Master Hand Gripping Device with Finger Gripping Force Feedback and Hardness Feedback

Abstract

The present invention discloses a master hand clamping device with finger clamping force feedback and hardness feedback. The clamping device includes a torque sensor, a helical gear transmission component, a hardness feedback clamping handle, and a first motor. Among them, the hardness feedback clamping handle is connected to the helical gear transmission component through a linkage shaft, and the helical gear transmission component is connected to the first motor, converting the opening and closing movement of the hardness feedback clamping handle driven by the operator's finger into the rotational movement of the first motor. The first motor receives the force signal detected by the clamp sensor for force output, and transmits it to the hardness feedback clamping handle through the helical gear transmission component for force feedback. An encoder is provided on the first motor, which is used to measure the rotation angle of the output shaft of the first motor, calculate the opening and closing angle of the hardness feedback clamping handle, and transmit the signal of the opening and closing angle to the clamp controller to control the opening and closing angle of the clamp. The torque sensor is connected to the output end of the first motor and is used to measure the output torque of the first motor and the force exerted by the clamping handle on the user's finger. The device is a master hand clamping device that can provide an intuitive clamping action and accurate force feedback and can also feedback the softness and hardness of tissues.

Description

Technical Field

[0001] The present invention relates to the technical field of surgical robots, and particularly to a master hand clamping device with finger clamping force feedback and hardness feedback. Background Art

[0002] With the development of surgical robot technology, more and more robot systems are involved in minimally invasive surgery, forming a robot-assisted minimally invasive surgery system. Due to the characteristics of high precision, high degrees of freedom and high stability of surgical robots, complex movements and control precision beyond human capabilities can be achieved in narrow spaces, greatly reducing the postoperative trauma area of patients, thus reducing the patient's recovery time and postoperative complications. The current robot-assisted minimally invasive surgery system mainly adopts a master-slave operation control mode. The doctor operates the master hand to control the slave hand (end surgical instrument) at the patient's surgical site for surgery, and the surgical image is displayed on the monitor through an endoscope. Doctors usually can only judge the surgical condition through visual feedback, which limits the doctor's perception ability of the tissue stress during the operation, especially in the narrow space of minimally invasive surgery when the endoscope cannot clearly display the surgical site. To overcome this problem, doctors should be able to feel the force applied to the tissue and the softness and hardness of the contacted tissue. Therefore, the master operating hand needs to be able to receive the contact force signal of the slave operating hand and be able to perform force and hardness feedback. In particular, the clamping force feedback is very important because tissue damage is usually caused by excessive clamping force during surgery.

[0003] Among the existing force feedback master hand clamping devices on the market, only the feedback of the clamping force can be provided, and the hardness of the clamped tissue cannot be reflected, making it difficult for doctors to judge the tissue condition through the master hand. Most of the force feedback master hand clamping devices use a rotary motor as the power source, and the force is transmitted to the clamping handle through spur gears or sector gears to provide the feedback force. In this structure, the motor is often perpendicular to the holding handle, and the structure is not compact enough. Some use steel wires for force transmission, making the structure more compact, but its reliability is not as good as gear transmission. And currently, there is a lack of a force detection device in the force feedback master hand clamping device, and the feedback of the force is only an open-loop control that controls the output force of the motor by controlling the current magnitude, and the precise closed-loop control of the feedback force cannot be achieved.

[0004] Currently, some scholars simulate different hardnesses by controlling the air pressure inside the airbag through an air pump to achieve hardness feedback. In this scheme, the hardness feedback device is externally connected to the trachea to form a loop with the air pump, making the whole system cumbersome and affecting the user's hand movement and immersive experience. Summary of the Invention

[0005] In order to solve the problems in the background art, the present invention aims to develop a master hand clamping device with a compact structure, capable of providing intuitive clamping actions and precise force feedback and being able to feedback the softness and hardness of tissues.

