Search

Cochlea Implant (CI) planning is usually based on preoperative obtained CT or MRI data, visualising risk structures in the petrosal bone. In the past years, Digital Volume Tomography (DVT) with an increased spatial resolution and reduced radiation has become more important in the clinical routine for otology. In this work we propose an extension of our interactive “wizard”-guided approach for the interactive segmentation of the middle and inner ear structures for the use with DVT data. Different filter pipelines enable the user to interactive segment the acoustic canal, ossicles, tympanic cavity, facial nerve, chorda tympani, round window, cochlea and semicircular canals. The approach has been evaluated on six pre-operative acquired DVT datasets by an ENT expert. Results imply that the proposed method can handle DVT well and can potentially be used for interactive OR planning.

Personalized medicine and treatment stratification of patients with head and neck squamous cell carcinoma (HNSCC) today mostly ignore genetic heterogeneity in HNSCC but especially the patient's genetic background. We hypothesized that particular human leukocyte antigen (HLA) class I (HLA-A, B, Cw) and II proteins (DR, DQ) confer susceptibility for and influence development of HNSCC and may be prognostic factors for progression-free survival (PFS).90 consecutive HNSCC patients of the prospective observational cohort study LIFE treated between 08/2010 and 05/2011 at the University Leipzig underwent low resolution typing of HLA-A, B, Cw, DR, and DQ. Antigen and haplotype frequencies were compared to those in German blood donors. Effects on PFS were analyzed using Kaplan-Meier curves and Cox models.HNSCC patients had overall altered HLA-B frequencies (P0.05); frequencies of B∗44 were lower, those of B∗13, B∗52, and B∗57 increased (P0.05). Almost all other antigen frequencies showed no deviation. Homozygous HLA-Cw and DRB4 were frequent and associated with reduced PFS (P0.05). Altered haplotype frequencies were common and particular haplotypes accompanied by differing PFS. B∗13/Cw∗06 carriers had poorest outcome (P=0.011). However, multivariate Cox proportional hazard models revealed 3 clinical covariates (localization oropharynx, loco-regional metastasis, and T4 category), HPV16-DNA positivity, and 10 HLA traits as independent predictors for PFS.The relevance of the genetic background of HNSCC patients calls for future research to clarify the role of HLA traits in HNSCC and if PFS depends on HLA.

In case of audiological and/or anatomical limitations in the provision of conventional hearing aids, semi- or fully-implantable hearing systems represent a modern therapy alternative. These hearing systems are divided according to their mode of action into active middle ear implants when stimulating the auditory ossicles or the round window, into bone conduction devices while stimulating the skull directly, into cochlear implants with direct acoustic stimulation to the cochlea with its auditory nerve and finally into auditory brainstem implants by bridging the peripheral auditory structures. Taking careful criteria of indications and anatomical specificities into account, significant improvements can be achieved in comfort, speech understanding and thus quality of life for a large number of patients.

"CI-Wizard" is a new, three-dimensional software planning tool for cochlear implant surgery with manual and semi-automatic algorithms to visualize anatomical risk structures of the lateral skull base preoperatively. Primary endpoints of the study represented the evaluation of the CI-Wizards usability, accuracy, subjectively perceived and objectively measured time in clinical practice. In a period from January 2014 to March 2015, n = 36 participants were included in this study. These members were divided into three groups of equal number (n = 12), but different level of experience. Senior doctors and consultants (group 1), residents (group 2) and medical students (group 3) segmented 12 different CT-scan data sets of the CI-Wizard (four per participant). In total, n = 144 data sets were collected. The usability of the CI-Wizard was measured by the given questionnaire with an interval rating scale. The Jaccard coefficient (JT) was used to evaluate the accuracy of the anatomical structures segmented. The subjectively perceived time was measured with an interval rating scale in the questionnaire and was compared with the objectively mean measured time (time interact). Across all three groups, the usability of the CI-Wizard has been assessed between 1 ("very good") and 2 ("with small defects"). Subjectively, the time was stated as "appropriate" by questionnaire. Objective measurements of the required duration revealed averages of t = 9.8 min for creating a target view. Concerning the accuracy, semi-automatic anatomical structures such as the external acoustic canal (JT = 0.90), the tympanic cavity (JT = 0.87), the ossicles (JT = 0.63), the cochlea (JT = 0.66), and the semicircular canals (JT = 0.61) reached high Jaccard values, which describes a great match of the segmented structures between the partcipants and the gold standard. Facial nerve (JT = 0.39) and round window (JT = 0.37) reached lower Jaccard values. Very little overlap tendency was found for the chorda tympani (JT = 0.11). This software program represents a further important step in the development of preoperative planning tools in cochlear implant surgery. The study revealed a high level of satisfaction in the usability. The subjectively required time was considered as "appropriate" and the objectively mean measured time was t = 9.8 min short enough, so that a clinical application seems realistic. Particularly for semi-automatically segmented structures, it represented a good accuracy. For purely manual segmented structures, further improvements are desirable. Finally, this program also provides a good learning tool for medical students and residents to become familiar with the anatomy of the lateral skull base.

