Navigation Guidance Research Articles

Branched Endovascular Thoracoabdominal Aneurysm Repair Under Electromagnetic Guidance in an in Vitro Model.

We report a new approach to perform endovascular treatment of thoracoabdominal aneurysms under electromagnetic navigation guidance using a modified system (IOPS; Centerline Biomedical, Inc., Cleveland, OH, USA) and a modified branched endograft (E-nside TAAA Multibranch Stent Graft System; Artivion Inc., Kennesaw, GA, USA). We performed this case in an aortic in vitro model made from transparent polyurethane in our research hybrid room (Discovery IGS 730; GE HealthCare, Chicago, IL, USA). While the implantation of this device typically involves several challenging steps, including precise endograft implantation, snaring of preloaded guide wires, and cannulation of target visceral arteries, all were successfully performed using electromagnetic navigation guidance. Our preliminary experience suggests that endograft implantation under electromagnetic navigation guidance in an integrated hybrid operating room is an innovative option to address technical challenges and reduce patient and operator radiation exposure associated with complex endovascular surgery. Most steps of a branched endografting procedure can be performed without X-Ray exposure when using electromagnetic navigation guidance and a modified branched endograft.

Quantification of Mechanical Characteristics of Conventional Steerable Ablation Catheters for Treatment of Atrial Fibrillation Using a Heart Phantom.

Accurate and reliable catheter navigation is important in formation of adequate lesions during radiofrequency cardiac catheter ablation. To inform future device design efforts and to characterize the limitations of conventional devices, the focus of this study is to assess and quantify the mechanical performance of manual ablation catheters for pulmonary vein isolation procedures within a phantom heart model. We measured three important metrics: accuracy of catheter tip navigation to target anatomical landmarks at the pulmonary veins (PVs), orientation of the catheter relative to the tissue at the targets, and the delivered force values and their stability and variations at those targets. A stereovision system was used for navigational guidance and to measure the catheter's tip position and orientation relative to the targets. To measure force, piezoelectric sensors were used which were integrated at the targets, whereby operators were instructed to stabilize the catheter to achieve a chosen reference force value. An overall positioning accuracy of 1.57 ± 1.71mm was achieved for all targets. No statistical significance was observed in position accuracy between the right and left PVs (p = 0.5138). The orientation of the catheter relative to tissue surface was 41° ± 21° with no statistical significance between targets. The overall force stability was 41 ± 6g with higher difficulty in force stabilization in the right compared to the left PV (40 ± 8 vs. 43 ± 2g, p < 0.0001). Based on our results, future improvements to manual catheter navigation for ablation should focus on improving device performance in orientation control and improved force stability.

Abstract No. 222 Accuracy of a Novel Augmented Reality Navigational Guidance Platform for Percutaneous Procedures

Abstract No. 222 Accuracy of a Novel Augmented Reality Navigational Guidance Platform for Percutaneous Procedures

Sonar glass—Artificial vision: Comprehensive design aspects of a synchronization protocol for vision based sensors

Supporting visually impaired people during their navigation is a challenging task that involves localization, tracking, navigation, obstacle avoidance, and path guidance. Many researchers have experimented with Sonar, RFID, GPS, NFC, walking sticks, waist-based devices, and even computer vision modules for blind navigation. Using five sonar sensors for obstacle detection with direction and timestamp, we developed Sonar Glass. As humans see in left, right, front, top, and bottom directions based on eye angle and the head pose, the sonar glass is designed to provide obstacle information at the same angle. The head movement of the visually impaired person activates a pair of sensors for each module. Understanding human eye movement mechanisms and developing a synchronization protocol for each pair of visual sensors on sonar glass sitting on both eyes is the main goal of this paper. The major challenge lies in understanding and simulating the human vision mechanism and to realize how the field of Artificial Intelligence can be a contributor in producing technologies for the visually impaired. We are using log-polar transform to simulate human retinal image mapping. The Scale Invariant Feature Transform (SIFT) algorithm has also been implemented. It is the first time that both human eyes can be replaced by vision sensors. After comparing the estimated obstacle information from one sensor pair with that of the other sensors, the voice track is activated. The blind person uses the nearest obstacle information to avoid the obstacle and to extract spatial information about obstacles ahead of the user and provide an early warning. Unique in its design, the sonar Glass’s synchronization protocol for a pair of related sensors provides possible object information in that direction. The executions were simulated in MATLAB and the results obtained in real time are found to be promising as the tests were carried out both indoor and outdoor. The sonar Glass design is unique of its kind and the synchronization protocol for the pair of related sensors provides the possible vision about the object information at that particular direction.

