Forearm mechanism of medical zero-gravity cantilever, medical zero-gravity cantilever and medical equipment

Abstract

The utility model discloses a forearm mechanism of a medical zero-gravity cantilever, the medical zero-gravity cantilever and medical equipment, relates to the technical field of medical instruments, aims to solve the problems of center-of-gravity shift, insufficient operation flexibility and multi-angle stress unbalance of an existing medical cantilever system, and provides the forearm mechanism which comprises a forearm hanging bracket and a Z-axis power supporting rod perpendicular to the forearm hanging bracket. The transverse connecting rod and the instrument connecting shaft form a kinematic chain through a longitudinal connecting rod, and the rocker assembly and the longitudinal connecting rod cooperatively control the motion trail. The adjusting sliding table slides along the guide rail to achieve gravity center dynamic compensation and is matched with the adjusting knob to complete accurate positioning. The vertical limiting sliding rail restrains vertical displacement of the longitudinal connecting rod, and the transverse sliding rod provides a transverse fine adjustment function. All the components form a composite motion system through mechanical optimization design, multi-dimensional accurate adjustment of the medical equipment is achieved under the condition that the zero gravity balance state is kept, the inertia offset phenomenon of a traditional cantilever is effectively eliminated, the suspension arm is suitable for suspension and accurate positioning of the medical equipment in an operation, and the operation stability and the body position adaptability are remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of medical devices, and particularly to a small arm mechanism of a medical zero-gravity cantilever. BACKGROUND

[0002] In modern medical operations, many delicate procedures require high-precision medical equipment, such as surgical microscopes, endoscopes, lymphatic probes, etc. These devices often need to be kept stable during surgery and have high-degree of freedom for flexible adjustment to meet the needs of doctors in different surgical scenarios. For example:

[0003] Surgical microscope suspension system

[0004] Currently, surgical microscopes are usually supported by mechanical arms or cantilevers, such as balanced arm structures or spring-assisted arms. These devices can achieve a certain degree of balance adjustment through springs or counterweights, but there are still the following problems in actual use:

[0005] Insufficient load adaptability: different models of surgical microscopes have different weights, and improper counterweight adjustment may cause instability during operation.

[0006] Limited flexibility: some mechanical arms have limited adjustment angles and cannot move freely in all directions, affecting the efficiency of the doctor's operation.

[0007] Complex damping adjustment: the force state of existing devices is different at different angles, and multiple joints need to be adjusted manually during adjustment, increasing the difficulty of operation.

[0008] Other medical devices (such as lymphatic probes, endoscopes, anesthesia equipment, etc.) also often use suspension structures for fixation, such as track suspension or single-arm support suspension:

[0009] Track suspension: the device slides along the fixed track, which ensures a certain degree of stability, but the track limits the range of movement and cannot adjust the position flexibly.

[0010] Single-arm support: usually uses a single support arm to fix the device, which is difficult to provide multi-degree of freedom adjustment, and the center of gravity of the device is easy to shift, causing instability during operation.

[0011] Problems in existing technology

[0012] Although the existing medical device suspension technology has improved the convenience of surgical operation to some extent, there are still the following main technical difficulties:

[0013] Center of gravity shift problem: the center of gravity adjustment of existing devices is complex, and some devices are prone to shift during adjustment, resulting in decreased stability.

[0014] Insufficient operational flexibility: Most cantilever mechanisms cannot achieve zero-gravity rotation on XYZ three axes, and doctors need to apply additional torque for adjustment, increasing fatigue.

[0015] Unbalanced force: The torque of some mechanical arms or cantilever systems is different at different angles, which may cause the device to swing or be difficult to maintain balance, affecting surgical precision.

[0016] Complex structure, inconvenient adjustment: Existing technologies often need to manually adjust multiple joints when adjusting the position of the device, which is inconvenient and time-consuming to adjust, making it difficult to meet the needs of high-precision surgery. SUMMARY

[0017] To solve the technical problems of the existing medical device suspension technology, such as center of gravity deviation, insufficient operational flexibility, and unbalanced force of some mechanical arms or cantilever systems at different angles, the present application provides the following technical solutions:

[0018] The small arm mechanism of the medical zero-gravity cantilever includes:

[0019] The small arm hanger connects and supports the small arm mechanism;

[0020] The Z-axis is perpendicular to the small arm hanger and serves as the core part of supporting and transmitting power;