[0006] To solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0007] A master hand clamping device with finger clamping force feedback and hardness feedback, the clamping device includes a torque sensor, a helical gear transmission component, a hardness feedback clamping handle, and a first motor; wherein, the hardness feedback clamping handle is connected to the helical gear transmission component through a linkage shaft, the helical gear transmission component is connected to the first motor, converting the opening and closing movement of the operator's finger driving the hardness feedback clamping handle into the rotational movement of the first motor, the first motor receives the force signal detected by the clamp sensor for force output, and is transmitted to the hardness feedback clamping handle through the helical gear transmission component. An encoder is provided on the first motor, the encoder is used to measure the rotational angle of the output shaft of the first motor, calculate the opening and closing angle of the hardness feedback clamping handle, and transmit the signal of the opening and closing angle to the clamp controller to control the opening and closing angle of the clamp;

[0008] The torque sensor is connected to the output end of the first motor, and is used to measure the output torque of the first motor and the force exerted by the clamping handle on the user's finger;

[0009] The clamping device further includes a housing, the housing is a columnar body, the first motor, the torque sensor, and the helical gear transmission component are arranged inside the housing, and the hardness feedback clamping handle extends out of the housing and is connected through a linkage shaft.

[0010] Further, the hardness feedback clamping handle is connected to the helical gear in the helical gear transmission component, and a hardness feedback device is installed inside the hardness feedback clamping handle;

[0011] The hardness feedback device includes an L-shaped airbag, a second motor, and a cam; an L-shaped airbag is provided at the contact between the hardness feedback clamping handle and the fingertip;

[0012] The clamp sends the detected hardness signal to the clamping device through the sensing device of the clamp part, the second motor rotates under the control of the hardness signal, and the second motor drives the cam to squeeze the lower part of the airbag, changing the air pressure inside the airbag, so as to simulate different hardnesses and achieve hardness feedback.

[0013] Further, the second motor in the hardness feedback device is a voice coil motor, the cam is cancelled, and the voice coil motor is used to squeeze the L-shaped airbag to change the air pressure inside it and simulate different hardnesses.

[0014] Further, one end of the torque sensor is connected to the output shaft of the first motor, and the other end is connected to the helical gear shaft, which is used to measure the output torque of the first motor and the force exerted by the clamping handle on the user's finger, realize the closed-loop control of force feedback, and adjust the output force of the motor in real time.

[0015] Further, the torque sensor is divided into a force - applying component, a force - receiving and deforming component, and a photoelectric - sensing printed circuit board (PCB) for measuring deformation. Among them, the force - applying component and the force - receiving and deforming component are respectively connected to the gear shaft and the first motor output shaft through fastening bolts;

[0016] The force - applying component conducts force to the deforming part of the force - receiving and deforming component through bolts, and the axes of the two components are connected by bearings;

[0017] The photoelectric - sensing printed circuit board (PCB) is installed between the surfaces of the deformable part, and is used to measure the distance between the surfaces after deformation caused by the action of force, so as to deduce the torque value.

[0018] Further, the housing is divided into two sections: the rear end is a motor base, and the first motor is installed inside the motor base; the front end is a helical - gear shaft seat;

[0019] The helical - gear transmission assembly is connected to the front end of the housing through a shaft and bearings. The front end of the housing is divided into two parts, left and right, which are connected by bolts and are fixedly connected to the rear end of the housing through grooves.

[0020] Compared with the prior art, the remarkable advantages of the present invention are as follows:

[0021] This master - hand clamping device can provide clamping actions and track the opening and closing actions of the fingers to control the opening and closing of the slave - manipulator clamp. And through this device, the doctor can accurately sense the magnitude of the clamping force of the slave - manipulator, and thus can feel the force applied to the tissue. At the same time, the doctor can also sense the softness and hardness of the tissue through this master - hand and can perform a certain degree of palpation. It increases the sensory feedback (except for visual feedback) of the doctor during the operation and reduces the probability of tissue damage caused by the lack of force perception. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic diagram of the overall structure of the master - hand clamping device with finger - clamping force feedback and hardness feedback;

