Field of view indicator and method of using a field of view indicator

Abstract

The application discloses a field of view indicator and a method of using the same, and belongs to the field of medical equipment. The field of view indicator comprises: a light emitting device arranged between an imaging device and a tracking target; a field of view indication unit provided with a predetermined pattern, the field of view indication unit is configured to project light from the light emitting device onto a target area of the tracking target via the field of view indication unit to allow a projection of the predetermined pattern to be formed on the target area. The field of view indicator of the application indicates whether the target area is located within the effective field of view range of the imaging device based on the projection of the predetermined pattern on the target area, thereby allowing the effective field of view range of the imaging device to be indicated in a simple, convenient and low-cost manner.

Description

Technical Field

[0001] This invention relates to the field of medical devices, and in particular to a visual field indicator and a method of using the visual field indicator. Background Technology

[0002] Various imaging devices are widely used in a variety of vision systems. In many applications, such as the medical field, medical image-guided coil placement and positioning are increasingly employed. Specifically, during treatment positioning, the patient or subject needs to be placed within the effective field of view of the imaging device (e.g., a camera) to ensure the corresponding positioning accuracy or recognition accuracy.

[0003] In practice, navigation systems typically include an effective field of view display, but this is only displayed when the system is activated. By this time, the patient is usually already positioned. Activating the navigation system necessitates readjusting the patient's position or the imaging device. However, the imaging device is generally positioned high and is securely fixed, making adjustments difficult and prone to instability. Therefore, frequent adjustments are not recommended. Instead, the patient is usually positioned before the navigation system is activated. This increases the frequency of changes in position or posture, leading to a poor treatment experience for the patient.

[0004] Therefore, there is a need for a simple, convenient, and low-cost solution to easily indicate the effective field of view of the imaging device. Summary of the Invention

[0005] To address at least one of the aforementioned problems and deficiencies in the prior art, embodiments of the present invention provide a field of view indicator and a method for using the field of view indicator. The field of view indicator and method of the present invention indicate whether a target area is within the effective field of view of an imaging device based on the projection of a predetermined pattern onto a target area, thereby allowing the effective field of view of the imaging device to be indicated in a simple, convenient, and low-cost manner.

[0006] One object of the present invention is to provide a field of view indicator.

[0007] Another object of the present invention is to provide a method for using a field of view indicator.

[0008] According to one aspect of the present invention, a field of view indicator is provided, the field of view indicator being adapted to an imaging device and comprising:

[0009] A light-emitting device is arranged between the imaging device and the tracking target;

[0010] A field of view indicator unit with a predetermined pattern is provided. The field of view indicator unit is configured to project light from a light-emitting device onto a target area of ​​the tracking target, so as to allow the projection of the predetermined pattern on the target area.

[0011] According to another aspect of the present invention, a method for using a field of view indicator is provided, wherein the field of view indicator is the field of view indicator according to the foregoing embodiments.

[0012] The method includes the following steps:

[0013] S1 provides a field of view indicator unit with a predetermined pattern;

[0014] S2 projects light from the light-emitting device onto the target area of ​​the tracking target via the field of view indicator unit, and forms a predetermined pattern projection on the target area;

[0015] S3 compares the relationship between the projection and the predetermined pattern, and determines whether the target area is within the effective field of view of the imaging device based on the relationship.

[0016] The field of view indicator and the method of using the field of view indicator according to the present invention have at least one of the following advantages:

[0017] (1) The field of view indicator and the method of using the field of view indicator of the present invention indicate whether the target area is within the effective field of view of the imaging device based on the projection of a predetermined pattern on the target area, thereby allowing the effective field of view of the imaging device to be indicated in a simple, convenient and low-cost manner.

[0018] (2) The visual field indicator and the method of using the visual field indicator of the present invention help to achieve accurate positioning, thereby ensuring the treatment effect in the later stage;

[0019] (3) The field of view indicator and the method of using the field of view indicator of the present invention eliminate the need to move the imaging device to determine whether the target area is within the effective field of view, thereby saving the user from adjusting the imaging device at a high position and laboriously loosening and tightening the imaging device.