[0021] The horizontal connecting rod rotating shaft is a circular metal shaft, which is arranged at the lower end of the small arm hanger and is used for the rotation of the horizontal connecting rod;

[0022] One end of the horizontal connecting rod is connected to the small arm hanger through the horizontal connecting rod rotating shaft, and the other end is connected to the vertical connecting rod;

[0023] The rocker is connected to the vertical connecting rod and acts together with the horizontal connecting rod;

[0024] The vertical connecting rod connects the horizontal connecting rod and the instrument connecting shaft, providing longitudinal movement of the device;

[0025] The instrument connecting shaft is a metal shaft that connects the medical device and the small arm mechanism;

[0026] The adjustment slide moves along the track to adjust the center of gravity of the device;

[0027] The adjustment knob is used to adjust the position of the adjustment slide;

[0028] The horizontal slide rod assists in the horizontal adjustment of the device;

[0029] The vertical limit slide rail limits the upward and downward translation movement path of the vertical connecting rod.

[0030] Further, a preferred embodiment is provided, in which the horizontal connecting rod rotating shaft one and the horizontal connecting rod rotating shaft two are both set as circular metal structures, connecting and supporting the horizontal connecting rod to ensure its stable rotation.

[0031] Further, a preferred embodiment is provided, in which the longitudinal link is connected to the rocker through a hinge.

[0032] Further, a preferred embodiment is provided, in which the instrument connecting shaft is used to connect the medical device, and the device center of gravity position is adjusted through the adjusting device to maintain the torque balance.

[0033] Further, a preferred embodiment is provided, in which the small arm hanger is a rectangular frame.

[0034] Further, a preferred embodiment is provided, in which the two ends of the Z-axis are connected to the small arm hanger and the longitudinal link through bearings.

[0035] Further, a preferred embodiment is provided, in which the connection between the horizontal link one and the horizontal link two is provided with a sliding device.

[0036] Further, a preferred embodiment is provided, in which the instrument connecting shaft is connected to the medical device through a quick locking device.

[0037] Based on the same inventive concept, the present application also provides a medical zero-gravity cantilever, which comprises the small arm mechanism.

[0038] Based on the same inventive concept, the present application also provides a medical device, which comprises the cantilever.

[0039] Compared with the prior art, the technical scheme provided by the present application has the advantages of:

[0040] The upper and lower double four-bar linkage mechanism linkage design adopted in the present application enables the suspended medical device to keep point rotation around its center of gravity, avoiding the additional torque problem caused by the center of gravity deviation of the traditional mechanical arm. Compared with the existing single-arm support or balanced arm structure, the present application reduces the torque compensation demand of the doctor during operation, makes the device hover more stably, and is more labor-saving to operate.

[0041] The present application limits the point rotation swing of the lower longitudinal four-bar linkage, so that the medical device can always be kept on the set center of gravity axis during the adjustment at different angles. Compared with the traditional spring balanced arm or counterweight adjusting mechanism, the present application can ensure the device balance without frequent adjustment of the counterweight, improves the operation convenience, and reduces the influence of device shaking on the operation accuracy.

[0042] The horizontal double linkage synchronous movement adjusting mechanism of the present application enables the device to be adjusted to translate left and right at equal distances, and realizes the accurate return of the device on the Z-axis. Compared with the fixed track movement mode of the track type suspension system, the present application provides higher freedom, the doctor can quickly adjust the device position according to the operation demand, improves the operation efficiency, and avoids the inconvenience caused by the track limitation.

[0043] The double-end sliding connection is adopted, one end of which is vertical sliding, so as to realize the synchronous adjustment of the horizontal connecting rod and limit the swing of the lower longitudinal four connecting rod, so that the device will not tilt or rotate unbalance due to unilateral force change during adjustment. Compared with the traditional single-point hinge suspension mode, the scheme greatly reduces the angle deviation caused by the change of the center of gravity of the device, and improves the controllability and stability of the device during the operation.

[0044] The C-shaped layout design makes the center of gravity of the small arm and the medical device always fall on the Z-axis axis, regardless of the change of the rotation angle of the device, so that the moment generated by the parallel arm is always constant. Compared with the conventional balance arm mechanism, the design eliminates the manipulation resistance caused by the change of the moment during the rotation of the device, so that the doctor can adjust the device more smoothly, improve the flexibility of operation and the accuracy of operation.

