Actuator of scanning apparatus

Abstract

The actuator (2) has a main shaft (4), a sub-shaft (6), and a head (10). The head (10) includes a cylinder (12), a cantilever (16), a cam receiver (22), and a cam (24). The cantilever (16) includes a pipe (30), a proximal-side block (32), and a distal-side block (34). The cam receiver (22) is generally cylindrical. The pipe (30) is passed through the cam receiver (22). The inner diameter of the cam receiver (22) is slightly larger than the outer diameter of the pipe (30). The cam receiver (22) is rotatable with respect to the pipe (30). The cam (24) is fixed to the sub-shaft (6). The cam (24) is in contact with the cam receiver (22).

Description

Actuator of a scanning device

[0001] This specification discloses an actuator of a scanning device.

[0002] For the purpose of diagnosing diseases such as malignant tumors, a scanning device having an actuator is used. This actuator has a cantilever. This cantilever is inserted into blood vessels, digestive organs, body cavities, etc. This cantilever performs a reciprocating motion. In this scanning device, an image of biological tissue or the like is obtained by imaging with ultrasonic waves, light, etc. Based on this image, the presence or absence of a disease, the degree of the disease, etc. are determined. An example of a scanning device is disclosed in Japanese Patent Application Laid-Open No. 2001-515382.

[0003] Japanese Patent Application Laid-Open No. 2001-515382

[0004] For appropriate treatment, accurate diagnosis is important. The image quality of the images obtained by conventional scanning devices is not sufficient. This image may inhibit accurate diagnosis. High-precision image quality is required.

[0005] A scanning device having an actuator is also used for inspecting internal defects of a building. High-precision image quality is also required for this scanning device.

[0006] A scanning device having an actuator is also used for a LiDAR system for autonomous driving of automobiles and robots. High-precision sensing is also required for this scanning device.

[0007] What the applicant intends is to provide an actuator of a scanning device with excellent accuracy.

[0008] The actuator of a scanning device disclosed in this specification has a cantilever, a cam that rotates to cause the cantilever to perform a reciprocating motion, and a cam follower that fits on the cantilever, contacts the cam, and has a structure that rotates with respect to the cantilever according to the rotation of the cam.

[0009] With the scanning device having this actuator, high-precision scanning can be performed.

[0010] Figure 1 is a cross-sectional view showing a part of an actuator according to one embodiment. Figure 2 is an exploded perspective view showing a part of the actuator in Figure 1. Figure 3 is an exploded perspective view showing a magnified part of the actuator in Figure 2. Figure 4 is a cross-sectional view along the line IV-IV in Figure 1. Figure 5 is a cross-sectional view showing a part of the actuator in Figure 1.

[0011] Preferred embodiments will be described in detail below, with reference to drawings as appropriate.

[0012] Figure 1-4 shows the actuator 2. This actuator 2 has a main shaft 4, a sub-shaft 6, a first cable 8a, a second cable 8b, and a head 10. In Figure 1, the right side is the tip side of the actuator 2, and the left side is the handle side of the actuator 2. Although not shown, this actuator 2 has a controller on the handle side of the main shaft 4. The main shaft 4, sub-shaft 6, first cable 8a, and second cable 8b are connected to this controller.

[0013] The main shaft 4 is hollow. In this embodiment, the main shaft 4 is flexible. This main shaft 4 can rotate around the axis Ax1 (described in detail later) shown in Figure 1. This main shaft 4 is rotated by a drive device in the controller. This main shaft 4 transmits rotational motion to the head 10.

[0014] The sub-shaft 6 may be hollow or solid. The outer diameter of the sub-shaft 6 is sufficiently smaller than the inner diameter of the main shaft 4. Therefore, the sub-shaft 6 can rotate freely within the main shaft 4. The sub-shaft 6 can rotate around the axis Ax2 shown in Figure 1 (explained in detail later). This sub-shaft 6 is rotated by other drive mechanisms of the controller.

[0015] In this embodiment, the first cable 8a has a fiber and a resin layer covering it. The first cable 8a extends from the controller to the head 10. In this embodiment, the second cable 8b has a fiber and a resin layer covering it. The second cable 8b extends from the controller to the head 10.

[0016] The head 10 is continuous with the main shaft 4. The head 10 includes a cylinder 12, a pair of supports 14, a cantilever 16, a guide 18, a cap 20, a cam receiver 22, a cam 24, and a spring 26.

[0017] The cylinder 12 is generally hollow. The cylinder 12 is fixed to the main shaft 4. The cylinder 12 rotates as the main shaft 4 rotates. The direction of rotation of the cylinder 12 is indicated by arrow R1 in Figure 4. The cylinder 12 may also rotate in the opposite direction to that of arrow R1. The cylinder 12 may be integrated with the main shaft 4.