Interoperability of medical devices based on standards starts to establish in the operating room (OR). Devices share their data and control functionalities. Yet, the OR technology rarely implements cooperative, intelligent behavior, especially in terms of active cooperation with the OR team. Technical context-awareness will be an essential feature of the next generation of medical devices to address the increasing demands to clinicians in information seeking, decision making, and human–machine interaction in complex surgical working environments. The paper describes the technical validation of an intelligent surgical working environment for endoscopic ear–nose–throat surgery. We briefly summarize the design of our framework for context-aware system’s behavior in integrated OR and present example realizations of novel assistance functionalities. In a study on patient phantoms, twenty-four procedures were implemented in the proposed intelligent surgical working environment based on recordings of real interventions. Subsequently, the whole processing pipeline for context-awareness from workflow recognition to the final system’s behavior is analyzed. Rule-based behavior that considers multiple perspectives on the procedure can partially compensate recognition errors. A considerable robustness could be achieved with a reasonable quality of the recognition. Overall, reliable reactive as well as proactive behavior of the surgical working environment can be implemented in the proposed environment. The obtained validation results indicate the suitability of the overall approach. The setup is a reliable starting point for a subsequent evaluation of the proposed context-aware assistance. The major challenge for future work will be to implement the complex approach in a cross-vendor setting.

Die Mehrzahl der Felsenbeineingriffe wird ohne Unterstutzung durch ein Navigationssystem durchgefuhrt, obwohl robuste Registrierverfahren verfugbar sind. Neben der einfachen Instrumentennavigation (IN) werden auch Funktionen wie Distance Control (DC) oder Navigated Control (NC) eingesetzt. Die vorliegende Studie analysiert die Anwendung dieser Funktionen in der Laterobasis- und Mittelohrchirurgie. In die Studie wurden 41 Patienten mit Indikationen fur einen operativen Zugang zum Felsenbein eingeschlossen. Dabei wurde ein optoelektrisches Navigationssystem mit nichtinvasiven oder invasiven Markern eingesetzt. Zum Messprotokoll gehorten Parameter wie Schnitt-Naht-Zeit, Qualitat der angebotenen Informationen („level of quality“, LOQ), Veranderung der chirurgischen Strategie („change of strategy“, COS). In 14,6% der Fallewurde der Eingriff ausschlieslich mit der Funktion IN unterstutzt. In 70,7% der Falle wurde zusatzlich die Funktion DC (DC) eingesetzt. In 14,6% der Falle wurde der Eingriff auserdem mit der Funktion NC (NC) unterstutzt. In 30 Fallen wurde der N. facialis (NF) als Risikostruktur fur eine der aktiven Schutzfunktionen definiert. Die Vorbereitungszeit (Rustzeit) fur die Navigationsfunktionen betrug im Durchschnitt 7,78 min. Der Mittelwert des LOQ betrug 66,1. In allen Fallen wurde aufgrund der verfugbaren Navigationsinformationen die chirurgische Strategie angepasst. In 17% der Falle bewerteten die Chirurgen die Navigationsfunktion als notwendig fur den Eingriff. Technisch bedingte Komplikationen traten nicht auf. Die Studie belegt die Brauchbarkeit der Navigationstechnologie fur Felsenbeinoperationen im klinischen Alltag. Die Verfahren DC und NC als Erweiterung der IN konnen zu groserer Akzeptanz der Navigation in der mikroskopischen Chirurgie fuhren.

Background Long-term laryngectomy-free (LFS), tumour-specific (TSS) and overall survival (OS) is achieved by non-surgical larynx preservation (LP) only in a proportion of patients with locally advanced laryngeal or hypopharyngeal cancer. A score facilitating decision-making after 1 cycle induction chemotherapy (IC-1) may improve LFS and TSS. Methods Early response to IC-1 with TPF ± cetuximab was assessed in 52 patients using endoscopic tumour staging for selecting total laryngectomy for non-responders with endoscopic tumour surface shrinkage max , SUV mean ) were measured by 18 F-FDG-PET/CT. Baseline and residual values after IC-1 were calculated and correlated with LFS, TSS and OS. Results After IC-1, 39/52 patients (75%) were early responders. Early response predicted complete response to IC + RT ( p = 8.48 × 10 −9 ). Early laryngectomised non-responders and responders with endoscopic tumour surface shrinkage > 70% had best OS. Significant independent predictors for LFS in responders are number of CT-staged suspect positive neck nodes (N+), residual primary tumour volume, residual total tumour volume and the ratio of residual SUV max and SUV mean (resSUV max /resSUV mean ). Our LFS-score combines >2N+, residual primary tumour volume > 20%, residual total tumour volume > 5.6 mL and resSUV max /resSUV mean > 1.51 weighted by their hazard ratio (12, 6, 5 and 4); LFS-score ≤ 16 predicts increased LFS, OS and TSS ( p Conclusion LFS-score ≤ 16 identifies in responders to IC-1 the patients with maximum benefit of non-surgical LP achieving long-term LFS. Even more importantly, a LFS-score > 16 defines patients unsuitable for LP applying the TPF/TP IC + RT protocol.

