Navigation Procedures Research Articles

Use of Image-Guided Surgical Navigation during Resection of Locally Recurrent Rectal Cancer.

Surgery for locally recurrent rectal cancer (LRRC) presents several challenges, which is why the percentage of inadequate resections of these tumors is high. In this exploratory study, we evaluate the use of image-guided surgical navigation during resection of LRRC. Patients who were scheduled to undergo surgical resection of LRRC who were deemed by the multidisciplinary team to be at a high risk of inadequate tumor resection were selected to undergo surgical navigation. The risk of inadequate surgery was further determined by the proximity of the tumor to critical anatomical structures. Workflow characteristics of the surgical navigation procedure were evaluated, while the surgical outcome was determined by the status of the resection margin. In total, 20 patients were analyzed. For all procedures, surgical navigation was completed successfully and demonstrated to be accurate, while no complications related to the surgical navigation were discerned. Radical resection was achieved in 14 cases (70%). In five cases (25%), a tumor-positive resection margin (R1) was anticipated during surgery, as extensive radical resection was determined to be compromised. These patients all received intraoperative brachytherapy. In one case (5%), an unexpected R1 resection was performed. Surgical navigation during resection of LRRC is thus safe and feasible and enables accurate surgical guidance.

Assessing and reducing registration and targeting uncertainty in video-based image-guided renal navigation: An in vitro study featuring virtual targets.

Minimally invasive image-guided interventions (IGIs) enable better therapy outcomes for patients, but navigation accuracy is highly dependent on the accuracy of the image-/model-to-patient registration. This requires methods to reduce the uncertainty to a level appropriate for the procedure being performed. Since sub-surface tissue landmarks cannot be easily sampled using a tracked stylus and used to perform the patient registration, here we present a method that employs a tracked camera (that mimics a laparoscope) to perform the patient registration or update this registration in case of suspected misalignment within the context of an image-guided renal navigation procedure. We implement and test the method using a simplified patient phantom, which consists of a foam block to which a virtual kidney model featuring both surface and sub-surface landmarks is registered. This setup mimics a situation when a surgeon would navigate a tracked needle to renal landmarks percutaneously, while relying on pre-procedural imaging, optical tracking, and surface video imaging. We conduct several experiments under both optimal phantom registration and purposely altered registration, to not only show the effect of phantom / patient mis-registration on subsequent navigation, but also demonstrate the use of the camera-based registration to restore navigation to an acceptable uncertainty. Our results illustrate that camera-based registration yields a target registration error on the order of 0.4 mm and a subsequent targeting error on the order of 0.6 mm, comparable to the performance achieved following gold-standard landmark-based registration. These results suggest that the proposed method can be used to perform or update the patient registration for image-guided interventions involving sub-surface organs.

Robotic-Assisted Lumbar Fusion: An Effective Technique for Pedicle Screw Placement.

Degenerative lumbar disease is a common condition in which progressive deterioration of the structures in the spine causes severely incapacitating pain and disability. Conservative management, including passive or active physical therapy, activity modification, and medications (eg, anti-inflammatory medications, oral and injectable steroids, opioids), may provide relief. However, when conservative management is unsuccessful or patients experience symptoms for an extended period of time, they may require spine surgery. Surgeons use a variety of techniques to perform lumbar fusion procedures with instrumentation, including open, percutaneous, minimally invasive, and robotic-assisted with navigation. The accuracy of pedicle-screw placement varies according to the technique used, and accuracy rates are high after robotic-assisted with navigation procedures. In addition, robotic-assisted spine procedures result in fewer infections than non-robotic-assisted spine procedures (P = .04). Perioperative nurses should understand basic lumbar spine anatomy, steps completed during robotic-assisted lumbar spine surgery, and the nursing considerations for patients undergoing this type of procedure.

