded configuration. Figure 6B It is shown in a second deployed configuration 650.

[0063] The transducer 602 has a first transducer array 604 and a second transducer array 606. The first transducer array 604 and the second transducer array 606 have similar dimensions, e.g., length, width, and thickness, and are each rectangular and longitudinally aligned with the x-axis, e.g., the length 608 of each transducer array is parallel to the x-axis. However, in other examples, the first transducer array 604 and the second transducer array 606 may have different dimensions from each other. For example, the first transducer array 604 may be wider and / or longer than the second transducer array 606. The SMP 610 is arranged between the transducer arrays along the z-axis. In other words, as Figure 6B As shown, the first transducer array 604 is spaced apart from the second transducer array 606 by a width 612 of the SMP 610. The width 612 of the SMP 610 can be less than the width 614 of each of the first transducer array 604 and the second transducer array 606, while the length of the SMP 610 defined along the x-axis can be similar to the length 608 of the transducer array.

[0064] The SMP 610 can be connected to the inner edge of the backing layer 616 of each of the first transducer array 604 and the second transducer array 606. For example, the SMP 610 can directly contact and adhere to the longitudinal inner edge 618 of the backing layer 616 of the first transducer array 604, for example, the edge of the backing layer 616 facing the second transducer array 606 and aligned with the x-axis, and directly contact and adhere to the longitudinal inner edge 620 of the backing layer 616 of the second transducer array 606, for example, the edge of the backing layer 616 facing the first transducer array 604 and aligned with the x-axis. The thickness of the SMP 610 can be similar to the thickness of the backing layer 616 of each of the first transducer array 604 and the second transducer array 606, which is defined along the y-axis. A matching layer 622 is stacked above the backing layer 616 of each of the transducer arrays. Elements (eg, piezoelectric elements) may be disposed between the matching layer 622 and the backing layer 616 ( Fig. 6A and Figure 6B not shown).

[0065] When in such Fig. 6A In the first configuration 600 shown, the SMP 610 is bent into a semicircular shape. The second transducer array 606 is stacked directly above and aligned with the first transducer array 604 relative to the y-axis and is spaced apart from the first transducer array 604 so that the two transducer arrays remain parallel to the xz plane. Fig. 6AThe transducer 602 may be folded in the opposite direction such that each matching layer 622 of the transducer array faces outward and away from each other, and the backing layers 616 of the transducer array face each other. The backing layers 616 may be spaced apart from each other by a distance 630 similar to the diameter of the semicircle formed by the SMP 610. However, in other examples, the transducer 602 may be folded in the opposite direction such that the backing layers 616 of the transducer array face each other and the matching layers 622 face away from each other.

[0066] In the first configuration 600, the width 624 of the transducer 602 is reduced relative to the width 626 of the transducer 602 in the second configuration 650. The active area of ​​the transducer 602 may be equal to the surface area of ​​one of the first transducer array 604 or the second transducer array 606. In the second configuration 650, where the first transducer array 604 and the second transducer array 606 are coplanar and juxtaposed with each other, when the sizes of the transducer arrays are similar, the active area of ​​the transducer 602 is doubled relative to the first configuration 600. Therefore, when deployed into the second configuration 650, the height aperture of the transducer 602 may be doubled, thereby increasing the resolution and penetration of the transducer 602.

[0067] In another example, the transducer of the imaging probe may include more than two segments or transducer arrays. A second example of transducer 702 is Fig. 7A 7B is shown in a first folded configuration 700, and in a second unfolded configuration 750. The transducer 702 includes a first transducer array 704, a second transducer array 706, and a third transducer array 708. All three transducer arrays may have similar dimensions (e.g., length, width, and thickness) and geometry, and may be connected by a first SMP 710 and a second SMP 712. However, in other examples, the transducer arrays may all have different dimensions from one another, or two of the three transducer arrays may be similar, and the remaining transducer arrays may have different sizes or shapes.

[0068] For example, in Figure 7B In the second configuration 750, the transducers may be spaced apart from each other but coplanar and aligned along the x-axis and the z-axis. The first transducer array 704 is spaced apart from the second transducer array 706 by the first SMP 710, and the second transducer array 706 is spaced apart from the third transducer array 708 by the second SMP 712. FIG. 6A to FIG. 6BAs described in the first example of the transducer 602, the SMP can be directly connected to the longitudinal inner edge of the transducer array along the backing layer 714 of each transducer array in the transducer array. The SMP can be coplanar and have a thickness similar to the backing layer 714 of the transducer array. The matching layer 716 of each transducer array in the transducer array is positioned above the backing layer 714 and aligned with each backing layer 714 along the y-axis. Therefore, the matching layer 716 protrudes above the first SMP 710 and the second SMP 712 relative to the y-axis. The elements can be arranged between the matching layer 716 and the backing layer 714 ( Fig. 7A and Figure 7B not shown).

[0069] exist Fig. 7A In the first configuration 700, the transducer 702 is folded into an S-shaped geometry when viewed along the x-axis. In the S-shaped geometry, the first SMP 710 is bent into a semicircle, thereby forming the right half of the circle. The first transducer array 704 can be pivoted relative to the second transducer array 706 by a first rotational direction, so that the second transducer array 706 is stacked above the first transducer array 704 relative to the y-axis and aligned with the first transducer array. Although the backing layer 714 of the second transducer array 706 and the backing layer 714 of the first transducer array 704 face each other without other components of the transducer 702 being positioned therebetween, the backing layers 714 of the transducer arrays are spaced apart by a distance similar to the diameter of the semicircle formed by the first SMP 710.