In der Fachliteratur und den Fachgesellschaften existieren keine verbindlichen didaktischen Empfehlungen bzw. Richtlinien zur Gestaltung chirurgischer Trainingskurse. Die fortbildenden Institutionen planen, organisieren und evaluieren in Eigeninitiative ihre Bildungsprogramme und -veranstaltungen. In den Kursen eines Bildungsanbieters wurden im Rahmen eines Forschungsprojekts mit einer padagogisch-wissenschaftlich arbeitenden Forschergruppe strukturierte Beobachtungen, Expertendiskussionen mit Kursverantwortlichen und Trainern sowie Auswertungen von Teilnehmerfragebogen durchgefuhrt. Erste Masnahmen wurden installiert und umgehend in den Prozess der fortlaufenden Evaluation einbezogen. Aus der Evaluation ergaben sich konkrete Veranderungen im organisatorischen und mikrodidaktischen Bereich, die schnellstmoglich eingebunden wurden. Des Weiteren ergaben sich langerfristig zu bearbeitende Aufgaben in den Bereichen (a) Rollenverstandnis des Trainers, (b) Feedback geben respektive Leistung bewerten und (c) Inhalte differenziert aufbereiten. Fur Fortbildungsveranstalter in der Medizin ist eine langerfristige Zusammenarbeit mit einer begleitenden padagogisch tatigen Institution nicht nur moglich sondern empfehlenswert.

Die chirurgische Genauigkeit in der mikroskopischen Ohrchirurgie wird zu grosen Teilen durch den limitierten Zugangsweg, aber auch durch einen potenziellen Tremor des Chirurgen negativ beeinflusst. Diese negativen Einflusse konnten durch ein Assistenzsystem im Sinne eines Manipulators reduziert, ggf. sogar eliminiert werden. Ziele dieser Arbeit waren daher: Ein Manipulator fur die Mittelohrchirurgie muss keine hochkomplexen Strukturen mit haptischer Ruckkopplung und multiplen Freiheitsgraden besitzen. Die Praparation vollzieht sich im Bereich des Mittelohres meist rein anterograd, ohne das die 15 potenziellen Freiheitsgrade der Hand umgesetzt werden konnen. Der in dieser Studie verwendete Mikromanipulator wurde entwickelt, um dem Chirurgen ein kompaktes, teleoperiertes Instrument zur Verfugung zu stellen mit der Moglichkeit der Verwendung verschiedener Standardinstrumente sowie die leichte Integration in das notwendige Operations- und Sterilisationskonzept vereinfachten seine Anwendung. Zehn HNO-Chirurgen wurden aufgefordert, eine Perforation der Stapesfusplatte an einem realitatsnahen Modell zu simulieren. Die vom Chirurgen durchgefuhrten Bewegungen wurden von einem Bildverarbeitungssystem automatisch erfasst. Sowohl manuell als auch manipulatorgestutzt waren jeweils mindesten 200 Durchlaufe gefordert, so ergaben sich mehr als 4000 Messwerte. In der Bewertung der Genauigkeit zeigte sich kein signifikanter Unterschied. Nominell fiel zwar die manuelle Genauigkeit besser aus, doch bei der manipulatorgestutzten Versuchsdurchfuhrung zeigte sich ein groserer Lerneffekt. Zusatzlich war in dieser Gruppe die Streuung um den Zielpunkt geringer (hohere Prazision). Die Anwendung des Manipulators dauerte signifikant langer, jedoch war fur die Zeit ebenfalls ein deutlich positiverer Lerneffekt erkennbar. Die subjektiv bewertete Arbeitsbelastung wahrend der Versuche war in der Manipulatorgruppe deutlich geringer. Der Mikromanipulator bot einen deutlicheren Effekt in der Verbesserung der individuellen Genauigkeit und der benotigten Zeit. Fur den Manipulator besteht ein Potenzial zur Verbesserung der chirurgischen Genauigkeit und zur Kompensation ergonomischer Defizite.

SURGICAL MANIPULATORS IN EAR SURGERY A FUTURE VISION?INTRODUCTION: Middle ear surgery bears a high risk for injury of difficult to differentiate risk structures. Thus, a precise preparation in this area must be the surgical task. LIMITATIONS: However, there are human (tremor) and systematic limitations (OR setup, narrow access). Assistance systems in terms of manipulators are so far not part of the clinical routine. Although, they could compensate for the above mentioned limitations. MANIPULATORS: This work reviews existing surgical manipulator systems. The expected value is an elevated patient safety through improving surgical accuracy and the reduction of ergonomic deficits. CLINICAL APPLICATION AND DEVELOPMENT: In clinical application there are simply modified industrial robots, highly complex master slave systems and small miniature master slave systems which are directly located at the patient. CONCLUSION: A disadvantage of most systems is the limited number of applicable instruments. Often, only especially designed instruments can be used. The goal in development should be to create a compact, short distance operated master slave system. The usability of standard (already available) instruments with an easy integration into the surgical and sterilisation procedure would lower the threshold for acceptance of such systems.The surgeon will remain the key player. He can only work efficiently in an ergonomic environment and will always have the responsibility for the intervention. From the authors perspective, highly automated systems should not be the research goal.