[0023] Figure 2 is a schematic diagram of the housing structure of the master - hand clamping device with finger - clamping force feedback and hardness feedback;

[0024] Figure 3 is a schematic diagram of the torque - sensor structure of the master - hand clamping device with finger - clamping force feedback and hardness feedback;

[0025] Figure 4 is a schematic diagram of the hardness - feedback clamping - handle structure of the master - hand clamping device with finger - clamping force feedback and hardness feedback;

[0026] Figure 5 is a schematic diagram of the working state of the master - hand clamping device with finger - clamping force feedback and hardness feedback;

[0027] In the figure, 1 - housing part, 2 - torque sensor, 3 - helical gear transmission component, 4 - hardness feedback clamping handle, 5 - first motor, 6 - hand clamp, 7 - tissue;

[0028] 11 - motor base, 12 - gear shaft base;

[0029] 21 - force - applying bolt, 22 - fastening bolt, 23 - force - applying component, 24 - bearing, 25 - optoelectronic sensing printed circuit board PCB, 26 - force - deformed component;

[0030] 41 - L - shaped airbag, 42 - second motor, 43 - cam. Specific embodiments

[0031] The present invention will be further described clearly and completely below in conjunction with specific embodiments and the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0032] The present application provides a master hand clamping device with finger clamping force feedback and hardness feedback. The clamping device includes a torque sensor, a helical gear transmission component, a hardness feedback clamping handle, and a first motor, as Figure 1 shown; wherein, the clamping device includes a torque sensor, a helical gear transmission component, a hardness feedback clamping handle, and a first motor; wherein, the hardness feedback clamping handle is connected to the helical gear transmission component through a linkage shaft, the helical gear transmission component is connected to the first motor, and the opening and closing movement of the hardness feedback clamping handle driven by the operator's finger is converted into the rotational movement of the first motor. The first motor receives the force signal detected by the clamp sensor for force output, which is transmitted to the hardness feedback clamping handle through the helical gear transmission component. An encoder is provided on the first motor, and the encoder is used to measure the rotational angle of the output shaft of the first motor, calculate the opening and closing angle of the hardness feedback clamping handle, and transmit the signal of the opening and closing angle to the clamp controller to control the opening and closing angle of the clamp;

[0033] The torque sensor is connected to the output end of the first motor and is used to measure the output torque of the first motor and the force exerted by the clamping handle on the user's finger;

[0034] The clamping device further includes a housing. The housing is a columnar body. The first motor, the torque sensor, and the helical gear transmission component are arranged inside the housing, and the hardness feedback clamping handle extends outside the housing and is connected through a linkage shaft.

[0035] Furthermore, the hardness feedback clamping handle is connected to the helical gear in the helical gear transmission component, and a hardness feedback device is installed inside the hardness feedback clamping handle;

[0036] The hardness feedback device includes an L-shaped airbag, a second motor, and a cam. An L-shaped airbag is provided at the contact between the hardness feedback clamping handle and the fingertip.

[0037] The clamp sends the detected hardness signal to the clamping device through the sensing device of the clamp part. The second motor rotates under the control of the hardness signal. The second motor drives the cam to squeeze the lower part of the airbag, changing the air pressure inside the airbag, so as to simulate different hardnesses and achieve hardness feedback.

[0038] As a preferred implementation of the present application, the second motor in the hardness feedback device is a voice coil motor. The cam is cancelled, and the L-shaped airbag is directly squeezed by the voice coil motor to change the air pressure inside it and simulate different hardnesses.

[0039] Further, one end of the torque sensor is connected to the output shaft of the first motor, and the other end is connected to the helical gear shaft, which is used to measure the output torque of the first motor and the force exerted by the clamping handle on the user's finger, realize the closed-loop control of force feedback, and adjust the output force of the motor in real time.

