Frontiers of robotic endoscopic capsules: a review.

Digestive diseases are a major burden for society and healthcare systems, and with an aging population, the importance of their effective management will become critical. Healthcare systems worldwide already struggle to insure quality and affordability of healthcare delivery and this will be a significant challenge in the midterm future. Wireless capsule endoscopy (WCE), introduced in 2000 by Given Imaging Ltd., is an example of disruptive technology and represents an attractive alternative to traditional diagnostic techniques. WCE overcomes conventional endoscopy enabling inspection of the digestive system without discomfort or the need for sedation. Thus, it has the advantage of encouraging patients to undergo gastrointestinal (GI) tract examinations and of facilitating mass screening programmes. With the integration of further capabilities based on microrobotics, e.g. active locomotion and embedded therapeutic modules, WCE could become the key-technology for GI diagnosis and treatment. This review presents a research update on WCE and describes the state-of-the-art of current endoscopic devices with a focus on research-oriented robotic capsule endoscopes enabled by microsystem technologies. The article also presents a visionary perspective on WCE potential for screening, diagnostic and therapeutic endoscopic procedures.

DC current pulses for OTSC clip fragmentation: technology and experimental study.

BACKGROUND: The OTSC clip is used in endoscopic management of gastrointestinal lesions. In rare cases, the removal of the OTSC clip might be desirable. The objective of the study is to investigate feasibility, efficacy, and safety of a novel endoscopic instrument system for removal of the OTSC clip. METHODS: The study series has been conducted in a porcine model. Clip removal is performed with a prototype instrumentation that is designed to locally melt the clip by applying an electrical current pulse onto the clip structure. This system has been evaluated in an animal study (n = 10) in a pig model. A cap prototype with an elongated sleeve has been used for extraction of the OTSC clip fragments. RESULTS: 23 of 24 implanted OTSC clips were successfully opened by applying in a total of 74 current pulses. Superficial mucosal coagulation marks were observed in 14 of the 24 application sites. No other findings such as hemorrhage, deep thermal wall lesions, or perforation were observed. CONCLUSIONS: The study confirms the effectiveness and safety of the proposed endoscopic removal technique. Safe extraction of the clip fragments was feasible with an elongated sleeve at the distal cap. Limitations of the methods are the animal model and the experimental nature of the prototype instrumentation.

A novel robotic system for single-port laparoscopic surgery: preliminary experience.

BACKGROUND: The concept of single-access procedures has gained greater attention from general surgeons during the past 5 years. Despite this wide momentum, these procedures pose several changes for the surgeon, such as impaired eye-hand coordination and restricted manipulation. In this context, robotic-assisted surgery represents a promising technology to enhance the dexterity of laparoscopic surgeons. METHODS: A novel teleoperated robotic system for minimally invasive surgery (MIS) called SPRINT (Single-Port lapaRoscopy bImaNual roboT) has been developed. SPRINT is a master-slave robotic platform designed for bimanual interventions through a single-access port. The system is basically composed by two main arms having a maximum diameter of 18 mm and a stereoscopic-camera (Karl-Storz, Tuttlingen, Germany). The arms may be inserted into a cylindrical introducer that has a maximum diameter of 30 mm. The surgeon console is composed of two master manipulators, a foot-switch, and a 3D full-HD display. RESULTS: In an animal study, a small-bowel enteroenterostomy and the ligation of a mesenteric vessel bundle have been performed. As preliminary experience, the system has been placed within the peritoneal cavity through an incision of approximately 10 cm: the robot has been suspended in an open fashion, due to some mechanical constraints of the current prototype. The procedures have been performed in an authorized laboratory on a female pig of approximately 50 Kg. CONCLUSIONS: Two typical surgical maneuvers have been performed successfully with the SPRINT surgical platform: an intestinal anastomosis and a vessel ligation. Moreover, the speed, precision, and force with which the SPRINT robot executed the commands by the surgeon controlling the master console have been subjectively described as adequate to the tasks. Based on this preliminary demonstration, bimanual robot solutions, such as the SPRINT robot, may offer more dexterity and precision to single-port techniques in the next future.

The anal fistula claw: the OTSC clip for anal fistula closure.

