Method for determining array relative position of a flexible array device

Abstract

The invention relates to a method for determining the relative position of an array of a flexible array device. According to an embodiment, the flexible array device comprises a plurality of arrays arranged in a deformable substrate at a predetermined interval, and the method for determining the relative position of the arrays comprises the steps of: measuring a first capacitance of adjacent arrays; measuring a second capacitance of the adjacent arrays after deformation of the substrate; and determining the relative position of the adjacent arrays on the basis of the measured values of the first and second capacitances. According to the embodiment, the capacitance between adjacent arrays is measured for a plurality of arrays arranged in a deformable substrate, and the change in capacitance caused by deformation (contraction, expansion, warping, etc.) of the substrate is measured, and thereby the relative position of the arrays is determined.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a method for determining relative positions between arrays of a flexible array device, and more particularly, to a method for determining relative positions of arrays by measuring a change in capacitance between adjacent arrays caused by deformation (contraction, relaxation, bending) of a deformable substrate in which a plurality of arrays are arranged.

[0002] [Statement as to U.S. Government Support]

[0003] This research was supported by the Korea Institute of Science and Technology under the Ministry of Science and ICT Biomedical Technology Development Project (Development of an ultrasound probe and connectable device using semiconductor technology, Project Serial No. 1711105874). BACKGROUND

[0004] An ultrasound probe includes an array of ultrasound transducers, and the ultrasound transducers are configured to serve as both a transmitter that outputs an ultrasound beam to a region of interest and a receiver that receives an ultrasound beam reflected back from an object in the region of interest. A time of flight can be measured from the transmission / reception time of the ultrasound beam, and using the time of flight, image information of the object in the region of interest can be generated. The generated ultrasound image information can be visualized through a display. The ultrasound probe is capable of imaging the inside of the body in a non-invasive manner, and thus it is widely used in the medical field.

[0005] Figure 1A A cross-sectional structure of an ultrasound output device 10 according to the related art is shown. Figure 1A The ultrasound output device 10 has an array structure in which a plurality of ultrasound transducers are arranged at a predetermined interval. Each transducer array outputs an ultrasound beam, and the output ultrasound is reflected back to the device by an object (e.g., organ tissue, a tumor, cancer cells) positioned on a travel path. A processing device connected to the device measures the time of flight of the ultrasound beam and converts it into an image.

[0006] As shown in FIG. 1, Figure 1A The ultrasound output device includes a plurality of ultrasound transducers arranged in a rigid substrate that does not deform at a predetermined interval, and generally, a body part to be imaged has a curved shape covered with soft skin, and the skin and the ultrasound probe device are in close contact through a coupling unit 11 such as coupling gel. However, the curve of the skin is different at each site, and thus even by using coupling gel, it can be difficult to attach the ultrasound probe device closely to the skin in some cases.

[0007] Figure 1B A cross-sectional structure of a flexible ultrasound output device 20 according to the related art is shown, and it can be more easily attached closely to the skin than the ultrasound output device 10. Figure 1A The ultrasound output device 20 includes a plurality of ultrasound transducers arranged in a deformable substrate that deforms at a predetermined interval, and the deformable substrate is deformed by a deformation unit 21 such as a motor.Figure 1B The ultrasound output device 20 of the related art includes a plurality of ultrasound transducers arranged in a flexible substrate that can be arbitrarily deformed at predetermined intervals. The flexible substrate is made of a material that can be deformed, such as, for example, polydimethylsiloxane (PDMS), and is attached to the skin without a separate coupling unit. Figure 1A In contrast to the structure of the related art, the flexible substrate can be closely attached along the curve of the skin as desired without a separate coupling unit.

[0008] Since the reference plane R for measuring the time of flight of the ultrasound beam does not move, the ultrasound output device (rigid) of the related art has a constant distance between the reference plane R and the focal point F to which the ultrasound beam converges. Figure 1A The structure of the ultrasound output device (rigid) of the related art can be used as an ultrasound probe for imaging. In contrast, as the movement of the skin or the change in pressure applied to the contact surface between the skin and the device changes over time, Figure 1B The ultrasound output device (flexible) of the related art has a change in the position of the reference plane (R→R') and a change in the position of the focal point (F→F') to which the ultrasound beam converges. Therefore, it is difficult to use as a reference for measuring the change in the time of flight of the ultrasound beam in an ultrasound imaging application.