[0070] The second SMP 712 is bent in a direction opposite to the first SMP 710 into a semicircle forming the left half of the circle. The bending of the second SMP 712 causes the third transducer array 708 to be stacked above the second transducer array 706 along the y-axis. The third transducer array 708 is pivoted by a second rotational direction opposite to the first rotational direction so that the third transducer array 708 is aligned with both the first transducer array 704 and the second transducer array 706 along the y-axis, and the matching layer 716 of the third transducer array 708 faces the matching layer 716 of the second transducer array 706. The matching layers 716 of the second transducer array 706 and the third transducer array 708 are separated by a gap that is less than the distance between the backing layers 714 of the first transducer array 704 and the second transducer array 706.

[0071] like Fig. 7AAs shown, the width 720 of the transducer 702 in the first configuration 700 may be narrower than the width 722 of the transducer 702 in the second configuration 750. In the case where the transducer arrays have similar sizes, when the transducer 702 is adjusted from the first configuration 700 to the second configuration 750, the effective area of ​​the transducer 702 determined by the total (e.g., cumulative) transducer array surface area along the xz plane facing the same direction can be increased by, for example, three times. Therefore, when the transducer is formed of three transducer arrays (hereinafter referred to as a 3-segment transducer) and the deployed 3-segment transducer (e.g., Figure 7B The second configuration 750 of ) is equal in size to an expanded transducer having two transducer arrays (hereinafter referred to as a 2-segment transducer) (e.g. Figure 6B When the transducer array of the 3-segment transducer is in the second configuration 650), the transducer array of the 3-segment transducer can be narrower in width than the transducer array of the 2-segment transducer. When folded, the 3-segment transducer can have a smaller footprint than the 2-segment transducer and can thus be inserted through a narrower channel.

[0072] Alternatively, the size of the transducer arrays of the 3-segment transducer and the 2-segment transducer may be similar. When folded, the two transducers may have a similar footprint. However, when deployed and unfolded at the target scanning site, the 3-segment transducer may have a larger effective area, allowing the 3-segment transducer to have greater resolution and penetration than the 2-segment transducer. In addition, 6A to 7B The first and second examples of transducers shown are non-limiting examples. Other examples may include transducers having more than three segments, or transducers and transducer arrays having different geometries and sizes than those shown. Thus, a transducer may be selected based on the required footprint of the folded and / or unfolded transducer. For example, when a 3-segment transducer and a 2-segment transducer have similar footprints in the folded configuration, the 3-segment transducer may be used when the target imaging site has a larger volume than when a 2-segment transducer is used.

[0073] like 6A to 7B As shown, positioning the SMP between each transducer array of the transducer allows the size of the transducer to vary along the height direction of the transducer. However, if the distance between the transducer arrays of the transducer is too large, the quality of the image generated by the transducer may be reduced. For example, in order to maintain the enhanced performance of the transducer provided by increasing the active area of ​​the transducer, the distance between each transducer array of the transducer may cumulatively not exceed a threshold percentage of the total active height aperture of the transducer, such as 5%. Therefore, it is desirable to minimize the distance between the transducer arrays during data acquisition at the transducer. However, as Figure 5 , Fig. 6A and Fig. 7AAs shown, folding of the transducer along the azimuth aperture may be the shape transition that provides the lowest complexity and is easy to initiate. To facilitate efficient packaging of the transducer by folding, an overall pitch of the distance between the transducer arrays greater than a threshold percentage of the total active height aperture may be required.

[0074] In one example, the distance between the transducer arrays when the transducer is deployed can be reduced by positioning the SMP outside the active area of ​​the transducer. Such an arrangement is hereinafter referred to as an external arrangement of the SMP. Repositioning the SMP outside the active area along the azimuth aperture of the transducer can allow the transducer to be bent away from the transducer array, thereby alleviating the need for a minimum distance between the transducer arrays to achieve adequate bending of the SMP. A first example of a transducer 802 equipped with an externally arranged SMP is FIG. 8A to FIG. 8D The transducer 802 is in a folded configuration. Fig. 8A 800 and is shown in perspective view. Figure 8B The transducer 802 is shown in an end view 830. Figure 8C 802 is further shown in perspective view 850 showing the transducer 802 in a transformed configuration and in Fig.8D 8 is further shown in a perspective view 870 of the transducer 802 in a deployed configuration.

[0075] like Fig. 8A As shown, the transducer 802 includes a first transducer array 804, a second transducer array 806, and an SMP 808 positioned at one end of the first transducer array 804 and the second transducer array 806 along the x-axis, which can also be the azimuth direction of the transducer 802. The transducer arrays can be longitudinally aligned with the azimuth direction and parallel to each other. The first transducer array 804 and the second transducer array 806 are not directly coupled to each other, for example, the transducer arrays can contact each other during the shape transition, but are not attached to each other at any point. Each transducer array in the transducer array has a matching layer 810 and a backing layer 812. As shown in FIG. Fig. 8A As shown, the first transducer array 804 and the second transducer array 806 may have similar widths 814 and similar lengths 816 and may be longitudinally aligned with the x-axis and parallel to each other.

