JP2015112214A - Subject information acquisition device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a unit for holding a subject in a subject information acquisition device that holds a subject using a flexible holding member.SOLUTION: A subject information acquisition device includes: a holding unit for pressing and holding a subject using a flexible holding member; an acoustic wave probe for receiving an acoustic wave that comes from within the subject through the holding member; and signal processing means for analyzing the acoustic wave that the acoustic wave probe receives. The holding member is stretched on a frame member that regulates the shape of the surface where the holding member and the subject come into contact with each other, and is fixed to a fixing part for applying tension to the holding member through a support side which is at least one of end sides of the frame member.

Description

  The present invention relates to a subject information acquisition apparatus that performs measurement while compressing and holding a subject.

Devices using acoustic waves are known as measurement devices that acquire information inside a living body. An apparatus using an acoustic wave is, for example, an apparatus that transmits ultrasonic waves to a subject and receives and analyzes reflected waves (echoes), or an acoustic wave that is generated by photoacoustic effects by irradiating the subject with light. The device etc. which receive and analyze. The acoustic wave used by such a device is an ultrasonic wave having a frequency band of several MHz to several tens of MHz.
On the other hand, in the living body, attenuation occurs in the process of propagation of acoustic waves, and the attenuation rate increases as the frequency increases. When the acoustic wave is attenuated, the depth of penetration into the living body is shortened or the SN ratio is deteriorated. Therefore, it is required to suppress the attenuation of the acoustic wave to a low level. For example, generally known is a method of reducing the thickness of a subject by pressing a plate-like holding member against the subject and pressing it.

  However, when the object is pressed by the holding plate, there is another problem that the acoustic wave is attenuated due to the holding plate being interposed, and that multiple reflections of the acoustic wave are generated.

  In order to solve this problem, Patent Document 1 describes a method of pressing a subject using a flexible thin film (membrane) instead of a plate-like member. When this method is used, the membrane stretched on the frame member is pressed against the subject, so that the subject can be held while suppressing attenuation and reflection of acoustic waves.

Japanese Patent No. 5059761

  In the apparatus described in Patent Document 1, it is necessary to apply a certain tension or more to the membrane in order to hold the subject. That is, strength for maintaining tension is required at the joint between the membrane and the frame member. Since the joint portion increases in size as the applied tension increases, there is a problem in that a unit for holding the subject is increased in size if a function equivalent to that of the holding plate is realized by the membrane.

  The present invention has been made in view of the problems of the prior art, and in a subject information acquisition apparatus that holds a subject using a flexible holding member, a unit for holding the subject is reduced in size. The purpose is to provide the technology to make it.

In order to solve the above problems, a subject information acquisition apparatus according to the present invention includes:
A holding unit that compresses and holds a subject using a flexible holding member, an acoustic probe that receives an acoustic wave coming from within the subject via the holding member, and the acoustic wave Signal processing means for analyzing an acoustic wave received by the probe, and the holding member is stretched on a frame member that defines a shape of a surface in contact with the holding member and the subject, and the frame It is fixed to a fixing portion for applying a tension to the holding member via a support side that is at least one of the end sides of the member.

  According to the present invention, in a subject information acquiring apparatus that holds a subject using a flexible holding member, a unit that holds the subject can be downsized.

The figure explaining the structure of the ultrasonic measurement apparatus which concerns on 1st embodiment. The figure explaining the structure of the frame member in 1st embodiment. The figure explaining the structure of the frame member in 2nd embodiment. The figure explaining the structure of the frame member in 3rd embodiment. The figure explaining the structure of the ultrasonic measuring device which concerns on 4th embodiment. The figure explaining the structure of the frame member in 4th embodiment. The figure explaining the structure of the ultrasonic measuring device which concerns on a modification.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In principle, the same components are denoted by the same reference numerals, and description thereof is omitted. In addition, dimensions, materials, shapes, and the like used in the description of the embodiments should be appropriately changed according to the configuration of the apparatus to which the invention is applied and various conditions, and are not intended to limit the scope of the present invention.

(First embodiment)
The ultrasonic measurement apparatus according to the first embodiment of the present invention irradiates a subject with ultrasonic waves, receives and analyzes ultrasonic echoes reflected within the subject, and thereby improves acoustic characteristics within the subject. It is an apparatus that images related information.

