Ultrasonic inspection device

Abstract

To stably maintain a contact force of an ultrasonic probe relative to the skin small and to stably maintain quality of an ultrasonic image in an ultrasonic inspection device.SOLUTION: An ultrasonic inspection device is provided, including: a probe unit 10 having an ultrasonic probe 11 and a holding body 12 for holding the same; a linear actuator 20 capable of driving the probe unit 10 in such a way as to reciprocally move linearly in a contact direction; an energizing spring 21 imparting a contact force enabling the ultrasonic probe 11 to come in contact with the skin M; a force detector 31 capable of detecting a contact force; a controller 40 controlling the linear actuator 20 in such a way as to adjust output value F3 of the contact force in such a way as to match detection value F2 of the contact force to target value F1 of the contact force l and a constant load spring 22 for energizing the probe unit 10 with a constant force in such a way as to resist weight of the probe unit 10 in the contact direction.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an ultrasonic inspection apparatus capable of controlling the contact force generated when an ultrasonic probe is brought into contact with the skin for ultrasonic inspection.

Background Art

[0002] Generally, in ultrasonic inspection, an ultrasonic image is acquired by transmitting and receiving an ultrasonic beam using an ultrasonic probe (hereinafter, simply referred to as a "probe" as necessary) while the probe is in contact with the skin of the subject's abdomen or the like, and the state of the subject is diagnosed based on the acquired ultrasonic image. And, for accurate ultrasonic inspection, it is important to appropriately manage the contact state of the probe with respect to the skin.

[0003] An examiner for ultrasonic inspection is required to have special skills to appropriately manage the contact state of the probe with respect to the skin. Therefore, in order to perform accurate ultrasonic inspection, it is necessary to secure an examiner who has acquired such special skills. However, securing such an examiner requires a great deal of effort. In addition, the work of ultrasonic inspection places a burden on the examiner's body, such as the waist and eyes, so the examiner's body is likely to develop disorders. Such disorders are occupational diseases peculiar to examiners of ultrasonic inspection.

[0004] Therefore, in order to reduce the burden on the body of an examiner for ultrasonic inspection, automation of ultrasonic inspection using a robot or the like has been promoted. However, when ultrasonic inspection is automated, it is difficult to appropriately manage the contact force of the probe with respect to the skin. Therefore, various contact force control techniques have been adopted in ultrasonic inspection apparatuses so that the contact force of the probe with respect to the skin can be appropriately managed.

[0005] As a first example of contact force control technology, admittance control is cited, which determines the position, velocity, etc. of a moving target part such as a robot arm based on the input external force. In admittance control, the target position of the moving target part is determined according to the external force, and the driving mechanism can gently move the moving target part toward the target position. (For example, refer to Patent Document 1.)

[0006] As a second example of contact force control technology, a series elastic actuator (SEA) is cited. The SEA has a motor, an output part, and a spring or other elastic element between the motor and the output part, and is configured to move the output part by transmitting the driving force of the motor to the output part. (For example, refer to Patent Document 2.)

[0007] As a third example of contact force control technology, an end effector having a passive scanning mechanism using a spring for installing a medical instrument is cited. When the medical instrument is placed at the placement position on the surface of the specimen by the passive operation mechanism of the end effector, the end effector can bring the moving target part into contact with the surface of the specimen with a constant contact force regardless of the pushing displacement by the moving target part such as a robot arm. Specifically, such an end effector has a linear servo actuator, a linear spring, an optical distance sensor, and a linear guide, and the linear actuator is configured to move in a direction perpendicular to the surface of the specimen while maintaining the compression amount of the linear spring at a predetermined constant amount. (For example, refer to Patent Document 3.)

[0008] As a fourth example of contact force control technology, there is an ultrasonic diagnostic apparatus configured such that when there is a defect in an ultrasonic image while an ultrasonic probe is pressed against the skin, a manipulator rotates the probe in the direction in which the defect has occurred. In this ultrasonic diagnostic apparatus, when a blood vessel collapses so as to change its diameter while the skin is being compressed by the probe, it can be determined that the blood vessel is a vein, and when the blood vessel does not collapse so as to change its diameter while the skin is being compressed by the probe, it can be determined that the blood vessel is an artery. (For example, see Non-Patent Document 1.)

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Patent Document 2

Patent Document 3

[0010]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0011] For example, in order to obtain ultrasonic images of delicate parts such as the thyroid gland and the neck, it is desirable to keep the contact force of the probe against the skin small from the viewpoints of the safety of the subject and the improvement of the image quality of the obtained ultrasonic images. In this case, it is desired to keep the contact force of the probe against delicate parts such as the thyroid gland and the neck small in the range of about 1 N to about 4 N.

[0012] However, in the first to fourth examples of the above contact force control technology, when controlling the contact force of the probe against the skin, the moving target part moves so as to adjust the contact force by driving a drive mechanism, an actuator, a linear actuator or a manipulator. With such control, it is difficult to stably maintain a small contact force such as about 1 N to about 4 N.

[0013] Also, in a dynamic contact environment based on the above driving, there is a possibility that unintended high-frequency vibrations may occur. In particular, when maintaining a small contact force, the control of the contact force may become unstable due to the influence of such high-frequency vibrations and the like. Furthermore, since the probe does not stably contact the skin, noise such as shadows is likely to occur on the ultrasonic image obtained by the probe.