The GNSS NavAer INCT Project Overview and Main Results

Air navigation is increasingly dependent on the use of Global Navigation Satellite Systems (GNSS). It allows the determination of the aircraft’s position in all phases of the flight and brings many advantages. Although GNSS navigation results in gains, the radio signals from these systems are strongly influenced by the ionospheric environment. It introduces errors that can affect the accuracy, integrity, availability and continuity requirements established by the International Civil Aviation Organization (ICAO). The ionospheric layer has different behaviors depending on the latitude, time of day, season of the year, geomagnetic activity and solar cycle. Since Brazil is located in a region of low latitudes, it experiences a series of unique challenges when compared to regions of mid-latitudes. For this reason, the application of GNSS-based technologies in aviation over the Brazilian territory requires an in-depth assessment of the ionosphere effects. Therefore, the Instituto Nacional de Ciência e Tecnologia (INCT) named GNSS Technology for Supporting Air Navigation was formed in 2017 to better assess the ionosphere impacts and assist government agencies and companies in the development of safe air navigation procedures over Brazil in a near future. This paper presents the most relevant advances achieved so far within this multidisciplinary project that involves Brazilian research centers and universities.

Simulation Technology in Anesthesiology.

Simulation Technology in Anesthesiology.

Performance-Based Navigation Flight Path Analysis Using Fast-Time Simulation

The growing demand for air transportation has led to an increase in worldwide air traffic inefficiency due to capacity constraints. The impacts associated with this situation can be reduced through operational changes. To better handle the problem, the Single European Sky ATM Research (SESAR) and the Next Generation Air Transportation System (NextGen) program suggest Performance-Based Navigation (PBN) as a solution. The Area Navigation (RNAV) and Required Navigation Performance (RNP) approaches belong to the group of PBN procedures. These procedures allow for a more efficient use of airspace by reducing route distances, fuel consumption and perceived aircraft noise. This article quantifies the benefits of PBN systems for two indicator parameters—fuel burn and flight time—and compares PBN systems to conventional instrument navigation procedures. The case studies use five airports in Brazil. The results of this analysis show that the benefits of the PBN approach vary with aircraft type and individual route characteristics.

Targeting repeatability of a less obtrusive surgical navigation procedure for total shoulder arthroplasty.

Surgical navigation systems have demonstrated improvements in alignment accuracy in a number of arthroplasty procedures, but they have not yet been widely adopted for use in total shoulder arthroplasty (TSA). We believe this is due in part to the obtrusiveness of conventional optical tracking systems, as well as the need for additional intraoperative steps such as calibration and registration. The purpose of this study is to evaluate the feasibility of adapting a less-intrusive dental navigation system for use in TSA. We developed a proof-of-concept system based on validated laser-engraved surgical tools recently introduced for use in dental surgery that are calibrated once when manufactured and not recalibrated at time of use. The design also features a notably smaller bone-mounted tracker that can be tracked from a wide range of viewing angles. To assess our system's performance, we modified the dental surgical software to support guidance of a TSA procedure. We then conducted a user study in which three participants with varying surgical experience used the system to drill 30 holes in a glenoid model. Using a coordinate measuring machine, we determined the resulting drilled trajectory and compared this to the pre-planned trajectory. Since we used a model glenoid rather than anatomical specimens, we report on targeting precision rather than overall procedure precision or accuracy. We found targeting precision < 1mm (standard deviation) for locating the entry hole and < ~ 1° (SD) for both version and inclination. The latter value was markedly lower than the end-to-end angular precision achieved by previously reported TSA navigation systems (approximately 3°-5° SD). We conclude that variability during the targeting phase represents a small fraction of the overall variability exhibited by existing systems, so a less obtrusive navigation system for TSA based on laser-engraved tooling is likely feasible, which could improve the uptake rates of surgical navigation for TSA, thereby potentially leading to improved overall surgical outcomes.

Utilizing Intraoperative Navigated 3D Color Doppler Ultrasound in Glioma Surgery.