[0020] (4) The visual field indicator and the method of using the visual field indicator of the present invention eliminate the need to adjust the subject’s position to determine whether the target area is within the effective visual field, thereby reducing the adjustment time and reducing the subject’s discomfort. Attached Figure Description

[0021] These and / or other aspects and advantages of the present invention will become apparent and readily understood from the following description of preferred embodiments taken in conjunction with the accompanying drawings, in which:

[0022] Figure 1 A field of view indicator according to an embodiment of the present invention is shown;

[0023] Figure 2A A light-blocking plate according to an embodiment of the present invention is shown;

[0024] Figure 2B A light-blocking plate according to another embodiment of the present invention is shown;

[0025] Figure 3 A clamp according to an embodiment of the present invention is shown;

[0026] Figure 4 A flowchart illustrating a method for using a field of view indicator according to an embodiment of the present invention is shown. Detailed Implementation

[0027] The technical solution of the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. In this specification, the same or similar reference numerals indicate the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the overall inventive concept of the present invention and should not be construed as a limitation thereof.

[0028] In an embodiment of the present invention, a field of view indicator is provided. For example... Figure 1 As shown, the field of view indicator 100 includes a light-emitting device 10 and a field of view indicator unit 20. The light-emitting device 10 is arranged between the imaging device and the tracking target (e.g., a subject). The field of view indicator unit 20 has a predetermined pattern and is configured to project light from the light-emitting device 10 onto a target area of ​​the tracking target (e.g., a body part of the subject, such as the head, feet, etc.) through the field of view indicator unit 20, so as to allow the projection of the predetermined pattern on the target area.

[0029] The embodiments of the present invention indicate whether the target area is within the effective field of view of the imaging device based on the projection of a predetermined pattern onto the target area, thereby allowing the effective field of view of the imaging device to be indicated in a simple, convenient and low-cost manner.

[0030] Embodiments of the present invention eliminate the need to move the camera to determine whether the target area is within the effective field of view, thereby saving the user from adjusting the imaging device at a high position and from laboriously loosening and tightening the imaging device.

[0031] In addition, embodiments of the present invention eliminate the need to adjust the subject's position to determine whether the target area is within the effective field of vision, thereby reducing the adjustment time and the subject's discomfort.

[0032] The imaging device includes a camera or photographic device that uses visible light and / or invisible light (such as infrared light) for imaging, such as a video camera. The following description of the invention will use a video camera as an example. The principles of the invention are also applicable to other imaging devices, which will not be elaborated upon here.

[0033] like Figure 1 As shown, the light-emitting device 10 includes a housing 12, a light source 14, a power supply device 16, and a control device 18.

[0034] A light source 14, located within the housing 12, emits visible light (white light or monochromatic light) or similar light to provide light to the field-of-view indicator unit 20, thereby allowing the field-of-view indicator unit 20 to project onto the target area. Specifically, the light source 14 passes through the light field formed by the field-of-view indicator unit 20 to simulate the effective field of view (e.g., a cone shape) of an imaging device (e.g., a camera). The light source 14 includes a point light source, a surface light source, or a line light source. When the field-of-view indicator 100 is fixed to the camera, the light source 14 is aligned in a straight line with the camera lens and the target area. In one example, the light source 14 is positioned close to the lens.

[0035] The power supply unit 16 is located within the housing 12 to supply power to the relevant components. The power supply unit 16 is connected to the light source 14 and / or the field-of-view indicator unit 20 to supply power to the light source 14 and / or the field-of-view indicator unit 20. The power supply unit 16 can be powered by a battery, a power socket, a separate adapter, or by the camera's vision system.

[0036] The control device 18 is located within the housing 12. The control device 18 communicates with the camera's vision system, the power supply 16, and the light source 14. In one example, the control device 18 includes a sound switch, an infrared switch, a touch switch, etc., to perform switching operations upon receiving instructions from the vision system.

[0037] like Figure 1 As shown, the field of view indicator unit 20 includes a moving mechanism 22 and a light-blocking plate 24.

[0038] The moving mechanism 22 is located on the outer surface of the housing 12 to allow for changes in the distance between the field of view indicator unit 20 and the light source 14. In one example, the moving mechanism 22 includes a fixing member 26 and a slide rail 28. The fixing member 26 is slidable on the slide rail 28.

[0039] The fixing member 26 is used to fix the light-blocking plate 24. The fixing member 26 can be electrically powered, for example, by a power supply device 16. The fixing member 26 can also be manually operated by a user. Specifically, the fixing member 26 includes a first slide rail connector 262 and a second slide rail connector 264. Both the first slide rail connector 262 and the second slide rail connector 264 are connected to the slide rail 28 and are capable of sliding on the slide rail 28. Figure 1In the example, the first slide rail connector 262 and the second slide rail connector 264 are arranged in parallel and symmetrically disposed on opposite sides of the housing 12.