Die Zielstellung dieser Arbeit ist die Erweiterung der bisherigen Instrumentennavigation um eine Funktion der Kollisionswarnung mit Hilfe einer zusatzlichen Abstandsanzeige und einer Warnsystematik. Das Kollisionswarnsystem (DCS) ist eine Erweiterung eines optoelektrischen Navigationssystems (NPU, Fa. Karl Storz, Tuttlingen). Die Messungen zur Situationsaufmerksamkeit erfolgten an Trainingsmodellen der Nasennebenhohlen (NNH; Fa. Phacon, Leipzig). Zur Analyse der Genauigkeit des Abstands des Instruments von der Risikostruktur (Frontobasis, Lamina papyracea, A. carotis interna) standen 450 Wertepaare zur Verfugung. Der Einfluss auf den klinischen Verlauf wurde an insgesamt 104 Patienten mit endoskopischen NNH-Eingriffen (FESS) anhand einer prospektiven Analyse der intraoperativen Komplikationen ermittelt. Dafur wurden eine Gruppe nur mit Navigation (NAV) mit 56 und eine Gruppe NAV+DCS mit 48 Patienten gebildet. Die Effizienz wurde anhand der Zeiten fur die Vorbereitung des Systems und die intraoperative Anwendung beurteilt. Die Annaherung zwischen angenommenen und tatsachlichen Werten des Abstands zwischen Instrumentenspitze und Risikostruktur bei Verwendung des DCS nahm signifikant um durchschnittlich 76% zu. In Bezug auf Komplikationen zeigte sich ein Vorteil fur die Gruppe NAV+DCS. Die Vorbereitungszeit des Navigationssystems stieg bei der Anwendung des DCS um durchschnittlich 48% oder 1,2 min. Das relative Verhaltnis zwischen Vorbereitungs- und Nutzungszeit war mit 53,5% in Gruppe NAV und 57,4% in Gruppe NAV+DCS annahernd gleich. Diese Arbeit belegt den klinischen Nutzen und die Effizienz eines Kollisionswarnsystems als Erganzung fur die Instrumentennavigation in der endo- und transnasalen Chirurgie. Die verwendete Segmentierung eignet sich fur die klinischen Anforderungen der bekannten Risikostrukturen.

Objective The goal of this study was to investigate the dependence of surgical accuracy with a navigated controlled (NC) drill on selected registration procedures. Study design The target registration error of the instrument and the maximum proximity to a typical high-risk structure (facial nerve) were determined within an artificial petrous bone. Setting The studies took place in two groups: group 1, navigation bow with six integrated markers and attachment at the upper jaw, and group 2, landmark registration with four titanium microscrews. Measurement of the target registration error took place at three targets (3 titanium screws) with 20 repeated registration procedures via evaluation of the deviation between a target and the indicated position in the navigation data. Subjects and Methods For measurement of the conversion accuracy of the planned cavity, 20 petrous bone models were milled by inexperienced test subjects. The evaluation of 20 cavities was conducted via a microscope by five jurors. Results Registration accuracy showed a maximum deviation between the actual position achieved and the computed position in the navigation system of 1.73 mm in group 1 and 0.93 mm in group 2. In group 1, the nerve in five of 20 cases was damaged, and a maximum penetration into the nerve of 1.5 mm (0.25 mm SD; milled beyond) was measured. In group 2, the facial nerve was not damaged at all, and a maximum deviation of 0.5 mm (0.63 mm SD; stopped before) was measured. Conclusion The results for registration and conversion accuracy are significantly better for the landmark-based registration than with the registration of the patient model with registration bow on the upper jaw.

Hintergrund Es existiert derzeit kein Verfahren, um bei endoskopischen oder anderweitig eingeschrankten chirurgischen Zugangen Distanzen oder Volumina direkt und mit hoher Genauigkeit zu messen. Hier wird ein Lasermesssystem erstmals in der klinischen Anwendung in der HNO-Chirurgie evaluiert.

Problemstellung: Diese Arbeit hat das Ziel, die Auswirkungen eines Navigationssystems bei der funktionellen endoskopischen Nasennebenhohlen-OP zu untersuchen. Material und Methoden: Dafur wurden zwei Gruppen mit je 150 Patienten mit vergleichbarer Auspragung einer chronischen Sinusitis gebildet. In Gruppe A wurde ein Navigationssystem eingesetzt. In Gruppe B erfolgte die OP nach dem bisherigen Goldstandard ohne Navigationssystem. Der Untersuchungszeitraum betragt fur beide Gruppen 12 Monate. Die mittlere Nachbeobachtungszeit betragt 22 (Gruppe A) und 26 (Gruppe B) Wochen. Es wurden perioperative, intraoperative und postoperative Parameter mithilfe von Workflowanalysen, klinischen und radiologischen Befunden und standardisierten Fragebogen dokumentiert und ausgewertet. Ergebnisse: Die Anwendung des Navigationssystems erfordert eine zusatzliche perioperative Vorbereitungszeit von durchschnittlich 1,1 min. Die Schnitt-Naht-Zeit fur die Operation betragt in Gruppe A im Durchschnitt 10,1 min weniger als in Gruppe B. Die Chirurgen gaben eine masige Belastung durch die Bedienung des Navigationsgerates an, die im Verlauf der Untersuchung deutlich abnahm. Die Information des Navigationssystems wurde uberwiegend als Informationsgewinn zum vorhandenen Wissen bewertet. Postoperativ zeigte Gruppe A einen Trend zu leicht besseren Befunden als Gruppe B (fruhe Re-Polyposis, erfolgreiche sphenoidale Sinusotomie). Schlussfolgerungen: Die vorliegenden Ergebnisse weisen auf die Effizienz eines Navigationssystems fur die FESS hin. Die Schnitt-Naht-Zeit kann verkurzt werden, die Ergonomie fur den Operateur kann verbessert werden, ein Trend zu besseren postoperativen Ergebnissen kann angenommen werden. Weitere Aspekte wie vermutete anatomische Fertigkeitsverluste mussen im Folgenden untersucht werden. Evaluation of a Daily used Navigation System for FESS Problem: The aim of this study is to proof the clinical efficiency by using a modern navigation system for Functional Endoscopic Sinus Surgery (FESS). Material and Methods: An optical navigation system was used in clinical routine of 300 patients. Two groups with 150 patients each were examined. Group A was treated with navigation assistance (Karl Storz Navigation Panel Unit NPU), Group B was treated without navigation by conventional FESS. Examination period was limited to 12 months. Median follow-up is 22 and 26 weeks. Perioperative, intraoperative and postoperative parameters were recorded by workflow-analysis, clinical and radiological findings and standardized questionnary. Results: Application of the navigation system needs 1.1 min additional perioperative time in average. Intraoperative time reduction by the navigation system was about 10 min per case (Group A 32.6 (SD 11.2) min, Gruppe B 42.7 (SD 9.5) min). Specific information by the navigation system was evaluated in all surgical areas as usefull and additional to a-priori-knowledge. Postoperatively patients from group A (10/89) show lower rate of re-polyposis then in group B (24/71). Fenestration of the sphenoid sinus were sufficient by CT-evaluation in 100% (group A) and 23% (group B). Conclusions: The advantages of the examined navigation system in comparison to the gold standard of FESS are proven. Navigation assistance led to an reduced intraoperative time consumption, increased postoperative results and lowered the workload of the surgeons.