[0076] For example, Fig. 8A , Figure 8C and Fig.8DAs shown, the SMP 808 is coupled to a first edge 818 of the backing layer 812 of each of the transducer arrays by an adhesive. However, in other examples, when the SMP has attenuation properties, such as when the SMP is configured as a matching layer, the SMP can be part of the transducer array, for example, integrated into the transducer array. The first edge 818 is parallel to the z-axis and extends along the width 814 of each transducer array. As shown in FIG. Fig.8D As shown, the thickness of SMP 808 can be less than the thickness of each of the transducer arrays, the thickness being defined along the y-axis, such that matching layer 810 protrudes higher than SMP 808 along the y-axis. A central region 820 of SMP 808 is not attached to the transducer arrays and is configured as Fig. 8A , Figure 8B and Figure 8C The central region 820 is positioned between planar regions 822 of the SMP 808 that do not bend due to the planar regions 822 being coupled to the first edge 818 of the backing layer 812 of each of the transducer arrays.

[0077] exist Fig. 8A and Figure 8B In the folded configuration shown, the SMP 808 is bent such that the planar regions 822 are stacked on top of each other along the y-axis and the central region 820 forms a semicircle. The bending of the SMP 808 causes the first transducer array 804 to fold under the second transducer array 806 to become stacked under the second transducer array 806 along the y-axis. For example, the first transducer array 804 can be folded relative to the deployed configuration along the y-axis. Fig.8D The first rotational direction (e.g., counterclockwise) indicated by the arrow 824 shown pivots through 180 degrees. In some examples, the first transducer array 804 can pivot greater than 180 degrees, such as 190 degrees or 210 degrees, or any angle less than 180 degrees. It should be understood that while the pivoting of the first transducer array 804 is described, in other examples, the second transducer array 806 can be pivoted instead.

[0078] like Figure 8B As shown, when adjusted to the folded configuration, the backing layers 812 of the first transducer array 804 and the second transducer array 806 can face each other, separated by a distance equal to the diameter 826 of the semicircle formed by the central area 820 of the SMP 808. In the folded configuration, the active area of ​​the transducer 802 can be the total surface area of ​​the transducer facing in one direction. Therefore, the active area can be equal to the area of ​​one of the transducer arrays.

[0079] In the collapsed configuration, the transducer 802 may have a footprint small enough to fit within the outer housing of a deployable catheter for intravenous passage. Upon reaching the target imaging site, the transducer 802 may expand to Fig.8D When the transducer 802 is deployed, the straightening of the SMP 808 causes the first transducer array 804 to rotate in a second rotational direction (e.g., clockwise) opposite to the direction indicated by arrow 824, thereby Figure 8C The first transducer array 804 and the second transducer array 806 are separated by a gap extending longitudinally between the transducer arrays until the transducer 802 is in the transition configuration shown. Fig.8D The expanded configuration.

[0080] like Fig.8D As shown, the transducer 802 is planar, e.g., coplanar with the xz plane, and includes a first transducer array 804 and a second transducer array 806 and an SMP 808. A central region 820 of the SMP 808 is coplanar with a planar region 822, thereby together forming a rectangular extension of the transducer 802 along the x-axis. A width 834 of the SMP 808 may be similar to the sum of the widths 814 of the transducer arrays, and a length 832 of the SMP 808 is less than a length 816 of the transducer arrays.

[0081] In the deployed configuration, the first transducer array 804 and the second transducer array 806 can be positioned very close to each other, for example, the first transducer array 804 and the second transducer array 806 are adjacent without any other transducer components arranged in the spatial region between the transducer arrays. The region between the transducer arrays can be defined or bounded by the inner edges of the transducer arrays and the edges of the transducer arrays perpendicular to the azimuth direction. The transducer arrays can be separated by a small gap, or in some examples, the inner edges of the backing layer 812 of each transducer array can touch when the transducer 802 is deployed. The active area of ​​the transducer 802 can be doubled relative to the folded configuration, and the distance between the transducer arrays can be less than the distance in the case where the SMP is positioned between the transducer arrays. For example, the total distance between the transducer arrays can be less than 5% of the height hole of the transducer 802.

[0082] By adapting the transducers of more than two transducer arrays, the active area of ​​the transducers can be more than doubled. 9A to 9D As shown, a second example of a transducer 902 equipped with two externally arranged SMPs may include a first transducer array 904, a second transducer array 906, and a third transducer array 908. The transducer arrays may be longitudinally aligned with an azimuth direction (e.g., an x-axis) and parallel to each other. Fig. 9Ais shown in a folded configuration according to a perspective view 900 and in Fig. 9B FIG. 9 is a diagram showing an end view 930 of the transducer 902. Fig. 9C 902 is further shown in perspective view 950 showing the transducer 902 in a transformed configuration and in Fig.9D 9 is further shown in a perspective view 970 of the transducer 902 in a deployed configuration.