BackgroundIn glioma surgery, the patient’s outcome is dramatically influenced by the extent of resection and residual tumor volume. To facilitate safe resection, neuronavigational systems are routinely used. However, due to brain shift, accuracy decreases with the course of the surgery. Intraoperative ultrasound has proved to provide excellent live imaging, which may be integrated into the navigational procedure. Here we describe the visualization of vascular landmarks and their shift during tumor resection using intraoperative navigated 3D color Doppler ultrasound (3D iUS color Doppler).MethodsSix patients suffering from glial tumors located in the temporal lobe were included in this study. Intraoperative computed tomography was used for registration. Datasets of 3D iUS color Doppler were generated before dural opening and after tumor resection, and the vascular tree was segmented manually. In each dataset, one to four landmarks were identified, compared to the preoperative MRI, and the Euclidean distance was calculated.ResultsPre-resectional mean Euclidean distance of the marked points was 4.1 ± 1.3 mm (mean ± SD), ranging from 2.6 to 6.0 mm. Post-resectional mean Euclidean distance was 4.7. ± 1.0 mm, ranging from 2.9 to 6.0 mm.Conclusion3D iUS color Doppler allows estimation of brain shift intraoperatively, thus increasing patient safety. Future implementation of the reconstructed vessel tree into the navigational setup might allow navigational updating with further consecutive increasement of accuracy.

곡선좌표계 변환에 기반한 협수로에서 선박 자율 충돌회피

This study addresses autonomous ship collision avoidance in narrow channels using curvilinear coordinates. Navigation in narrow channels or fairways is known to be much more difficult and challenging compared with navigation in the open sea. It is not straightforward to apply the existing collision avoidance framework designed for use in the open sea to collision avoidance in narrow channels due to the complexity of the problem. In this study, to generalize the autonomous navigation procedure for collision avoidance in narrow channels, we introduce a curvilinear coordinate system for collision-free path planning using a parametric curve, B-spline. To demonstrate the feasibility of the proposed algorithm, ship traffic simulations were performed and the results are presented.

Utilization of low cost motion capture cameras for virtual navigation Procedures: Performance evaluation for surgical navigation

Thanks to recent advances in medical robotics, various traditional surgical procedures have been started to be carried out by the help of robot manipulators. In order to enhance visual feedback and operation efficiency in these scenarios, utilization of virtual navigation techniques with specialized hardware has become a widespread choice. On the other hand, relatively high equipment costs have risks to slow down researches and mass adoption on the field. In light of this, current study represents performance evaluation of a low cost motion capture cameras on a scenario that tries to demonstrate robotic surgery like operation on a target patient through virtual navigation. Throughout the study least squares point based registration technique was utilized to correlate different reference frames with each other. A new approach was proposed for the calibration between robot manipulator and motion capture system to allow operation without using markers on manipulator side. Innovative patient mockup design with precisely formed landmark points was also introduced in order to verify performances of utilized low cost hardware. At the end of the study, hardware verification results showed the possibility of sub millimeter precisions in demonstrated navigation procedures.

Research on Satellite Selection Strategy for Receiver Autonomous Integrity Monitoring Applications

Satellite selection is an effective way to overcome the challenges for the processing capability and channel limitation of the receivers due to superabundant satellites in view. The satellite selection strategies have been widely investigated to construct the subset with high accuracy but deserve further studies when applied to safety-critical applications such as the receiver autonomous integrity monitoring (RAIM) technique. In this study, the impacts of subset size on the accuracy and integrity of the subset and computation load are analyzed at first to confirm the importance of the satellite selection strategy for the RAIM process. Then the integrated performance impact of a single satellite on the current subset is evaluated according to the performance requirement of the flight phase. Subsequently, a performance-requirement-driven fast satellite selection algorithm is proposed based on the impact evaluation to construct a relatively small subset that satisfies the accuracy and integrity requirements. Comparison simulations show that the proposed algorithm can keep similar accuracy and better integrity performances than the geometric algorithm and the downdate algorithm when the subset size is fixed to 12, and can achieve an average 1.0 to 2.0 satellites smaller subset in the Lateral Navigation (LNAV) and approach procedures with vertical guidance (APV-I) horizontal requirement trial. Thus, it is suitable for real-time RAIM applications and low-cost navigation devices.