Problem. The aim of this study was the development and clinical evaluation of a new method for virtual endoscopy of the nose and paranasal sinuses. Material and methods. The surgical planning system "sinus endoscopy" (SPS-SE) was completely newly developed. The surfaces of the CT images are represented with direct volume rendering (raycasting) which allows a sufficiently high image repetition frequency with the movement of the virtual endoscopy and material effects for a natural appearance were added. Detail accuracy of the virtual illustrations was examined with the help of a picture-statistic comparison between optical and the virtual endoscopy. The evaluation of the system by the patients and physicians was made with a validated questionnaire. Results. The deviations from defined landmarks of virtual in comparison to optical endoscopy are between 1.4 mm and 11.1 mm. Manoeuvering the virtual endoscope was found to be better than with the optical endoscope but the important parameters for visualization were similar.The accuracy of volume rendering, the high variability of scaling of the anatomical borders and orientation were judged to be negative factors. Altogether there was a balanced opinion from the ENT surgeons but without exception patients judged the system positively. Discussion. This investigation proved the efficiency of SPS-SE for three-dimensional real time reconstruction of high-resolution CT data of the nose and paranasal sinuses. However, some modifications are necessary before introduction into routine use.

BACKGROUND This work examines the application possibilities of the panoramic visualization system (HD-PVS) in ENT surgery. The HD-PVS is a new optical system that is neither an endoscope nor a microscope. It has a focal length of 200 mm and a wide field of view. PATIENT AND METHODS The analysis of the visualization quality took place under laboratory conditions at 4 close-to-surgery scenarios with a total of 40 result values. Furthermore, the system was used for 45 operative procedures on patients (tympanoplasty, parotidectomy, neck dissection, septumplasty, transfacial approaches). The results were analyzed following the ICCAS workflow-scheme and with standardized questionnaires. RESULTS The analysis of the visualization quality of the PVS exhibited the best total evaluation in 2 out of 4 scenarios, in 1 scenario HD-PVS attained the maximum score possible, as did the microscope and the endoscope was better than HD-PVS in 1 scenario. The microscope was never evaluated as being better than HD-PVS. Apart from its use in middle ear surgery, the HD-PVS can be considered operational in 4 out of 5 clinical applications with only slight modifications. CONSEQUENCES The advantages of HD-PVS over gold standards such as the surgical microscope are lower initial costs for the optical system with frequently already existing HD-video system, smaller space requirements, equal or sometimes better visualization quality, possibility of videoendoscopic representation of surgery and better ergonomic conditions.

Der Einsatz von navigiert-kontrollierten Instrumenten in der HNO-Chirurgie erfordert eine robuste und genaue Registrierung des Patienten. Eine Moglichkeit ist die Registrierung des Patienten mit Hilfe einer Bissschiene im Tiefziehverfahren (Goldstandard, GS). Diese muss bisher vor der CT-Bildgebung von einem zahntechnischen Labor angefertigt werden. Die zusatzlichen Kosten und der hohere zeitliche Aufwand konnten durch den Einsatz eines Direktabdrucks vermieden werden, der vom HNO-Arzt in einem Arbeitsgang angefertigt wird. Diese Studie untersucht 3 alternative Abdruckmaterialien auf die erreichbare Repositioniergenauigkeit im Vergleich zum GS. Auserdem werden die ergonomischen Eigenschaften fur den Patienten und den Behandler untersucht. Die mittlere Abweichung fur die Repositioniergenauigkeit nach den ersten 2 Messzyklen ist fur alle 3 Materialien geringer als fur den GS. Das C-Silikon Optosil erfullt mit maximal 0,17 mm Abweichung die Vorgaben des bisherigen GS (0,28 mm). Die Bewertung der Patientenergonomie und die Bewertung durch die Chirurgen fallen fur Optosil am besten aus. Auch hinsichtlich der Materialkosten von 10 EUR im Vergleich zu uber 100 EUR fur den GS wird Optosil fur die Anwendung am Patienten favorisiert. Infolge der vorliegenden Untersuchung wurde Optosil vom 01.09.2007–30.11.2007 an 6 Patienten eingesetzt. Die Abformschiene wurde vollstandig in der HNO-Klinik hergestellt und wahrend des Planungs-CT und des Eingriffs verwendet. Die resultierende Genauigkeit entsprach mit maximal 0,87 mm Abweichung am chirurgischen Instrument den Erfahrungen der vorangegangenen NC-Eingriffe. Die gunstigen ergonomischen Eigenschaften fur Patient und Behandler wurden bestatigt. Als Konsequenz wird an der Klinik der Autoren bis auf weiteres ausschlieslich das hier geschilderte Verfahren zur bisschienenbasierten Registrierung eingesetzt.

