W. Kunert

Comparative study of two-dimensional and three-dimensional vision systems for minimally invasive surgery

AbstractBackground: The aim of this comparative study was to gain subjective and objective data to determine for which operative tasks three-dimensional (3-D) vision systems are superior to two-dimensional (2-D) systems and to demonstrate any advantages or disadvantages of 3-D systems. Methods: A model with five standardized tasks including sewing and knotting was developed to objectively measure performance times and to count technical faults. In our training center for minimally invasive surgery, surgeons involved in basic and advanced laparoscopic courses trained using both 2-D and 3-D vision systems. They subsequently completed analog scale questionnaires to record a subjective impression of comparative ease of operation tasks under 2-D and 3-D vision and to identify perceived deficiencies in the 3-D system. Results: Compared to 2-D vision, the objective performance time was significantly shorter and significantly less mistakes were made using 3-D vision. All operative tasks were subjectively judged significantly easier under 3-D vision. Conclusions: Users with a normal capability for spatial perception can perform standard tasks more quickly and safely using 3-D vision, and a greater benefit is apparent for more complicated surgical maneuvers.

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.

BackgroundIn 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).MethodsWe 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.ResultsThe 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.ConclusionWe 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.

Vergleichsstudie verschiedener 2-D- und 3-D-Sichtsysteme in der minimal-invasiven Chirurgie

Summary. The aim of this comparative study was to gain subjective and objective data to determine for which operative tasks it is useful to work with 3-D rather than 2-D vision systems and to show the advantages and disadvantages of 3-D systems. A series of five standardized tasks like sewing and tying knots was set up to measure performance times objectively and to count errors. Compared with 2-D vision, the performance time was 32 % shorter and 43 % fewer errors were made under 3-D vision (P < 0.001). In our endoscopic training centre, surgeons involved in basic and advanced laparoscopic courses trained using both 2-D and 3-D vision systems. They subsequently completed analogue scale questionnaires to record a subjective impression of comparative ease of operation tasks under 2-D and 3-D vision, and to identify perceived deficiencies in the 3-D system. In both courses, all operative tasks were judged significantly easier under 3-D vision (P < 0.001). It was concluded that users with a normal capacity for spatial perception can work faster and safer under 3-D vision, especially for more complicated surgical manoeuvres.Zusammenfassung. Ziel dieser Studie war es, subjektive und objektive Daten darüber zu gewinnen, für welche Arten von Operationen 3-D-Sicht von Vorteil ist, bzw. wo die Vor- und Nachteile von 3-D-Systemen liegen. Ein Parcours mit fünf standardisierten Aufgaben wie Nähen und Greifen wurde aufgebaut, um objektive Zahlenwerte über Ausführungsdauer und Fehlerrate zu erlangen. Bei der Gesamtauswertung aller Übungen zeigte sich eine statistisch signifikante (p < 0,001) Fehlerreduktion von 43 % und eine Zeitersparnis von 32 % unter 3-D-Sicht, gegenüber 2-D-Sicht. Im Trainingszentrum für Minimal Invasive Chirurgie arbeiteten die Teilnehmer im Kurs für die laparoskopische Cholecystektomie (LC) und im Kurs für Naht- und Knotentechniken (N&K) im Rotationsverfahren mit 2-D- und 3-D-Sichtsystemen. Anschließend bewerteten sie in Fragebögen die Durchführung der einzelnen Operationsschritte jeweils unter 2-D- und 3-D-Sicht und beantworteten Fragen zum Arbeiten mit dem 3-D-System. Die statistische Auswertung ergab, daß die Durchführung der einzelnen Operationsschritte in beiden Trainingskursen unter 3-D-Sicht signifikant (p < 0,001) besser bewertet wurde, als unter 2-D-Sicht. Bei richtiger Anwendung und normalem stereoskopischem Sehvermögen, kann der Chirurg vor allem komplexere Aufgaben unter 3-D-Sicht sicherer und schneller bewältigen.Schlüsselwörter: 3-D-Videosysteme – 3-D-Sichtsysteme – Stereoskopie.

For 3D laparoscopy: a step toward advanced surgical navigation: how to get maximum benefit from 3D vision

The authors are grateful for the interesting perspectives given by Buchs and colleagues in their letter to the editor entitled “3D Laparoscopy: A Step Toward Advanced Surgical Navigation.” Shutter-based 3D video systems failed to become established in the operating room in the late 1990s. To strengthen the starting conditions of the new 3D technology using better monitors and high definition, the authors give suggestions for its practical use in the clinical routine. But first they list the characteristics of single-channeled and bichanneled 3D laparoscopes and describe stereoscopic terms such as “comfort zone,” “stereoscopic window,” and “near-point distance.” The authors believe it would be helpful to have the 3D pioneers assemble and share their experiences with these suggestions. Although this letter discusses “laparoscopy,” it would also be interesting to collect experiences from other surgical disciplines, especially when one is considering whether to opt for bi- or single-channeled optics.

[3D in laparoscopy: state of the art].