[0083] The transducer 902 may include a first SMP 910 positioned at a first end 912 of the transducer 902 and a second SMP 914 positioned at a second end 916 of the transducer 902. The first SMP 910 and the second SMP 914 may each be attached to two of the transducer arrays and may be formed of the same or different materials. More specifically, the first SMP 910 is coupled to the first transducer array 904 and the second transducer array 906 at the first end 912, and the second SMP 914 is coupled to the second transducer array 906 and the third transducer array 908 at the second end 916. Fig. 9A As shown, each of the transducer arrays has a matching layer 918 and a backing layer 920, and may each have a similar width 922 and a similar length 924. The transducer arrays may each be longitudinally aligned with the x-axis. The thickness of each of the first SMP 910 and the second SMP 914 may be similar to each other and less than the thickness of each of the transducer arrays, the thickness being defined along the y-axis, such that the matching layer 918 protrudes above the y-axis. Fig.9D SMP in its expanded configuration.

[0084] The second transducer array 906 is positioned between the first transducer array 904 and the third transducer array 908, and the transducer arrays are not directly coupled to each other. Instead, the transducer arrays are connected by the first SMP 910 and the second SMP 914, and the transition of the transducer 902 between the folded configuration and the unfolded configuration is guided by the SMP. Each of the SMPs includes a central region 926 configured to flex and a planar region 928 arranged on opposite sides of the central region 926. The planar region 928 makes edge-sharing contact with the edge of the backing layer 920 of the transducer array and is fixedly coupled to the edge of the backing layer 920.

[0085] When adjusted to Fig.9A and Fig. 9B In the folded configuration shown: the first SMP 910 can be bent so that the first transducer array 904 is relative to Fig.9DThe deployed configuration of the first transducer array 904 and the third transducer array 908 can be pivoted, for example, 180 degrees in a first rotational direction to become stacked below the second transducer array 906 along the y-axis. The second SMP 914 can be bent in a direction opposite to the first SMP 910 so that the third transducer array 908 can be pivoted, for example, 180 degrees in a second rotational direction opposite to the first rotational direction to become stacked above the second transducer array 906 along the y-axis. As described above, other examples may include the first transducer array 904 and the third transducer array 908 being rotated by greater than or less than 180 degrees. In addition, in other examples, the transducer 902 can be folded in an opposite configuration, for example, the first transducer array 904 is located above the second transducer array 906, and the third transducer array 908 is located below the second transducer array 906. Fig. 9B As shown, in the folded configuration, the stacked transducer arrays are aligned along the y-axis but spaced apart from each other.

[0086] Fig. 9B The end view 930 of the transducer 902 shows the S-shaped geometry of the transducer. The backing layers 920 of the first transducer array 904 and the second transducer array 906 face each other in the folded configuration, while the matching layers 918 of the second transducer array 906 and the third transducer array 908 face each other. The first transducer array 904 and the second transducer array 906 are spaced apart by a distance similar to the diameter 932 of the semicircle formed by the first SMP 910. The second transducer array 906 and the third transducer array 908 are spaced apart by a distance less than the diameter of the semicircle formed by the second SMP 914. Therefore, when the transducer 902 is in the folded configuration, the transducer arrays do not contact each other.

[0087] When the transducer is transformed from the folded configuration to the deployed configuration, the first SMP 910 may straighten, causing the first transducer array 904 to pivot through the Fig. 9B The second SMP 914 can also be straightened so that the third transducer array 908 is rotated in the direction indicated by the arrow 934 in FIG. Fig. 9B The transducer 902 may be swung in a first rotational direction as indicated by arrow 936 in FIG. Fig. 9C The transition configuration is shown, where the transducer arrays are still spaced apart and not in contact with each other.

[0088] exist Fig.9DIn the deployed configuration shown, the first SMP 910 and the second SMP 914 become aligned with the xz plane (e.g., flat). The SMPs form rectangular extensions along the x-axis at opposite sides of the transducer 902 and may be offset from each other along the x-axis. For example, the first SMP 910 has a width 972 similar to or slightly larger than the combined width 922 of the first transducer array 904 and the second transducer array 906, and is positioned at the first end 912 of the transducer 902. The second SMP 914 has a width 974 similar to or slightly larger than the combined width 922 of the second transducer array 906 and the third transducer array 908, and is positioned at the second end 916 of the transducer 902. The second SMP 914 is positioned higher than the first SMP 910 relative to the z-axis.

[0089] In the deployed configuration, the transducer arrays are aligned along the x-axis, y-axis, and z-axis and are coplanar with each other along a common plane. The transducer arrays are depicted as being spaced apart from each other by a small gap that is less than the distance of the transducer arrays if the SMP is instead disposed between the transducer arrays. In some examples, the transducer arrays may be in edge-sharing contact in the deployed configuration, e.g., the inner edges of the transducer arrays are in contact with each other. As described above with respect to FIG. 8A to FIG. 8D As shown in the transducer 802, when the transducer 902 is deployed, the first transducer array 904, the second transducer array 906, and the third transducer array 908 are arranged adjacently without any other transducer components arranged in the spatial region between the transducer arrays. The region between the transducer arrays can be defined or bounded by the inner edges of the transducer arrays and the edges of the transducer arrays perpendicular to the azimuth direction.

[0090] With similar dimensions of the transducer arrays, the active area of ​​the transducer 902 can be tripled when the transducer 902 is unfolded relative to when the transducer is folded. By placing the SMP outside the active area, the transducer arrays are positioned closer together so that the total distance between the transducer arrays can be less than 5% of the height aperture of the transducer. The external arrangement of the SMP can allow the distance between the transducer arrays to be reduced without introducing additional complexity to the shape transformation of the SMP or the manufacturing process of the transducer. The SMP can be arranged outside the active area of ​​the transducer when the packaging space along the azimuthal direction of the transducer is not limited.