Hintergrund Die „Funktionelle Endoskopische Nasennebenhohlenoperation“ (FESS) ist durch eine einhandige Praparation und die Fuhrung des Endoskops mit der nichtdominanten Hand gekennzeichnet. Daraus ergeben sich eine Verlangerung der Operationszeit von bis zu 15% und ergonomische Defizite fur den Chirurgen. Das Ziel der vorliegenden Arbeit ist die Fortfuhrung der Konzeption eines automatisierten Assistenzsystems fur die Endoskopfuhrung bei der FESS. Dabei stehen folgende Fragen im Mittelpunkt: 1. Welches Design ist fur eine teilautomatisierte Endoskopfuhrung bei der FESS geeignet? 2. Wie sind die technischen Systemeigenschaften (Planung, Zeitaufwand, Genauigkeit, Prazision) des gewahlten Systems? 3. Bietet das System Potenzial fur eine klinische Anwendung?

Deep analysis of common aspects influencing the surgical process is an important prerequisite for the work on training and supports systems for the operating room (OR) of the future. The surgical instrument descriptions used by scrub nurses play an important role in the daily interaction with the surgeon. One common interruption of the surgical flow is a delay caused by a misunderstanding between the surgeon and the scrub nurse when requesting a certain surgical instrument. This paper presents the evaluation of a multi-center study, which was conducted to analyze and compare the instrument descriptions for 35 surgical instruments from four surgical domains given by 15 scrub nurses of three different clinics. The study results indicate central factors which affect the common understanding of surgical instrument descriptions.

Background The aim of this study was to evaluate the Navibase navigation system for ear, nose, and throat (ENT) surgery. A new methodology for evaluating surgical and human factors is developed. Patients and methods The evaluation is based on 102 ENT surgical applications, including 89 cases of functional endoscopic sinus surgery (FESS). The evaluation of surgical and human factors was performed by seven ENT surgeons. To evaluate surgical performance, level of quality (LOQ) in the 89 cases of FESS was determined, comparing the surgeon's own impressions with those of the navigation system on a scale from 0 to 100 and further comparing them with clinical results. Intraoperative changes in surgical strategy were documented. The human factors of total confidence (trust), situation awareness, skill set requirement and workload shift were recorded as level of reliance (LOR). Results The maximum deviation amounted to 1.93 mm. Averaging the quality of information resulted in an LOQ of 63.59. Every second application of the navigation system (47.9%) led to a change in surgical strategy. Total confidence showed a positive evaluation of 3.35 points in LOR. Conclusion Application-relevant information relevant to the application beyond only technical details permits comparison with other assisting systems.

Background: The feasibility of a navigate-controlled Shaver for the paranasal sinus surgery was proven in an initial study. Deficits showed up in the conversion of the planed cavity. Goal of this study is (1) the development and evaluation of a FESS demonstrator for the investigations to the surgical accuracy and (2) the evaluation of the resulting surgical accuracy for registration and conversion of the work space with an improved rigidity of the Shaver and a completely revised study design. Methods: As a demonstrator for the navigate-controlled resection of a volume through the Shaver a two-piece plastic head with an anatomical head and soft tissue model was designed. The investigation of the surgical accuracy takes place with 417 measurements to 4 different fiducial markers on the demonstrator head. The measurements for the deviation of the resulting cavity from the planned volume was realised with a work space by 24 x 24 × 30 mm. The 5 walls of the cavity were seized with 80 measuring points for each level and thus altogether 2000 measured values (5 models × 5 levels × 200 points). Results: The described demonstrator showed itself suitable for the close-to-application attempts to the surgical accuracy. The maximum deviation A max indicated position of the Shaver from the reference value amounted to 1,93 mm. The maximum average value of the exceeding of a planned cavity amounts to 1,62 mm. Conclusions: Based on these results a virtual safety passage of 2.00 mm is sufficient. The study refers the clinical serviceability of the navigate-controlled Shaver in paranasal sinus surgery.

Die Genauigkeit von Navigationssystemen stellt das herausragende Kriterium fur die Evaluation von Navigationssystemen dar. Die Angaben zur Genauigkeit variieren erheblich, und es besteht eine Diskrepanz zwischen Literaturangaben und der intraoperativen Genauigkeit. Es existiert kein einheitliches Verstandnis fur die Begriffe Genauigkeit und Prazision von Navigationssystemen, falschlicherweise werden diese auch gleichbedeutend verwendet. Daruber hinaus ist die klinische Genauigkeit nicht mit der technischen Bestimmung gleichzusetzen. Die vorliegende Arbeit hat das Ziel, den Begriff Genauigkeit und verwandte Begriffe grundlegend zu definieren, den Begriff der Prazision abzugrenzen, den Begriff chirurgische Genauigkeit abzuleiten, einen Vorschlag fur die Anwendung des Begriffs der chirurgischen Genauigkeit eines Navigationssystems zu unterbreiten, die vorhandenen Literaturangaben entsprechend einzuordnen. Dafur kamen die Normen nach der International Standardisation Organisation-ISO und dem Deutschen Institut fur Normung e.V.-DIN zur Anwendung.

