Precision in stitches: Radius Surgical System.

BACKGROUND: The Radius Surgical System is a manual manipulator with two additional degrees of freedom compared with conventional laparoscopic instruments (CLIs). This study aimed to compare the performance of laparoscopic suturing tasks with the use of the Radius Surgical System and CLIs, respectively. METHODS: Five experienced laparoscopic surgeons performed laparoscopic surgical tasks in a training box. The tasks consisted of knot-tying, suturing, and needle control tasks. The needle control task was performed to evaluate the precision of the needle drive by analysis of the needle exit point on a suture pad. In the knot-tying and suturing tasks, required time and accuracy value were measured. Needle control tasks were performed on three different angulations of plane. The angles between the instrument plane and the target plane (AIT) were 30 degrees, 60 degrees, and 90 degrees. The distance of the exit point to the center of the target field, the number of actions needed to fulfill a single task, and the required time were recorded and analyzed. RESULTS: In the knot-tying and frontal suturing tasks, there were no significant differences between the two groups. In the sagittal suturing task, the required time in the Radius group was significantly shorter than in the CLI group. In the needle control tasks on 30 degree and 60 degree AIT, the distance was significantly shorter in the Radius group than in the CLI group. There were no significant differences in the number of actions or the required time. In the frontal and sagittal needle control task on 90 degree AIT, the distance was significantly shorter in the Radius group than in the CLI group. The number of actions and the required time were significantly less in the Radius group than in the CLI group. CONCLUSIONS: The two additional degrees of freedom contributed to accurate and controlled needle guidance, especially in difficult spatial situations.

Ergonomics with the use of curved versus straight laparoscopic graspers during rectosigmoid resection: results of a multiprofile comparative study.

BACKGROUND: A detailed ergonomic comparison of motions and muscular activity in the left upper extremity using a laparoscopic straight or curved grasper in rectosigmoid resection is presented. METHODS: The study had two parts: experimental and clinical. In the experiment part, 30 laparoscopic sigmoid resections were performed under animal organ phantom conditions. The operations were divided into three groups according to instrument and trocar position. Group 1 (n = 10) underwent operations performed with a curved grasper in the excentral trocar position (in relation to the telescope trocar), with the left-hand curved grasper placed in the right flank and the right hand instrument in the right lower quadrant. In group 2 (n = 10), straight forceps were used in the excentral trocar position. Group 3 (n = 10) underwent laparoscopic sigmoid resection performed with a straight grasper in the central position (in relation to the telescope trocar), with the instruments placed at both sides of the lower abdomen. To measure ergonomic aspects during rectosigmoid resection, several overview video cameras, surface electromyography (EMG), an ultrasound tracking system (UTS), and a questionnaire were used. In the clinical part of the study, laparoscopic rectosigmoid resections (n = 5) were performed using a curved instrument in the excentral trocar position. The surgeon's left-hand movement and body posture were recorded for further analysis. RESULTS: The curved grasper required the fewest contractions (group 1) of the measured muscles. A comparison of the UTS analysis in the experimental part of the study and the video analysis in the clinical part showed economy of movements in group 1. According to subjective estimation, both physical activity and mental stress remain at the lowest level when the excentral trocar position is used (groups 1 and 2). CONCLUSIONS: The combination of the curved grasper and the excentral trocar position (in relation to the telescope trocar) is, according to our examinations, the best ergonomic adjustment for laparoscopic rectosigmoid surgery.

Experimental results of mesh fixation by a manual manipulator in a laparoscopic inguinal hernia repair model.