[0091] like Figures 5 to 9DAs shown, the SMP can be attached to a backing layer of the transducer, such as a separate backing layer for each transducer array of the transducer. Alternatively, in some examples, the SMP can be similarly coupled to a matching layer for each transducer array. The material of the SMP can be selected to be physically compatible with the material of the backing layer to reduce the likelihood of separation between the SMP and the matching layer or backing layer during the transition of the SMP between shapes. However, manufacturing and material selection can be simplified by incorporating the SMP as the acoustic layer of the transducer. Thus, as Figure 10 to Figure 11 As shown, the SMP may form a backing layer or matching for the transducer.

[0092] Fig.10 A first example of a transducer 1000 having an SMP forming an acoustic layer is shown. The transducer 1000 has a first transducer array 1002 and a second transducer array 1004 spaced apart from each other along the x-axis. The SMP 1006 extends between the transducer arrays and across the entire width 1008 of the transducer 1000, thereby forming a continuous backing layer across the transducer 1000. Thus, each transducer array is coupled to a common backing layer, and the remaining components of the acoustic stack of each transducer array, such as the matching layer 1010 and the element 1012, can be laminated to the SMP 1006. The transducer 1000 can be cut from the top of the matching layer 1010 through the element 1012 down to the top of the SMP 1006 relative to the y-axis. When forming the backing layer of the transducer 1000, the SMP 1006 can include additives to provide the SMP 1006 attenuation properties. For example, SMP 1006 may have an increased density and / or contain silicone and tungsten as additives.

[0093] Alternatively, the SMP may form a matching layer for the transducer. A second example of a transducer 1100 is shown in FIG. 11 , where the SMP 1102 forms a continuous matching layer that extends completely across the width 1104 of the transducer 1100. The transducer 1100 has a first transducer array 1106 and a second transducer array 1108. The transducer arrays are spaced apart from one another along the x-axis, with the SMP 1102 extending between the transducer arrays. The transducer 1100 may be cut from the bottom of the backing layer 1110 through the element 1112 upward to the bottom of the SMP 1102 relative to the y-axis. When forming the matching layer for the transducer 1100, the SMP 1102 may be formed of a matrix polymer.

[0094] By implementing the SMP as an acoustic layer of the transducer, rather than as a connector between the transducer array of the transducer, adhesion of the SMP to the backing layer (or matching layer) of the transducer array is eliminated. Therefore, fewer materials and components are required for the manufacturing process, thereby reducing costs. In addition, the shape-changing properties provided by the SMP are incorporated into the transducer without adding thickness to the transducer. The thickness and footprint of the transducer are maintained (e.g., not increased) while enhancing the transducer gain.

[0095] As mentioned above, whether SMP is 6A to 7B As shown, segments are formed between the transducer arrays, or as Figure 10 to Figure 11 The continuous common acoustic layer forming the transducer array is shown, and the performance of the transducer having the transducer array separated by the SMP extending between the transducer arrays can be hindered by separating the transducer arrays from each other by a certain distance. Since the packaging space along the azimuth direction of the transducer is limited, the positioning of the SMP outside the effective area can be eliminated. However, a minimum cumulative distance between the transducer arrays greater than a threshold amount (e.g., 5% of the height hole) may be required to allow the SMP to bend and fold the transducer into a folded configuration. This problem can be solved at least in part by configuring the SMP to change shape via more than one transition path. For example, the SMP can be folded in response to a first stimulus and can be tightened along at least one dimension in response to a second stimulus.

[0096] The SMP may have a large deformation capability, for example, up to 800%. By using an SMP adapted to contract along at least one dimension in response to a stimulus, the distance between the transducers may be reduced. Fig.12 Shown in the second illustration 1200, the transducer 1250 has a first transducer array 1202 and a second transducer array 1204 spaced apart from the first transducer array 1202 by a SMP 1206. The transducer 1250 is depicted in a first folded configuration 1201 wherein the active area of ​​the transducer 1250 is reduced relative to a second expanded configuration 1203.

[0097] When exposed to a first stimulus S1, the SMP 1206 transforms to a second configuration 1203. The first stimulus S1 may be any of the above stimuli. The active area of ​​the transducer 1250 (e.g., the total surface area of ​​the transducer 1250 facing the same direction along the y-axis) is doubled relative to the first configuration 1201. The first transducer array 1202 is separated from the second transducer array 1204 by the SMP 1206, which has a first width 1208 in the second configuration 1203, which is defined along the x-axis, which may also be the height direction of the transducer 1250.

[0098] The SMP 1206 may be exposed to a second stimulus S2 different from the first stimulus S1, which may drive the SMP 1206 to contract along the x-axis. In one example, the first stimulus S1 may be temperature, and the second stimulus S2 may be humidity. In other examples, the first stimulus S1 and the second stimulus S2 may be any combination of various chemical stimuli, physical stimuli, and biological stimuli. The contraction of the SMP 1206 in the height direction causes the transducer 1250 to transform into a third contracted configuration 1205. In the third configuration 1205, the SMP 1206 has a second width 1210 that is smaller than the first width 1208. Thus, the distance between the first transducer array 1202 and the second transducer array 1204 is reduced. The transducer 1250 may be transformed from the third configuration 1205 to the second configuration 1203 and from the second configuration 1203 to the first configuration 1201 by exposing the SMP 1206 to more than one stimulus. SMP 1206 may be similarly applied to transducers having more than two transducer arrays, such as 9A to 9D transducer 902.