Barriers to guideline-concordant use of bone modifying agents for prostate cancer.

68 Background: NCCN Guidelines recommend the use of bone-modifying agents (BMAs) to prevent skeletal-related events (SRE) for patients with castrate-resistant prostate cancer (CRPC) and bone metastasis, but not for castrate-sensitive prostate cancer (CSPC). Prior studies have identified both underuse of BMAs for CRPC and overuse for CSPC, but the clinical circumstances underlying these apparent gaps in care are unknown. Methods: Qualitative interview study, with physicians who treat prostate cancer within an academic cancer center and an affiliated network of community-based practices. Using a semi-structured interview guide, an experienced moderator probed participants’ experiences and perceptions around NCCN Guidelines recommendations, guideline adherence and non-adherence, and barriers to adherence. Interviews also probed participants’ views of potential interventions to promote guideline-concordant BMA use. Participants used Likert-scale items to rate the likely effectiveness of each intervention in influencing BMA practice patterns. They also identified the 3 most helpful interventions for reducing BMA underuse and overuse separately. Results: 19 physicians were invited, of whom 15 agreed to participate; 1 physician did not respond to some questions as outside scope of practice. All were aware of the recommendation for use of BMAs in CRPC. 14% (2/14) were unaware of the recommendation against BMA use for CSPC; an additional 29% (4/14) believed that BMA use could be appropriate for CSPC depending on the burden of bony metastatic disease. 36% (5/14) were unaware of recommendations for baseline DEXA scan and BMA for patients with low bone mineral density. The most commonly reported barriers (occurring “often” or “sometimes”) to BMA use for CRPC were obtaining dental clearance (11/15) and insufficient time in clinic (6/15). The interventions perceived as most helpful to reduce underuse for CRPC were dental navigation (11/15) and EMR-based guidance (9/15). The interventions identified as most helpful to reduce overuse for CSPC were peer-to-peer education (14/15) and EMR-based guidance (13/15). Conclusions: Among physicians treating prostate cancer in our study, there was incomplete awareness of guideline recommendations for screening and treatment of low bone mineral density, and against BMA use for SRE prevention in CSPC. Dental navigation, peer-to-peer education, and EMR-based guidance were preferred implementation strategies to reduce underuse and overuse of BMAs.

Proposal and Validation of a New Nonradiological Method for Postoperative Three-Dimensional Implant Position Analysis Based on the Dynamic Navigation System: An In Vitro Study

To propose a novel, radiation-free method for postoperative three-dimensional (3D) position analysis of dental implants based on the dynamic navigation system (DNS) and evaluate its accuracy in vitro. A total of 60 implants were digitally planned and then placed in the standardized plastic models with a single-tooth gap and a free-end gap under the guidance of the DNS. Postoperative 3D positions of the inserted implants were evaluated using specially designed navigation-based software, and its datasets were superimposed onto those of cone beam computed tomography (CBCT) for accuracy analyses. Deviations at the coronal, apical, and angular levels were measured and statistically analyzed. The mean 3D deviation was 0.88 ± 0.37 mm at the entry point and 1.02 ± 0.35 mm at the apex point. The mean angular deviation was 1.83 ± 0.79 degrees. No significant differences were noted in the deviations between implants placed in the single-tooth gap and the free-end situation (p > 0.05) or between different tooth positions at distal extensions (p > 0.05). This non-radiographic method provides facile, efficient, and reliable postoperative implant position evaluation and may be a potential substitute for CBCT, particularly for implants placed under the guidance of dynamic navigation.