BACKGROUND: Laparoscopic mesh fixation using a stapler can lead to complications such as nerve injury and bowel injury. However, mesh fixation by suturing with conventional laparoscopic instruments (CLI) is difficult because of limited degrees of freedom. A manual manipulator--Radius Surgical System (Radius)--whose tip can deflect and rotate, gives the surgeon two additional degrees of freedom. The aim of this study is to evaluate the introduction of Radius to mesh fixation in laparoscopic inguinal hernia repair. METHODS: A model for inguinal hernia repair was prepared using animal organs in a trainer. Mesh fixation was performed using Radius, stapler, and CLI. Tensile strength during extraction of mesh toward the vertical direction, and execution time, were measured. RESULTS: The mean number of fixation points of Radius, stapler, and CLI was 9.3 +/- 1.5, 8.5 +/- 1.4, and 9.0 +/- 1.0, respectively. The mean tensile strength of fixation of mesh of Radius, stapler, and CLI was 140.7 +/- 48.9, 73.1 +/- 23.4, and 53.6 +/- 31.5 (N), respectively. The mean tensile strength per one fixation point by Radius, stapler, and CLI was 16.5 +/- 5.3, 8.7 +/- 2.8, and 6.3 +/- 3.6 (N), respectively. The mean execution time of Radius, stapler, and CLI was 479 +/- 108, 54 +/- 31, and 431 +/- 77 (sec), respectively. CONCLUSIONS: The mesh fixation by Radius was stronger than that by staples and CLI. Two additional degrees of freedom were useful in difficult angles. The introduction of Radius is feasible and facilitates the fixation of mesh with sutures in laparoscopic inguinal hernia repair.

Experimental assessment of a new mechanical endoscopic solosurgery system: Endofreeze.

BACKGROUND: The assistance received by the surgeon from support personnel during operative laparoscopy is extremely important. This includes retraction of instruments and endoscope positioning. However, human assistance is costly and often does not provide satisfaction for the surgeon. The aim of this study was to develop a mechanical arm capable of allowing easy handling and holding of laparoscopic instruments under the surgeon's control. METHODS: We designed a system, named Endofreeze, based on a particular kinematical construction that maintains an invariant point of constraint motion just above the trocar puncture site through the abdominal wall. The goal was to develop this way a highly intuitive mechanical holding system for laparoscopic instruments, with sufficient precision of action, activated by a single hand movement. We tested a couple of prototypes with different holding arms while performing cholecystectomy in phantom models with swine inserts and compared the results obtained in similar conditions using different holding and positioning systems. RESULTS: The system allows transparent and intuitive operation, and its setup is easy and quick. It may be adapted either as an instrument retractor or as an optic positioning device. Compared to different systems available or prototypes previously tested, such as AESOP 2000, ENDOASSIST, FIPS Endoarm, TISKA Endoarm, and the Martin Arm, in similar conditions, it was more intuitive, allowing shorter time for completion of surgery. CONCLUSION: Endofreeze is a new intuitive mechanical positioning system for endoscopic solo surgery. In phantom models, it demonstrated a shorter time requirement for completion of surgery when compared to other systems available. In our opinion, it represents a valid compromise between human and robotic control for conventional laparoscopic instruments.

An innovative trainer for surgical procedures using animal organs.

Since 1990, almost 3000 surgeons have absolved the training course for minimally invasive surgery in our training center. A phantom trainer using animal organs has been used as a training device. Based on this experience, we have developed an innovative trainer for surgical procedures using animal organs. The form of this trainer was copied from a human body with gas insufflation; abdominal organs from the slaughterhouse can be integrated into this trainer. Surgeons can repeat operations such as laparoscopic cholecystectomy, appendectomy, fundoplication, colon resection and transanal endoscopic microsurgery in a realistic way and acquire a training effect in a short time.

Transanal endoscopic microsurgery.

Transanal endoscopic microsurgery, although technically challenging, offers a viable and perhaps superior outcome to radical abdominal or traditional transanal excision of rectal neoplasia. Appropriate training and case selection, as with any new technology, are mandatory to help ensure optimal results.

[Robotic and systems technology for advanced endoscopic procedures]. / Tecnologia robotica e dei sistemi per procedure endoscopiche avanzate.