The multi-level table and circular diagnostic chart as alternative taxonomic key formats for plant identification

Correct identification of plants is a prerequisite to achieving desirable results in health care delivery, sustainable food production and housing, forest resources management and environmental protection. However, many of the paper-based/printable taxonomic key formats available to the taxonomist for this important responsibility are fraught with inadequacies some of which include fixed sequence of plant identification steps, non- or hardly-susceptible to computerisation, lack of provision for confirmation of suspected plant identity and indeterminable character states, and tedious construction and navigation procedures. This paper with the aim of making the practice of plant taxonomy more attractive, less laborious and dreaded, proposes two new key formats with highlights of their design/features, construction procedures and usage. These alternative key formats, with varying capacities to circumvent some of the enumerated challenges are multi-level table of identification and multi-layer circular diagnostic chart. The status of each of the proposed key formats is discussed with reference to the inadequacies observed in the dichotomous key format with which most taxonomists are familiar. Based on their structural features and functionality attributes, it is conclusive that the two alternative key formats constitute useful templates upon which reliable plant diagnostic tools can be based. Key words: Automated plant identification, computerised key, diagnostic key, dichotomous key, multi-access key, plant identification, single-access key, taxonomic key.

Accuracy of Computer-Assisted Dynamic Navigation as a Function of Different Intraoral Reference Systems: An In Vitro Study.

The aim of this in vitro study was to determine whether the process chain influences the accuracy of a computer-assisted dynamic navigation procedure. Four different data integration workflows using cone-beam computed tomography (CBCT), conventional impressions, and intraoral digitization with and without reference markers were analyzed. Digital implant planning was conducted using data from the CBCT scans and 3D data of the oral models. The restoration of the free end of the lower jaw was simulated. Fifteen models were each implanted with two new teeth for each process chain. The models were then scanned with scan bodies screwed onto the implants. The deviations between the planned and achieved implant positions were determined. The evaluation of all 120 implants resulted in a mean angular deviation of 2.88 ± 2.03°. The mean 3D deviation at the implant shoulder was 1.53 ± 0.70 mm. No significant differences were found between the implant regions. In contrast, the workflow showed significant differences in various parameters. The position of the reference marker affected the accuracy of the implant position. The in vitro examination showed that precise implantation is possible with the dynamic navigation system used in this study. The results are of the same order of magnitude that can be achieved using static navigation methods. Clinical studies are yet to confirm the results of this study.

Evaluation of an Ultrasound-Based Navigation System for Spine Neurosurgery: A Porcine Cadaver Study.

BackgroundWith the growing incidence of patients receiving surgical treatment for spinal metastatic tumours, there is a need for developing cost-efficient and radiation-free alternatives for spinal interventions. In this paper, we evaluate the capabilities and limitations of an image-guided neurosurgery (IGNS) system that uses intraoperative ultrasound (iUS) imaging for guidance.MethodsUsing a lumbosacral section of a porcine cadaver, we explored the impact of CT image resolution, ultrasound depth and ultrasound frequency on system accuracy, robustness and effectiveness. Preoperative CT images with an isotropic resolution of , and were acquired. During surgery, vertebrae L1 to L6 were exposed. For each vertebra, five iUS scans were acquired using two depth parameters (5 cm and 7 cm) and two frequencies (6 MHz and 12 MHz). A total of 120 acquisition trials were evaluated. Ultrasound-based registration performance is compared to the standard alignment procedure using intraoperative CT. We report target registration error (TRE) and computation time. In addition, the scans’ trajectories were analyzed to identify vertebral regions that provide the most relevant features for the alignment.ResultsFor all acquisitions, the median TRE ranged from 1.42 mm to 1.58 mm and the overall computation time was 9.04 s ± 1.58 s. Fourteen out of 120 iUS acquisitions (11.66%) yielded a level-to-level mismatch (and these are included in the accuracy measurements reported). No significant effect on accuracy was found with CT resolution (F (2,10) = 1.70, p = 0.232), depth (F (1,5) = 0.22, p= 0.659) nor frequency (F (1,5) = 1.02, p = 0.359). While misalignment increases linearly with the distance from the imaged vertebra, accuracy was satisfactory for directly adjacent levels. A significant relationship was found between iUS scan coverage of laminae and articular processes, and accuracy.ConclusionIntraoperative ultrasound can be used for spine surgery neuronavigation. We demonstrated that the IGNS system yield acceptable accuracy and high efficiency compared to the standard CT-based navigation procedure. The flexibility of the iUS acquisitions can have repercussions on the system performance, which are not fully identified. Further investigation is needed to understand the relationship between iUS acquisition and alignment performance.