[0014] In view of such circumstances, in an ultrasonic inspection apparatus, it is desired to stably maintain the contact force of the ultrasonic probe against the skin even if it is small, and to stably maintain the quality of the ultrasonic image obtained by the ultrasonic probe.

Means for Solving the Problems

[0015] To solve the above problems, an ultrasonic inspection apparatus according to one aspect includes an ultrasonic probe having a contact portion that can contact the skin for ultrasonic inspection, and a holding body configured to hold the ultrasonic probe with its contact portion facing the skin. A probe unit including, a linear actuator configured to be driven so as to linearly reciprocate the probe unit in the contact direction to adjust the position of the ultrasonic probe in the contact direction perpendicular to the skin, a biasing spring for biasing the probe unit to apply a contact force for contacting the ultrasonic probe with the skin, a force detector configured to be able to detect the contact force, and a controller configured to be able to control the linear actuator so as to adjust the output value of the contact force so that the detected value of the contact force detected by the force detector matches the target value of the contact force. And a constant load spring for biasing the probe unit with a constant force so as to counteract the weight of the probe unit in the contact direction.

Effect of the Invention

[0016] According to the ultrasonic inspection apparatus according to one aspect, even if the contact force of the ultrasonic probe against the skin is small, it can be stably maintained, and the quality of the ultrasonic image obtained by the ultrasonic probe can be stably maintained.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

DETAILED DESCRIPTION OF THE INVENTION

[0018] An ultrasonic inspection apparatus according to an embodiment will be described. The ultrasonic inspection apparatus according to the present embodiment can control the contact force for bringing the ultrasonic probe into contact with the skin in the range of about 1 N to about 10 N. The inspection targets of the ultrasonic inspection according to the present embodiment can be the neck, breast, upper limb vein, lower limb vein, upper limb artery, lower limb artery, shunt vein, thyroid gland, abdomen, lung, fetus, heart, etc. However, the inspection targets are not limited to these.

[0019] "Overview of Ultrasonic Inspection Apparatus" Referring to FIGS. 1 to 6, the ultrasonic inspection apparatus according to this embodiment is generally configured as follows. As shown in FIGS. 1 and 2, the ultrasonic inspection apparatus includes a probe unit 10 having an ultrasonic probe 11 and a holder 12 capable of holding the same. In the following, as necessary, the "ultrasonic inspection apparatus" is simply referred to as the "inspection apparatus", and the "ultrasonic probe" is simply referred to as the "probe".

[0020] The probe 11 has a contact portion 11a that can contact the skin M for ultrasonic inspection. The holder 12 is configured to be able to hold the probe 11 with its contact portion 11a facing the skin M.

[0021] The inspection apparatus has a linear actuator 20 that can be driven to linearly reciprocate the probe unit 10 in the contact direction (indicated by the double-sided arrow C) so as to be able to adjust the position of the probe 11 in the contact direction perpendicular to the skin M. The inspection apparatus has a biasing spring 21 that biases the probe unit 10 to apply a contact force for bringing the probe 11 into contact with the skin M. The inspection apparatus has a force detector 31 configured to be able to detect the contact force.

[0022] The inspection apparatus has a controller 40 configured to be able to control the linear actuator 20 so as to adjust the output value F3 of the contact force to match the detected value F2 of the contact force detected by the force detector 31 with the target value F1 of the contact force. The inspection apparatus has a constant load spring 22 that biases the probe unit 10 with a substantially constant force so as to counteract the weight of the probe unit 10 in the contact direction. Such a constant load spring 22 can pull the probe unit 10 with a substantially constant force in the contact direction so as to compensate for or cancel out the force generated by the weight of the probe unit 10 in the contact direction. The substantially constant force of the constant load spring 22 that biases the probe unit 10 in the contact direction can be made substantially equal to the force acting in the contact direction based on the weight and gravity of the probe unit.

[0023] Furthermore, the ultrasonic inspection apparatus according to this embodiment can be configured generally as follows. Referring to FIG. 2, the holder 12 is configured to be able to hold the probe 11 with its contact portion 11a facing downward, and the contact direction is substantially parallel to the vertical direction or inclined with respect to the vertical direction.

[0024] Referring to FIGS. 1 and 2, the ultrasonic probe 11 is configured to transmit an ultrasonic beam (indicated by the one-sided arrow B1) through its contact portion 11a to the skin M, and receive the ultrasonic beam (indicated by the one-sided arrow B2) returning from the skin M through the contact portion 11a. The controller 40 is configured to be able to analyze the ultrasonic image P obtained based on the signal of the ultrasonic beam received by the ultrasonic probe 11, and to be able to increase or decrease the target value F1 of the contact force according to the state of the ultrasonic image P. Note that the signal of the ultrasonic beam received by the ultrasonic probe 11 is converted into the ultrasonic image P by a scan converter 43 described later.

[0025] Referring to FIGS. 1, 3, 4, and 6, when it is determined that there is a shadow Q on the ultrasonic image P obtained by the probe 11, such a controller 40 is configured to increase the target value F1 of the contact force in order to remove the shadow Q.