[0040] The slide rail 28 is connected to the fixing member 26 and is used to adjust the distance between the light-blocking plate 24 and the light source 14. The slide rail 28 is arranged on opposite sides of the housing 12.

[0041] The light-blocking plate 24 is fixed to the moving mechanism 22. The light-blocking plate 24 is located outside the light-emitting device 10 (specifically, the light source 14) and opposite to the light-emitting device (specifically, the light source 14) to receive light from the light-emitting device (specifically, the light source 14) and allow the light to pass through the light-blocking plate 24.

[0042] The light-blocking plate 24 is made of a light-transmitting material, such as inorganic glass, transparent ceramics, organic polymers, etc. In one example, the organic polymer may include polymethyl methacrylate (PMMA).

[0043] The light-blocking plate 24 is connected to a first slide rail connector 262 and a second slide rail connector 264 at its two ends, respectively. It slides under the influence of the first and second slide rail connectors 262 and 264 to adjust the distance between the light-blocking plate 24 and the light source 14. Typically, a camera's field of view is cone-shaped, and the effective field of view increases with the distance from the camera lens. The distance between the light-blocking plate 24 and the light source 14 can be adjusted according to the depth of the camera's effective field of view to ensure that the projection of a predetermined pattern can determine whether the target area is within the camera's effective field of view.

[0044] The light-blocking plate 24 is provided with the predetermined pattern, which displays the effective field of view or center through the predetermined pattern (specifically, a projection of a preset pattern), thereby achieving a simple effective field of view display method. The predetermined pattern includes at least one of the following: line segments; line segments with scales; cross-shaped patterns; cross-shaped patterns with scales (such as...). Figure 2A (as shown); circular pattern; square pattern; rectangular pattern; hand-shaped pattern (as shown) Figure 2B (as shown); hand-shaped patterns with scales. For example, line segments and cross patterns can show the center of the effective field of view; line segments and cross patterns with scales can help determine whether the projection is within the effective field of view; circular, square, or rectangular patterns can show the range of the effective field of view; hand-shaped patterns and hand-shaped patterns with scales can help determine whether the projection is within the effective depth of view by the size of the projection of the hand-shaped pattern and the size marked by the hand-shaped pattern (described in detail later).

[0045] Taking a cross-shaped pattern with graduations as an example, the size of the predetermined pattern can be determined by the graduations. The distance between the light-blocking plate 24 and the light source 14 is adjusted according to the depth of the effective field of view, so that when the target area is at the boundary of the effective field of view, the size of the projection of the predetermined pattern onto the target area is equal to the size represented by the predetermined pattern. Thus, when using this field of view indicator, by measuring the size of the projection, it can be determined whether the target area is within the effective field of view of the camera (described in detail below).

[0046] Taking a hand-shaped pattern as another example, the size represented by the hand-shaped pattern can be the size of an adult's palm or a child's palm. The distance between the light-blocking plate 24 and the light source 14 is adjusted according to the depth of the effective field of view, so that when the target area is at the boundary of the effective field of view, the size of the projection of the hand-shaped pattern on the target area is equal to the size of the predetermined pattern (e.g., the size of an adult's palm).

[0047] The predetermined pattern is projected onto the target area by light projected through the light-blocking plate 24. This light has a magnifying effect, allowing the size of the projection to be larger than the size of the pattern itself. Thus, by adjusting the distance between the light-blocking plate 24 and the light source 14 according to the depth of the effective field of view, it is possible to ensure that the size of the projection of the predetermined pattern onto the target area is equal to the size represented by the predetermined pattern when the target is located at the boundary of the effective field of view. Note that the size represented by the predetermined pattern is not the actual size of the predetermined pattern itself, but rather a size greater than or equal to the actual size of the predetermined pattern.

[0048] In one example, the field of view indicator 100 also includes a projection receiving member (not shown) for receiving the projection. By presenting the projection on the projection receiving member, the size of the projection on the projection receiving member is measured to determine whether the target area is within the effective field of view of the camera. For example, before aligning the field of view indicator 100 with the target area, the field of view indicator 100 (specifically, the light shield 24) can be aligned with the projection receiving member, which is located at the target area to be observed. The clarity of the projection is determined by observing the projection on the projection receiving member. The projection receiving member may include, for example, white paper, white cloth, white plastic film, white panel, etc. Embodiments of the present invention do not limit the material, shape, etc., of the projection receiving member, as long as it can present a projection.