Flexible endoscopes are used in ENT surgery for examination tasks in cases wherever rigid endoscopes are unsuitable to reach certain positions in the nasal cavity. Until today they are steered by hand and no robotized system has been put into clinical practice. One qualification a robot manipulator system has to fulfill to be accepted is not to create new disadvantages compared to the conventional method in surgery. An important factor is the time needed to steer the new system compared to the time needed to steer the conventional system. In this article a robot manipulator system and an experiment are presented to compare the particular times test persons need to perform a certain task. This approach offers the possibility to benchmark the developed robot manipulator system and future systems for flexible rhino endoscopes.

In this article, a new Micromanipulator System (MMS-II) for middle ear surgery is presented. The purpose of this work was to develop a simple but effective manipulator that would enable the surgeon to move standard surgical instruments in a precise way even under non-ergonomic conditions. The MMS-II is lightweight, small, and easy to use; it requires no PC, besides a small microcontroller-based joystick console. Such features, together with a practicable sterilization concept and the availability of a multiplicity of surgical instruments, allow the system to be used in standard surgical procedures.

This work examines the application possibilities of a new visualization system, the Panoramic Visualization System (HD-PVS), in ENT surgery. The Panoramic Visualization System (PVS) is a novel optical system that is neither an endoscope nor a microscope. It has a focal length of 200 mm, a wide field of view and is used together with an HD camera and an HD monitor (HD-PVS). The analysis of the visualization quality took place in laboratory conditions using 4 close-to-surgery scenarios with altogether 40 data points. Further, the system was used on patients in 45 procedures (tympanoplasty, parotidectomy, neck dissection, septumplasty, transfacial approaches). The results were analyzed following the ICCAS workflow-scheme and with standardized questionnaires. In the analysis of the visualization quality, the PVS exhibited the best total evaluation in the lab test in two out of four scenarios. In one of four scenarios, the PVS as well as the microscope achieved the maximum attainable score. In one out of four scenarios, the endoscope attained a better result than the PVS. The microscope was never superior to the HD-PVS in terms of image quality. In four out of five clinical applications, the PVS was evaluated as operational with slight modifications. Most development is needed in middle ear surgery applications. The remaining procedures already benefit in the system configuration examined here, and they were regularly accomplished with support of the PVS. The present study offers a good basis for introducing the PVS to ENT surgery. The advantages over the existing gold standard include lower initial costs for the optical system than for an operating microscope since the HD-video system is often already in place, smaller space requirements than a microscope, equal or at times better visualization quality than the microscope, the possibility of videoendoscopic representation of surgeries in which this was impossible before, and better ergonomic conditions.

For the pre-operative de“nition of a surgical workspace for Navigated Control R Functional Endoscopic SinusSurgery (FESS), we developed a semi-automatic image processing system. Based on observations of surgeonsusing a manual system, we implemented a work”ow-based engineering process that led us to the development ofa system reducing time and workload spent during the workspace de“nition. The system uses a feature based onlocal curvature to align vertices of a polygonal outline along the bone structures de“ning the cavities of the innernose. An anisotropic morphologic operator was developed solve problems arising from artifacts from noise andpartial volume eects. We used time measurements and NASAs TLX questionnaire to evaluate our system. 1. INTRODUCTIONFunctional Endoscopic Sinus Surgery Functional Endoscopic Sinus Surgery (FESS) is a minimally invasive surgical technique removing in”amed tissuefrom the nasal cavity and paranasal sinuses. It improves the air ”ow and leads to a regular drainage of thesinuses. In FESS, surgeons use conventional and power instruments, usually a shaver, for manual preparation.Orientation in sinus surgery is very dicult for a surgeon and the intervention site is usually observed with anendoscope. Atypical anatomy (low scull base, former operation, missing bone tissue) increases the complexityand elevates the risk of an iatrogenic injury.

Background: This study examines the feasibility of a navigation-controlled (NC) drill for surgery on the petrosal bone in an experimental environment. According to the principle of NC, the drill is to be switched off automatically once the borders of the workspace are exceeded during a mastoidectomy. Materials and Methods: The registration is based on an optical navigation system with navigation software (MiMed). As surgery engine, the Unidrive-system (Karl Storz GmbH & CO. Kg, Tuttlingen, Germany) was integrated. The definition of the workspace was performed manually in axial computed tomography (CT) slices of the petrosal bone phantom. The mastoidectomy on the model was accomplished in three runs with 10 trial surgeons altogether (5 experienced [exp.] in otologic (ear) surgery, 5 inexperienced [nonexp.]). During each run, the following were logged: the total length of time for the procedure as well as the number and extent of injuries to the risk structures (facial nerve, horizontal semicircular canal, sigmoid sinus). The resultant petrosal bone cavities were measured on the CT. Results: The time for the segmentation of the workspace for the mastoidectomy amounted to 17 minutes. The mean value of the drilling (e.g., milling) performance ranges from 6.61 mm3/s (group 1 [nonexp. + NC]), 9.62 mm3/s (group 2 [exp. w/o NC]), to 10.08 mm3/s (group 3 [exp. + NC]). The relative deviation to the segmented volume amounts to +7.4% (794.3 mm3) for group 1, –39.9% for group 2, and –34% (3,647.0 mm3) for group 3. In the groups with NC guidance of the drill, no damage to a risk structure could be logged. In the group of exp. ear surgeons without NC assistance, one injury to the facial nerve in the petrosal bone phantom occurred. Discussion: The results that follow prove the fundamental feasibility of an NC drill for surgery of the petrosal bone using the example of the simple mastoidectomy in the laboratory test. When using NC, tissue resection is faster, more precise, and has fewer related complications than the same procedure without. The results offer a very promising basis for the introduction of a newly conceived system to the procedure of NC surgery on the petrosal bone. The device configuration used here was originally conceived for NC guidance of a shaver in functional endoscopic sinus surgery. Individual errors will have to be mitigated through the new version of the control unit presently in development.

