Background Holding endoscopes by hand when performing eye surgery reduces the dexterity of the surgeon. Methods A robotic endoscope holder called “Eye Explorer” is proposed to hold the endoscope and free the surgeon's hand. Results This device satisfies the engineering and clinical requirements of eye surgery. The force for manual operation is less than 0.5 N. The observable ranges inside the patient's eye considering horizontal and vertical perspectives are 118° and 97°, and the motion of the holder does not interfere with the surgeon's hand and other surgical devices. The self‐weight compensation can prevent the endoscope from falling when extra supporting force is released. When comparing the external force exerted on the eye by the Eye Explorer with that in case of manual operation, a decrease of more than 15% can be observed. Moreover, the consumption time of endoscope view adjustment using the Eye Explorer and manual operation does not significantly differ. Conclusion The Eye Explorer allows dual‐hand operation, facilitating a successful endoscopic eye surgery.

A pair of miniaturized robotic forceps with a flexible wrist joint has a problem of a trade-off relationship between rigid and flexible characteristics of the joint with metal parts. Regarding the problem, in this paper, we present a pair of robotic forceps in which the flexible wrist is made of super engineering plastic that is widely used for medical instruments because of its superior heat resistance, chemical stability, and mechanical strength. A prototype flexible wrist part is designed using polyetheretherketone (PEEK) with 12 machined slits, and the bending and grasping motions of the forceps are realized by wire actuation. The performance evaluation results show that the PEEK flexible joint can maintain its bending range even if an axial compressive force is exerted. It is durable to a compressive force of 30 N, and the relationship between the compression extent and the compression force is linear. The PEEK flexible joint is durable to bending up to 10000 times without markedly changing its bending mechanical property. Finally, it is rigid enough to output a force more than 1.2 N from the forceps gripper to the environment. Experimental results in this study indicate that the developed forceps has a basic feasible performance for robotic surgery.

Background: Robotic ophthalmic endoscope holders allow surgeons to execute dual-hand operations in eye surgery. To prevent needle-like endoscopes from invading the retina when moving, surgeons expect visual and real-time information about the relative special relationship between the endoscope and fundus. Methods:This study develops a real-time fundus reconstruction method. First, using deep learning, the method estimates the distance between the fundus part corresponding to every pixel of the RGB endoscopic image and the endoscope.Then, by combining the estimated distance with the kinematics of a robotic holder, the point cloud representing the present fundus area is generated, and by which the size and position of the eyeball are estimated. Results:This method shows a real-time frequency of 10 Hz, which is robust to eyeball movement. The error of fundus reconstruction is about 0.5 mm, and the error of eyeball estimation is about 1 mm. Conclusion:Using this fundus reconstruction method can map the position of the endoscope inside the eyeball when using a robotic endoscope holder in eye surgery.The overall accuracy level meets the ophthalmologists' accuracy requirements of ophthalmologists.

Robotic forceps with a rigid-link joint mechanism is orthodox for current robotic-assisted surgery systems. However, external force estimation without force sensors during operations is difficult for such electrically driven forceps. This work introduces a pneumatically driven multi-DOF (DOF: degree of freedom) forceps using a rigid-link mechanism with less interference of the wire drive between joints and realizes external force estimation by utilizing high back-drivability of pneumatic cylinders. We developed a position controller with dynamic compensation of the mechanical friction, in which the rotational angles of the three movable joints of the forceps are independently controlled. Moreover, we designed an external force observer in the position controller by applying the disturbance observer scheme. The results of the performance evaluation experiments are as follows. First, in the joint position control experiments, smooth and stable controllability is confirmed for sinusoidal reference inputs with the mean absolute errors of less than 2°. The resolution of the joint position control is approximately 1° for the response of step increasing reference inputs, which is acceptable for laparoscopic surgery. Second, the external force observer can correctly estimate the translational and the grasping forces with less than 20% errors of the maximum output forces. The practical sensitivities of the external force estimation are better than 0.5 N for translational forces and 0.2 N for grasping forces. The achieved performance of the developed forceps can be applicable for interactive force control in some particular surgical tasks such as suturing, ligation, organ traction and exclusion.

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