[0049] In one example, the field of view indicator 100 also includes a clamp 30 for securing the field of view indicator unit 20 to the camera. Figure 3 As shown, the clamp 30 includes a main body 31, a first fixing plate 32, a second fixing plate 33, a movable plate 34, a receiving groove 35, and a fastener 36.

[0050] The first fixing plate 32 and the second fixing plate 33 are located from one side of the main body 31 (e.g., Figure 3 (Extending to the left of the main body 31). In one example, the first fixing plate 32 and the second fixing plate 33 are arranged in parallel and perpendicular to the main body 31.

[0051] The first fixing plate 32 is configured to connect to the light-emitting device 10 of the field of view indicator 100, thereby connecting the first fixing plate 32 to the field of view indicator unit 20. In one example, the first fixing plate 32 is configured to connect to the light-emitting device 10 via adhesive, snap-fit, threaded connection, or shape adaptation, thereby connecting the field of view indicator unit 20. However, those skilled in the art will understand that the embodiments of the present invention do not limit the specific connection method, as long as the connection can be achieved.

[0052] The movable plate 34 is located from one side of the main body 31 (e.g.) Figure 3 The movable plate 34 extends from the left side of the main body 31 and is located between the first fixed plate 32 and the second fixed plate 33. Furthermore, the movable plate 34 is configured to move between the first fixed plate 32 and the second fixed plate 33 to allow the camera to be secured to the clamp 30. In one example, the movable plate 34 is arranged parallel to the first fixed plate 32 and the second fixed plate 33 and perpendicular to the main body 31.

[0053] The receiving slot 35 is located between the first fixed plate 32 and the movable plate 34. The receiving slot 35 is configured to receive a camera to secure the camera to the clamp 30.

[0054] Fastener 36 is configured to pass through the second fixed plate 33. Fastener 36 is rotatable and can abut against the movable plate 34 by rotation. The rotation of fastener 36 causes the movable plate 34 to move between the first fixed plate 32 and the second fixed plate 33, thereby changing the size of the receiving slot 35 and securely clamping the camera onto the clamp 30. In one example, fastener 36 includes screws, bolts, threaded rods, or any component capable of changing the space of the receiving slot 35. It is understood that in this example, fastener 36 achieves this spatial change through rotation, but any method that performs a similar function can be used, which will not be elaborated here.

[0055] The clamp 30 is connected to the field of view indicator unit 20 via the first fixing plate 32, and to the camera via the receiving slot 35 and fastener 36, thus realizing the connection between the field of view indicator unit 20 and the camera.

[0056] In alternative embodiments, the field of view indicator 100 is attached to the camera by means of adhesive, snap fasteners, threaded connection, or shape-fitting method.

[0057] In another embodiment of the present invention, a method for using a field of view indicator is also provided, wherein the field of view indicator is a field of view indicator according to any of the foregoing embodiments.

[0058] like Figure 4 As shown, the method includes the following steps:

[0059] S1 provides a field of view indicator unit 20 with a predetermined pattern. In one example, the predetermined pattern includes at least one of the following: a line segment; a line segment with graduations; a cross-shaped pattern; a cross-shaped pattern with graduations (such as...). Figure 2A (as shown); circular pattern; square pattern; rectangular pattern; hand-shaped pattern (as shown) Figure 2B (As shown); a hand-shaped pattern with markings.

[0060] S2 projects light (e.g., visible light) from the light-emitting device 10 onto the target area of ​​the tracking target via the field of view indicator unit 20 (e.g., the light-blocking plate 24 of the field of view indicator unit 20), and forms a projection of a predetermined pattern on the target area.

[0061] S3 compares the relationship between the projection and the predetermined pattern, and determines whether the target area is within the effective field of view of the imaging device based on the relationship.

[0062] In embodiments of the present invention, by comparing the projection of a predetermined pattern with the relationship between the predetermined pattern and the predetermined pattern, and determining whether the target area is within the effective field of view of the imaging device based on the relationship, the effective field of view of the imaging device is indicated in a simple, convenient and low-cost manner.

[0063] Furthermore, step S3 also includes:

[0064] Compare the proportional relationship between the projection and the predetermined pattern.

[0065] When the ratio of the projection to the predetermined pattern is less than or equal to 1, the target area is determined to be within the effective field of view of the camera.