AIM: Surgical closure of high or complex anal fistulae is often a difficult challenge. A special Nitinol clip, the OTSC clip (Ovesco AG), was evaluated for fistula closure in a porcine model. METHOD: A total of 20 fistulae were created in 10 animals by seton insertion. Four weeks after fistula induction the setons were removed: one internal fistula opening per animal was left untreated as control whereas the other opening was closed by the OTSC clip using a specially developed transanal clip applicator. The safety and technical feasibility of the clip application were tested. Another 4 weeks later, fistulae were macroscopically assessed for closure. For histological examination, the anorectum including the fistula tract was excised en bloc. RESULTS: Four weeks after clip placement, all external and internal fistula openings were macroscopically closed. The clip application site presented with an increased scarring. Microscopically, 40% of residual tracts and a more intense chronic inflammation were seen in the untreated control fistulae. After clip placement, 10% of the fistulae persisted associated with a higher density of collagen fibres indicating a better fistula scarring and healing. No unexpected side-effects or complications caused by the clip were observed. CONCLUSION: Fistula closure using the OTSC clip represents a promising sphincter-preserving minimally invasive procedure. This study demonstrated the safety and feasibility of the 'anal fistula claw' for fistula closure. In spite of limitations of the porcine model the results justify clinical applications and further investigations.

Laparoscopic-assisted transgastric cholecystectomy and secure endoscopic closure of the transgastric defect in a survival porcine model.

BACKGROUND AND STUDY AIMS: Natural orifice transluminal endoscopic surgery holds promise for surgical interventions. Before the feasibility of this technique can be established, however, secure sealing of the transluminal access needs to be thoroughly investigated. PATIENTS AND METHODS: Following antibiotic prophylaxis and gastric disinfection, nine pigs underwent transgastric cholecystectomy by means of a flexible endoscope with the aid of a transabdominal 5-mm trocar. The gastric wall was punctured and dilated. The gallbladder was retracted with a laparoscopic grasper. The cystic duct and artery were dissected with a flexible monopolar ball electrode. The cystic duct was interrupted with flexible scissors between endoclips. Cholecystectomy was completed and the gallbladder was retrieved through the stomach. The gastric defect was closed using a single modified over-the-scope clip (OTSC) (Ovesco, Tübingen, Germany) and grasping the serosal and muscle layer of the gastric wall. The animals were sacrificed 4 weeks later. RESULTS: Laparoscopic-assisted transgastric cholecystectomy was successful in all cases without significant perioperative complications. All animals survived without postoperative complications. The mean operating time was 128 minutes (range, 85 - 205 minutes). The gastric defect closure resulted in inversion of the gastric wall layers within an average time of 6.8 +/- 5 minutes. At 4 weeks postoperative, only minimal thin adhesions were observed in the right hypochondrium. CONCLUSIONS: We found gastric closure using the OTSC to be a reliable tool for closing the transgastric access. Laparoscopic-assisted transgastric cholecystectomy by means of a flexible endoscope was technically feasible, but remains a demanding procedure.

Wireless therapeutic endoscopic capsule: in vivo experiment.

BACKGROUND AND STUDY AIM: Capsule endoscopy is becoming well established as a diagnostic technique for the gastrointestinal tract. Nevertheless swallowable capsule devices that can effectively perform surgical and therapeutic interventions have not yet been developed. Such devices would also be a valuable support for natural orifice transluminal endoscopic surgery (NOTES). The objective of this study was to assess the feasibility of using a swallowable wireless capsule to deploy a surgical clip under remote control. MATERIALS AND METHODS: A wireless endoscopic capsule, diameter 12.8 mm and length 33.5 mm, was developed. The device is equipped with four permanent magnets, thus enabling active external magnetic steering. A nitinol clip is loaded on the topside of the capsule, ready to be released when a control command is issued by an external operator. Repeated ex vivo trials were done to test the full functionality of the therapeutic capsule in terms of efficiency in releasing the clip and reliability of the remote control. An in vivo test was then carried out in a pig: the capsule was inserted transanally and steered by means of an external magnetic arm towards an iatrogenic bleeding lesion. The clip, mounted on the tip of the capsule, was released in response to a remote signal. The procedure was observed by means of a flexible endoscope. RESULTS: A wireless capsule clip-releasing mechanism was developed and tested. During ex vivo trials, the capsule was inserted into the sigmoid section of a phantom model and steered by means of the external magnet to a specific target, identified by a surgical suture at a distance of 3 cm before the left flexure. The capsule took 3 to 4 minutes to reach the desired location moving under external magnetic guidance, while positioning of the capsule directly on the target took 2 to 3 minutes. Successful in vivo clipping of an iatrogenic bleed by means of a wireless capsule was demonstrated. CONCLUSIONS: This study reports the first successful in vivo surgical experiment using a wireless endoscopic capsule, paving the way to a new generation of capsule devices able to perform both diagnostic and therapeutic tasks.

An over-the-scope clip (OTSC) system for closure of iatrogenic colon perforations: results of an experimental survival study in pigs.