The advent of endoscopic techniques changed surgery in many regards. This paper intends to describe an overview about technologies to facilitate endoscopic surgery. The systems described have been developed for the use in general surgery, but an easy application also in other fields of endoscopic surgery seems realistic. The introduction of system technology and robotic technology enables today to design a highly ergonomic solo-surgery platform. This consists of a system of devices for endoscopic surgery (HF, light source, etc...) with which the surgeon interacts directly, positioning systems for optic and instruments that the surgeon drives as the likes without assistance, and a chair to increase the comfort of the surgeon during surgery. The system of endoscopic devices named OREST (Dornier, München) designed already in 1992 opened the way to a number of systems available today that allow to the surgeon a direct control of the instrumentation. A considerable step ahead in endoscopic technology is the introduction of robotic technology to design assisting systems for solo-surgery and microsurgical instrument manipulators. Results of a number of experimental trials on combinations of different positioning devices are presented and commented. A further step in the employment of robotic technology is the design of "master-slave manipulators" to provide the surgeon with additional degrees of freedom of instrumentation. In 1996 a first prototype of an endoscopic manipulator system, named ARTEMIS, designed in cooperation with the Research Center in Karlsruhe, could be used in experimental applications. Clinical use of the system, however, will require further development of the arm mechanics and the control system. The combination with the implementation of telecommunication technology will open new frontiers, such as teleconsulting, teleassistance and telemanipulation.

Experimental trial on solo surgery for minimally invasive therapy: comparison of different systems in a phantom model.

BACKGROUND: Robotic aid in minimally invasive surgery (MIS) is becoming more and more common. We designed an experimental trial in a phantom model to verify the feasibility of solo surgery for MIS. By performing laparoscopic cholecystectomy on a phantom model, we compared combinations of different systems available in terms of safety, comfort, and time requirements. METHODS: Two surgeons skilled in endoscopic procedures tested the following systems as endoscope holders: the robotic system (AESOP), foot-controlled (AESOP 1000), and voice-controlled (AESOP 2000); the remote controlled FIPS Endoarm, electrically driven and controlled by a finger-ring joystic; the passive system TISKA Endoarm, a mechanical arm moved by hand and fixed by electromagnetical brakes. All of these systems combined with a second TISKA Endoarm as an instrument holder. A combination of two mechanical Martin arms, c, also was tested. The results were compared with those from a control group involving an assistant surgeon. A total of 70 experiments were performed. RESULTS: The shortest dissection time was registered by the combination of two TISKA Endoarms, with a statistically significant difference as compared with the control group (p < 0.05) and experiments using AESOP 1000 (p < 0.05). The TISKA Endoarm also proved to be more comfortable when used as an instrument holder (p < 0.001 vs Martin arm), and rated second only to AESOP 2000 as an endoscope holder. The rating of AESOP 2000 as endoscope holder was significantly higher than that of all other groups (p < 0.001). The study proved the feasibility of solo surgery. The time needed for dissection was shortest when two TISKA Endoarms were used, demonstrating the possible advantages of solo surgery. The TISKA Endoarm received a subjective positive rating when used as both endoscope holder and instrument holder. The voice control of AESOP 2000 seemed to be a major improvement in the development of an optimal man-machine interface. Nevertheless, the system presents considerable space requirements and does not supply control of 30 degrees optics. The principle of the finger-ring joystick adopted by the FIPS Endoarm seemed very intuitive but lacking in ergonomy. CONCLUSION: Laparoscopic solo surgery can be considered a safe procedure, although further technologic developments should lead to improved ergonomy, intuitiveness of handling, and architecture of the systems, offering the surgeon better control, increased precision of action, and reduction in operation time.

The Tübingen balloon. A new method for adjusting the tension of the fundic wrap during laparoscopic Nissen fundoplication.

An adequate fundic wrap is fundamental to the success of conventional and laparoscopic Nissen fundoplications. Nevertheless, up to now there has been no standardized method for the surgeon to determine intraoperatively the width and tension of the fundic wrap according to objective criteria. With the support of Rüsch (Kernen, Germany), we developed a measurement balloon for use in laparoscopic Nissen fundoplication. The balloon allows the surgeon to define the width of the wrap and predetermine its length, as well as to measure its tension. Depending on the measured balloon pressure, the surgeon can perform fundic sutures more or less tightly. On the basis of 41 fundoplication model tests, we found that a fundic wrap typically described as "loose and floppy" produced a balloon pressure of 50-60 mmHg. In 10 laparoscopic Nissen fundoplications on domestic pigs, we were able to adjust the fundic wrap intraoperatively to a balloon pressure in this range (mean; 53.5; SD; 2.25). After the optimal intraoperative balloon pressure in humans has been investigated in a prospective study that is in progress, the Tübingen balloon is expected to serve as an instrument for quality assurance in reflux surgery.