[0099] To return the transducer 1250 to the first configuration 1201, the transducer 1250 may be exposed to a variation of the second stimulus S2 to expand the SMP 1206 along the x-axis. For example, if the second stimulus S2 is pH, the SMP 1206 may be subjected to a first lower pH to induce contraction, and a second higher pH to promote expansion. The transducer 1250 may then be exposed to a variation of the first stimulus S1 to induce bending of the SMP 1206, thereby folding the transducer 1250. For example, if the first stimulus S1 is humidity, the transducer 1250 may be exposed to lower humidity to drive the SMP 1206 to bend, and may be exposed to higher humidity to trigger the straightening of the SMP 1206.

[0100] Contraction and expansion of the SMP 1206 allows the spacing between the transducer arrays to be adjusted based on the response of the SMP 1206 to a stimulus. FIG. 6A to FIG. 7B As shown, when the SMP 1206 is constructed as a segment disposed between and coupled to the inner edge of the transducer array, the entire segment of the SMP can be contracted and expanded. Figure 10 to Figure 11 As shown, when SMP 1206 forms a continuous common acoustic layer of transducers, SMP 1206 may be adapted to extend only in areas between transducer arrays (e.g., Fig.10 and Fig.11 In some examples, the SMP 1206 can be configured to contract and expand in an azimuth direction in addition to or instead of an elevation direction. By constraining the contraction and expansion regions, undesirable separation of the SMP from a transducer component coupled to the SMP can be mitigated.

[0101] It should be understood that the above-mentioned examples of shape transformation (e.g., bending and tightening) are non-limiting examples. Various other modes of shape change used in deployable catheters have been envisioned. For example, in addition to bending and tightening, the SMP can also curl, twist and / or expand. The SMP can be configured to change shape via more than one mode depending on the stimulus applied and the desired level of complexity.

[0102] In this way, a transducer for a deployable catheter can be easily passed intravenously through a patient and provide an enhanced field of view, resolution, penetration, and image update rate for an image. The transducer arrays of the transducer can be connected to each other through the SMP, and the transducer can be transformed between at least a first folded shape and a second unfolded shape due to the response of the SMP to a stimulus. The effective area of ​​the transducer can be selectively increased, thereby enhancing the performance of the transducer. The SMP can be incorporated into the transducer via more than one configuration. For example, the SMP can be attached to the edge of the transducer array and extend between the transducer arrays. Alternatively, the SMP can form a continuous common acoustic layer of the transducer array and bend at the area between the transducer arrays. In order to reduce the distance between the transducer arrays during data acquisition, the SMP can be configured to be tightened along at least one dimension. In addition, when packaging space is available along the azimuth aperture of the transducer, the SMP can be located outside the effective area of ​​the transducer, also resulting in a reduced distance between the transducer arrays. Thus, the data quality and data acquisition speed of the transducer may be increased at a low cost while allowing the transducer to be adjusted to a conformation that facilitates intravenous passage of a deployable catheter.

[0103] As used herein, the elements or steps listed in the singular and beginning with the word "one" or "a kind of" should be understood as not excluding a plurality of the elements or steps, unless such exclusion is explicitly stated. In addition, the reference to "an embodiment" of the present invention is not intended to be interpreted as excluding the existence of additional embodiments that also include the cited features. In addition, unless explicitly stated to the contrary, the embodiment of "including", "comprising" or "having" an element or multiple elements with a specific characteristic may include additional such elements without the characteristic. The terms "including" and "in..." are used as the concise language equivalents of the corresponding terms "including" and "wherein". In addition, the terms "first", "second" and "third" etc. are only used as marks, and are not intended to impose numerical requirements or specific positional order on their objects.