[0018] Each support 14 is fixed to the cylinder 12. Each support 14 has a hole 28 (see Figure 3).

[0019] The cantilever 16 includes a pipe 30, a proximal block 32, a distal block 34, a pair of arms 36, a pair of rotors 38, a cover 40, a first sensor 42a, and a second sensor 42b. The proximal end of the pipe 30 is fixed to the proximal block 32. The distal end of the pipe 30 passes through the distal block 34 and is fixed to this distal block 34. Each arm 36 extends from the proximal block 32. Each arm 36 is fitted into a hole 28. Each arm 36 can rotate relative to the hole 28. The distal block 34 has two chambers 46. Each chamber 46 houses a rotor 38. The rotor 38 has a spherical shape. The cover 40 prevents the rotor 38 from detaching from the chamber 46. Parts of the rotor 38 are exposed from the chamber 46. The rotor 38 can rotate relative to the chamber 46. This cantilever 16 can swing around the arm 36 as its axis.

[0020] The first sensor 42a is located near the tip of the pipe 30. The first sensor 42a is fixed to the pipe 30 by means (not shown). The first cable 8a is connected to the first sensor 42a. The second sensor 42b is located near the front end of the pipe 30. The second sensor 42b is fixed to the pipe 30 by means (not shown). The second cable 8b is connected to the second sensor 42b.

[0021] The guide 18 is located near the tip of the cylinder 12. The guide 18 is fixed to the cylinder 12. As shown in Figure 4, the guide 18 has a guide groove 48. The guide groove 48 extends radially to the cylinder 12. The tip block 34 is inserted into this guide groove 48. The width of the guide groove 48 is slightly greater than the width of the tip block 34. The tip block 34 does not contact the guide groove 48. The rotor 38 is in contact with the guide groove 48. The cap 20 is located on the tip side of the guide 18.

[0022] The cam bearing 22 (see Figure 1) is generally cylindrical. This cam bearing 22 is fitted into the pipe 30. The inner diameter of the cam bearing 22 is slightly larger than the outer diameter of the pipe 30. The cam bearing 22 is rotatable relative to the pipe 30. The cam bearing 22 has a flange 50.

[0023] The cam 24 is fixed to the subshaft 6. The cam 24 is in contact with the cam holder 22. The cam 24 can rotate in accordance with the rotation of the subshaft 6. The cam 24 has a long diameter portion 52. In Figure 3, the long diameter portion 52 is located below the subshaft 6.

[0024] One end of the spring 26 is fixed to the cylinder 12. The other end of the spring 26 is fixed to the hand-side block 32. In this embodiment, the spring 26 is a compression coil. The spring 26 biases the cantilever 16 toward the cam 24.

[0025] In this actuator 2, the subshaft 6 rotates relative to the cylinder 12. This rotation causes the cam 24 to rotate relative to the cantilever 16. Figure 5 shows the state after the cam 24 has rotated 180° from the state shown in Figures 1 and 4. In Figure 5, the long diameter portion 52 is located above the subshaft 6. As is clear from comparing Figure 1 and Figure 5, in Figure 5, the vicinity of the tip of the cantilever 16 is pushed up by the cam 24. When transitioning from the state shown in Figure 1 to the state shown in Figure 5, the cantilever 16 moves guided by the guide groove 48 (see Figure 4). Similarly, when transitioning from the state shown in Figure 5 to the state shown in Figure 1, the cantilever 16 moves guided by the guide groove 48. When the cam 24 repeats rotational motion, the cantilever 16 repeats swinging reciprocating motion. The guide 18 restricts the direction of the reciprocating motion of the cantilever 16. The direction of the reciprocating motion coincides with the radial direction of the cylinder 12. The guide 18 suppresses meandering of the cantilever 16 during the reciprocating motion.

[0026] As mentioned above, the rotor 38 is in contact with the guide groove 48. The rotation of this rotor 38 suppresses the frictional force between the cantilever 16 and the guide groove 48. The rotor 38 can contribute to the smooth movement of the cantilever 16. The rotor 38 can contribute to high-precision imaging.

[0027] As mentioned above, the cam support 22 is rotatable relative to the pipe 30. When the cam 24 rotates, the cam support 22 rotates in response to the force from the cam 24. The cam support 22 rotates relative to the cantilever 16 while slipping relative to the pipe 30. This cam support 22 suppresses the transmission of the rotational force of the cam 24 to the cantilever 16. This cam support 22 can contribute to the smooth movement of the cantilever 16. The cam support 22 can contribute to high-precision imaging.