[0026] Furthermore, referring to FIGS. 1, 3, 5, and 6, when it is determined that there is a rupture of the blood vessel N under the skin M on the ultrasonic image P obtained by the probe 11, the controller 40 is configured to decrease the target value F1 of the contact force in order to remove the rupture of the blood vessel N.

[0027] "Details of the Ultrasonic Inspection Apparatus" Referring to FIGS. 1 and 2, the ultrasonic inspection apparatus can be configured in detail as follows. As shown in FIG. 2, the contact portion 11a of the probe 11 is located on the tip side of the probe 11. The probe 11 has a base portion 11b located on the proximal side of the probe 11. The probe 11 has a cable 11c for electrically connecting the base portion 11b to the main body 1 (shown in FIG. 1) of the ultrasonic inspection apparatus.

[0028] The holding body 12 has a holding portion 12a configured to hold the base portion 11b of the probe 11. The holding portion 12a is located closer to the tip of the holding body 12 facing the skin M. The holding body 12 has a connecting portion 12b connected to the linear actuator 20. The connecting portion 12b is located closer to the base end of the holding body 12 facing away from the skin M. The force detector 31 is positioned so as to be sandwiched between the holding portion 12a and the connecting portion 12b in the contact direction.

[0029] The linear actuator 20 has a rotational drive unit 20a. The rotational drive unit 20a has a motor 20b capable of rotational drive and a speed reducer 20c configured to decelerate the rotational movement of the motor 20b. Further, the linear actuator 20 has a ball screw 20d. Note that the linear actuator can also have a lead screw instead of the ball screw.

[0030] The ball screw 20d is relatively movable in its longitudinal direction with respect to the rotational drive unit 20a. In the linear actuator 20, the speed reducer 20c is configured to be able to transmit the rotation of the motor 20b to the ball screw 20d while decelerating it. The ball screw 20d is configured to be able to convert the rotation transmitted from the speed reducer 20c into translational movement in the longitudinal direction of the ball screw 20d. The linear actuator 20 has a carriage 20e attached to the ball screw 20d so as to be translatable by the translational movement of the ball screw 20d.

[0031] In such a linear actuator 20, the ball screw 20d is arranged along the contact direction. Further, the ball screw 20d can be arranged along the vertical direction. However, the ball screw can also be arranged inclined with respect to the contact direction or the vertical direction.

[0032] The inspection device has a support bar 23 used to support the biasing spring 21. The support bar 23 is formed in an elongated shape. The base end portion in the longitudinal direction of the support bar 23 is connected to the connecting portion 12b of the holder 12. The support bar 23 extends from the connecting portion 12b of the holder 12 so as to be substantially parallel to the translation direction of the ball screw 20d. The tip end portion in the longitudinal direction of the support bar 23 is in a freely supported state.

[0033] The carriage 20e is formed with a through hole 20f through which the support bar 23 can pass. The through hole 20f is formed so as to penetrate the carriage 20e along the longitudinal direction of the support bar 23.

[0034] The biasing spring 21 is positioned between the carriage 20e of the linear actuator 20 and the connecting portion 12b of the holder 12 of the probe unit 10. The biasing spring 21 can be a linear spring. In particular, the biasing spring 21 can be a compression coil spring. When the biasing spring 21 is a compression coil spring, the biasing spring 21 is arranged so as to be compressed between the carriage 20e and the connecting portion 12b while being passed through the support bar 23.

[0035] Such an inspection device can have a plurality of biasing springs 21 and a plurality of support bars 23 respectively corresponding to these plurality of biasing springs 21. Further, the carriage 20e can be formed with a plurality of through holes 20f respectively corresponding to the plurality of support bars 23. For example, the inspection device can have two biasing springs 21 and two support bars 23 respectively corresponding to these two biasing springs 21. Further, the carriage 20e can be formed with two through holes 20f respectively corresponding to the two support bars 23.

[0036] In this case, the ball screw 20d can be arranged between the two biasing springs 21 when viewed from the translation direction of the ball screw 20d. Note that the inspection device can have one biasing spring and one support bar, and further, one through hole can be formed in the carriage.

[0037] In such an inspection apparatus, when the carriage 20e of the linear actuator 20 moves translationally toward the probe unit 10, the biasing spring 21 is compressed. When the carriage 20e of the linear actuator 20 moves translationally, the plurality of support bars 23 pass through the through-holes 20f of the carriage 20e corresponding to them respectively, and the biasing force generated by the compression of the plurality of biasing springs 21 is transmitted to the connecting portion 12b of the holder 12 of the probe unit 10. The contact portion 11a of the probe 11 of the probe unit 10 contacts the skin M while being given a contact force based on such a biasing force.

[0038] Note that the linear actuator is not limited to an actuator driven by an electric motor. For example, the linear actuator can be an actuator such as a pneumatic type, a hydraulic type, a solenoid type, or a piezo type.

[0039] The constant load spring 22 has a spring portion 22a formed in a long shape. The constant load spring 22 has a drum portion 22b configured to be able to wind up and unwind the spring portion 22a so that the spring portion 22a can expand and contract. The connecting portion 12b of the holder 12 is attached to the longitudinal end of the spring portion 22a. The constant load spring 22 is capable of providing a substantially constant biasing force regardless of the amount of expansion and contraction of the spring portion 22a.