BACKGROUND AND STUDY AIM: Perforation of the colon is a relatively rare complication of flexible endoscopy of the lower gastrointestinal tract. It has a reported incidence from between 0.2 % in diagnostic procedures to 0.5 % - 3 % in therapeutic procedures. Given the growing number of colonoscopies, the absolute number of iatrogenic perforations is not unimportant. The treatment of choice is most often surgical repair, since reliable and simple endoscopic techniques for perforation closure are currently unavailable. We aimed to evaluate our novel over-the-scope clip (OTSC) system for closure of iatrogenic perforations. MATERIAL AND METHODS: We have developed a nitinol clip that will capture perforations of 10 - 15 mm, compressing the lesions until healing. The OTSC was studied in a prospective experimental trial in pigs (50 - 60 kg, n=10) for the closure of an iatrogenic perforation of approximately 5 --10 mm on the serosal side, that was created by repeated endoscopic biopsy. The follow-up period was 12 weeks. Follow-up colonoscopy was performed at 4 and 12 weeks. Successful, tight closure of the lesion with absence of peritonitis in the postoperative course was the primary endpoint of the study. RESULTS: Nine animals had an uneventful clinical course. At termination of the study, macroscopic and microscopic examination of the clipping sites in the bowel wall showed normal tissue healing. One animal died 1 day postoperatively for reasons unrelated to the procedure. CONCLUSIONS: In this experimental study the OTSC clip system was found to be a simple and secure closure method for iatrogenic colon perforations, and thus might be an alternative to surgical repair.

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.

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.

Microsystems in medicine - results of an international survey.

The utilization of microsystems technology (MST) in medical applications is instrumental in opening up new market segments, in the creation of novel, more effective diagnosis and therapy options in medicine, as well as in the further development of MST. However, the players in the healthcare industry are faced with technical and non-technical difficulties. The present study analyzes this emerging field from the viewpoint of medicine, market, and MST. It identifies applications of medical devices with microsystems components and analyzes their potentials in great detail. Thus, especially the creation of new market segments is expected from a broad use of MST in medicine. Furthermore, problems and conditions during the entry of microsystems into medical products are illuminated, in particular considering the specific market features of the healthcare industry. The high expenditure necessary for establishing this technology in healthcare industry is the most significant obstacle, since this market is dominated by small and medium-sized enterprises (SMEs). But there are non-technical difficulties as well. This article presents selected results of the study, which was carried out in the scope of the EU project netMED (virtual institute on micromechatronics for biomedical industry).

Indirect coronary angiography: a feasibility study.

The diagnostic method of choice to proof coronary artery disease and to localize stenoses and to judge the stage of the disease is coronary angiography. A new angiographic technique invented by. Wolffgram and Krieter that works without cannulation of the coronary arteries could simplify the interventional procedure. In addition, a technique like this could be used for angiography after CABG surgery directly on the table for quality assurance reasons. This angiography could be performed by the cardiac surgeon without necessarily involving a cardiologist. A feasibility study was successfully done in a cooperation of the Departments. for Cardiology and Cardiac Surgery, Munich University, Steinbeis Transfer Centre for rHealthcare Technologies, Tuebingen and Fraunhofer Technology Development Group (TEG), Stuttgart.

[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.

Robotics and telemanipulation technologies for endoscopic surgery. A review of the ARTEMIS project. Advanced Robotic Telemanipulator for Minimally Invasive Surgery.

In endoscopic surgery, the ability to guide the instrument is significantly decreased compared with open surgery. Rigid laparoscopic instruments offer only four of the six degrees of freedom required for the free handling of objects in space. Robotics technology can be used to restore full mobility of the endoscopic instrument. Therefore, we designed a master-slave manipulator system (ARTEMIS) for laparoscopic surgery as a prototype. The system consists of two robotic arms holding two steerable laparoscopic instruments. These two work units are controlled from a console equipped with two master arms operated by the surgeon. The systems and its components were evaluated experimentally. Laparoscopic manipulations were feasible with the ARTEMIS system. The placement of ligatures and sutures and the handling of catheters were possible in phantom models. The surgical practicability of the system was demonstrated in animal experiments. We conclude that robotic manipulators are feasible for experimental endoscopic surgery. Their clinical application requires further technical development.

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.

[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.

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.

The medical engineering program of Forschungszentrum Karlsruhe.

The research activities of the Forschungszentrum Karlsruhe on minimally-invasive surgery (MIS) have for several years improved techniques and instrumentation for different types of MIS. Many types of instruments and robotic devices have been developed and new techniques implemented. In this paper we present the most recent results from our different projects, such as endoscopic heart surgery, tracking systems, a camera guidance device, telemanipulator systems, minimally-invasive breast biopsy in closed-bore MRI, endoscopic training simulators and developments using smart materials (e.g. Nitinol).