Electromagnetic surgical navigation in patients undergoing mandibular surgery

The purpose of this study was to evaluate the feasibility of electromagnetic (EM) navigation for guidance on osteotomies in patients undergoing oncologic mandibular surgery. Preoperatively, a 3D rendered model of the mandible was constructed from diagnostic computed tomography (CT) images. Cutting guides and patient specific reconstruction plates were designed and printed for intraoperative use. Intraoperative patient registration was performed using a cone beam CT scan (CBCT). The location of the mandible was tracked with an EM sensor fixated to the mandible. The real-time location of both the mandible and a pointer were displayed on the navigation system. Accuracy measurements were performed by pinpointing four anatomical landmarks and four landmarks on the cutting guide using the pointer on the patient and comparing these locations to the corresponding locations on the CBCT. Differences between actual and virtual locations were expressed as target registration error (TRE). The procedure was performed in eleven patients. TREs were 3.2 ± 1.1 mm and 2.6 ± 1.5 mm using anatomical landmarks and landmarks on the cutting guide, respectively. The navigation procedure added on average half an hour to the duration of the surgery. This is the first study that reports on the accuracy of EM navigation in patients undergoing mandibular surgery.

Accuracy of Dynamic Computer-Assisted Implant Placement: A Systematic Review and Meta-Analysis of Clinical and In Vitro Studies.

The aim of this systematic review and meta-analysis is to analyze the accuracy of implant placement using computer-assisted dynamic navigation procedures. An electronic literature search was carried out, supplemented by a manual search. The literature search was completed in June 2020. The results of in vitro and clinical studies were recorded separately from each other. For inclusion in the review, the studies had to examine at least the prosthetically relevant parameters for angle deviation, as well as global deviation or lateral deviation at the platform of the implant. Sixteen of 320 articles were included in the investigation: nine in vitro and seven clinical studies. The meta-analysis showed values of 4.1° for the clinical studies (95% CI, 3.12–5.10) and 3.7° for the in vitro studies (95% CI, 2.31–5.10) in terms of the angle deviation. The global deviation at the implant apex of the implant was 1.00 mm for the clinical studies (95% CI, 0.83–1.16) and 0.91 mm for the in vitro studies (95% CI, 0.60–1.12). These values indicate no significant difference between the clinical and in vitro studies. The results of this systematic review show a clinical accuracy of dynamic computer-assisted navigation that is comparable to that of static navigation. However, the dynamic navigation systems show a great heterogeneity that must be taken into account. Moreover, currently there are few clinical data available. Therefore, further investigations into the practicability of dynamic navigation seem necessary.

Multi-crew cooperation training manual for air training and education centre

The main goal of the training manual is to create a study material for the theoretical and practical part of the multi-crew cooperation training course, which is provided by the Air Training and Education Centre of the University of Žilina since 2007. At the same time, the purpose of the training manual will be to contribute to the quality of education, streamlining the multi-crew cooperation training course and to provide a comprehensive study material for pilots in training that reflects on the changes made from 2007 to the present. The reason which stimulated the elaboration of the training manual is mainly the already existing study material which has now proved to be outdated and insufficient for the needs of the training course. The training manual will reflect the legislative changes made, the modifications to the flight and navigation procedures trainer and some training elements, which are currently emphasized in the training process and will meet all the currently required criteria. The content of training manual which is based on valid and effective regulations, on the airplane flight manual of Beechcraft Super King Air B200 / B200C, inspired by internal operation manuals of the airline operators, internal manuals of the Air Training and Education Centre and is also based on the already existing study material. At the same time, it will be possible to implement some parts of the training manual into the internal manuals of the Air Training and Education Centre. Expected date of issue of training manual is May 2022.

Laparoscopic fluorescence navigation for left-sided colon and rectal cancer: Blood flow evaluation, vessel and ureteral navigation, clip marking and trans-anal tube insertion