[0009] Therefore, to acquire an ultrasound image using a flexible material that can be arbitrarily deformed, a system for determining the relative positions with respect to each other in real time as the ultrasound transducer array moves and adjusting the image according to the position information is required. SUMMARY

[0010] TECHNICAL PROBLEM

[0011] The present disclosure aims to provide a method for determining the relative positions between each array of a flexible array device and an embodiment of a flexible array device using the same.

[0012] TECHNICAL SOLUTION

[0013] In the method for determining the relative positions between arrays of a flexible array device according to the embodiment, the flexible array device includes a plurality of arrays arranged in a deformable substrate at predetermined intervals, and the method includes measuring a first capacitance between adjacent arrays, measuring a second capacitance between the adjacent arrays after the substrate is deformed, and determining the relative positions between the adjacent arrays based on the first capacitance measurement value and the second capacitance measurement value.

[0014] According to the embodiment, determining the relative positions between the adjacent arrays can include calculating the distance between the adjacent arrays based on the first capacitance measurement value, and calculating the changed distance between the adjacent arrays caused by the deformation of the substrate based on the second capacitance measurement value.

[0015] According to the embodiment, the first capacitance C1 can be calculated by the following equation, and

[0016]

[0017] The second capacitance C2 can be calculated by the following equation,

[0018]

[0019] where t denotes a length in a direction perpendicular to a surface of the substrate of the plurality of arrays, L denotes a length in a direction parallel to the surface of the substrate of the plurality of arrays, d denotes a distance between adjacent arrays, θ denotes an angle between adjacent arrays caused by deformation of the substrate, and ε r and ε0 denote dielectric constants of the substrate and vacuum, respectively.

[0020] According to an embodiment, the dielectric constant ε r may vary according to a material in which the substrate is made, compression or stretching of the substrate, and determining the relative positions between the adjacent arrays can include determining the relative positions between the arrays in the compression or the stretching based on the capacitance measurements between the arrays.

[0021] According to an embodiment, each of the plurality of arrays can include a first portion and a second portion having a smaller width than the first portion, a distance between the first portions in the adjacent arrays and a distance between the second portions are different, and a bending direction of the substrate is determined based on capacitances between the adjacent arrays varying according to the bending direction of the substrate.

[0022] A computer program stored in a computer-readable recording medium for executing a method for determining relative positions between arrays of a flexible array device according to an embodiment is provided.

[0023] The flexible ultrasound imaging apparatus according to an embodiment includes a plurality of ultrasound output units arranged in a deformable substrate to output ultrasound to a region of interest, an ultrasound receiving unit that receives ultrasound reflected from an object disposed in the region of interest, and a processing unit that calculates a time of flight of the ultrasound based on a difference between an output time and a reception time of the ultrasound and acquires an image of the object based on the time of flight information, wherein the processing unit can be configured to measure a first capacitance between adjacent ultrasound output units, measure a second capacitance between the adjacent ultrasound output units after deformation of the substrate, determine relative positions of the plurality of ultrasound output units based on the first capacitance measurement and the second capacitance measurement, and correct the image of the object based on the relative positions of the plurality of ultrasound output units.

[0024] According to an embodiment, the processing unit can be configured to determine the relative positions of the plurality of ultrasound output units by calculating a distance between adjacent arrays based on the first capacitance measurement and a changed distance between the adjacent arrays caused by deformation of the substrate based on the second capacitance measurement.

[0025] According to an embodiment, the first capacitance C1 can be calculated by the following equation, and

[0026]

[0027] The second capacitance C2 can be calculated by the following equation,

[0028]

[0029] where t denotes a length in a direction perpendicular to a surface of the substrate of the plurality of arrays, L denotes a length in a direction parallel to the surface of the substrate of the plurality of arrays, d denotes a distance between adjacent arrays, θ denotes an angle between adjacent arrays caused by a deformation of the substrate, and ε r and ε0denote dielectric constants of the substrate and vacuum, respectively.

