Pneumatic-type surgical robot end-effector for laparoscopic surgical-operation-by-wire

Combination design of drive mechanism considering delay of surgical robot

Surgical robots have contributed greatly to the development of minimally invasive surgery. However, these robots suffer from issues such as the looseness of wires acting as the robot's drive mechanism, and high maintenance cost. The objective of this study was to derive a combination of driving mechanisms other than wires that satisfies the required positional accuracy of a surgical robot. The robot operation trajectory was obtained using a virtual surgical simulator. Based on the operation trajectory obtained in the suture task experiment, the delay of each joint was virtually simulated, and the robot's position was calculated. The positions of the robot with and without delay were compared, and the drive mechanism combinations that satisfy the required positional accuracy were obtained. Thus, satisfactory accuracy was achieved when the alternative drive mechanism was properly placed.Clinical Relevance- This paper presents an accurate and low-maintenance surgical robot that uses few wires and alternative drive mechanisms.

Force sensing in robot-assisted keyhole endoscopy: A systematic survey

Instrument–tissue interaction forces in minimally invasive surgery (MIS) provide valuable information that can be used to provide haptic perception, monitor tissue trauma, develop training guidelines, and evaluate the skill level of novice and expert surgeons. Force and tactile sensing is lost in many robot-assisted surgery (RAS) systems. Therefore, many researchers have focused on recovering this information through sensing systems and estimation algorithms. This article provides a comprehensive systematic review of the current force sensing research aimed at RAS and, more generally, keyhole endoscopy, in which instruments enter the body through small incisions. Articles published between January 2011 and May 2020 are considered, following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. The literature search resulted in 110 papers on different force estimation algorithms and sensing technologies, sensor design specifications, and fabrication techniques.

Multi-DOF (Degree of Freedom) Articulating Laparoscopic Instrument is an Effective Device in Performing Challenging Sutures

Purpose

Although laparoscopic surgery had been performed in clinical practice for over 30 years, there has not been much improvement on instruments. Several articulating laparoscopic instruments have been developed including the robotic system. A new multi-degree of freedom (DOF) articulating laparoscopic device has been developed. We compared the ability to perform challenging sutures between the new device and the robotic system.

Methods

Five experienced surgeons with over 100 laparoscopic surgery cases performed the suture task with both instruments. Everyone was new at articulating instruments including a robotic system. The suturing task consisted of two vertical sutures, downward and upward vertical direction. The duration of needle grabbing, first surgical tie, square tie, and the final reverse tie was measured.

Results

When doing the downward suture, the median time to complete the suture was 127 vs. 136 seconds for ArtiSential^® and the robot, respectively (p=0.754). Other measurements such as needle grabbing, first tie, second tie and final knot did not show any significant difference between the two instruments. Upward suture also did not show a significant difference. The total completion time was 127 vs. 112 seconds for for ArtiSential^® and the robot, respectively (p=0.675). Time taken in each interval did not show any significant difference.

Conclusion

Both instruments performed the suturing tasks with no difference in duration. ArtiSential^® can be mixed up with usual instruments. Surgeons can choose any device, but when articulation is needed, ArtiSential^® could be an alternative choice to the robotic system.

Head-mounted interface for intuitive vision control and continuous surgical operation in a surgical robot system

Although robot-assisted surgeries offer various advantages, the discontinuous surgical operation flow resulting from switching the control between the patient-side manipulators and the endoscopic robot arm can be improved to enhance the efficiency further. Therefore, in this study, a head-mounted master interface (HMI) that can be implemented to an existing surgical robot system and allows continuous surgical operation flow using the head motion is proposed. The proposed system includes an HMI, a four degrees of freedom endoscope control system, a simple three-dimensional endoscope, and a da Vinci Research Kit. Eight volunteers performed seven head movements and their data from HMI was collected to perform support vector machine (SVM) classification. Further, ten-fold cross-validation was performed to optimize its parameters. Using the ten-fold cross-validation result, the SVM classifier with the Gaussian kernel (σ = 0.85) was chosen, which had an accuracy of 92.28%. An endoscopic control algorithm was developed using the SVM classification result. A peg transfer task was conducted to check the time-related effect of HMI's usability on the system, and the paired t test result showed that the task completion time was reduced. Further, the time delay of the system was measured to be 0.72 s. Graphical abstract A head-mounted master interface (HMI), which can be implemented to an existing surgical robot system, was developed to allow simultaneous surgical operation flow. The surgeon's head motion is detected through the proposed HMI and classified using a support vector machine to manipulate the endoscopic robotic arm. A classification accuracy of 92.28% was achieved.