A new remote-controlled endoscope positioning system for endoscopic solo surgery. The FIPS endoarm.

In the field of endoscopic solo surgery, the assistance received by the surgeon from ergonomical positioning devices is extremely important. They aid in both the retracting of instruments and the positioning of the endoscope. However, passive systems derived from open surgery have not proved satisfactory. Therefore, we set out to develop a remote-controlled arm capable of moving a rigid endoscope with about four degrees of freedom, while maintaining an invariant point of constraint motion coincident with the trocar puncture site through the abdominal wall. The system is driven by means of speaker-independent voice control or a finger-ring joystick clipped onto the instrument shaft close to the handle. When the joystick is used, the motion of the endoscope is controlled by the fingertip of the operating surgeon, which is inserted into the small ring of the controller in such a way as to make the motion of the fingertip correspond directly to the motion of the tip of the endoscope. A study was performed to compare the two different interfaces available for the system. With both interfaces, the guiding system allows for transparent and intuitive operation. Its set-up is easy; it is safe and reliable to use during the intervention; and it is faster than human assistance. With its improved ergonomy, this new generation of remote-controlled endoscope positioning system represents a further step toward the diffusion of solo surgery techniques in minimally invasive therapy. In our opinion, this prototype creates a valid compromise between human and robotic control of rigid endoscopes.

Robotics and allied technologies in endoscopic surgery.

Endoscopic surgery was developed in the 1970s and 1980s, with initial work conducted by pioneering surgeons. After the development of laparoscopic cholecystectomy, the breakthrough of endoscopic surgery had a great effect on all surgical specialties. Starting with rather simple procedures, such as cholecystectomy, a rapid progression toward more complex procedures, such as reflux or colonic surgery, took place. It was realized at this time that the existing endoscopic instruments allowed only a limited preciseness when performing the procedures, and part of the information from inside the abdominal cavity was not available to the surgeon. This prompted a discussion with engineers concerning the development of more advanced technologies to give those performing endoscopic surgery the same quality of information and manipulation that surgeons have when performing open surgery. These qualities include (1) instruments and manipulators that allow surgical action under endoscopic control with all degrees of freedom; (2) devices that provide surgeons with tactile feedback; and (3) vision systems that provide surgeons with the same quality of visual information as with open surgery, namely, high resolution, excellent color quality, precise spatial information, and a constant clear view for optimal surgical action. At the end of 1999, some of the aforementioned quality concepts found their way into the surgical routine, but most of the concepts are still being developed. Another decade will pass before endoscopic surgery procedures will be closer to the technological goals.

The effect of high-definition imaging on surgical task efficiency in minimally invasive surgery: an experimental comparison between three-dimensional imaging and direct vision through a stereoscopic TEM rectoscope.

BACKGROUND: In 1995, when we first used a high-definition television (HDTV) video system during a laparoscopic cholecystectomy in Tuebingen, we were surprised by the excellence of the spatial impression achieved by an image with improved resolution. Although any improvement in vision systems entails a trade-off among cost, quality, and complexity, high-definition imaging may well become an essential part of 3-D video systems. The aim of this experimental study was to assess the impact of high definition on surgical task efficiency in minimally invasive surgery and to determine whether it is preferable to use a 3-D system or a 2-D system with perfect resolution and color--for instance, HDTV or the three-chip charge-coupled device (3CCD). METHODS: We compared a 3-D video system with the vision through a stereoscopic rectoscope for transanal endoscopic microsurgery (TEM). Because its stereoscopic direct vision is not restricted to either shutter technology or video resolution, TEM optics represents the state of the art. For objective comparison, inanimate phantom models with suturing tasks were set up. The setups allowed the approach of parallel instruments as in TEM operations or via a laparoscopic approach, with oblique instruments coming laterally. Both types of procedure were carried out by highly experienced laparoscopic surgeons as well as those inexperienced in endoscopic surgery. These volunteers worked under 3-D video vision and/or TEM vision. Altogether, the model tasks were performed by 54 different persons. RESULTS: The evaluation did not show a significant (p > 0.05) difference in performance time in all models, but there was a clear trend showing the benefit of a higher resolution. CONCLUSION: We found a tendency for both endoscopically inexperienced and experienced surgeons to benefit from the use of a system with improved resolution (direct vision) rather than a 3-D shutter video system.