[0030] According to embodiments, the dielectric constant ε r may vary depending on a material of which the substrate is made, compression or stretching of the substrate, and the processing unit can determine a relative position between the arrays based on the capacitance measurement between the arrays.

[0031] According to embodiments, the substrate can include at least two material layers having different dielectric constants, the capacitance can be differently measured for each material layer in adjacent arrays, and the processing unit can be further configured to determine a bending direction of the substrate based on the capacitance between adjacent arrays varying depending on the bending direction of the substrate.

[0032] According to embodiments, each of the plurality of ultrasonic output units can include a micromachined ultrasonic transducer (MUT) and a support array supporting the micromachined ultrasonic transducer, the support array can include a first portion and a second portion having a smaller width than the first portion, a distance between the first portions and a distance between the second portions are different, and the processing unit can be further configured to determine a bending direction of the substrate based on the capacitance between adjacent arrays varying depending on the bending direction of the substrate.

[0033] Advantageous effects

[0034] According to embodiments of the present disclosure, a change in capacitance between adjacent arrays of a plurality of arrays arranged in a deformable flexible substrate caused by a deformation (contraction, relaxation, bending) of the flexible substrate is measured. The capacitance measurement can be used to determine a relative position between the arrays, as it varies depending on a distance between the arrays and an angle between the arrays.

[0035] The method according to the embodiment can be applied to, for example, various flexible devices, including an ultrasound imaging system including a flexible substrate and an ultrasound transducer array, an ultrasound therapy system for determining the position of a focused ultrasound focus, a sensor attached to a human body to measure a change in curvature, a system for controlling an interface based on a change in curvature and a tactile sensor, and technology using the method. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1A The cross-sectional structure of an array device including a rigid substrate and ultrasound imaging using the rigid substrate is shown.

[0037] Figure 1B The cross-sectional structure of an array device including a flexible substrate is shown, as well as the changes in the reference plane and focus position as the curved surface changes.

[0038] Figure 2 is a perspective view showing the structure of a flexible array device according to an embodiment.

[0039] Figure 3A and Figure 3B The change in capacitance between adjacent arrays caused by deformation (stretching, bending) of a substrate in a flexible array device according to an embodiment is shown.

[0040] Figure 4A and Figure 4B Simulation results of capacitance variation according to the angle between adjacent arrays are shown.

[0041] Figure 5 is a graph showing the variation of capacitance between adjacent arrays as a function of angle.

[0042] Figures 6A to 6C Simulation results showing a change in capacitance according to pressure applied to a flexible array device according to an embodiment are shown.

[0043] Figure 7 FIG. 4 shows a change in capacitance between adjacent arrays in a flexible array device according to an embodiment according to a bending direction of a substrate.

[0044] Figure 8 is an electron microscope image of a cross-sectional structure of a flexible array device according to an embodiment.

[0045] Figures 9A to 9C The figure shows simulation results of capacitance variation according to a bending direction of a substrate in a flexible array device according to an embodiment.

[0046] Figure 10 Substrates made of materials with different dielectric constants in a flexible array device according to an embodiment are shown. DETAILED DESCRIPTION

[0047] The present disclosure is described in detail below with reference to the attached drawing figures, which are incorporated in this disclosure by way of explanation, and demonstrate the principles of the disclosure. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure. It is to be understood that the various embodiments of the present disclosure are different but not necessarily mutually exclusive. For example, a particular feature, structure, or characteristic described herein in connection with one embodiment can be implemented within other embodiments without departing from the spirit and scope of the present disclosure. It is to be further understood that the position or placement of individual elements within each disclosed embodiment can be altered without departing from the scope of the present disclosure. Thus, the following detailed description is not intended to limit the scope of the disclosure, as claimed, but is merely intended to describe aspects of some embodiments in sufficient detail to enable those skilled in the art to practice the disclosure. In the drawings, like reference numerals refer to like components throughout the several views.

[0048] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings, but the scope of protection is not limited or defined by the embodiments.