BackgroundRecently, the indocyanine green (ICG) fluorescence navigation method has attracted much attention as a means of intraoperative navigation, especially during laparoscopic surgery. The newly developed near-infrared (NIR) fluorescent resin also emits NIR fluorescence, as does ICG. Presently, new devices made with this resin are being developed. The purpose of this study was to present our fluorescence navigation techniques for left-sided colon and rectal cancer. MethodFifty-nine patients with left-sided colon and rectal cancer underwent laparoscopic surgery with fluorescence navigation between July 2019 and April 2020. The surgeries included 54 intestinal blood flow (IBF) evaluations using ICG, 16 preoperative fluorescence clip marking (FCM) procedures, 7 fluorescence ureteral navigation procedures, 4 fluorescence vessel navigation (FVN) procedures during lateral lymph node dissection, and 3 fluorescence-guided trans-anal tube insertion procedures. Laparoscopic surgery and fluorescence observation were performed using a VISERA ELITE 2. In FCM, the Zeoclip FS device was used. In ureteral navigation and trans-anal tube insertion, the Near-Infrared Ray Catheter (NIRC™) fluorescent ureteral catheter (NIRFUC) was used. ResultsNo complications related to the fluorescence navigation techniques, including those involving ICG, the Zeoclip FS and the NIRFUC, occurred. In 5 cases, the surgical plan was changed according to the IBF evaluation with ICG, and no anastomotic leakage occurred in those cases. These fluorescence navigation techniques provide previously unavailable visual information regarding the IBF, vessel and ureter routes and accurate endoscopic clip and drainage tube locations in the intestinal tract. ConclusionsTechnology to visualize blood flow dynamics and structures using fluorescence can be considered innovative, especially when applied in laparoscopic surgery, which relies on vision. The popularity of fluorescence navigation has also appeared to increase the safety of colorectal surgery. Clinical trial registrationExamination of fluorescence navigation for laparoscopic colorectal cancer surgery.Research Ethics Committee of the Kawaguchi Municipal Medical Center (Saitama, Japan) approval number: 2020-3. https://kawaguchi-mmc.org/wp-content/uploads/clinicalresearch-r02.pdf.

Intraoperative assessment of pelvic tilt and cup position in total hip arthroplasty: the relevance of navigation and robotics

The optimal 3D positioning of the prosthesis components is of great importance for the stability and function of atotal hip endoprosthesis. Pelvic tilt has a particular influence on the position of the implant. In order to use intraoperatively the knowledge on pelvic kinematics gained through preoperative imaging procedures and movement analyses, "image-based" and "image-free" robotic and navigation procedures are available. With the "image-based" procedures, a3D CT scan serves as the surgeon's basis for operative planning. The "image-free" procedures are based on the principles of stereotaxy. In the future, information about static and dynamic pelvic tilt will be conntected with navigation and robotic systems for total hip arthroplasty. Along with intraoperative data a patientindividual optimized implant position can be achieved.

Intraoperative radiation exposure to patients in idiopathic scoliosis surgery with freehand insertion technique of pedicle screws and comparison to navigation techniques.

In surgical correction of scoliosis with pedicle screw dual-rod systems, frequently used freehand technique of screw positioning is challenging due to 3D deformity. Screw malposition can be associated with serious complications. Image-guided technologies are already available to improve accuracy of screw positioning and decrease radiation to surgeon. This study was conducted to measure intraoperative radiation to patients in freehand technique, evaluate screw-related complications and compare radiation values to published studies using navigation techniques. Retrospective analysis of prospectively collected data of 73 patients with idiopathic scoliosis, who underwent surgical correction with pedicle screw dual-rod system. Evaluated parameters were age, effective radiation dose (ED), fluoroscopy time, number of fused segments, correction and complications. Parameters were compared with regarding single thoracic curve (SC) and double thoracic and lumbar curves (DC), adolescent (10-18years) or adult (> 18years) idiopathic scoliosis, length of instrumentation. ED was compared with values for navigation from online database. Average age was 21.0 ± 9.7years, ED was 0.17 ± 0.1mSv, time of fluoroscopy was 24.1 ± 18.6s, 9.5 ± 1.9 fused segments. Average correction for SC was 75.7%, for DC 69.9% (thoracic) and 76.2% (lumbar). No screw-related complications. ED was significantly lower for SC versus DC (p < 0.01), short versus long fusions (p < 0.01), no significant difference for age (p = 0.1). Published navigation data showed 6.5- to 8.8-times higher radiation exposure for patients compared to our results. Compared to navigation procedures, freehanded positioning of pedicle screws in experienced hands is a safe and effective method for surgical correction of idiopathic scoliosis with a significant decrease in radiation exposure to patients.