[0104] The present disclosure also provides support for a deployable invasive device, the deployable invasive device comprising: a transducer having a plurality of transducer arrays connected by at least one shape memory material, the at least one shape memory material being configured to cause the transducer to transition between a first folded shape and a second unfolded shape in response to one or more stimuli, wherein in the second unfolded shape, the plurality of transducer arrays are arranged adjacent to each other without any other transducer components positioned in an area between each of the plurality of transducer arrays, the area being defined by inner edges of the plurality of transducer arrays and edges of the plurality of transducer arrays perpendicular to the azimuth direction, and the effective area of ​​the transducer is increased relative to the first folded shape. In a first example of the system, the at least one shape memory material is a bidirectional shape memory polymer. In a second example of the system, optionally including the first example, the at least one shape memory material is positioned along one side of the transducer in the azimuth direction and extends between edges of each of the plurality of transducer arrays perpendicular to the azimuth direction. In a third example of the system, optionally including the first and second examples, at least one shape memory material is coupled to an edge of each transducer array in a plurality of transducer arrays at a planar segment of the at least one shape memory material, and wherein the planar segments are spaced apart from each other by a central segment of the at least one shape memory material. In a fourth example of the system, optionally including the first to third examples, a central segment of the at least one shape memory material is not coupled to the plurality of transducer arrays, and wherein the central segment of the at least one shape memory material is configured to transition between a bent geometry when the transducer is in a first folded shape and a less bent geometry when the transducer is in a second unfolded shape. In a fifth example of the system, optionally including the first to fourth examples, the plurality of transducer arrays include a first transducer array and a second transducer array, each of the first transducer array and the second transducer array being coupled to the at least one shape memory material at the same side of the transducer along an edge perpendicular to the azimuth direction. In a sixth example of the system, optionally including the first to fifth examples, the plurality of transducer arrays include a first transducer array, a second transducer array, and a third transducer array, the second transducer array is positioned between the first transducer array and the third transducer array, and wherein at least one shape memory material includes a first shape memory material and a second shape memory material, the first shape memory material being coupled to edges of the first transducer array and the second transducer array perpendicular to the azimuthal direction at a first side of the transducer, the second shape memory material being coupled to edges of the second transducer array and the third transducer array perpendicular to the azimuthal direction at a second side of the transducer, the second side being opposite to the first side.In a seventh example of the system, optionally including the first to sixth examples, when the transducer transforms from the first folded shape to the second deployed shape, at least one transducer array pivots relative to an adjacent transducer array in a first rotational direction, and wherein at least one transducer array is more coplanar with the adjacent transducer array in the second deployed shape than in the first folded shape. In an eighth example of the system, optionally including the first to seventh examples, when at least one transducer transforms from the second deployed shape to the first folded shape, at least one transducer array pivots in a second rotational direction opposite to the first rotational direction, and wherein at least one transducer array is aligned and parallel with the adjacent transducer along a vertical axis of the transducer in the first folded shape.

[0105] The present disclosure also provides support for a transducer for an imaging catheter, the transducer comprising: two or more transducer arrays, the two or more transducer arrays being connected by a shape memory polymer (SMP), the SMP being configured to undergo one or more shape transitions to adjust the effective area of ​​the transducer, the effective area comprising the cumulative surface area of ​​the two or more transducer arrays facing the same direction, and the distance between each of the two or more transducer arrays. In a first example of the system, the one or more shape transitions comprise the SMP bending into a curved shape and the SMP straightening into a planar geometry. In a second example of the system, optionally including the first example, when the SMP is bent into a curved shape, the transducer is adjusted to a folded configuration, and when the SMP is straightened into a planar geometry, the transducer is adjusted to an expanded configuration, and wherein the effective area of ​​the transducer is larger in the expanded configuration than in the folded configuration. In a third example of the system, optionally including the first example and the second example, the effective area is increased by at least 1.5 times in the expanded configuration relative to the folded configuration of the transducer. In a fourth example of the system, optionally including the first to third examples, one or more shape transitions include contraction and expansion of the SMP at least in an area of ​​the SMP extending between two or more transducer arrays, and wherein the contraction and expansion occur along the height aperture of the transducer. In a fifth example of the system, optionally including the first to fourth examples, contraction and expansion of the SMP are triggered by exposing the SMP to one or more stimuli when the effective area of ​​the transducer increases. In a sixth example of the system, optionally including the first to fifth examples, the SMP is positioned as a segment coupled to the inner edge of the two or more transducer arrays and extending between the inner edges of the two or more transducer arrays. In a seventh example of the system, optionally including the first to sixth examples, the SMP is constructed as a continuous layer across the entire transducer and forms one of a common matching layer or a common backing layer of two or more transducer arrays. In an eighth example of the system, optionally including the first to seventh examples, each of the one or more shape transitions is induced by a different stimulus, and the different stimulus includes any one of a chemical stimulus, a physical stimulus, and a biological stimulus.

[0106] The present disclosure also provides support for a transducer for a deployable catheter, the transducer comprising: two or more transducer arrays connected by a shape memory polymer (SMP), the SMP being configured to contract and expand along an altitude aperture and / or an azimuth aperture of the transducer in a region of the SMP extending between each of the two or more transducer arrays. In a first example of the system, when the SMP is contracted, the cumulative width of the SMP is 5% or less of the altitude aperture and / or the azimuth aperture of the transducer.

[0107] This written description uses examples to disclose the invention, including the best mode, and also to enable a person of ordinary skill in the relevant art to practice the invention, including making and using any devices or systems and performing any included methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to a person of ordinary skill in the art. Such other examples are intended to fall within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insignificant differences from the literal language of the claims.

Claims

1. A deployable invasive device comprising: a transducer having a plurality of transducer arrays connected by at least one shape memory material, each transducer array in the plurality of transducer arrays having a backing layer, the at least one shape memory material being configured to cause the transducer to transition between a first folded shape and a second expanded shape in response to one or more stimuli; Wherein in the second expanded shape, the multiple transducer arrays are arranged coplanarly with each other, and the at least one shape memory material is positioned in a region between the backing layers of a pair of transducer arrays among the multiple transducer arrays, the region being defined by the edges of the backing layers of the pair of transducer arrays that are opposite to each other, and the at least one shape memory material is coplanar with the backing layers of the pair of transducer arrays, and the effective area of ​​the transducer is increased relative to the first folded shape.

2. The deployable invasive device of claim 1, wherein the at least one shape memory material is a two-way shape memory polymer.

