A new locally operated detachable end-effector manipulator (LODEM) as the portable forceps robot that can be used by a surgeon as a third arm during laparoscopic surgery was developed. The portable forceps manipulator which has motor controlled three DOFs consists of a separable pivot restraint device that can be sterilized and an actuator unit draped with a sterilized cover. This manipulator uses a gimbal-mounted parallel linkage mechanism of the closed loop structure for the pitch and the yaw axes, and a wire driven linear slider mechanism for the insertion axis attached to the forceps. The manipulator placed above the abdominal wall using a fixed arm connected to a bed rail is motor controlled by a handheld interface with button switches. The positional accuracy and the mechanical deflection of the manipulator were evaluated. Simulated laparoscopic cholecystectomy using the prototype manipulator was performed on a surgically realistic gall bladder model. It was confirmed that the organ model could be pulled in various directions using the forceps attached to the manipulator manually and driven by the motors. The results of the present study indicate that the proposed manipulator could be used for robotically assisted laparoscopic surgery by a surgeon working near the patient.

We are developing a CT-guided needle insertion robot for the purpose of reducing physician exposure dose. Automatic needle insertion will help a physician because it is a little difficult for unskilled operators to control the robot manually. In this paper, we propose a control law to realize full automatic needle insertion for a CT-guided needle insertion robot. In the control law, speed to insert a needle is given based on the result of our observation on the animal experiment. We found that the number of corrections increases as the needle approaches the target in a robotic needle insertion controlled by a physician. We propose the idea that needle insertion velocity decreases exponentially. The effectiveness of the control law is verified by a simulation experiment in which the needle start at having offset to the target trajectory. As a result, the robot in the simulation environment achieves to reach the target point by decreasing its puncture speed as the needle approaches the target.

Despite the use of surgical navigation systems in endoscopic sinus surgery (ESS), complications are still reported. Surgical outcome can be improved through the provision of adequate support for skills learning. The objectives of this study were to construct a system capable of automatically providing a clear skill evaluation result and to assess the extent to which our system could observe residents’ learning curve. We used the clinical data from the image-guided ESS obtained from the navigation system, which included the tip position and rod orientation of the instrument, using the previous method. Further this study, we calculated the surgical feature parameters (SFPs) and calculated the score for SFPs and constructed the assessment and visualization system. Six expert sinus surgeons and 10 residents performed ESS to evaluate our system, and two residents were tracked over 10 months to establish their learning curve. Our system showed a clear difference between the experts’ and residents’ results. Furthermore, through the 10-month tracking of two residents, our system demonstrated an upward trend. Our system can fully assess residents’ current skill levels. Being able to confirm their progress and skill level through this system is likely to serve as motivation for improvement of residents’ performance.

Background : Laparoscopic surgeons manipulate instruments placed through ports in the abdominal wall and can develop fatigue in the elbow and shoulder. We developed the Surgical Assist Suit (SAS), an exoskeleton wearable device that maintains upper extremity position at the surgeon's discretion. We conducted a pilot simulation study of the effectiveness of the SAS to reduce fatigue of the surgeon's upper extremities.

Materials and Methods : The SAS maintains the upper extremities in a lifted position and has both locked and unlocked modes. Electromyography of both deltoid muscles of four skilled male laparoscopic surgeons was performed. The surgeon stood to the left of a laparoscopic training box and sutured with the right elbow elevated. The task involved placing interrupted sutures to close a 120mm incision in the posterior wall of an ex-vivo porcine stomach. Electromyography of both deltoid muscles was recorded, and the number of continuous sutures determined. A written questionnaire was administered after the simulation.

Results : Electromyography of the right deltoid muscle with the SAS was 63% lower than without the SAS (p＝0.013) while the left deltoid muscle was higher (p＝0.020). The number of sutures increased while wearing the SAS (p＝0.073). The questionnaire showed a favorable opinion of the SAS.

Conclusions : The SAS decreases muscle activity in the shoulder on the side of suturing and may increase suturing efficiency during laparoscopic surgery, especially with the elbow raised. Exoskeleton support devices may reduce surgeon physical fatigue while performing surgery.