[0028] As mentioned above, the arm 36 can rotate relative to the hole 28. The reciprocating motion of the cantilever 16 is accompanied by the rotation of the arm 36. The arm 36 is the axis of the reciprocating motion. The arm 36 can contribute to the smooth movement of the cantilever 16. The arm 36 can contribute to high-precision imaging.

[0029] As mentioned above, the spring 26 biases the cantilever 16 toward the cam 24. The spring 26 can prevent the cantilever 16 from separating from the cam 24. The spring 26 can contribute to high-precision imaging.

[0030] When a living organism is examined using the actuator 2, the head 10 is inserted into the living organism. Following the head 10, a part of the main shaft 4 and other components are also inserted into the living organism. As the main shaft 4 rotates, the cylinder 12 rotates. As the cylinder 12 rotates, the cantilever 16 rotates relative to the living organism. The sub-shaft 6 rotates relative to the cylinder 12. Due to the relative rotation of the sub-shaft 6, the cam 24 rotates relative to the cylinder 12. Due to the rotation of the cam 24, the cantilever 16 performs a reciprocating motion. In other words, the cantilever 16 performs rotational and reciprocating motions within the living organism. In conjunction with these motions, the first sensor 42a or the second sensor 42b performs two-dimensional scanning. Furthermore, as the head 10 moves forward or backward, three-dimensional imaging can be performed. Three-dimensional imaging can be performed over a wide area. Since the guide 18 guides the reciprocating motion of the cantilever 16, the vibration of the cantilever 16 during scanning is suppressed, resulting in highly accurate images.

[0031] When the absolute direction of rotation of the subshaft 6 is different from the direction of rotation of the main shaft 4, the cam 24 may rotate relative to the cylinder 12. When the absolute direction of rotation of the subshaft 6 is the same as the direction of rotation of the main shaft 4, and the rotational speed of the subshaft 6 is different from the rotational speed of the main shaft 4, the cam 24 may rotate relative to the cylinder 12. When the absolute rotational speed of the subshaft 6 is zero and the main shaft 4 is rotating, the cam 24 may rotate relative to the cylinder 12. Preferably, the controller has a sensor capable of measuring the rotational speed of the cylinder 12. Preferably, the controller has a sensor capable of measuring the rotational speed of the cam 24.

[0032] The cantilever 16 may be attracted to the cam 24 by magnetic or electrostatic force. This cantilever 16 does not separate from the cam 24 during reciprocating motion. This cantilever 16 allows for high-precision imaging. The cantilever 16 may be pressed against the cam 24 by another cam 24.

[0033] In Figure 1, the symbol Ax1 represents the axis of rotation of the main shaft 4. The cylinder 12 and cantilever 16 can rotate within the body around the axis of rotation Ax1. In Figure 1, the symbol Ax2 represents the axis of rotation of the sub-shaft 6. The cam 24 can rotate relative to the cantilever 16 around the axis of rotation Ax2. The axis of rotation Ax2 is offset from the center of the cylinder 12. The axis of rotation Ax2 does not coincide with the axis of rotation Ax1. In this head 10, a cam 24 with a large lift amount may be used. The image obtained by this actuator 2 is highly accurate.

[0034] Examples of sensors 42 included in the cantilever 16 include photoacoustic imaging sensors, ultrasonic imaging sensors, and millimeter-wave sensors. The actuator 2 may have a cantilever 16 that does not include a sensor 42. In an actuator 2 that does not include a sensor 42, image information obtained by the head 10 is sent to a controller via a cable, and imaging is performed. Typically, light is sent to the controller via a cable containing an optical fiber, and imaging using this light is achieved. In other words, the actuator 2 has either a sensor 42 or an optical fiber, or both. In an actuator 2 that performs imaging using light, the head 10 may have a lens. This lens is located on the tip side of the cantilever 16. This lens may be located in a guide groove 48, etc. This lens may contribute to light focusing.

[0035] It is preferable that the sensor (including the optical fiber) has a mechanism different from the mechanism of the other sensors. In this cantilever 16, each sensor (or optical fiber) performs its function to obtain a high-precision image. For example, the first sensor 42a performs scanning with low resolution but deep depth, and the second sensor 42b performs scanning with shallow depth but high resolution, so that the two sensors complement each other. This complementarity allows for a high-precision image to be obtained, and diseases can be diagnosed with high accuracy. It is preferable that the cantilever 16 can perform imaging using light and imaging using ultrasound. Imaging using light has excellent resolution. Imaging using ultrasound has excellent depth. The cantilever 16 may have three or more sensors (or optical fibers). The number of sensors (or optical fibers) in the cantilever 16 may be one.

[0036] This actuator 2 is useful for tomographic imaging in endoscopic treatment, laparoscopic surgery, endovascular treatment, and intracerebral examinations. This actuator 2 is also useful for imaging for microsurgery and ultrasound imaging.