The aim of this study is the evaluation of a navigation system (NaviBase) for ENT surgery. For this purpose, a new methodology for the evaluation of surgical and ergonomic system properties has been developed. The practicability of the evaluation instruments will be examined using the example of the overall assessment of the system in comparison with the current surgical standard and with other systems using clinical efficiency criteria. The evaluation is based on 102 ENT surgical applications; of these, 89 were functional endoscopic sinus surgeries (FESS). The evaluation of surgical and ergonomic performance factors was performed by seven ENT surgeons. To evaluate surgical system properties, the Level of Quality (LOQ) in 89 cases of the FESS was determined. It compares the existing information of the surgeon with that of the navigation system on a scale of 0 to 100 and with a mean value of 50 and places it in a relationship to the clinical impact. The intraoperative change of the planned surgical strategy (Change of Surgical Strategy) was documented. The ergonomic factors of the system with the categories of Overall Confidence (Trust), awareness of the situation (Situation Awareness), influence on the operating team, requirements for specific skills (Skill Set Requirement), and cognitive load (Workload Shift) were recorded for all surgical procedures as Level of Reliance (LOR). In the evaluation of the surgical system properties, an average evaluation of the quality of the information, as an LOQ of 63.59, resulted. Every second application of the navigation system (47.9%), on average, led to a change in the surgical strategy. An extension/enhancement of the indication of the endonasal approach through the use of the navigation system was shown in 7 of 102 (6.8%) cases. The completion of the resection in the FESS was rated by 74% of group I and 11% of group II as better in comparison with the standard approach. Total confidence shows a positive evaluation of 3.35 in the LOR. To supplement the evaluation of the navigation system, the technical parameters were included. The maximum deviation, Amax, of the displayed position of the reference value amounted to 1.93 mm. The average deviation was at 1.29 mm with an SD above all values, sd, of 0.29. The subsequent economic evaluation resulted in an effective average extra expenditure of time of 1.35 minutes per case. The overall evaluation of the system imparts application-relevant information beyond the technical details and permits comparability between different assistance systems.

International audience; This paper describes the ElePhant (Electronic Phantom)-an anatomical correct simulation system based on 3D rapid prototyping models for the otologic intervention "Mastoidectomy". The anatomical structures of the head are created with plaster as base material using 3D-printing as rapid prototyping technology (RPT). Structures at risk, represented by electrically conductible material and fiber optics, are realized as an electric circuit and can be detected during the simulation of the surgical procedure. An accuracy study of 15 identical RPT-models compared to the 3D reconstructed CT-dataset of the patient showed that the mean accuracy is lower than the reconstructed CT layer thickness of 0.5 mm. An evaluation study of the ElePhant-system for "Mastoidectomy" was performed by 7 ENT-surgeons. The mean value of the study questionnaire (evaluation range from -2 (not at all) to +2 (very good)) was +1.2. The results showed that the ElePhant can simulate "Mastoidectomy" realistically. It is especially suitable for the simulation of the correct representation and position of the anatomical structures, realistic operation setting, and realistic milling properties of the bone structure. Furthermore it is applicable for training of surgeons.

OBJECTIVE The current trend toward increasingly integrated technological support systems and the rise of streamlined processes in the OR have led to a growing demand for personnel with higher levels of training. Although simulation systems are widely used and accepted in surgical training, they are practically non-existent for perioperative nursing, especially scrub nursing. This paper describes and evaluates an interactive OR environment simulation to help train scrub nurses. METHODS A system comprising multiple computers and monitors, including an interactive table and a touchscreen combined with a client-server software solution, was designed to simulate a scrub nurse's workplace. The resulting demonstrator was evaluated under laboratory conditions with a multicenter interview study involving three participating ear, nose, and throat (ENT) departments in Germany and Switzerland. RESULTS The participant group of 15 scrub nurses had an average of 12.8 years hands-on experience in the OR. A series of 22 questions was used to evaluate various aspects of the demonstrator system and its suitability for training novices. DISCUSSION The system received very positive feedback. The participants stated that familiarization with instrument names and learning the instrument table setup were the two most important technical topics for beginners. They found the system useful for acquiring these skills as well as certain non-technical aspects. CONCLUSIONS Interactive training through simulation is a new approach for preparing novice scrub nurses for the challenges at the instrument table in the OR. It can also improve the lifelong training of perioperative personnel. The proposed system is currently unique in its kind. It can be used to train both technical and non-technical skills and, therefore, contributes to patient safety. Moreover, it is not dependent on a specific type of surgical intervention or medical discipline.