<System configuration>
The configuration of the ultrasonic measurement apparatus according to the first embodiment will be described with reference to FIG. The ultrasonic measurement apparatus according to the first embodiment includes a fixed holding unit 100, a movable holding unit 200, an ultrasonic scanning unit 300, an arithmetic processing unit 400, and a bed 600. Reference numeral 500 denotes a subject (a part of the subject, which is a human breast in this embodiment).

  The subject lies on the bed 600 in a prone position and inserts a breast into the opening between the fixed holding unit 100 and the movable holding unit 200. The inserted breast is compressed and held by the fixed holding unit 100 and the movable holding unit 200. The fixed holding unit 100 is a unit including a non-movable holding plate, and the movable holding unit 200 is a unit that applies a compressive force to the subject by the movable holding plate.

The fixed holding unit 100 will be described with reference to FIG. 2 which is an enlarged view of the unit.
The fixed holding unit 100 includes a holding member 101 that is a sheet-like holding member, and a frame member 102 that is a member for stretching the holding member 101.

  The holding member 101 is a thin-film member that is in contact with the subject, and is stretched around the frame member 102 in a state where an initial tension is applied in order to suppress deflection when the subject is pressed. FIG. 2A is a perspective view of the frame member 102 viewed from an oblique direction, and a dotted line in the drawing represents a region where the holding member 101 is stretched. When the holding member 101 is stretched around the frame member 102, the shape of the surface where the holding member 101 and the subject are in contact with each other is defined.

The holding member 101 is desirably formed of a flexible member such as a thin sheet member or a net-like member. By doing in this way, the multiple reflection and attenuation of an ultrasonic wave can be reduced. Moreover, it is preferable that the thickness of a sheet | seat member is shorter than the wavelength of the ultrasonic wave to be used, for example, it is preferable that it is the range of 0.01 mm-1 mm.
In the case of using a net-like member, a fiber braided one can be used. The diameter of the fiber is preferably shorter than the wavelength of the ultrasonic wave, and can be, for example, 0.01 mm to 0.5 mm. The opening ratio of the mesh member is preferably 50% or more.
The size of the holding member 101 is preferably larger than the desired imaging range, and the material of the holding member 101 is a material whose acoustic impedance with the subject 500 is matched and in which the attenuation of ultrasonic waves is small. Is preferred. In addition, a material having a tensile strength that does not cause plastic deformation or fracture even when an initial tension and a holding load act is preferable, and a material having a small elastic deformation rate is preferable. For example, polyethylene terephthalate or polyarylate can be suitably used.

The frame member 102 is a frame-shaped member that stretches the holding member 101. The frame member 102 has an L-shape that is bent at a substantially right angle with an end side (hereinafter referred to as a support side) indicated by reference numeral 103 as a vertex, and a holding member 101 is stretched in a central hollow portion. .
The holding member 101 is preferably fixed by being attached to the frame member 102 in a state where an initial tension of a certain level or more is applied. Specifically, the initial tension is preferably 10 N / cm or more. In this way, by applying the initial tension, it is possible to ensure the compression force applied to the subject, and to make the subject thin and flat.

The fixing region 104 as a fixing portion is provided at a location where the holding member is fixed in order to hold the tension of the holding member 101. FIG. 2B is a cross-sectional view of the fixed holding unit 100 as viewed from the Z-axis direction. 2C is a top view of the fixed holding unit 100 viewed from the Y-axis direction, and FIG. 2D is a front view of the fixed holding unit 100 viewed from the X-axis direction (holding member). 101 is partially omitted).
Regions 104A and 104B indicated by dotted lines in FIGS. 2C and 2D are regions (fixed portions) provided for attaching the holding member 101 (hereinafter referred to as fixed regions). The fixing regions 104 </ b> A and 104 </ b> B are so-called margins for fixing the holding member 101. It is preferable that the fixed region has an area where the holding member 101 to which the initial tension is applied is held, and when the subject 500 is pressed and held, a strength that does not cause breakage due to the tension can be realized.

  The method of fixing the fixing region and the holding member may be adhesive fixing with an adhesive, welding with a chemical, or the like. Also, any method such as laser welding such as laser, fixing with screws, clamping between members, and the like may be used.