[0040] The inspection apparatus has a distance detector 32 configured to be able to detect the distance between the tip of the rotation drive unit 20a facing the skin M and the connecting portion 12b of the holder 12 to which the carriage 20e is attached. The distance detector 32 can be attached to the rotation drive unit 20a. Note that the distance detector can also be attached to the carriage or the holder. The detected value of the distance detected by the distance detector 32 is obtained for the purpose of ensuring the accuracy of the detected value of the force detected by the force detector 31, and for auxiliary use when the force detector 31 fails.

[0041] Such an ultrasonic inspection apparatus can be defined as including a probe unit 10, a linear actuator 20, a biasing spring 21, a constant load spring 22, a force detector 31, and a contact force control mechanism 2 having a distance detector 32. The inspection apparatus has a support base 3 that supports the contact force control mechanism 2.

[0042] The support base 3 is disposed on the side opposite to the skin M with respect to the contact force control mechanism 2. The proximal end of the contact force control mechanism 2 facing the side opposite to the skin M is attached to the support base 3. The support base 3 has a rotary drive unit 20a of the linear actuator 20 and a drum portion 22b of the constant load spring 22 attached thereto.

[0043] Referring to FIG. 1, the controller 40 can have a control unit 40a configured to give an instruction for a contact force control method described later. For example, the control unit 40a can be a PID controller. However, the control unit is not limited to a PID controller.

[0044] The controller 40 can have an arithmetic unit 40b capable of data processing, arithmetic processing, etc. For example, the arithmetic unit 40b can be a computer including a CPU (Central Processing Unit) or the like. However, the arithmetic unit is not limited to a computer.

[0045] The controller 40 can have a storage medium 40c readable by the arithmetic unit 40b. The storage medium 40c can store a program for executing each step of the contact force control method described later. The storage medium 40c can also be included in the arithmetic unit 40b. For example, the storage medium 40c can be a magnetic disk such as an HDD (Hard Disc Drive), a semiconductor memory such as a flash memory such as an SSD (Solid State Drive), an optical disc such as a DVD, a Blu-ray (registered trademark), or the like.

[0046] The inspection device has a transmission unit 41 configured to transmit a signal to the probe 11 to send an ultrasonic beam toward the skin M. The inspection device has a reception unit 42 configured to receive a signal based on the ultrasonic beam returned from the skin M.

[0047] The inspection device has a scan conversion unit 43 configured to be able to convert a signal related to an ultrasonic scan in which the probe 11 is scanned on the skin M into a signal related to a scan for displaying the ultrasonic image P. The inspection device has a display unit 44 configured to display the ultrasonic image P based on the signal converted by the scan conversion unit 43.

[0048] In the ultrasonic inspection device, the main body 1 can include a controller 40, a transmission unit 41, a reception unit 42, a scan conversion unit 43, and a display unit 44. However, the control unit among the controllers can be included in the contact force control mechanism.

[0049] The controller 40 is electrically connected to the ultrasonic probe 11. The controller 40 is electrically connected to the linear actuator 20, particularly, its motor 20b. The controller 40 is electrically connected to the force detector 31 and the distance detector 32. The controller 40 is electrically connected to the transmission unit 41, the reception unit 42, the scan conversion unit 43, and the display unit 44. Each of the transmission unit 41 and the reception unit 42 is electrically connected to the ultrasonic probe 11 and the scan conversion unit 43. The scan conversion unit 43 is electrically connected to the display unit 44.

[0050] Such an ultrasonic inspection device can control the contact force in the range of about 1 N to about 4 N even when the inspection target is a delicate part such as the neck, breast, upper limb vein, lower limb vein, upper limb artery, lower limb artery, shunt vein, thyroid gland, etc. The ultrasonic inspection device according to the present embodiment can control the contact force in the range of about 5 N to about 10 N when the inspection target is the abdomen, lung, fetus, heart, etc. Note that even for such inspection targets, depending on the situation of the subject, it may be necessary to perform the inspection with a weak contact force of less than about 5 N. Even in such a case, the ultrasonic inspection device can perform the inspection while controlling the contact force in the range of less than about 5 N.

[0051] However, the ultrasonic inspection device is not limited to this. The ultrasonic inspection device can control the contact force in the range of about 1 N to about 10 N and can also control it in a range exceeding about 10 N, regardless of the part of the inspection target.

[0052] The type, number, etc. of the biasing spring 21 are determined according to the range of the contact force to be output in this way. When the target value F1 of the contact force is about 1 N, which is the lower limit value of the above range, it is necessary to set the spring constant K of the biasing spring 21 according to the resolution for controlling the linear actuator 20.

[0053] For example, in order to control with a resolution of about 1 / 20 with respect to the target value F1 of about 1 N, it is necessary to adjust the displacement amount of the biasing spring 21 in units of 0.05 N. As a specific example, when the resolution of the linear actuator 20 is 0.03 mm, it is necessary to set the spring constant K of the biasing spring 21 to 1.67 N / mm or less.