[0049] Method for determining relative positions between arrays of a flexible array device

[0050] Figure 2 The structure of a flexible array device according to an embodiment is shown. The flexible array device 30 can include a deformable substrate 300 and a plurality of arrays 301, 302, 303, … 30n arranged in the substrate 300 at predetermined intervals. The device can be manufactured in a suitable form for the target and purpose and include additional components. For example, as shown, a micromachined ultrasonic transducer 311 can be positioned for each array and used as an ultrasonic imaging probe or a focused ultrasonic treatment device. Figure 2

[0051] According to an embodiment, the flexible array device 30 can be manufactured by placing micromachined ultrasonic transducers (e.g., micromachined ultrasonic transducers such as capacitive micromachined ultrasonic transducers (CMUT) or piezoelectric micromachined ultrasonic transducers (PMUT)) on a silicon substrate at predetermined intervals, patterning photoresist thereon, and filling etched regions with a flexible polymer such as polydimethylsiloxane (PDMS). The manufactured flexible array device 30 can be bent, compressed, or relaxed by an external force. According to an embodiment, relative position information of each array with respect to each other can be obtained by comparing capacitance measurements between the arrays 301, 302, 303, … 30n of the flexible array device.

[0052] Figure 3A ​and Figure 3B Changes in capacitance caused by deformation (stretching, bending) of the substrate in a flexible array device according to an embodiment are shown. Figure 3A Stretching of the substrate to the left and to the right is shown, and Figure 3B Stretching of the substrate to the left and to the right is shown, and

[0053] Referring to Figure 3A First, a first capacitance C1 between adjacent arrays 301, 302 is measured in a non-deformed state of the flexible array device 30. When other variables are known, the capacitance can be determined by the current value flowing through the array. However, this is provided by way of illustration, and the capacitance can be measured by various known methods in the art.

[0054] In this example, the first capacitance C1 can be calculated by the following Equation 1.

[0055]

Equation 1

[0056]

[0057] Here, t denotes a length in a direction perpendicular to the upper surface of the substrate 300 of the plurality of arrays (i.e., a vertical length of the array), L denotes a length in a direction parallel to the surface of the substrate 300 of the plurality of arrays (i.e., a horizontal length of the array), and d denotes a distance between adjacent arrays. ε r and ε0 denote the dielectric constants of the substrate and vacuum, respectively.

[0058] When the actual measured value of the first capacitance C1 and the remaining variables are known, the distance d between the adjacent arrays 301, 302 can be calculated by the above Equation 1. According to an embodiment, a processing device (not shown) can be configured to receive the first capacitance measurement value in a state in which the remaining variables are input, and to calculate the distance between the adjacent arrays in real time.

[0059] Subsequently, after the flexible array device 30 is deformed, i.e., after the substrate 300 is stretched to the left and to the right, a second capacitance C2 between the adjacent arrays 301, 302 is measured. As Figure 3A shown, when the substrate 300 is stretched to the left and to the right, the distance d' between the arrays 301, 302 changes, and the capacitance value between the adjacent arrays changes accordingly.

[0060] In this example, the second capacitance C2 can be calculated by the following Equation 2, and the distance d' between the arrays after deformation can be calculated by comparing the measured first capacitance C1 with the measured second capacitance C2.

[0061]

Equation 2

[0062]

[0063] In this way, for all the other arrays 301, 302, 303,... 30n, the relative position information of each array with respect to each other can be obtained by comparing the measured capacitance values before and after the deformation of the substrate.

[0064] Figure 3B The change in the measured capacitance when the substrate 300 is bent is shown. In Figure 3A In the case where the substrate is stretched to the left and right, in contrast to the substrate, the distance d' between each array is not uniform and varies depending on the degree of bending of the substrate (i.e., the angle between the arrays). The second capacitance C2 between the adjacent arrays 301, 302 after the substrate 300 is bent can be calculated by Equation 3 below.