When the subject 500 is pressed and held by the holding member 101, the holding member 101 is deformed by receiving a load, and the tension of the holding member 101 increases. Therefore, the frame member 102 preferably has a strength that does not greatly deform due to the tension received from the holding member 101. Specifically, a metal material such as stainless steel or aluminum is preferable, but any material may be used as long as the material does not undergo significant deformation due to the tension acting from the holding member 101.
Further, in order to reduce the possibility that the holding member 101 is torn, the support side 103 preferably has no burr, and more preferably has a curvature.

The L-shaped part of the frame member 102 may be formed by bending, or may be rotatable by a hinge. Further, it may be formed in an L shape with a milling cutter or the like, and the frame portion and the L shape portion may be two parts and connected by an adhesive or a screw. As described above, the L-shaped portion of the frame member 102 may be formed by any method.
Note that the holding member 101 may be fixed with an adhesive or the like before the L-shaped portion is formed on the frame member 102, and then the L-shaped portion may be formed by bending or the like. Alternatively, after the L-shaped portion is formed first, the holding member 101 may be attached while applying initial tension.

The description of the configuration of the ultrasonic measurement apparatus according to the first embodiment will be continued.
The movable holding unit 200 is a unit for moving a holding plate for pressing the subject. Specifically, using the compression mechanism 202, the movable holding plate 201 is moved in the compression holding direction to compress the subject. As a result, the subject is held and held between the holding member 101 and the movable holding plate 201.
Any material may be used for the movable holding plate 201 as long as it does not cause a large deflection when the subject is pressed and held. A material or the like is preferable.
The compression mechanism 202 is a mechanism that moves the movable holding plate 201 relative to the holding member 101. For example, a linear motion mechanism such as a ball screw, a linear guide, a chain, or a timing belt can be used. Moreover, you may comprise by rotation mechanisms, such as a thrust bearing, R guide, and a cross roller bearing. The mechanism may be determined according to the desired movement of the apparatus, and may be a combination of a plurality of mechanisms. The power may be electric or manual. In the case of electric drive, a DC motor or a brushless motor is used, and in the case of manual operation, a mechanism such as a handle or a grip is used.
Although the compression mechanism 202 is provided only on the movable holding unit side in this embodiment, it may be provided on the fixed holding unit side as long as it is provided on at least one side.

The ultrasonic scanning unit 300 is a unit that is installed on the back side of the fixed holding unit 100 and transmits / receives ultrasonic waves to / from the subject that is pressed and held. Specifically, the ultrasonic probe 301 and a scanning mechanism 302 that moves the ultrasonic probe 301 are configured.
The ultrasonic probe 301 is a probe (acoustic wave probe) that transmits / receives ultrasonic waves to / from a subject, and includes one or more acoustic elements that convert ultrasonic waves and electrical signals. What kind of acoustic element can be used if it can receive ultrasonic waves and convert them into electrical signals, such as transducers using piezoelectric effects, transducers using optical resonance, and transducers using capacitance changes? It may be a simple element. By arranging a plurality of elements that transmit and receive ultrasonic waves in one or two dimensions, ultrasonic waves can be received at a plurality of locations at the same time, and the reception time can be shortened.
Note that a material for matching the acoustic impedance with the subject, such as gel, oil, or water, may be interposed between the holding member 101 and the ultrasonic probe 301.

The scanning mechanism 302 is a means for scanning the ultrasonic probe 301 within the range of the imaging region, and includes a moving mechanism such as a ball screw, a linear guide, a chain, and a timing belt, and a mechanism for generating power. The mechanism may be a linear motion mechanism or a rotation mechanism. Moreover, these combinations may be sufficient.
The power may be electric or manual. In the case of electric drive, a DC motor or a brushless motor may be used. In the case of manual operation, a mechanism such as a handle or a grip may be used.

  The arithmetic processing unit 400 is a means for performing signal processing such as noise reduction processing on the electrical signal converted by the ultrasound probe 301 to reconstruct an image, and is typically a workstation or the like. . In addition, general processing for operating the ultrasonic measurement device such as control of the ultrasonic scanning unit 300 is performed.