Systems technology in the operating theatre: a prerequisite for the use of advanced devices in surgery.

The development of endoscopic techniques has significantly changed surgery. The increasing complexity of devices being used has increased the demand for improved ergonomics and functionality. Since the early 1990s the development of system solutions for the operating room (OR) has been a topic of major interest for surgeons and industry. The first integrated surgical workplace system was introduced by Dornier (Orest) in 1994. Several other solutions are now commercially available. Their common feature is the ability to control the different functions of the individual devices (e.g. high-frequency waves, camera, or insufflation) via remote control systems directly from the operating table. Other developments in OR systems include ergonomic aids for the surgeon, such as a chair dedicated to the functional needs of endoscopic surgery. The chair is powered by electric motors controlled by a foot-pedal joystick and its position can be altered to achieve the desired position in the OR. Also significant in endoscopic surgery was the introduction of robotic technology, namely devices that assist solo-surgery and manipulators for microsurgical instrumentation.

[Positioning systems for endoscopic solo surgery]. / Sistemi di posizionamento per solo chirurgia endoscopica.

BACKGROUND: Endoscopic surgery has acquired undisputed importance in the field of both general and specialised surgery. The introduction of robotic technology in surgery has recently led to the development of new positioning systems for endoscopic surgery. These allow direct control of the endoscopic procedures by the surgeon, whose vision currently depends on the assistant in charge of positioning the optic camera in compliance with his wishes. METHODS: We experimented different positioning systems for optics and rigid endoscopic instruments for laparoscopy, some of which were our own design. Over 400 cholecystectomies were carried out by six different surgeons on phantoms containing animal organs. The experimental systems were AESOP (Computer Motion, USA), with both foot-pedal and voice control, ENDOASSIST (Armstrong Healthcare Co. UK), controlled by a device worn by the surgeon, FIPS Endoarm (Karlsruhe Research Centre, Germany), controlled by a joystick and voice, and the passive TISKA Endoarm system (Karlsruhe Research Centre, Germany). Combinations of two systems were compared, using one to position the optic and one to position the retractor instrument. RESULTS: Phantom tests, which are preferable owing to constant conditions, showed the feasibility of experiments in Solo Surgery conditions and highlighted the advantages and drawbacks of the various systems. In particular, the surgeons appreciated the intuitive use of the TISKA Endoarm system as a positioner for the retractor instrument and the optics, in spite of the fact that it was only a passive movement apparatus. Among the remote-control systems tested as an optics positioner, FIPS Endoarm controlled by a joystick was particularly intuitive and produced the best results in terms of time taken to complete the procedure. The time taken was even shorter than that in a large control group with human assistance. CONCLUSIONS: In our experience endoscopic Solo Surgery was found to be applicable to clinical practice. This will bring numerous advantages in terms of the precision of surgical procedures and savings in terms of time and human resources, with a consequent reduction of management costs. There is no doubt that this method represents a step forward in the application of technology to surgery.

Robotics and systems technology for advanced endoscopic procedures: experiences in general surgery.