[0065]

Equation 3

[0066]

[0067] Here, θ denotes the angle between the adjacent arrays caused by the deformation of the substrate 300. t denotes the length in the direction perpendicular to the upper surface of the substrate 300 of the plurality of arrays (i.e., the vertical length of the array), L denotes the length in the direction parallel to the surface of the substrate 300 of the plurality of arrays (i.e., the horizontal length of the array), and d' denotes the distance between the adjacent arrays after the deformation of the substrate. ε r and ε0 denote the dielectric constants of the substrate and vacuum, respectively.

[0068] Likewise, the distance between the adjacent arrays after the deformation of the substrate can be calculated by comparing the first capacitance C1 with the second capacitance C2, and for all the other arrays 301, 302, 303,... 30n, the relative position information of each array with respect to each other can be determined by measuring the change in the capacitance.

[0069] Figure 4A and Figure 4B The simulation results of the capacitance varying depending on the angle between two adjacent arrays are shown. As Figure 4A and Figure 4B shown, the capacitance when the angle between the two arrays is 0 (i.e., the substrate is not bent and the two arrays are parallel) and the capacitance when the angle between the two arrays is 5° are measured differently. As described above, the angle and the distance between the arrays can be calculated by comparing the measured values of the capacitance before and after the change.

[0070] Figure 5 is a graph showing the capacitance varying depending on the angle between the adjacent arrays. As shown, it can be seen that the measured capacitance value between the arrays changes when the angle between the arrays changes, and the angle between the arrays can be calculated by comparing the measured values of the capacitance before and after the change.

[0071] Figures 6A to 6CAnalog results showing that capacitance according to embodiments varies according to pressure applied to a flexible array device are shown. When pressure is applied to the substrate, the position of each array arranged in a 2D array on a deformable substrate relative to each other changes, and by comparing the capacitance measurements between each array before and after deformation, relative position information of the arrays can be obtained. As shown in Figure 6A and 6B It can be seen that when no pressure is applied to the substrate, the arrays remain parallel to each other, while when pressure is applied to the substrate, the angle between the arrays changes and the capacitance values between the arrays change. As shown in Figure 6C It can be seen that when a higher pressure is applied to the substrate, the angle between the arrays increases and the capacitance values between the arrays change accordingly.

[0072] Figure 7 Analog results showing that capacitance between adjacent arrays in a flexible array device according to embodiments varies according to the bending direction of the substrate are shown. When the thickness of the arrays is equal over all regions, as shown in Figure 3A and Figure 3B It can be seen that the capacitance change is independent of the bending direction of the substrate depending on the degree of bending of the substrate. That is, there is no change between the capacitance when the substrate is bent upwards and the capacitance when the substrate is bent downwards.

[0073] On the contrary, when each array includes a first portion T and a second portion B having a smaller width than the first portion, as shown in Figure 7 It can be seen that the distance d between the first portions T and the distance d' between the second portions B of each array are different, and thus the capacitance measurements between adjacent arrays vary according to the bending direction of the substrate. In other words, when the thickness of the arrays is not the same for each region, the capacitance change depends on the bending direction of the substrate (i.e., C2 and C2' are different), and thus the bending direction of the substrate can be determined therefrom.

[0074] Figure 8 is a scanning electron microscope image of a cross-sectional structure of a flexible array device according to the above-described embodiments. Each array is divided into a first portion and a second portion having a smaller width, and there is a change in capacitance measurements between the arrays caused by deformation (bending, compression / relaxation) of the substrate, and thus the relative position between the arrays and the bending direction of the substrate can be determined.

[0075] Figures 9A to 9C Analog results showing that capacitance in a flexible array device according to embodiments varies according to the bending direction of the substrate are shown. When each array includes a first portion and a second portion having a smaller width than the first portion, from Figures 9A to 9CAs shown, it can be seen that even if the degree of bending of the substrate is equal (θ = 4°), the capacitances C2, C2' have different values according to the bending direction of the substrate. Thus, the relative positions between the arrays and the bending direction of the substrate are identified based on the change in the capacitance measurement values.

[0076] In the equation and simulation, it is assumed that the dielectric constant ε r has a uniform constant value independently in each of compression and stretching, but the dielectric constant ε r may vary depending on the material of the substrate 300 actually used. Through this, the relative positions between each array can be determined by the capacitance measurement values between the arrays in each of compression and stretching.