[0054] When the target value F1 of the contact force is about 10 N, which is the upper limit value of the above range, and assuming that the constant load is 1.5 times that, it is necessary to set the maximum load of the biasing spring 21 to about 15 N. However, the resolution of the linear actuator, the spring constant of the biasing spring, the maximum load, etc. are not limited to this.

[0055] "Contact Force Control Method" With reference to FIGS. 3 to 8, the contact force control method according to the present embodiment will be described. Here, the case where the contact direction is substantially parallel to the vertical direction will be described.

[0056] Referring to FIGS. 7 and 8, initially, a target value F1 of the contact force is indicated (target value indication step S1). The detector 31 acquires a detected value F2 of the contact force (detected value acquisition step S2). It is determined whether the difference (=F2 - F1) between the detected value F2 of the contact force and the target value F1 of the contact force is within a predetermined allowable range (difference determination step S3). For example, the lower limit value of the allowable range can be selected from the range of about -0.5 N or more and less than 0 N, and the upper limit value of the allowable range can be selected from the range of more than 0 N and about 0.5 N or less.

[0057] If the difference is outside the allowable range in the difference determination step S3 (NO), the controller 40 determines the movement amount ΔX of the carriage 20e of the linear actuator 20 based on the difference between the detected value F2 of the contact force and the target value F1 of the contact force (movement amount determination step S4). The controller 40 drives the motor 20b to move the carriage 20e of the linear actuator 20 by the movement amount ΔX, and adjusts the output value F3 of the contact force as follows (movement instruction step S5). Then, it returns to the detected value acquisition step S2.

[0058] Here, the output value F3 of the contact force is determined by subtracting the vertical direction (contact direction) force E by the constant load spring 22 from the sum of the vertical direction (contact direction) force by the linear actuator 20 and the biasing spring 21 (spring constant K) and the vertical direction force Mgcosθ based on the self-weight of the probe unit 10 or the like (explanation of each parameter will be described later). Note that the vertical direction force E by the constant load spring 22 acts in the opposite direction to the vertical direction (contact direction) force by the linear actuator 20 and the biasing spring 21 (spring constant K) and the vertical direction force Mgcosθ based on the self-weight of the probe unit 10 or the like.

[0059] The vertical direction force by the linear actuator 20 and the biasing spring 21 is determined based on the relationship between the position X1 of the tip of the rotary drive unit 20a in the linear actuator 20, the position X2 of the connecting portion 12b of the holder 12 to which the carriage 20e is attached, and the spring constant K of the biasing spring 21, and can be adjusted by the movement amount ΔX of the carriage 20e of the linear actuator 20.

[0060] The vertical force based on the self-weight of the probe unit 10 or the like is determined based on the weight of the probe unit 10 (in some cases, the weights of the probe unit 10, the ball screw 20d of the linear actuator 20, and the carriage 20e), the gravitational force g, and the inclination angle θ of the probe 11 with respect to the vertical direction. Specifically, the inclination angle θ is an acute angle between the axis passing through the contact portion 11a and the base portion 11b of the probe 11 and the axis extending in the vertical direction.

[0061] On the other hand, referring to FIGS. 3 to 5 and 8, when the difference is within the allowable range in the difference determination step S3 (YES), it is determined whether or not the ultrasonic image P includes a shadow Q (shadow determination step S6). When it is determined that the shadow Q is included (YES), the target value F1 of the contact force is corrected to increase (target value increase step S7). Then, the process returns to the detection value acquisition step S2. On the other hand, when it is determined that the shadow Q is not included (NO), a blood vessel (for example, a vein, an internal jugular vein, etc.) N on the ultrasonic image P is detected (blood vessel detection step S8). Then, it is determined whether or not the blood vessel N is collapsed on the ultrasonic image P (blood vessel determination step S9).

[0062] When it is determined that the blood vessel N is collapsed in the blood vessel determination step S9 (YES), the target value F1 of the contact force is corrected to decrease (target value decrease step S10). Then, the process returns to the detection value acquisition step S2. On the other hand, when it is determined that the blood vessel N is not collapsed in the blood vessel determination step S9 (NO), it is determined whether or not to continue the contact force control method (continuation determination step S11).

[0063] When it is determined to continue the contact force control method in the continuation determination step S11 (YES), the process returns to the detection value acquisition step S2. When it is determined not to continue the contact force control method in the continuation determination step S11 (NO), the contact force control method is terminated.

[0064] Here, in the continuation determination step S4, for example, when there is no end instruction for the ultrasonic inspection, it can be determined that the contact force control method is continued, and when there is an end instruction for the ultrasonic inspection, it can be determined that the contact force control method is continued. However, the criteria for continuation determination are not limited to this.

[0065] In the shadow determination step S7, whether the ultrasonic image P includes the shadow Q can be determined based on, for example, the brightness of the ultrasonic image P. For example, when the brightness of the ultrasonic image P is equal to or lower than a predetermined threshold value, it can be determined that the shadow Q is included, and when the brightness of the ultrasonic image P exceeds the predetermined threshold value, it can be determined that the shadow Q is not included. For example, this brightness threshold value can be determined within a range of approximately 3 to approximately 6 in the Munsell color system. However, the brightness threshold value is not limited to this.