[0045] It is suitable for suspending and accurately adjusting medical devices such as surgical microscopes and lymphatic probes during operation, and provides stable and flexible operation support. BRIEF DESCRIPTION OF DRAWINGS

[0046] Fig. 1 It is a front view of the small arm mechanism;

[0047] Fig. 2 It is a side view of the small arm mechanism;

[0048] Fig. 3 It is a schematic view of the swing angle of the instrument connecting shaft.

[0049] In the figure, 1 is a small arm hanger, 2 is a Z-axis, 3 is a horizontal connecting rod rotating shaft, 4 is a horizontal connecting rod rotating shaft, 5 is a horizontal connecting rod, 6 is a horizontal connecting rod, 7 is a rocker, 8 is a vertical connecting rod, 9 is an instrument connecting shaft, 10 is an adjusting sliding table, 11 is an adjusting knob, 12 is a horizontal sliding rod, and 13 is a vertical limiting sliding rail. DETAILED DESCRIPTION

[0050] In order to make the advantages and benefits of the technical solutions provided by the present application more clear, the technical solutions provided by the present application will be described in further detail in combination with the drawings, specifically:

[0051] Embodiment one, the embodiment provides a small arm mechanism of a medical zero-gravity cantilever, comprising:

[0052] The small arm hanger 1 is connected and supports the small arm mechanism;

[0053] The Z-axis 2 is in the form of a long rod and is located in the vertical direction of the small arm hanger 1, serving as the core part of supporting and transmitting power;

[0054] The horizontal connecting rod rotating shaft is a circular metal shaft, which is arranged at the lower end of the small arm hanger 1 and is used for horizontal connecting rod rotation;

[0055] The horizontal connecting rod 5 is connected to the small arm hanger 1 through the horizontal connecting rod rotating shaft at one end and connected to the vertical connecting rod 8 at the other end;

[0056] The rocker 7 is connected to the vertical connecting rod 8 and works together with the horizontal connecting rod;

[0057] The vertical connecting rod 8 connects the horizontal connecting rod and the instrument connecting shaft 9, providing longitudinal movement of the device;

[0058] The instrument connecting shaft 9 is a metal shaft that connects the medical device and the small arm mechanism;

[0059] The adjusting sliding platform 10 slides along the track for adjusting the center of gravity of the device;

[0060] The adjusting knob 11 is used to adjust the position of the adjusting sliding platform 10;

[0061] The horizontal sliding rod 12 assists in the lateral adjustment of the device;

[0062] The vertical limiting sliding rail 13 limits the up and down translation path of the vertical connecting rod 8.

[0063] Specifically, it includes:

[0064] The small arm hanger 1 is in a rectangular or rectangular structure, usually a medium-thickness metal frame, and is connected to the upper medical device through the installation support point at the top, with a relatively simple overall shape.

[0065] The small arm hanger 1 is the supporting foundation of the entire small arm mechanism, responsible for bearing and fixing other components. The lower end of the hanger is connected to the horizontal connecting rod rotating shaft, which is connected to other connecting rod structures through these shafts. The material of the small arm hanger 1 is usually a lightweight and strong alloy material, with high bearing capacity, while the design takes into account the reduction of weight as much as possible to reduce the burden in the operation process.

[0066] The Z-axis 2 is in a long rod structure, usually in the vertical direction of the small arm hanger 1. It has a relatively long length and is fixed with other mechanical parts.

[0067] The Z-axis 2 is the core longitudinal support part of the small arm mechanism, playing a role in transmitting power and stability. During the operation process, the Z-axis 2 allows other components to rotate or translate around it. The Z-axis 2 structure, through cooperation with other connecting rods, ensures the balance and stability of the entire mechanism in space.

[0068] The horizontal connecting rod rotating shaft 3 is circular in shape, usually made of metal material, with a relatively simple appearance, smooth surface, and appropriate size to ensure flexible rotation.

[0069] The rotating shaft is part of the cross four-bar linkage mechanism, mainly used to support and rotate the cross link 5 in the vertical direction. It is installed at the lower part of the small arm bracket 1, providing the rotating shaft center of the linkage. The rotating shaft one is the key component to ensure the smooth movement of the cross link.

[0070] The shape and size of the cross link rotating shaft two 4 are similar to those of the cross link rotating shaft one 3, which is also a circular metal structure, used to carry and support the second cross link.

[0071] The shaft is connected to the position of the first rotating shaft, cooperating with the cross link two 6, so that the entire cross four-bar linkage mechanism can realize stable rotation during operation. Its structure design ensures high strength stability under load, avoiding excessive swing.