[0077] According to an embodiment, the substrate 300 can include at least two material layers having different dielectric constants. In this case, the capacitance is measured differently for each material layer in the adjacent arrays. That is, the capacitance between the adjacent arrays is different according to the bending direction of the substrate 300, and thus, with this, the bending direction of the substrate can be determined.

[0078] For example, when the substrate 300 includes a first material layer 310 and a second material layer 320 having different dielectric constants, as Figure 10 shown, the distance d between the arrays 301, 302, 303, …, 30n is equal in the first material layer 310 portion and the second material layer 320 portion, but the capacitance values between the adjacent arrays are measured differently from each other due to the different dielectric constants for each material layer. That is, the capacitance measurement values change when the substrate 300 is bent upward and when the substrate 300 is bent downward (in contrast to this, when the substrate is made of a single material, the capacitance changes only according to the degree of bending of the substrate regardless of the bending direction of the substrate). Since the dielectric constant of the substrate material is known, and the capacitance values can be identified from the distance between each array, the direction in which the substrate is bent can be determined.

[0079] The method for determining the relative positions between the arrays of a flexible array device according to an embodiment can be implemented as an application program or in the form of program instructions that can be executed by various computer components and can be recorded in a computer-readable recording medium. The computer-readable recording medium can include program instructions, data files, and data structures individually or in combination.

[0080] Examples of the computer-readable recording medium include hardware devices specifically designed to store and execute program instructions, such as magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, magneto-optical media such as floptical disks, and ROMs, RAMs, and flash memories.

[0081] According to the method for determining the relative positions between arrays of a flexible array device as described above, the relative positions between arrays can be determined by measuring the capacitance between adjacent arrays among a plurality of arrays arranged in a deformable substrate and measuring the capacitance change caused by the deformation (contraction, relaxation, bending) of the substrate.

[0082] Specific application examples

[0083] Hereinafter, an example of a specific application using the method for determining the relative positions between arrays of a flexible array device will be described.

[0084] When the method is applied to the field of ultrasonic imaging, an ultrasonic probe including an ultrasonic transducer array of a flexible material can be provided. The ultrasonic probe is a device that outputs an ultrasonic beam using a plurality of ultrasonic transducer arrays, measures the time of flight of the ultrasonic beam reflected by an object positioned on a travel path, and converts it into an image. In order to measure the time of flight of the ultrasonic beam, the reference plane of the measurement needs to be changed over time, so a substrate of a flexible material cannot be used, and accordingly it is difficult to apply it to a contact surface having a high curvature or a region of frequent motion.

[0085] According to embodiments of the present disclosure, it can be closely attached to any body part using a flexible ultrasonic output device including an ultrasonic transducer array arranged in a deformable substrate (without the help of ultrasonic gel), and even when the position of the transducer array changes as the contact surface curvature or motion changes, it can obtain an ultrasonic image by tracking the relative position of each array in real time and reflecting the imaging process.

[0086] The flexible ultrasonic imaging device according to the embodiments includes a plurality of ultrasonic output units arranged in a deformable substrate to output ultrasonic waves to a region of interest, an ultrasonic receiving unit that receives ultrasonic waves reflected from an object positioned in the region of interest, and a processing unit to calculate the time of flight of the ultrasonic waves based on the difference between the output time and the reception time of the ultrasonic waves, and acquire an image of the object based on the time of flight information.

[0087] The processing unit is configured to measure a first capacitance between adjacent ultrasonic output units after deformation of the substrate and a second capacitance between adjacent ultrasonic output units, determine the relative positions of the plurality of ultrasonic output units based on the first capacitance measurement value and the second capacitance measurement value, and correct the image of the object based on the relative positions of the plurality of ultrasonic output units. The capacitance measurement of each ultrasonic output unit can be performed by Equations 1 to 3 as described above.