[0066] In the blood vessel determination step S10, whether the blood vessel N is collapsed can be determined using a threshold value based on a preset lower limit value of the inner diameter of the blood vessel N. The lower limit value of the inner diameter of the blood vessel N can be determined according to the type of the blood vessel N. Specifically, when the inner diameter of the blood vessel N on the ultrasonic image P is equal to or less than a predetermined threshold value, it can be determined that the blood vessel N is collapsed, and when the ratio exceeds the predetermined threshold value, it can be determined that the blood vessel N is not collapsed.

[0067] For example, the inner diameter of the internal jugular vein is typically in the range of approximately 5.6 mm to approximately 11.2 mm. In this case, the lower limit value of the inner diameter of the internal jugular vein can be set to approximately 5.6 mm, and the threshold value based on this lower limit value can also be set to approximately 5.6 mm.

[0068] In the contact force control method, the blood vessel N that can be displayed on the ultrasonic image P is used as the inspection target. For example, the internal jugular vein is a blood vessel N that can be displayed on the ultrasonic image P. Such an internal jugular vein is located within a depth range of approximately 5 mm to approximately 30 mm from the surface of the skin M.

[0069] As shown in FIG. 6, the controller 40 has the following components related to such a contact force control method. That is, the controller 40 includes a target value instruction unit 51, a detection value acquisition unit 52, a difference determination unit 53, a movement amount determination unit 54, a movement instruction unit 55, a shadow determination unit 56, a target value increase unit 57, a blood vessel detection unit 58, a blood vessel determination unit 59, a target value decrease unit 60, and a continuation determination unit 61.

[0070] The target value instruction unit 51 is configured to execute the target value instruction step S1. The detection value acquisition unit 52 is configured to execute the detection value acquisition step S2. The difference determination unit 53 is configured to execute the difference determination step S3. The movement amount determination unit 54 is configured to execute the movement amount determination step S4.

[0071] The movement instruction unit 55 is configured to execute the movement instruction step S5. The shadow determination unit 56 is configured to execute the shadow determination step S6. The target value increase unit 57 is configured to execute the target value increase step S7. The blood vessel detection unit 58 is configured to execute the blood vessel detection step S8.

[0072] The blood vessel determination unit 59 is configured to execute the blood vessel determination step S9. The target value decrease unit 60 is configured to execute the target value decrease step S10. The continuation determination unit 61 is configured to execute the continuation determination step S11.

[0073] As described above, the ultrasonic inspection apparatus according to the present embodiment includes an ultrasonic probe 11 having a contact portion 11a that can contact the skin M for ultrasonic inspection, and a holding body 12 configured to hold the ultrasonic probe 11 with its contact portion 11a facing the skin M. A probe unit 10, a linear actuator 20 configured to be driven so as to linearly reciprocate the probe unit 10 in the contact direction to adjust the position of the ultrasonic probe 11 in the contact direction perpendicular to the skin M, and an urging spring 21 that urges the probe unit 10 to apply a contact force for contacting the ultrasonic probe 11 with the skin M, a force detector 31 configured to be able to detect the contact force, and a controller 40 configured to be able to control the linear actuator 20 so as to adjust the output value F3 of the contact force so that the detected value F2 of the contact force detected by the force detector 31 matches the target value F1 of the contact force. And a constant load spring 22 that urges the probe unit 10 with a substantially constant force so as to counteract the weight of the probe unit 10 in the contact direction.

[0074] In such an ultrasonic inspection apparatus, since the compression amount of the biasing spring 21 can be controlled by driving the linear actuator 20 in a state where the weight of the probe unit 10 is compensated by the constant load spring 22, the contact force for contacting the ultrasonic probe 11 with the skin M can be maintained small within a range not exceeding the weight of the probe unit 10, particularly within a range such as about 1 N to about 4 N. Therefore, in the inspection of delicate parts (for example, the thyroid gland, the neck, etc.) that require a small contact force such as about 1 N to about 4 N, the ultrasonic probe 11 can be stably contacted with the skin M. On the ultrasonic image P obtained by the ultrasonic probe 11 in such a stable contact state, blood vessels N and other organs under the skin M are less likely to be crushed. Therefore, the quality of the ultrasonic image P obtained by the ultrasonic probe 11 can be stably maintained.

[0075] In the ultrasonic inspection apparatus according to the present embodiment, the holding body 12 is configured to be able to hold the ultrasonic probe 11 with its contact portion 11a facing downward, and the contact direction is parallel to the vertical direction or inclined with respect to the vertical direction.

[0076] In such an ultrasonic inspection apparatus, since the compression amount of the biasing spring 21 can be controlled by driving the linear actuator 20 in a state where the weight of the probe unit 10 is compensated by the constant load spring 22, the contact force for bringing the ultrasonic probe 11 into contact with the skin M can be surely kept small within a range not exceeding the weight of the probe unit 10, particularly within a range such as about 1 N to about 4 N.

[0077] In the ultrasonic inspection apparatus according to the present embodiment, the ultrasonic probe 11 is configured to transmit an ultrasonic beam to the skin M through its contact portion 11a and receive the ultrasonic beam returned from the skin M through the contact portion 11a. The controller 40 is configured to be able to analyze an ultrasonic image P obtained based on the signal of the ultrasonic beam received by the ultrasonic probe 11, and is configured to be able to increase or decrease the target value F1 of the contact force according to the state of the ultrasonic image P.