[0066] Comparing the scale of the projection and the predetermined pattern involves comparing the size of the projection with the size represented by the predetermined pattern. Specifically, comparing the scale of the projection and the predetermined pattern includes:

[0067] The dimensions of the projected image and the dimensions represented by the predetermined pattern are obtained respectively. For a predetermined pattern with graduations, the represented dimension can be obtained from the marked graduations; for a predetermined pattern without graduations, the represented dimension can be determined based on a predetermined size, such as the size of a hand shape (e.g., the size of an adult's hand or a child's hand). The dimensions of the projected image can be measured using a measuring tool (e.g., a ruler), estimated manually, or determined using a tool with a fixed length.

[0068] Determine the proportional relationship between the size of the projection and the size represented by the predetermined pattern. This proportional relationship can be obtained by comparing the size of the projection with the size represented by the predetermined pattern.

[0069] When the ratio of the projection to the predetermined pattern is less than or equal to 1, the target area is determined to be within the effective field of view of the camera. As mentioned earlier, the distance between the light-blocking plate and the light source is adjusted according to the depth of the effective field of view. This adjustment means that when the target area is located at the boundary of the effective field of view, the size of the projection of the predetermined pattern onto the target area is equal to the size represented by the predetermined pattern; when the target area is within the effective field of view, the size of the projection of the predetermined pattern onto the target area is smaller than the size represented by the predetermined pattern. Thus, when the ratio of the projection to the predetermined pattern is less than or equal to 1, the target area is determined to be within the effective field of view of the camera.

[0070] Furthermore, step S1 also includes: adjusting the distance between the field of view indicator unit 20 and the light-emitting device 10 (specifically, the light source 14) based on the depth of the camera's effective field of view, so as to ensure that the ratio of the projection to the predetermined pattern is less than or equal to 1 when the target area is within the camera's effective field of view.

[0071] Specifically, the distance between the field of view indicator unit and the light source 14 is adjusted by sliding the first slide rail connector 262 and the second slide rail connector 264. For example, when the effective field of view of the camera is 1m, the first slide rail connector 262 and the second slide rail connector 264 are moved to adjust the distance between the light-blocking plate 24 and the light source 14 to a first distance, so that the 1m mark on the projection is 1m away from the light-blocking plate 24 and has a corresponding length of 1m. As another example, when the effective field of view of the camera is 0.5m, the first slide rail connector 262 and the second slide rail connector 264 are moved to adjust the distance between the light-blocking plate 24 and the light source 14 to a second distance (the second distance is less than the first distance), so that the 1m mark on the projection is 1m away from the light-blocking plate 24 and has a corresponding length of 1m.

[0072] The camera field of view indicator and the method of using the camera field of view indicator according to the present invention have at least one of the following advantages:

[0073] (1) The camera field of view indicator and the method of using the camera field of view indicator of the present invention indicate whether the target area is within the effective field of view of the camera based on the projection of a predetermined pattern on the target area, thereby allowing the effective field of view of the camera to be indicated in a simple, convenient and low-cost manner.

[0074] (2) The camera field of view indicator and the method of using the camera field of view indicator of the present invention help to achieve accurate positioning, thereby ensuring the subsequent treatment effect;

[0075] (3) The camera field of view indicator and the method of using the camera field of view indicator of the present invention eliminate the need to move the camera to determine whether the target area is within the effective field of view, thereby saving the user from adjusting the camera at a high position and laboriously loosening and tightening the camera.

[0076] (4) The camera field of view indicator and the method of using the camera field of view indicator of the present invention eliminate the need to adjust the subject’s position due to determining whether the target area is within the effective field of view, thereby reducing the adjustment time and reducing the subject’s discomfort.

[0077] While some embodiments of the present general inventive concept have been shown and described, those skilled in the art will understand that changes may be made to these embodiments without departing from the principles and spirit of the present general inventive concept, the scope of which is defined by the claims and their equivalents.

Claims

1. A field of view indicator, the field of view indicator being adapted to an imaging device and comprising: A light-emitting device is arranged between the imaging device and the tracking target; A field of view indicator unit, the field of view indicator unit including a moving mechanism and a light-blocking plate with a predetermined pattern fixed on the moving mechanism; The field of view indicator unit is configured to project light from the light-emitting device onto the target area of ​​the tracking target via the field of view indicator unit, so as to allow the projection of a predetermined pattern on the target area; The moving mechanism is configured to adjust the distance between the light-blocking plate and the light-emitting device; In use, the size of the projection is measured to determine whether the target area is within the effective field of view of the imaging device.