[0088] When a flexible device is closely attached to the skin by the existing method, a reference plane for measuring the time of flight of ultrasound varies with the curvature change or motion of the skin, and thus it is difficult to obtain an accurate image, but according to the embodiment, the change in the position of the array (ultrasound transducer array) is reflected in the imaging process in real time, thereby eliminating the effect of device deformation and obtaining an accurate image.

[0089] According to the embodiment, each of the plurality of ultrasound output units can include a micro-machined ultrasonic transducer (MUT) and a support array supporting the micro-machined ultrasonic transducer, and the support array can include a first portion and a second portion having a narrower width than the first portion. As described above, when the widths of the support arrays are equal, the capacitance is independent of the direction of the substrate bending depending on the degree of the substrate bending, but when the widths of the arrays are different, the capacitance measurement value depends on the direction of the substrate bending, and thus the direction of the substrate bending can be identified. According to the embodiment, the processing unit can be further configured to determine the direction of the substrate bending based on a capacitance difference due to a distance between the first portions of adjacent support arrays and a distance between the second portions of adjacent support arrays.

[0090] Meanwhile, in the case of non-invasive ultrasound detection of a curved structure such as a pipe, it is necessary to include each ultrasound transducer having a curve matching the diameter of each pipe, or to measure and correct the length of each pipe, but using the embodiment of the disclosure, it can be accurately and closely attached to the surface regardless of the type of pipe having various curves, and thus it is possible to measure the curve of the pipe, and at the same time, measure a failure in each pipe structure via ultrasound imaging.

[0091] Further, in an ultrasound treatment device directly stimulating a body part using high-intensity focused ultrasound (HIFU) or low-intensity focused ultrasound (LIFU), the existing flexible ultrasound output device changes the focus position of focused ultrasound as the curvature of the body contact surface changes or moves (because the position of each transducer changes), making it difficult to accurately emit ultrasound to the desired point.

[0092] According to the embodiment of the disclosure, it is possible to acquire relative position information of the ultrasound transducer array and track the change in the focus position of focused ultrasound in real time. Based on the position information, a user can arbitrarily control the direction of the ultrasound beam and the focus position from each transducer array. Therefore, it is possible to design different response characteristics necessary for imaging diagnosis and treatment by respectively further improving the intensity and resolution of the focus point necessary for ultrasound imaging and treatment.

[0093] Further, the present disclosure can be applied to a sensor attached to a human body to measure a change in curvature. For example, a sensor including a thin flexible substrate and a plurality of arrays can be attached to the skin, and when the skin curvature changes due to joint movement, breathing, and swelling, the corresponding change in capacitance between the arrays can be measured, and the change in skin curvature can be identified from the change in the relative positions of the arrays. In particular, it can be used as a kind of wearable device attached to a body part to collect repeatedly measured data such as changes in breathing, heartbeat, and pulse.

[0094] Further, based on the idea that the position of each array device is changed by pressing pressure, the present disclosure can be applied to a pressure sensor for an input device, for example, a keyboard. For example, the present disclosure can be used as a wearable interface device that uses a change in capacitance between arrays caused by skin movement or pressing force after being attached to the skin.

[0095] Further, when the flexible array device is used to manufacture a robot skin, it can be used as a tactile sensor that can measure pressing pressure and sense a pulling or pinching situation as if it would be human skin.

[0096] Although the present disclosure has been described herein with reference to the embodiments, it will be understood by those of ordinary skill in the corresponding arts that various modifications and changes can be made to the present disclosure without departing from the spirit and scope of the present disclosure as defined by the appended claims.

Claims

1. A method for determining the relative position between arrays of a flexible array device, wherein, The flexible array device comprises a plurality of arrays arranged in a deformable substrate at predetermined intervals, the method comprising: measuring a first capacitance between adjacent arrays; measuring a second capacitance between the adjacent arrays after deformation of the substrate; and determining a relative position between the adjacent arrays based on the first and second capacitance measurements, wherein each of the plurality of arrays comprises a first portion and a second portion having a smaller width than the first portion, and a distance between the first portions and a distance between the second portions of the adjacent arrays are different, and the method further comprises determining a bending direction of the substrate based on the capacitance between the adjacent arrays varying depending on the bending direction of the substrate.