[0078] In such an ultrasonic inspection apparatus, by controlling the linear actuator 20, the contact force for bringing the ultrasonic probe 11 into contact with the skin M can be stably maintained so as to stably maintain the quality of the ultrasonic image P.

[0079] In the ultrasonic inspection apparatus according to the present embodiment, when the controller 40 determines that there is a shadow Q on the ultrasonic image P, the controller 40 is configured to adjust the target value F1 of the contact force so as to remove the shadow Q.

[0080] In such an ultrasonic inspection apparatus, by controlling the linear actuator 20, the contact force for bringing the ultrasonic probe 11 into contact with the skin M can be stably maintained so as to prevent a decrease in the contact force that causes a shadow Q in the ultrasonic image P.

[0081] In the ultrasonic inspection apparatus according to the present embodiment, when the controller 40 determines that there is a rupture of the blood vessel N under the skin M on the ultrasonic image P, the controller 40 is configured to adjust the target value F1 of the contact force so as to remove the rupture of the blood vessel N.

[0082] In such an ultrasonic inspection apparatus, by controlling the linear actuator 20, the contact force with which the ultrasonic probe 11 contacts the skin M can be stably maintained so as to prevent an excess of the contact force that causes the collapse of the blood vessel N.

[0083] Although the embodiments of the present invention have been described so far, the present invention is not limited to the above-described embodiments, and the present invention can be modified and changed based on its technical idea.

Example

[0084] Examples 1 to 7 and Comparative Example 1 will be described. In each of Examples 1 to 7, an ultrasonic inspection was performed on a training phantom (Model 074 manufactured by CIRS) for thyroid ultrasonic inspection using the ultrasonic inspection apparatus according to the above-described embodiment. The target values F1 of the contact force in Examples 1, 2, 3, 4, 5, 6, and 7 were 1 N, 2 N, 2 N, 2 N, 2 N, 3 N, and 4 N, respectively.

[0085] In Comparative Example 1, an ultrasonic inspection was performed on a training phantom (Model 074 manufactured by CIRS) for thyroid ultrasonic inspection using an ultrasonic inspection apparatus similar to the above-described embodiment except that it did not have the constant load spring 22. The target value F1 of the contact force in Comparative Example 1 was 1 N. In Examples 1 to 7 and Comparative Example 1, the weight of the probe unit 10 was about 0.4 kg.

[0086] In each of Examples 1 to 7 and Comparative Example 1, the ultrasonic probe 11 was scanned over a length of 80 mm in the cranio-caudal direction at the central portion in the left-right direction of the above-described training phantom. At this time, an ultrasonic gel (Aquasonic CLEAR manufactured by PARKER) was applied to the surface of the training phantom. The scanning speed of the ultrasonic probe 11 in each of Examples 1, 3, 6, and 7 and Comparative Example 1 was 2 mm / sec. The scanning speeds of the ultrasonic probe 11 in Examples 2, 4, and 5 were 1 mm / sec, 5 mm / sec, and 10 mm / sec, respectively.

[0087] In Examples 1, 3, 6, and 7 and Comparative Example 1, while the ultrasonic probe 11 was being scanned, the detected value F2 of the contact force was continuously acquired. In Examples 2 to 5, the variation width of the detected value F2 of the contact force while the ultrasonic probe 11 was being scanned with the target value F1 of the contact force set to 2 N was measured.

[0088] When comparing such Examples 1, 3, 6, and 7 and Comparative Example 1, the relationship between the detected value F2 (N) of the contact force and the elapsed time (sec) in the state where the ultrasonic probe 11 was being scanned was as shown in FIG. 9. In FIGS. 9 and 10, the horizontal axis T represents the elapsed time (sec), and the vertical axis F represents the detected value F2 (N) of the contact force. In FIG. 9, the solid line J1 represents the result of Example 1, the broken line J2 represents the result of Example 3, the one-dot chain line J3 represents the result of Example 6, and the two-dot chain line J4 represents the result of Example 7. In FIG. 10, the solid line J1 represents the result of Example 1, and the dotted line H1 represents the result of Comparative Example 1.

[0089] As shown in FIGS. 9 and 10, in Example 1, the detected value F2 of the contact force was stably maintained near 1 N, which was the target value F1 of the contact force. As shown in FIG. 9, in Example 3, the detected value F2 of the contact force was stably maintained near 2 N, which was the target value F1 of the contact force. In Example 6, the detected value F2 of the contact force was stably maintained near 3 N, which was the target value F1 of the contact force. In Example 7, the detected value F2 of the contact force was stably maintained near 4 N, which was the target value F1 of the contact force.

[0090] On the other hand, as shown in FIG. 10, in Comparative Example 1, the detected value F2 of the contact force was not maintained near 1 N, which was the target value F1 of the contact force. Specifically, in Comparative Example 1, the detected value F2 of the contact force was maintained near 4 N until 20 sec, and further changed to increase from 4 N with the passage of time after more than 20 sec.