2. The field of view indicator according to claim 1, wherein, The light-emitting device includes: case; The light source is located inside the housing; A power supply unit located inside the housing and connected to the light source and / or field of view indicator unit; A control device located inside the housing that communicates with a vision system including an imaging device, a power supply device, and a light source.

3. The field of view indicator according to claim 2, wherein, The light source includes point light sources, surface light sources, or line light sources.

4. The field of view indicator according to claim 3, wherein, The effective field of view of the light field simulation imaging device formed by the light source through the field of view indicator unit.

5. The field of view indicator according to claim 4, wherein, The light source, the lens of the imaging device, and the target area are arranged on the same straight line.

6. The field of view indicator according to claim 5, wherein, The light source is positioned close to the lens.

7. The field of view indicator according to any one of claims 2-6, wherein, The moving mechanism is located on the outer surface of the housing, and the light-blocking plate is located outside the light-emitting device and opposite to the light-emitting device.

8. The field of view indicator according to claim 7, wherein, The moving mechanism includes a fixing member for fixing the light-blocking plate and a slide rail for adjusting the distance between the light-blocking plate and the light source, wherein the fixing member is connected to the slide rail.

9. The field of view indicator according to claim 8, wherein, The fixing component includes a first slide rail connector and a second slide rail connector, both of which are connected to the slide rail. The slide rails are arranged on opposite sides of the housing. The two ends of the light-blocking plate are respectively connected to the first slide rail connector and the second slide rail connector.

10. The field of view indicator according to any one of claims 1-6, wherein, The field of view indicator also includes a clamp for fixing the field of view indicator unit to the imaging device.

11. The field of view indicator according to claim 10, wherein, The clamp includes: Main body; A first fixing plate extends from one side of the main body and is configured to connect the light-emitting device; A second fixing plate extending from one side of the main body; A movable plate extending from one side of the main body, located between the first fixed plate and the second fixed plate, and capable of moving between the first fixed plate and the second fixed plate; A receiving slot is configured between the first fixed plate and the movable plate to accommodate the imaging device; A fastener is configured to pass through a second fixed plate, the fastener being rotatable, the fastener abutting against a movable plate by rotation, and the movable plate moving between a first fixed plate and a second fixed plate by rotation.

12. The field of view indicator according to claim 11, wherein, The first fixing plate is configured to connect the light-emitting device by means of adhesive, snap fastener, threaded connection, or shape adaptation.

13. The field of view indicator according to any one of claims 1-6, wherein, The field of view indicator is fixed to the imaging device by means of adhesive, snap fastener, threaded connection, or shape adaptation.

14. The field of view indicator according to any one of claims 1-6, wherein, The field of view indicator also includes a projection receiving component for receiving the projection. In use, the projection is displayed through the imaging component, and then the size of the projection on the imaging component is measured to determine whether the target area is within the effective field of view of the imaging device.

15. The field of view indicator according to any one of claims 1-6, wherein, The predetermined pattern includes at least one of the following: line segment; Line segments with markings; Cross-shaped pattern; A cross-shaped pattern with markings; Circular pattern; Square pattern; Rectangular pattern; Hand-shaped pattern; A hand-shaped pattern with markings.

16. A method using a field of view indicator, The field of view indicator is the field of view indicator according to any one of claims 1-15. The method includes the following steps: S1 provides a field of view indicator unit with a predetermined pattern; S2 projects light from the light-emitting device onto the target area of ​​the tracking target via the field of view indicator unit, and forms a predetermined pattern projection on the target area; S3 compares the relationship between the projection and the predetermined pattern, and determines whether the target area is within the effective field of view of the imaging device based on the relationship.

17. The method according to claim 16, wherein, Step S3 further includes: Compare the proportional relationship between the projection and the predetermined pattern. When the ratio of the projection to the predetermined pattern is less than or equal to 1, the target area is determined to be within the effective field of view of the imaging device.

18. The method according to claim 17, wherein, Step S1 further includes: adjusting the distance between the field of view indicator unit and the light-emitting device based on the depth of the effective field of view of the imaging device, so as to ensure that when the target area is within the effective field of view of the imaging device, the ratio of the projection to the predetermined pattern is less than or equal to 1.

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