[0072] The cross link one 5 is long and one end is connected to the small arm bracket 1 through the rotating shaft, and the other end is connected to the linkage two.

[0073] The cross link one 5 is one of the main support parts of the four-bar linkage mechanism, responsible for connecting the rotating shaft at the upper part and the linkage at the lower part. Its design requires a certain degree of flexibility and strength to support medical equipment and allow it to rotate within a specified range.

[0074] The cross link two 6 is long and symmetrical to the cross link one 5, usually similar in structure to the cross link one 5, but its length and thickness may be different to meet the actual operation needs.

[0075] The cross link two 6 has a similar function to the cross link one 5, responsible for linkage with other linkage components to achieve precise adjustment of the equipment. Its connection point is connected to the cross link rotating shaft two 4, so that the equipment can rotate stably in space.

[0076] The rocker 7 is usually a short and solid rod structure, with the end connected to the longitudinal linkage through a hinge. Its structure design is simple, easy to connect and adjust.

[0077] The function of the rocker 7 is to control the linkage of the four-bar linkage mechanism, ensuring that the equipment can work stably during rotation. The rocker 7 is connected to the longitudinal linkage and adjusts the center of gravity of the equipment through this linkage. The rocker 7 is usually equipped with an adjustment mechanism to fine-tune the angle and position of the equipment in actual operation.

[0078] The longitudinal linkage 8 is a long rod structure, usually installed vertically in the small arm mechanism, connected to the cross link.

[0079] The longitudinal linkage 8 serves to connect the upper cross link mechanism and the lower equipment. It cooperates with the rocker 7 to keep the equipment on the axis of the Z-axis 2 vertical line during operation. The design of the longitudinal linkage 8 ensures the stability and rotation accuracy of the equipment.

[0080] The instrument connecting shaft 9 is usually a relatively sturdy metal shaft that connects the instrument and the small arm mechanism. It is relatively simple in shape but has high load-bearing capacity.

[0081] The instrument connecting shaft 9 is responsible for connecting the medical device and the small arm mechanism. It is usually located at the center of the device, ensuring that the device remains centered during rotation and adjustment, avoiding deviation.

[0082] The adjustment slide 10 is rectangular or square in shape, usually equipped with tracks or grooves to achieve smooth adjustment.

[0083] The adjustment slide 10 can be used to adjust the center of gravity of the instrument. It can slide along a specific track and be precisely controlled by the adjustment knob 11. The design of the adjustment slide 10 allows the operator to adjust the device position as needed, ensuring that the center of gravity of the device always remains on the Z-axis 2.

[0084] The adjustment knob 11 is round in shape, usually made of ergonomic plastic or metal materials for easy operation.

[0085] The adjustment knob 11 is connected to the adjustment slide 10 and is used to precisely control the position of the device. By rotating the knob, the operator can adjust the length of the horizontal link, thereby re-aligning the center of gravity of the device with the Z-axis 2.

[0086] The horizontal sliding rod 12 is in the shape of an elongated strip, usually located in the horizontal part of the small arm mechanism, designed for easy sliding.

[0087] The horizontal sliding rod 12 serves to assist in adjusting the horizontal movement of the device, ensuring that the device can be precisely adjusted according to the needs during operation. By combining with the adjustment slide 10, the horizontal sliding rod 12 helps to achieve the balance and position adjustment of the center of gravity of the device.

[0088] The vertical limiting slide rail 13 is in the shape of a straight line, usually made of metal, with a simple shape and equipped with a sliding channel.

[0089] The vertical limiting slide rail 13 serves to limit the up and down sliding of the vertical link, allowing it to only perform vertical parallel motion, thereby avoiding deviation caused by rotational swing. It ensures that the device does not lose stability during operation and maintains the precise positioning of the device.

[0090] Overall, the structural design of the small arm mechanism realizes stable suspension and accurate adjustment of the medical equipment by combining a precise four-bar linkage mechanism, an adjusting device, and a sliding rail. The entire small arm mechanism provides high operational flexibility through the cooperation of various parts, while ensuring that the center of gravity of the equipment is always maintained on the Z axis 2, avoiding unstable operation caused by the offset of the center of gravity. The design of each component is simple and efficient, enabling the medical equipment to maintain accurate torque balance during rotation and adjustment, greatly improving the stability and operational convenience of the equipment.