3. A deployable invasive device according to claim 1, wherein the at least one shape memory material is positioned along a side of the transducer in an azimuthal direction and extends between edges of each of the multiple transducer arrays that are perpendicular to the azimuthal direction.

4. A deployable invasive device according to claim 3, wherein the at least one shape memory material is coupled to the edge of each of the multiple transducer arrays at a planar segment of the at least one shape memory material, and wherein the planar segments are separated from each other by a central segment of the at least one shape memory material.

5. A deployable invasive device according to claim 4, wherein the central segment of the at least one shape memory material is not coupled to the multiple transducer arrays, and wherein the central segment of the at least one shape memory material is configured to transition between a bent geometry when the transducer is in the first folded shape and a less bent geometry when the transducer is in the second expanded shape.

6. A deployable invasive device according to claim 1, wherein the multiple transducer arrays include a first transducer array and a second transducer array, each of the first transducer array and the second transducer array being coupled to the at least one shape memory material along an edge perpendicular to the azimuthal direction at the same side of the transducer.

7. A deployable invasive device according to claim 1, wherein the multiple transducer arrays include a first transducer array, a second transducer array, and a third transducer array, the second transducer array is positioned between the first transducer array and the third transducer array, and wherein the at least one shape memory material includes a first shape memory material and a second shape memory material, the first shape memory material is coupled to edges of the first transducer array and the second transducer array perpendicular to the azimuthal direction at a first side of the transducer, and the second shape memory material is coupled to edges of the second transducer array and the third transducer array perpendicular to the azimuthal direction at a second side of the transducer, the second side being opposite to the first side.

8. A deployable invasive device according to claim 1, wherein when the transducer transforms from the first folded shape to the second expanded shape, at least one transducer array pivots along a first rotational direction relative to an adjacent transducer array, and wherein the at least one transducer array is more coplanar with the adjacent transducer array in the second expanded shape than in the first folded shape.

9. A deployable invasive device according to claim 8, wherein when the at least one transducer transforms from the second expanded shape to the first folded shape, the at least one transducer array pivots along a second rotational direction opposite to the first rotational direction, and wherein the at least one transducer array is aligned and parallel with the adjacent transducer along the vertical axis of the transducer in the first folded shape.

10. A transducer for an imaging catheter, the transducer comprising: Two or more transducer arrays, the two or more transducer arrays being connected by a shape memory polymer (SMP), each transducer array of the plurality of transducer arrays having a backing layer, the SMP being configured to undergo one or more shape transitions to adjust an active area of ​​the transducer, the active area comprising a cumulative surface area of ​​the two or more transducer arrays facing the same direction, and a distance between each transducer array of the two or more transducer arrays, Wherein, when transformed into the expanded shape, the multiple transducer arrays are arranged coplanarly with each other, and the SMP is positioned in an area between the backing layers of a pair of transducer arrays among the multiple transducer arrays, wherein the area is defined by the edges of the backing layers of the pair of transducer arrays that are opposite to each other, and the SMP is coplanar with the backing layers of the pair of transducer arrays.

11. The transducer of claim 10, wherein the one or more shape transitions include bending of the SMP into a curved shape and straightening of the SMP into a planar geometry.

12. A transducer according to claim 11, wherein when the SMP is bent into the curved shape, the transducer is adjusted to a folded configuration, and when the SMP is straightened into the planar geometry, the transducer is adjusted to an expanded configuration, and wherein the active area of ​​the transducer is larger in the expanded configuration than in the folded configuration.

13. The transducer of claim 12, wherein the active area is increased by at least 1.5 times in the deployed configuration relative to the folded configuration of the transducer.

14. The transducer of claim 10, wherein the one or more shape transitions comprise contraction and expansion of the SMP at least in a region of the SMP extending between the two or more transducer arrays, and wherein the contraction and the expansion occur along a height aperture of the transducer.

15. The transducer of claim 13, wherein contraction and expansion of the SMP is triggered by exposing the SMP to one or more stimuli as the active area of ​​the transducer increases.

16. The transducer of claim 10, wherein the SMP is positioned as a segment coupled to and extending between inner edges of the two or more transducer arrays.

17. The transducer of claim 10, wherein the SMP is constructed as a continuous layer across the entire transducer and forms one of a common matching layer or a common backing layer for the two or more transducer arrays.

18. The transducer of claim 10, wherein each of the one or more shape transitions is induced by a different stimulus, and the different stimulus comprises any one of a chemical stimulus, a physical stimulus, and a biological stimulus.

19. A transducer for a deployable catheter, the transducer comprising: two or more transducer arrays, the two or more transducer arrays being connected by a shape memory polymer (SMP), each of the plurality of transducer arrays having a backing layer, the SMP being configured to contract and expand along an elevation aperture and / or an azimuth aperture of the transducer in a region of the SMP extending between each of the two or more transducer arrays, Wherein in the expanded shape, the multiple transducer arrays are arranged coplanarly with each other, and the SMP is positioned in a region between the backing layers of a pair of transducer arrays among the multiple transducer arrays, the region being defined by the edges of the backing layers of the pair of transducer arrays that are opposite to each other, and the SMP is coplanar with the backing layers of the pair of transducer arrays.

20. The transducer of claim 19, wherein when the SMP is constricted, a cumulative width of the SMP is less than a threshold percentage of the altitude aperture and / or the azimuth aperture of the transducer.

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