[0040] Further, the torque sensor is divided into a force application component, a force-receiving deformation component, and a photoelectric sensing printed circuit board PCB for measuring deformation. Among them, the force application component and the force-receiving deformation component are respectively connected to the gear shaft and the output shaft of the first motor through fastening bolts;

[0041] The force application component conducts the force to the deformation part of the force-receiving deformation component through bolts, and the shafts of the two components are connected by bearings;

[0042] The photoelectric sensing printed circuit board PCB is installed between the surfaces of the deformable part, and is used to measure the distance between the surfaces after deformation due to the action of force, and thus deduce the torque value.

[0043] Furthermore, the housing is divided into two sections: the rear end is a motor base, and the first motor is installed inside the motor base; the front end is a helical gear shaft seat;

[0044] The helical gear transmission component is connected to the front end of the housing through a shaft and bearings. The front end of the housing is divided into two left and right parts, which are connected by bolts and are connected and fixed to the rear end of the housing through grooves.

[0045] The finger clamping movement is transmitted from the clamping handle to the torque sensor through the helical gear transmission component, and then from the torque sensor to the output shaft of the motor. The output force of the motor is also transmitted reversely through this structure. The encoder of the motor is used to measure the opening and closing angle of the clamping handle and control the opening and closing of the operating hand clamp. The torque sensor is used to measure the output torque of the motor and the force exerted by the clamping handle on the user's finger, realize the closed-loop control of force feedback, and adjust the output force of the motor in real time.

[0046] The above-mentioned housing is divided into two sections: the rear end is the motor base, and the front end is the helical gear shaft seat. Its structure is as shown in Figure 2 . The motor is fixed to the motor base by bolts. The helical gear transmission assembly is connected to the front end of the housing through a shaft and bearings, playing a role in installation and positioning. The front end of the housing is divided into two parts, left and right, which are connected by bolts and are also connected and fixed to the rear end of the housing through grooves.

[0047] The above-mentioned motor is equipped with an encoder, which can record the rotation angle of the motor output shaft. The opening and closing angle of the clamping handle can be calculated through the rotation angle, so as to output a signal to control the opening and closing angle of the clamp in the hand. The motor serves as the power source for force feedback and provides the force exerted by the clamping handle on the human finger.

[0048] One end of the above-mentioned torque sensor is connected to the motor output shaft, and the other end is connected to the helical gear shaft, which is used to measure the motor output torque and the force exerted by the clamping handle on the user's finger, realize the closed-loop control of force feedback, and adjust the output force of the motor in real time. The principle and structure of the torque sensor are as shown in Figure 3 . The sensor is divided into a force-applying component, a force-deforming component, and a photoelectric sensing printed circuit board (PCB) for measuring deformation. The force-applying component and the force-deforming component are respectively connected to the gear shaft and the motor output shaft through fastening bolts. The force-applying component conducts the force to the deformed part of the force-deforming component through bolts, and the shafts of the two components are connected by bearings. The photoelectric sensing PCB is installed between the surfaces of the deformable part and is used to measure the distance between the surfaces after deformation due to the action of force, from which the torque value can be deduced.

[0049] The master hand clamping device of this application installs a miniature torque sensor inside, which can detect the force exerted by the clamping handle on the hand in real time and realize the closed-loop control of force feedback. The sensor is divided into a force-applying component, a force-deforming component, and a photoelectric sensing printed circuit board (PCB) for measuring deformation. The force-applying component and the force-deforming component are respectively connected to the gear shaft and the motor output shaft through fastening bolts. The force-applying component conducts the force to the deformed part of the force-deforming component through bolts, and the shafts of the two components are connected by bearings. The photoelectric sensing PCB is installed between the surfaces of the deformable part and is used to measure the distance between the surfaces after deformation due to the action of force, from which the torque value can be deduced.

[0050] The above-mentioned clamping handle is connected to the helical gear through a buckle, and a hardness feedback device is installed inside it, as shown in Figure 4 . An L-shaped airbag is placed at the contact between the handle and the fingertip. The motor drives the cam to squeeze the lower part of the airbag, changing the air pressure inside the airbag, so as to simulate different hardnesses and realize hardness feedback. In addition, the airbag can also be squeezed by a voice coil motor to change the air pressure inside it and simulate different hardnesses.