When the compression holding of the subject 500 is completed, the ultrasonic probe 301 transmits an ultrasonic pulse to the subject 500 while scanning a desired imaging range by the scanning mechanism 302, and the ultrasonic echo reflected in the subject. Is received and converted into an electrical signal. A signal output from the ultrasound probe 301 is input to the arithmetic processing unit 400, converted into an image representing characteristic information in the subject, and then output to a display device (not shown).

Next, problems in the conventional ultrasonic measurement apparatus and advantages of the ultrasonic measurement apparatus according to the present embodiment will be described.
The holding member 101 is fixed to the frame member 102 in a state where an initial tension of a certain level or more is applied in order to apply a pressing force to the subject. As described above, by fixing the holding member with initial tension applied thereto, it is possible to suppress the deflection during the compression holding. However, in order to hold the initial tension of the holding member 101, a high strength is required for a portion fixed to the frame member 102. For this reason, since it is necessary to take a wide fixing area on the frame member 102, the width of the frame portion of the frame member 102 (hereinafter referred to as the frame width) must be expanded in the Y-axis direction.
However, if the frame width of the frame member is increased in order to ensure the strength, a blind spot is generated in the imaging region by an amount corresponding to the increased width of the frame. In particular, if a sufficient imaging area cannot be ensured at the edge of the subject on the chest wall side, there is a possibility that an object such as a tumor near the chest wall is overlooked during diagnosis. On the other hand, when the frame width of the frame member is narrowed, the frame member may be deformed due to the tension, or the holding member may be peeled off.

Therefore, in the first embodiment, the holding member 101 is stretched via the support side 103 (that is, the end side that comes into contact with the inserted subject) at the end of the frame member 102 on the subject side. The direction is refracted and fixed at the L-shaped part. By doing in this way, the frame width of a frame member can be made small, and the area | region for fixing the holding member 101 to which initial tension was applied can be ensured now.
The holding member 101 is preferably fixed to the frame member in an applied state with an initial tension of 10 N / cm (more preferably 20 N / cm) or more in order to compress and hold the subject to make it thin and flat. In this embodiment, since the initial tension can be secured without increasing the frame width of the frame member, both the downsizing of the measurement unit and the deformation prevention of the frame member due to the action of the tension can be achieved. .

(Second embodiment)
The second embodiment is an embodiment in which a frame-like member that is not L-shaped is used for the frame member 102. Except for the shape of the frame member 102 and the method of fixing the holding member 101, it is the same as in the first embodiment.

FIG. 3A is a perspective view of the frame member 102 according to the second embodiment viewed from an oblique direction, and a dotted line in the drawing is a region where the holding member 101 is stretched. FIG. 3B is a cross-sectional view of the fixed holding unit 100 according to the second embodiment as viewed from the Z-axis direction.
In the present embodiment, the holding member 101 is stretched around the hollow portion on the frame member as in the first embodiment, but the fixing regions 104A and 104C are provided on the upper surface and the back surface of the frame member 102. . That is, the holding member 101 goes around to the back side of the frame member via the support side 103 and is fixed.

  3C is a top view of the fixed holding unit 100 viewed from the Y-axis direction, and FIG. 3D is a front view of the fixed holding unit 100 viewed from the X-axis direction (holding member). 101 is partially omitted).

  As in the first embodiment, the fixing regions 104A to 104C are formed by fixing the holding member 101 with an adhesive, welding, or the like in an initial tension state. The fixing region may be formed in any way as long as a desired fixing strength can be obtained.

  In the second embodiment, as described above, the holding member is fixed using the upper surface and the back surface of the frame member, so that it is applied to the holding member 101 without separately adding a member for fixing the holding member. Tension can be secured.

In this example, the holding member 101 is fixed using the upper surface and the back surface of the frame member 102. However, the holding member may be wound around the frame member several times to ensure strength.
In this case, since the holding member 101 is wound many times around the frame portion of the frame member 102, the holding member 101 may interfere with an imaging region scanned by the ultrasonic probe 301. In such a case, for example, the imaging region may be secured by cutting the interfering portion after fixing the holding member 101.

(Third embodiment)
The third embodiment is an embodiment using an independent member for fixing the holding member. The second embodiment is the same as the first embodiment except that an independent member is used for fixing the holding member, the shape of the frame member 102, and the method of fixing the holding member 101.