The advent of endoscopic techniques changed surgery in many regards. This paper intends to describe an overview about technologies to facilitate endoscopic surgery. The systems described have been developed for the use in general surgery, but an easy application also in the field of cardiac surgery seems realistic. The introduction of system technology and robotic technology enables today to design a highly ergonomic solo-surgery platform. To relief the surgeon from fatigue we developed a new chair dedicated to the functional needs of endoscopic surgery. The foot pedals for high frequency, suction and irrigation are integrated into the basis of the chair. The chair is driven by electric motors controlled with an additional foot pedal joystick to achieve the desired position in the OR. A major enhancement for endoscopic technology is the introduction of robotic technology to design assisting devices for solo-surgery and manipulators for microsurgical instrumentation. A further step in the employment of robotic technology is the design of 'master-slave manipulators' to provide the surgeon with additional degrees of freedom of instrumentation. In 1996 a first prototype of an endoscopic manipulator system. named ARTEMIS, could be used in experimental applications. The system consists of a user station (master) and an instrument station (slave). The surgeon sits at a console which integrates endoscopic monitors, communication facilities and two master devices to control the two slave arms which are mounted to the operating table. Clinical use of the system, however, will require further development in the area of slave mechanics and the control system. Finally the implementation of telecommunication technology in combination with robotic instruments will open new frontiers, such as teleconsulting, teleassistance and telemanipulation.

Three-dimensional (3-D) video systems: bi-channel or single-channel optics?

BACKGROUND AND STUDY AIMS: This paper presents the results of a comparison between two different three-dimensional (3-D) video systems, one with single-channel optics, the other with bi-channel optics. The latter integrates two lens systems, each transferring one half of the stereoscopic image; the former uses only one lens system, similar to a two-dimensional (2-D) endoscope, which transfers the complete stereoscopic picture. MATERIAL AND METHODS: In our training centre for minimally invasive surgery, surgeons were involved in basic and advanced laparoscopic courses using both a 2-D system and the two 3-D video systems. They completed analog scale questionnaires in order to record a subjective impression of the relative convenience of operating in 2-D and 3-D vision, and to identify perceived deficiencies in the 3-D system. As an objective test, different experimental tasks were developed, in order to measure performance times and to count pre-defined errors made while using the two 3-D video systems and the 2-D system. RESULTS AND CONCLUSION: Using the bi-channel optical system, the surgeon has a heightened spatial perception, and can work faster and more safely than with a single-channel system. However, single-channel optics allow the use of an angulated endoscope, and the free rotation of the optics relative to the camera, which is necessary for some operative applications.

Trocar and instrument positioning system TISKA. An assist device for endoscopic solo surgery.

The assistance received by the surgeon from support personnel during surgical laparoscopy is extremely important. This includes the retracting of instruments and the positioning of the endoscope. However, human assistance is costly and often does not provide satisfaction for the surgeon. The aim of the project was to develop a mechanical arm capable of manipulating a laparoscopic instrument under the control of the operating surgeon. The system design is based on a particular kinematic construction that maintains an invariant point of constraint motion coincident with the trocar puncture site through the abdominal wall. The guidance system allows transparent and intuitive operation, and its setup is easy and quick. It may be adapted either as an instrument retractor or as an optic positioning device. A new generation of instrument positioning systems, with improved ergonomy, will be a first step toward the diffusion of solo surgery techniques in minimally invasive therapy. We believe this prototype represents a valid compromise between human and robotic control for conventional laparoscopic instruments.

Ergonomic surgeon's chair for use during minimally invasive surgery.

The characteristic working situation in laparoscopic surgery involves elongated instruments and limited mobility of the surgeon during the operation. These circumstances require new technical solutions to enhance the surgeon's comfort. In other surgical fields with special ergonomic situations, such as microsurgery, some surgeons prefer to operate from a seated position at the operating room table. We developed a new surgeon's chair dedicated to the ergonomic and functional requirements of laparoscopic surgery. The chair allows the surgeon to maintain a semi-standing position during the operation. Foot pedals for high frequency and suction/irrigation are integrated into the base of the chair. The pedals are purposely aligned to be comparable to foot pedals in a car. The chair is driven by electromotors, controlled with a special foot switch that operates independent of assisting personnel during surgery. Initial clinical testing of the chair could prove the theory that supporting the surgeon with a cockpit type of operating room chair helps to avoid fatigue during long endoscopic procedures. Such assistance is especially important in combination with robotic devices for use during solo surgery.