[0091] Embodiment two, the embodiment is a further limitation of the small arm mechanism of the medical zero-gravity suspension arm provided in embodiment one, the horizontal connecting rod rotating shaft one 3 and the horizontal connecting rod rotating shaft two 4 are both set as circular metal structures, connecting and supporting the horizontal connecting rod, ensuring its stable rotation.

[0092] Embodiment three, the embodiment is a further limitation of the small arm mechanism of the medical zero-gravity suspension arm provided in embodiment one, the vertical connecting rod 8 is connected with the rocker 7 through a hinge.

[0093] Embodiment four, the embodiment is a further limitation of the small arm mechanism of the medical zero-gravity suspension arm provided in embodiment one, the instrument connecting shaft 9 is used to connect the medical equipment and adjust the center of gravity position of the equipment through the adjusting device to maintain torque balance.

[0094] Embodiment five, the embodiment is a further limitation of the small arm mechanism of the medical zero-gravity suspension arm provided in embodiment one, the small arm hanger 1 is a rectangular frame.

[0095] Embodiment six, the embodiment is a further limitation of the small arm mechanism of the medical zero-gravity suspension arm provided in embodiment one, the two ends of the Z axis 2 are connected with the small arm hanger 1 and the vertical connecting rod 8 through bearings.

[0096] Embodiment seven, the embodiment is a further limitation of the small arm mechanism of the medical zero-gravity suspension arm provided in embodiment one, the connecting part of the horizontal connecting rod one 5 and the horizontal connecting rod two 6 is provided with a sliding device.

[0097] Embodiment eight, the embodiment is a further limitation of the small arm mechanism of the medical zero-gravity suspension arm provided in embodiment one, the instrument connecting shaft 9 is connected with the medical equipment through a quick locking device.

[0098] Embodiment nine, the embodiment provides a medical zero-gravity suspension arm, which includes the small arm mechanism provided in embodiment one.

[0099] Embodiment ten, the embodiment provides a medical device, which includes the suspension arm provided in embodiment nine.

[0100] Embodiment eleven, in combination Figs. 1-3This embodiment describes the specific implementation method, which further defines the technical solution provided above through specific examples. Specifically:

[0101] A forearm mechanism for a medical zero-gravity cantilever relates to the suspended use of medical instruments. Most commonly used with surgical microscopes and lymphatic probes, surgeries are often performed under intense psychological stress and are frequently lengthy. Such prolonged surgeries increase physical and mental fatigue for both patients and surgeons. Therefore, there is a strong demand for instruments that are lightweight, flexible, labor-saving, stable, and fast, minimizing fatigue. The medical zero-gravity cantilever, combined with surgical microscopes and other medical instruments, plays a crucial role in highly precise surgeries. In these procedures, every second counts; sometimes a single second's difference can mean the difference between success and failure, impacting the patient's life or death.

[0102] A pair of connecting rods, capable of simultaneous rotation and equidistant parallel movement, are mounted on the lower frame of the forearm hanger 1 connected to the parallel arm. These, along with a rocker arm 7, form an upper transverse four-bar linkage. One of these connecting rods and the extended rocker arm 7 form two sides of a lower longitudinal four-bar linkage. The other side of the lower four-bar linkage is parallel to the extended rocker arm 7. The fourth side connects to medical equipment, such as a surgical microscope or lymphatic probe, but is not limited to these two types of medical optical equipment; it also includes other medical equipment requiring cantilever. A mechanism for adjusting the center of gravity is also provided at the connection point to the medical equipment. Because the two four-bar linkages share a common side, they can be linked. Furthermore, to prevent the medical equipment from shifting due to the fixed-point rotation and swing of the lower longitudinal four-bar linkage during operation, a mechanism is provided to keep the lower longitudinal four-bar linkage always vertical, limiting its swing. The two vertically connected rods that are restricted can only move vertically in parallel. Since the center of gravity of the medical equipment passes through the axes of the XYZ axes, its torque is zero, keeping the medical equipment suspended in the air, making operation very easy and flexible.

[0103] The medical equipment is suspended on one side of a longitudinal balance double four-bar linkage mechanism. By utilizing the linkage of the double four-bar linkage, the medical equipment can rotate with its center of gravity fixed.

[0104] The center of gravity of the suspended medical equipment is simultaneously on the XYZ axis, and the torque on the rotational center of gravity is zero or infinitely close to zero.

[0105] The two lateral connecting rods can be simultaneously adjusted to move left and right at equal intervals, so that the center of gravity of the medical equipment returns to the Z-axis.