FIGS. 4A to 4D are views showing the fixed holding unit 100 according to the third embodiment.
In the present embodiment, the holding member 101 is stretched via the support side 103 as in the first embodiment, but the fixing member 105 is disposed at a position away from the frame member 102, and the holding member 101. Are connected to a fixing region 104B provided on the fixing member 105. The fixing member 105 may be connected to the bed 600 or may be configured to be movable in the X-axis direction by a linear motion mechanism such as a linear guide or a ball screw.

  In the third embodiment, the member for applying the tension to the holding member 101 is arranged separately from the frame member 102 as described above. That is, since the fixing region is formed on the members other than the frame member 102, the frame portion on the subject side of the frame member 102 can be further narrowed compared to the first and second embodiments. When the fixing member 105 is configured to be movable, the tension applied to the holding member 101 can be adjusted.

  According to the ultrasonic measurement apparatus according to the first to third embodiments, by using a thin film as the holding member, it is possible to achieve both fixation of the subject during measurement and improvement of the signal-to-noise ratio of the signal. Further, by stretching the holding member via the support side of the frame member, the width of the frame for holding the tension of the holding member can be reduced, and the apparatus can be miniaturized. Moreover, the blind spot part at the time of a measurement can be reduced.

(Fourth embodiment)
In the ultrasonic measurement apparatus according to the first embodiment, a breast as a subject is inserted into the apparatus, and compression holding is performed using two sets of holding units. On the other hand, the fourth embodiment is an embodiment in which the subject is pressed and held by pressing only the fixed holding unit 100 against the subject surface.

FIG. 5 is a configuration diagram of an ultrasonic measurement apparatus according to the fourth embodiment.
The ultrasonic measurement apparatus according to the present embodiment is an apparatus that performs ultrasonic measurement on a supine subject by holding a single-sided compression. Specifically, it is composed of a fixed holding unit 100, an ultrasonic scanning unit 300, an arithmetic processing unit 400, and a bed 600. The fixed holding unit 100 and the ultrasonic scanning unit 300 are housed in a casing 700 having a handle. The description of the same components as those shown in the first to third embodiments will be omitted.
In the present embodiment, the movable holding unit 200 is not used, and the fixed breast unit 100 is pressed by moving the fixed holding unit 100 in the vertical direction in the figure. The casing 700 is configured to be movable in a three-dimensional direction with respect to the subject by an arm (not shown).

When the subject lies on the bed 600 in a supine position, the operator holds the handle, moves the housing 700 to a desired position (subject surface), and presses and holds the subject under pressure.
When the compression holding of the subject 500 is completed, the ultrasonic probe 301 transmits an ultrasonic pulse to the subject 500 while scanning a desired imaging range by the scanning mechanism 302, and the ultrasonic echo reflected in the subject. Is received and converted into an electrical signal. A signal output from the ultrasound probe 301 is input to the arithmetic processing unit 400, converted into an image representing characteristic information in the subject, and then output to a display device (not shown).

The structure of the fixed holding unit 100 in this embodiment will be described.
FIG. 6A is a front view of the fixed holding unit 100 in the fourth embodiment (the holding member 101 is omitted), and FIG. 6B is a cross-sectional view of the fixed holding unit 100.
In the fourth embodiment, all four sides of the frame member 102 are processed into an L shape, and the holding member 101 is fixed by the same method as in the first embodiment. That is, all four sides when the frame member 102 is viewed from the front are the support sides 103.
FIG. 6C is a top view of the frame member 102. Similarly, the other three surfaces are provided with the fixing region 104 in the L-shaped portion. The method for forming the L-shaped part is the same as in the first embodiment.

In this embodiment, in the L-shaped part of the frame member 102, the holding member 101 is fixed by the same method as in the first embodiment, but the method of fixing the holding member is not limited to this. For example, the fixed region may be provided by the method exemplified in the second embodiment or the third embodiment.
In this embodiment, the L-shaped portion is provided on all four sides of the frame member 102. However, for example, it may be provided only on two end sides.

As described above, in the conventional ultrasonic measurement apparatus, since the region for fixing the holding member 101 is large, the frame member 102 is larger than the surface (holding surface) where the holding member 101 contacts the subject. There was a problem of becoming.
In an apparatus that performs single-sided compression holding, the subject is pressed and held by pressing the fixed holding unit 100 against the subject. Therefore, if the frame member is larger than the holding surface, the apparatus becomes larger, and the holding surface and the subject It will be difficult to confirm the relative position of. Further, when the subject is pressed and held, there is a possibility of interference with other parts.