2. The method for determining the relative position between arrays of a flexible array device of claim 1, wherein, Determining the relative position between the adjacent arrays comprises: calculating a distance between the adjacent arrays based on the first capacitance measurement; and calculating a changed distance between the adjacent arrays caused by the deformation of the substrate based on the second capacitance measurement.

3. The method for determining the relative position between arrays of a flexible array device of claim 2, wherein, The first capacitance C1 is calculated by the equation, where t represents a length in a direction perpendicular to a surface of the substrate of the plurality of arrays, L represents a length in a direction parallel to the surface of the substrate of the plurality of arrays, d represents a distance between the adjacent arrays, and ε r and ε0respectively represent dielectric constants of the substrate and vacuum.

4. The method for determining the relative position between arrays of a flexible array device of claim 3, wherein, the dielectric constant ε of the substrate r depending on the material from which the substrate is made, the compression or stretching of the substrate, and Determining the relative position between the adjacent arrays comprises determining the relative position between the arrays in compression or stretching based on the capacitance measurements between the arrays.

5. The method for determining the relative position between arrays of a flexible array device of claim 4, wherein, The substrate comprises at least two material layers having different dielectric constants, and for each material layer of the adjacent arrays, the capacitance is measured differently, and the method further comprises determining a bending direction of the substrate based on the capacitance between the adjacent arrays varying depending on the bending direction of the substrate.

6. A flexible ultrasound imaging apparatus, comprising: a plurality of ultrasound output units arranged in a deformable substrate for outputting ultrasound to a region of interest; an ultrasound receiving unit for receiving ultrasound reflected from an object disposed in the region of interest; and a processing unit for calculating a time of flight of ultrasound based on a difference between an output time and a reception time of ultrasound, and acquiring an image of the object based on the time of flight information, wherein the processing unit is configured to: measure a first capacitance between adjacent ultrasound output units, measure a second capacitance between the adjacent ultrasound output units after deformation of the substrate, determine a relative position of the plurality of ultrasound output units based on the first and second capacitance measurements, and correct the image of the object based on the relative position of the plurality of ultrasound output units. The processing unit is configured to determine the relative position of the plurality of ultrasound output units by calculating a distance between adjacent arrays based on the first capacitance measurement, and calculating a changed distance between the adjacent arrays caused by the deformation of the substrate based on the second capacitance measurement.

7. The flexible ultrasonic imaging device of claim 6, wherein, The first capacitance C1 is calculated by the equation, 8. The flexible ultrasonic imaging device of claim 7, wherein, The processing unit determines the relative position between the arrays in compression or stretching based on the capacitance measurements between the arrays. where t represents a length in a direction perpendicular to a surface of the substrate of the plurality of arrays, L represents a length in a direction parallel to the surface of the substrate of the plurality of arrays, d represents a distance between the adjacent arrays, and ε r and ε0respectively represent dielectric constants of the substrate and vacuum.

9. The flexible ultrasonic imaging device of claim 8, wherein, the dielectric constant ε of the substrate r depending on the material in which the substrate is made, the compression or stretching of the substrate, and The substrate comprises at least two material layers having different dielectric constants, and for each material layer of the adjacent arrays, the capacitance is measured differently, and 10. The flexible ultrasonic imaging device of claim 9, wherein, ​ The processing unit is further configured to determine a bending direction of the substrate based on a capacitance between the adjacent arrays that varies according to the bending direction of the substrate.

11. The flexible ultrasonic imaging device of claim 6, wherein, Each of the plurality of ultrasonic output units comprises a micro-machined ultrasonic transducer (MUT) and a support array supporting the micro-machined ultrasonic transducer, The support array comprises a first portion and a second portion having a smaller width than the first portion, and a distance between the first portions and a distance between the second portions in adjacent arrays are different, and The processing unit is further configured to determine a bending direction of the substrate based on a capacitance between the adjacent arrays that varies according to the bending direction of the substrate. 12.A computer-readable recording medium having stored thereon a computer program for executing a method for determining relative positions between arrays of a flexible array device according to any one of claims 1 to 5.

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