[0037] This actuator 2 is useful for inspecting rust and cracks in roads, bridges, tunnels, buildings, etc.

[0038] This actuator 2 is useful for sensing for autonomous robot driving, sensing for autonomous driving of automobiles, and 3D mapping.

[0039] [Disclosure Items] Each of the following items discloses a preferred embodiment.

[0040] [Item 1] An actuator for a scanning device, comprising a cantilever, a cam that rotates to cause the cantilever to reciprocate, and a cam receiver that is fitted onto the cantilever, contacts the cam, and has a structure that rotates relative to the cantilever in accordance with the rotation of the cam.

[0041] [Item 2] The actuator according to Item 1, further comprising a main shaft for rotating the cantilever.

[0042] [Item 3] The actuator according to Item 2, further comprising a cylinder to which the cantilever is attached and that rotates according to the rotation of the main shaft, and a sub-shaft that is connected to the cam, passes through the cylinder, and is capable of rotating relative to the cylinder.

[0043] [Item 4] The actuator according to Item 3, wherein the cantilever is inserted and has a guide groove extending in the radial direction of the cylinder.

[0044] [Item 5] The actuator according to any one of Items 1 to 4, wherein the rotation axis of the cam is different from the rotation axis of the cantilever.

[0045] [Item 6] The actuator according to any one of Items 1 to 5, wherein the reciprocating motion of the cantilever is a swing, and the cantilever has an axis of this swing.

[0046] [Item 7] The actuator according to any one of Items 1 to 6, wherein the cantilever includes an optical fiber, a photoacoustic imaging sensor, an ultrasonic imaging sensor, or a millimeter-wave sensor.

[0047] [Item 8] The actuator according to Item 7, wherein the cantilever includes two or more sensors.

[0048] [Item 9] The actuator according to Item 8, wherein the cantilever includes an imaging sensor using light and an imaging sensor using ultrasonic waves.

[0049] [Item 10] The actuator according to Item 7, wherein the cantilever includes an optical fiber and a sensor.

[0050] [Item 11] The actuator according to any one of Items 1 to 10, further comprising a spring for biasing the cantilever toward the cam.

[0051] [Item 12] The actuator according to any one of items 1 to 11, wherein the cantilever is attracted to the cam by magnetic or electrostatic force.

[0052] The actuators described above are suitable for various scanning devices.

[0053] 2...Actuator 4...Main shaft 6...Sub shaft 8a...First cable 8b...Second cable 10...Head 12...Cylinder 14...Support 16...Cantilever 18...Guide 20...Cap 22...Cam receiver 24...Cam 26...Spring 28...Hole 30...Pipe 32...Hand side block 34...Tip side block 36...Arm 38...Rotor 40...Cover 42a...First sensor 42b...Second sensor 46...Chamber 48...Guide groove 50...Flange 52...Long diameter section

Claims

1. An actuator for a scanning device, comprising a cantilever, a cam that rotates to cause the cantilever to reciprocate, and a cam receiver that is fitted onto the cantilever, contacts the cam, and has a structure that rotates relative to the cantilever in accordance with the rotation of the cam.

2. The actuator according to claim 1, further comprising a main shaft for rotating the cantilever described above.

3. The actuator according to claim 2, further comprising a cylinder to which the above-mentioned cantilever is attached and which rotates in accordance with the rotation of the above-mentioned main shaft, and a sub-shaft connected to the above-mentioned cam, passing through the above-mentioned cylinder and capable of rotating relative to the above-mentioned cylinder.

4. The actuator according to claim 3, wherein the cantilever is inserted and the cylinder has a guide groove extending radially.

5. The actuator according to claim 1 or 2, wherein the axis of rotation of the cam is different from the axis of rotation of the cantilever.

6. The actuator according to claim 1 or 2, wherein the reciprocating motion of the cantilever is a swing, and the cantilever has an axis for this swing.

7. The actuator according to claim 1 or 2, wherein the cantilever includes an optical fiber, a photoacoustic imaging sensor, an ultrasonic imaging sensor, or a millimeter-wave sensor.

8. The actuator according to claim 7, wherein the cantilever includes two or more sensors.

9. The actuator according to claim 8, wherein the cantilever includes an imaging sensor that utilizes light and an imaging sensor that utilizes ultrasound.

10. The actuator according to claim 7, wherein the cantilever includes an optical fiber and a sensor.

11. The actuator according to claim 1 or 2, further comprising a spring that biases the cantilever toward the cam.

12. The actuator according to claim 1 or 2, wherein the cantilever is attracted to the cam by magnetic or electrostatic force.

Images