On the other hand, in the fourth embodiment, the width of the frame member 102 can be reduced by making all four sides of the frame member 102 have the same structure as in the first embodiment. Thereby, similarly to the 1st thru | or 3rd embodiment, the fixed holding | maintenance unit 100 can be reduced in size and the blind spot part by the frame member 102 can be reduced. In addition, it is possible to reduce interference with other than the test site of the subject.
Thus, the present invention can also be applied to an apparatus that compresses and holds a subject on a single surface.

(Modification)
The description of each embodiment is an exemplification for explaining the present invention, and the present invention can be implemented with appropriate modifications or combinations without departing from the spirit of the invention. For example, the present invention can also be implemented as a method for controlling a subject information acquisition apparatus including at least a part of the above processing. The above processes and means can be freely combined and implemented as long as no technical contradiction occurs.

For example, in the description of the embodiment, an ultrasonic measurement apparatus that irradiates a living body as a subject with ultrasonic waves and acquires a tomographic image based on ultrasonic echoes has been described, but the present invention comes from within the subject. As long as an acoustic wave is acquired and analyzed, it can be applied to other devices. For example, the present invention can be applied to a photoacoustic measurement apparatus that irradiates a subject with pulsed light and analyzes an acoustic wave generated inside the subject. Further, the present invention can also be applied to an X-ray mammography apparatus that irradiates a subject that has been pressed and held with X-rays and images the acquired X-ray.
As described above, the present invention can be applied to various apparatuses as long as the apparatus performs measurement while pressing and holding the subject with the holding plate.

  In each embodiment, the acoustic elements of the ultrasonic probe are arranged on the same plane. However, as shown in FIG. 7, they may be arranged on a curved surface such as a bowl. By doing in this way, the viewing angle of an ultrasonic probe can be expanded and the measurement with respect to a wide range can be performed using fewer acoustic elements. The arrangement method of the acoustic elements on the ultrasonic probe is not particularly limited as long as the ultrasonic wave can be transmitted and received and converted into an electric signal.

  DESCRIPTION OF SYMBOLS 100 ... Fixed holding unit, 101 ... Holding member, 300 ... Ultrasonic scanning unit, 301 ... Ultrasonic probe, 400 ... Arithmetic processing unit

Claims (10)

A holding unit that compresses and holds the subject using a flexible holding member;
An acoustic wave probe for receiving an acoustic wave coming from within the subject via the holding member;
Signal processing means for analyzing the acoustic wave received by the acoustic wave probe;
Have
The holding member is stretched over a frame member that defines a shape of a surface where the holding member and the subject are in contact with each other via a support side that is at least one of end sides of the frame member. An object information acquiring apparatus, wherein the object information acquiring apparatus is fixed to a fixing portion for applying tension to the holding member. The holding unit compresses and holds a subject that is a part of the subject inserted in the apparatus,
2. The subject according to claim 1, wherein the support side is an end side that comes into contact with the subject in a state where the inserted subject is pressed and held among the end sides of the frame member. Sample information acquisition device. The holding member is configured such that the stretching direction is refracted when the support side abuts, and is fixed to the fixing unit in a direction different from the direction of the surface in contact with the subject. The subject information acquisition apparatus according to claim 1 or 2. The object information acquiring apparatus according to claim 3, wherein the holding member is refracted in a substantially perpendicular direction when the support side comes into contact therewith. The subject information acquiring apparatus according to claim 1, wherein the fixing unit is provided at least on a back side of the surface of the frame member facing the subject. The subject information acquiring apparatus according to claim 1, wherein the fixing unit is provided on a member different from the frame member. The object information acquiring apparatus according to claim 6, wherein the fixing unit is capable of adjusting a tension applied to the holding member by moving. The object information acquiring apparatus according to claim 1, wherein the holding member is a sheet-like member. The object information acquiring apparatus according to any one of claims 1 to 7, wherein the holding member is a net-like member made of a braided fiber. 9. The subject information acquisition apparatus according to claim 1, wherein a tension of 10 N / cm or more is applied to the holding member in a state where the subject is not compressed and held.

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