[0106] The synchronous movement adjustment of the two lateral links is achieved by using a double-ended sliding connection (one end of which is vertically sliding), and the fixed-point swing of the lower longitudinal four-link is restricted.

[0107] The two-dimensional C-shaped layout ensures that the center of gravity of the medical device falls on the Z-axis.

[0108] When the gravity center of the small arm and the medical equipment falls on the Z axis 2, the moment generated by the parallel arm is constant regardless of the angle of the Z axis 2 rotation.

[0109] When the doctor rotates the medical equipment a around the instrument connecting shaft 9, the rocker 7 and the vertical connecting rod 8 cannot swing around the upper hinge due to the limitation of the vertical slide rail, and can only keep vertical up-and-down parallel movement, which ensures that the gravity center of the equipment always falls on the axis center line of the Z axis 2, and the moment generated by the small arm and the equipment gravity on the parallel arm remains constant regardless of the rotation, which is beneficial to simplify the mechanical structure design of the parallel arm part. Since the upper edge of the lower longitudinal four-bar linkage is co-edge with the upper transverse four-bar linkage, the upper two hinge connections of the lower longitudinal four-bar linkage mechanism can swing a around the horizontal connecting rod rotation shaft one 3 and the horizontal connecting rod rotation shaft two 4, thereby driving the lower longitudinal four-bar linkage mechanism to move up and down. At the same time, the gravity center of the medical equipment also falls on the rotation center line of the X axis and the Y axis, so the rotation moments of the three axes are all zero, which can make the operation flexible and convenient. If the gravity center of the medical equipment deviates from the axis center line (for example, auxiliary equipment is added), the length of the horizontal connecting rod one 5 and the horizontal connecting rod two 6 can be adjusted by rotating the adjusting knob 11 to make the gravity center return to the axis center line to achieve moment balance.

[0110] The above further describes the technical solutions provided by the present application through several specific embodiments, in order to highlight the advantages and benefits of the technical solutions provided by the present application. However, the above several specific embodiments are not used as a limitation of the present application, and any reasonable modification and improvement of the present application, combination and equivalent replacement of the embodiments, etc. based on the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A medical zero-gravity cantilevered forearm mechanism, characterized by, The small arm mechanism comprises: A small arm hanger is connected to and supports the small arm mechanism; A Z-axis is arranged perpendicularly to the small arm hanger and serves as a core part for supporting and transmitting power; A cross link rotating shaft is a circular metal shaft arranged at the lower end of the small arm hanger and used for the rotation of the cross link; One end of the cross link is connected to the small arm hanger through the cross link rotating shaft, and the other end is connected to the vertical link; A rocker is connected to the vertical link and cooperates with the cross link; The vertical link connects the cross link and the instrument connecting shaft and provides the longitudinal movement of the device; The instrument connecting shaft is a metal shaft connecting the medical device and the small arm mechanism; An adjusting slide is used for adjusting the center of gravity of the device; An adjusting knob is used for adjusting the position of the adjusting slide; A cross slide is used for assisting the lateral adjustment of the device; A vertical limiting slide rail limits the up-and-down translation path of the vertical link.

2. The medical zero-gravity cantilevered arm mechanism of claim 1, wherein, Both the cross link rotating shaft one and the cross link rotating shaft two are circular metal structures, which are connected to and support the cross link and ensure the stable rotation of the cross link.

3. The medical zero-gravity cantilevered arm mechanism of claim 1, wherein, The vertical link is connected to the rocker through a hinge.

4. The medical zero-gravity cantilevered arm mechanism of claim 1, wherein, The instrument connecting shaft is used for connecting the medical device and adjusting the center of gravity of the device through the adjusting device to maintain the balance of the moment.

5. The medical zero-gravity cantilevered arm forearm mechanism of claim 1 wherein, The small arm hanger is a rectangular frame.

6. The medical zero-gravity cantilevered arm mechanism of claim 1, wherein, Both ends of the Z-axis are connected to the small arm hanger and the vertical link through bearings.

7. The medical zero-gravity cantilevered arm mechanism of claim 1, wherein, The connection between the cross link one and the cross link two is provided with a sliding device.

8. The medical zero-gravity cantilevered arm mechanism of claim 1, wherein, The instrument connecting shaft is connected to the medical device through a quick locking device.

9. A medical zero-gravity cantilever, characterized by The device comprises the small arm mechanism of claim 1.

10. A medical device, characterized by The device comprises the cantilever of claim 9.

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