ZusammenfassungDie stereoskopische Sicht (das beidäugige 3-D-Sehen) wurde in hoher Auflösung (HD) in den Operationssaal eingeführt. Diese Übersichtsarbeit zeigt die optischen und physiologischen Grundlagen sowie den Stand der Technik für den Einsatz von 3-D in der Laparoskopie auf. Es werden die Merkmale von 3-D-Endoskopen und -Monitoren aufgeführt und Besonderheiten der Stereoskopie, wie Komfortzonen und Ghosting, erläutert. Empfehlungen für den praktischen Einsatz in der Klinikroutine sollen dabei helfen, optimalen Nutzen aus der neuen Technik zu ziehen.AbstractHigh definition stereoscopic (3D) vision has been introduced into the operation theatre. This review exposes the optical and physiological background as well as the state of the art of 3D in laparoscopy. The distinguishing marks of 3D laparoscopes and monitors are listed and characteristics of stereoscopy, such as comfort zones and ghosting are explained. Suggestions for the practical use in the clinical routine should help to extract the best benefit possible from the new technology.High definition stereoscopic (3D) vision has been introduced into the operation theatre. This review exposes the optical and physiological background as well as the state of the art of 3D in laparoscopy. The distinguishing marks of 3D laparoscopes and monitors are listed and characteristics of stereoscopy, such as comfort zones and ghosting are explained. Suggestions for the practical use in the clinical routine should help to extract the best benefit possible from the new technology.

3-D in der Laparoskopie

ZusammenfassungDie stereoskopische Sicht (das beidäugige 3-D-Sehen) wurde in hoher Auflösung (HD) in den Operationssaal eingeführt. Diese Übersichtsarbeit zeigt die optischen und physiologischen Grundlagen sowie den Stand der Technik für den Einsatz von 3-D in der Laparoskopie auf. Es werden die Merkmale von 3-D-Endoskopen und -Monitoren aufgeführt und Besonderheiten der Stereoskopie, wie Komfortzonen und Ghosting, erläutert. Empfehlungen für den praktischen Einsatz in der Klinikroutine sollen dabei helfen, optimalen Nutzen aus der neuen Technik zu ziehen.AbstractHigh definition stereoscopic (3D) vision has been introduced into the operation theatre. This review exposes the optical and physiological background as well as the state of the art of 3D in laparoscopy. The distinguishing marks of 3D laparoscopes and monitors are listed and characteristics of stereoscopy, such as comfort zones and ghosting are explained. Suggestions for the practical use in the clinical routine should help to extract the best benefit possible from the new technology.High definition stereoscopic (3D) vision has been introduced into the operation theatre. This review exposes the optical and physiological background as well as the state of the art of 3D in laparoscopy. The distinguishing marks of 3D laparoscopes and monitors are listed and characteristics of stereoscopy, such as comfort zones and ghosting are explained. Suggestions for the practical use in the clinical routine should help to extract the best benefit possible from the new technology.

How Much Stereoscopic Effect Does Laparoscopy Need? Controlled, Prospective Randomized Trial on Surgical Task Efficiency in Standardized Phantom Tasks

Background. To regain 2-eyed vision in laparoscopy, dual-channeled optics have been introduced. With this optics design, the distance between the 2 front lenses defines how much stereoscopic effect is seen. This study quantifies the impact of an enhanced and a reduced stereo effect on surgical task efficiency. Methods. A prospective single-blinded study was performed with 20 laparoscopic novices in an inanimate experimental setting. A standard bichannelled stereo system was used to perform a suturing and knotting task. The working distance and the task size were scaled to vary the stereo effect and, thereby, simulate hypothetic stereo optics with enhanced and reduced optical bases. The task performances were timed, and the number of trials for stitching out was counted. The participants finally filled out a questionnaire to collect subjective impressions. Results. The increase of the stereo effect by 50% caused no objective improvement in laparoscopic knotting compared with typical 3D (control group with stereo basis of 4.5 mm). But ergonomic disadvantages (headache) were subjectively reported in 1 of 20 cases in the questionnaire. The reduction of the stereo effect by one-third led to a significantly longer average execution time. There was no significant dependence found between stereo effect and number of stich-out trials, stitching precision, or knotting quality. Conclusions. Considering laparoscopy, it does not seem advisable to enhance the stereo effect because of ergonomic problems. Otherwise, a miniaturization of the 3D scope (5 mm version) is problematic because its benefit mostly shrinks with the reduced stereo effect.

3-D in der Laparoskopie@@@3D in laparoscopy: Stand der Technik@@@State of the art

ZusammenfassungDie stereoskopische Sicht (das beidäugige 3-D-Sehen) wurde in hoher Auflösung (HD) in den Operationssaal eingeführt. Diese Übersichtsarbeit zeigt die optischen und physiologischen Grundlagen sowie den Stand der Technik für den Einsatz von 3-D in der Laparoskopie auf. Es werden die Merkmale von 3-D-Endoskopen und -Monitoren aufgeführt und Besonderheiten der Stereoskopie, wie Komfortzonen und Ghosting, erläutert. Empfehlungen für den praktischen Einsatz in der Klinikroutine sollen dabei helfen, optimalen Nutzen aus der neuen Technik zu ziehen.AbstractHigh definition stereoscopic (3D) vision has been introduced into the operation theatre. This review exposes the optical and physiological background as well as the state of the art of 3D in laparoscopy. The distinguishing marks of 3D laparoscopes and monitors are listed and characteristics of stereoscopy, such as comfort zones and ghosting are explained. Suggestions for the practical use in the clinical routine should help to extract the best benefit possible from the new technology.High definition stereoscopic (3D) vision has been introduced into the operation theatre. This review exposes the optical and physiological background as well as the state of the art of 3D in laparoscopy. The distinguishing marks of 3D laparoscopes and monitors are listed and characteristics of stereoscopy, such as comfort zones and ghosting are explained. Suggestions for the practical use in the clinical routine should help to extract the best benefit possible from the new technology.