Efficiency and Power Limits of Electrical and Tendon-Sheath Transmissions for Surgical Robotics

A popular design choice in current surgical robotics is to use mechanical cables to transmit mechanical energy from actuators located outside of the body, through a minimally invasive port, to instruments on the inside of the body. These cables enable high performance surgical manipulations including high bandwidth control, precision position control, and high force ability. However, cable drives become less efficient for longer distances, for paths that involve continuous curves, and for transmissions involving multiple degrees of freedom. In this paper, we consider the design tradeoffs for two methods of transmitting power through an access port with limited cross sectional area and curved paths - tendon/sheath mechanical transmissions and electrical wire transmissions. We develop a series of analytic models examining fundamental limits of efficiency, force and power as constrained by access geometry, material properties, and safety limits of heat and electrical hazards for these two transmission types. These models are used to investigate the potential of achieving the required mechanical power requirements needed for surgery with smaller access ports and more difficult access pathways. We show that an electrical transmission is a viable way of delivering more than sufficient power needed for surgery, highlighting the opportunity for next-generation actuators to enable more minimally invasive surgical devices.

Development of stereo endoscope system with its innovative master interface for continuous surgical operation

Background

Although robotic laparoscopic surgery has various benefits when compared with conventional open surgery and minimally invasive surgery, it also has issues to overcome and one of the issues is the discontinuous surgical flow that occurs whenever control is swapped between the endoscope system and the operating robot arm system. This can lead to problems such as collision between surgical instruments, injury to patients, and increased operation time. To achieve continuous surgical operation, a wireless controllable stereo endoscope system is proposed which enables the simultaneous control of the operating robot arm system and the endoscope system.

Methods

The proposed system consists of two improved novel master interfaces (iNMIs), a four-degrees of freedom (4-DOFs) endoscope control system (ECS), and a simple three-dimensional (3D) endoscope. In order to simultaneously control the proposed system and patient side manipulators of da Vinci research kit (dVRK), the iNMIs are installed to the master tool manipulators of dVRK system. The 4-DOFs ECS consists of four servo motors and employs a two-parallel link structure to provide translational and fulcrum point motion to the simple 3D endoscope. The images acquired by the endoscope undergo stereo calibration and rectification to provide a clear 3D vision to the surgeon as available in clinically used da Vinci surgical robot systems. Tests designed to verify the accuracy, data transfer time, and power consumption of the iNMIs were performed. The workspace was calculated to estimate clinical applicability and a modified peg transfer task was conducted with three novice volunteers.

Results

The iNMIs operated for 317 min and moved in accordance with the surgeon’s desire with a mean latency of 5 ms. The workspace was calculated to be 20378.3 cm³, which exceeds the reference workspace of 549.5 cm³. The novice volunteers were able to successfully execute the modified peg transfer task designed to evaluate the proposed system’s overall performance.

Conclusions

The experimental results verify that the proposed 3D endoscope system enables continuous surgical flow. The workspace is suitable for the performance of numerous types of surgeries. Therefore, the proposed system is expected to provide much higher safety and efficacy for current surgical robot systems.

A development of assistant surgical robot system based on surgical-operation-by-wire and hands-on-throttle-and-stick

BACKGROUND

Robot-assisted laparoscopic surgery offers several advantages compared with open surgery and conventional minimally invasive surgery. However, one issue that needs to be resolved is a collision between the robot arm and the assistant instrument. This is mostly caused by miscommunication between the surgeon and the assistant. To resolve this limitation, an assistant surgical robot system that can be simultaneously manipulated via a wireless controller is proposed to allow the surgeon to control the assistant instrument.

METHODS

The system comprises two novel master interfaces (NMIs), a surgical instrument with a gripper actuated by a micromotor, and 6-axis robot arm. Two NMIs are attached to master tool manipulators of da Vinci research kit (dVRK) to control the proposed system simultaneously with patient side manipulators of dVRK. The developments of the surgical instrument and NMI are based on surgical-operation-by-wire concept and hands-on-throttle-and-stick concept from the earlier research, respectively. Tests for checking the accuracy, latency, and power consumption of the NMI are performed. The gripping force, reaction time, and durability are assessed to validate the surgical instrument. The workspace is calculated for estimating the clinical applicability. A simple peg task using the fundamentals of laparoscopic surgery board and an in vitro test are executed with three novice volunteers.

RESULTS

The NMI was operated for 185 min and reflected the surgeon's decision successfully with a mean latency of 132 ms. The gripping force of the surgical instrument was comparable to that of conventional systems and was consistent even after 1000 times of gripping motion. The reaction time was 0.4 s. The workspace was calculated to be 8397.4 cm(3). Recruited volunteers were able to execute the simple peg task within the cut-off time and successfully performed the in vitro test without any collision.

CONCLUSIONS

Various experiments were conducted and it is verified that the proposed assistant surgical robot system enables collision-free and simultaneous operation of the dVRK's robot arm and the proposed assistant robot arm. The workspace is appropriate for the performance of various kinds of surgeries. Therefore, the proposed system is expected to provide higher safety and effectiveness for the current surgical robot system.