[0051] In the present invention, an L-shaped airbag is used to provide hardness feedback for the fingers. The method of changing the internal air pressure of the airbag by an air pump is abandoned. Instead, a motor drives a cam to squeeze the lower part of the airbag, changing the internal air pressure of the airbag to simulate different hardness levels, enabling doctors to perceive the hardness of the tissue being clamped.

[0052] The present invention can track the opening and closing movements of the fingers and send instructions to control the opening and closing of the clamp of the slave hand.

[0053] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. The master hand clamping device with finger clamping force feedback and hardness feedback is characterized in that, The clamping device includes a torque sensor, a helical gear transmission component, a hardness feedback clamping handle, and a first motor. Among them, the hardness feedback clamping handle is connected to the helical gear transmission component through a linkage shaft, and the helical gear transmission component is connected to the first motor, converting the opening and closing movement of the hardness feedback clamping handle driven by the operator's finger into the rotational movement of the first motor. The first motor receives the force signal detected by the clamp sensor for force output, which is transmitted to the hardness feedback clamping handle through the helical gear transmission component. An encoder is provided on the first motor, which is used to measure the rotational angle of the output shaft of the first motor, calculate the opening and closing angle of the hardness feedback clamping handle, and transmit the signal of the opening and closing angle to the clamp controller to control the opening and closing angle of the clamp. The torque sensor is connected to the output end of the first motor and is used to measure the output torque of the first motor and the force exerted by the clamping handle on the user's finger. The clamping device further includes a housing, which is a cylinder. The first motor, torque sensor, and helical gear transmission component are arranged inside the housing, and the hardness feedback clamping handle extends outside the housing and is connected through the linkage shaft. The hardness feedback clamping handle is connected to the helical gear in the helical gear transmission component, and a hardness feedback device is installed inside the hardness feedback clamping handle. The hardness feedback device includes an L-shaped airbag, a second motor, and a cam. An L-shaped airbag is provided at the contact between the hardness feedback clamping handle and the fingertip. The clamp sends the detected hardness signal to the clamping device through the sensing device of the clamp part. The second motor rotates under the control of the hardness signal, and the second motor drives the cam to squeeze the lower part of the airbag, changing the air pressure inside the airbag to simulate different hardnesses and achieve hardness feedback.

2. The clamping device according to claim 1, wherein, The second motor in the hardness feedback device is a voice coil motor. The cam is cancelled, and the voice coil motor is used to squeeze the L-shaped airbag to change the air pressure inside it and simulate different hardnesses.

3. The clamping device according to claim 1, characterized in that, One end of the torque sensor is connected to the output shaft of the first motor, and the other end is connected to the helical gear shaft, which is used to measure the output torque of the first motor and the force exerted by the clamping handle on the user's finger, realize the closed-loop control of force feedback, and adjust the output force of the motor in real time.

4. The clamping device according to claim 3, characterized in that, The torque sensor is divided into a force application component, a force-receiving deformation component, and a photoelectric sensing printed circuit board PCB for measuring deformation. Among them, the force application component and the force-receiving deformation component are respectively connected to the gear shaft and the output shaft of the first motor through fastening bolts. The force application component conducts the force to the deformed part of the force-receiving deformation component through bolts, and the central axes of the two components are connected by bearings. The photoelectric sensing printed circuit board PCB is installed between the surfaces of the deformable part and is used to measure the distance between the surfaces after deformation due to the action of force, and thus deduce the torque value.

5. The clamping device according to any one of claims 1 to 4, characterized in that, The housing is divided into two sections: the rear end is a motor seat, and the first motor is installed inside the motor seat; the front end is a helical gear shaft seat. The helical gear transmission component is connected to the front end of the housing through a shaft and bearings. The front end of the housing is divided into left and right parts, which are connected by bolts and are fixedly connected to the rear end of the housing through grooves.

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