[0091] Therefore, in Comparative Example 1, not only could the detected value F2 of the contact force not reach the target value F1 of the contact force, but it could not be stably maintained either. That is, in Comparative Example 1, not only could the ultrasonic inspection device not output a small contact force, but the output contact force could not be stably maintained either.

[0092] Next, when comparing Examples 2 to 5, the relationship between the variation in the detected value F2 of the contact force in the state where the ultrasonic probe 11 was scanned and the scanning speed was as shown in FIG. 11. In FIG. 11, the vertical axis F represents the detected value F2 (N) of the contact force, and the horizontal axis D represents the scanning speed. In FIG. 11, the results of Examples 2, 3, 4, and 5 are indicated by reference numerals K1, K2, K3, and K4, respectively.

[0093] As shown in FIG. 11, in Example 2, when the target value F1 of the contact force was 2 N and the scanning speed was 1 mm / sec, the maximum and minimum values of the detected value F2 of the contact force were within the range of ±5% with respect to the target value F1 of the contact force, and the interquartile range of the detected value F2 of the contact force was within the range of ±1% with respect to the target value F1 of the contact force.

[0094] In Example 3, when the target value F1 of the contact force was 2 N and the scanning speed was 2 mm / sec, the maximum and minimum values of the detected value F2 of the contact force were within the range of ±8% with respect to the target value F1 of the contact force, and the interquartile range of the detected value F2 of the contact force was within the range of ±5% with respect to the target value F1 of the contact force.

[0095] In Example 4, when the target value F1 of the contact force was 2 N and the scanning speed was 5 mm / sec, the maximum and minimum values of the detected value F2 of the contact force were within the range of ±8% with respect to the target value F1 of the contact force, and the interquartile range of the detected value F2 of the contact force was within the range of ±5% with respect to the target value F1 of the contact force.

[0096] In Example 5, when the target value F1 of the contact force was 2 N and the scanning speed was 10 mm / sec, the maximum value of the detected value F2 of the contact force exceeded +15% with respect to the target value F1 of the contact force. However, the minimum value of the detected value F2 of the contact force was within the range of -8% with respect to the target value F1 of the contact force, and the interquartile range of the detected value F2 of the contact force was within the range of ±5% with respect to the target value F1 of the contact force.

[0097] According to the above, in Examples 1 to 7 using the ultrasonic inspection apparatus having the constant load spring 22, when scanning the probe 11 at a scanning speed of 10 mm / sec or less, particularly at a scanning speed of 5 mm / sec or less, it was confirmed that a small contact force equal to or less than the weight of the probe unit 10, particularly a small contact force such as 1 N to 4 N, could be stably maintained. On the other hand, in Comparative Example 1 using the ultrasonic inspection apparatus not having the constant load spring 22, it was confirmed that a small contact force could not be stably maintained. Therefore, it was confirmed that the ultrasonic inspection apparatus according to the above embodiment can stably maintain a small contact force such as 1 N to 4 N.

Explanation of Reference Numerals

[0098] 10…probe unit, 11…ultrasonic probe (probe), 11a…contact portion, 12…holder, 20…linear actuator, 21…biasing spring, 22…constant load spring, 31…force detector, 40…controller M…skin, N…blood vessel, F1…target value of contact force, F2…detected value of contact force, F3…output value of contact force, P…ultrasonic image, Q…shadow

Claims

1. a probe unit including an ultrasonic probe having a contact portion capable of contacting the skin for ultrasonic testing, and a holder configured to be able to hold the ultrasonic probe with the contact portion facing the skin; a linear actuator configured to be driven to linearly reciprocate the probe unit in a contact direction perpendicular to the skin so as to adjust the position of the ultrasonic probe in the contact direction; a biasing spring that biases the probe unit so as to apply a contact force that brings the ultrasonic probe into contact with the skin; A force detector configured to detect the contact force; a controller configured to be able to control the linear actuator so as to adjust an output value of the contact force so that a detection value of the contact force detected by the force detector coincides with a target value of the contact force; a constant load spring that biases the probe unit with a constant force in the contact direction against the weight of the probe unit; An ultrasonic inspection device comprising:

2. The holder is configured to be capable of holding the ultrasonic probe with a contact portion of the ultrasonic probe facing downward, The ultrasonic inspection device according to claim 1 , wherein the contact direction is parallel to a vertical direction or inclined with respect to the vertical direction.

3. The ultrasonic probe is configured to transmit an ultrasonic beam to the skin through a contact portion thereof and to receive an ultrasonic beam returning from the skin through the contact portion; 2. The ultrasonic inspection device of claim 1, wherein the controller is configured to analyze an ultrasonic image obtained based on a signal of an ultrasonic beam received by the ultrasonic probe, and is configured to be able to increase or decrease the target value of the contact force depending on a state of the ultrasonic image.

4. The ultrasonic inspection apparatus according to claim 3 , wherein the controller is configured to increase the target value of the contact force when it is determined that a shadow is present on the ultrasonic image, so as to remove the shadow.

5. The ultrasonic inspection device of claim 3, wherein the controller is configured to reduce the target value of the contact force to remove the crushing of the blood vessel when it is determined that the crushing of the blood vessel exists under the skin on the ultrasonic image.

Images