Guided Lateral Window Osteotomy Using Dynamic Navigation for Maxillary Sinus Augmentation: A Novel Technique.

The size and the position of the sinus antrostomy play a key role in making sinus grafting surgery more predictable and effective with less complications. A cone beam computed tomography and intraoral scan of the maxilla were taken for a patient who is missing maxillary first molar tooth with limited residual bone. Data were exported to the dynamic navigation (DN) system software. Sinus lateral window osteotomy position and dimensions were determined and planned using four 1.5 mm diameter implants placed on the maxillary sinus lateral wall. The osteotomy was initiated following the planned four 1.5 mm implants in a parallel motion to the bone surface using dynamic navigation guidance; thus, creating an outline for the lateral sinus window. Afterword's, the lateral sinus window was greenstick fractured and the membrane was lifted; first molar implant osteotomy done, implant placed, and bone graft material was placed. The flap was sutured, and post-operative instructions and medications were given. No post-operative complications noticed. The outline of the lateral window osteotomy along with implant osteotomy can be accurately planned and executed using DN technology, which may potentially reduce complications and insure accurate placement of the implant and the graft.

Cooperative optimal guidance of hypersonic glide vehicles by real-time optimization and deep learning

This paper investigates the cooperative optimal guidance of hypersonic glide vehicles (HGVs) in the terminal phase with consideration on time-varying velocity, aerodynamic forces, and practical constraints. The cooperative optimal guidance problem is formulated as an optimal control problem with time as the independent variable, which brings great convenience in controlling the impact time. We propose proper convexification techniques to convexify this problem and apply successive convex optimization to get the solution of the original problem. To achieve cooperative guidance of multiple HGVs with time coordination constraint, a deep learning–based approach is proposed to find an optimal common impact time assigned to all the HGVs. The training samples required by deep learning are obtained by convex optimization. An algorithm is then presented to summarize the cooperative optimal guidance strategy. In each guidance loop, the common impact time is updated according to mission conditions, and the guidance commands are generated by the successive solution procedure in real time. Numerical examples will be provided to demonstrate that the proposed cooperative optimal guidance algorithm is effective and efficient, and it can achieve better performance than a popular cooperative proportional navigation guidance law.

A generalized three-dimensional cooperative guidance law for various communication topologies with field-of-view constraint

In this paper, a generalized three-dimensional (3D) cooperative guidance law with seeker’s field-of-view (FOV) constraints is designed for multiple missiles to achieve salvo attack against a stationary target. The proposed generalized guidance law is composed of two parts: a proportional navigation guidance (PNG) component for target capture and a biased feedback component for simultaneous arrival. Two novel auxiliary functions are integrated into the biased feedback component to guarantee the satisfaction of FOV constraint. Furthermore, a time-varying lower bound that contains the impact time error is utilized to avoid the guidance command singularity. The proposed guidance law can be easily applied to various missile communication topologies, including centralized connected, distributed connected, and no-connected topologies. The convergence of impact time error, FOV constraint satisfaction, and command non-singularity of the proposed guidance law are theoretically analyzed and proved. Extensive numerical simulations with comparative studies are conducted to demonstrate the effectiveness and advantages of the proposed guidance law.

Health impacts of aircraft noise - a UK communities' perspective

UK Air Navigation Guidance regards 51dB LAeq16hr for day time noise and 45dB Lnight for night time noise as the levels at which aircraft noise annoyance occurs. WHO guidelines (2018) concluded that health effects can occur at lower levels of 45 dB Lden and 40 dB Lnight. Current policy recognises that noise annoyance can occur below 51dBLAeq yet it is not known how many people around UK airports may be adversely affected at these lower levels. This paper will seek to estimate the population size impacted by aircraft noise below 51dB LAeq around Heathrow airport. It will also seek to provide an international comparison of the noise policies of different airports in Europe and globally, the size of the population impacted and the minimum threshold for the onset of health effects. The most radical changes in UK airspace history will take place in the next decade. If more people are adversely impacted by aircraft noise at lower levels then this has significant ramifications for the cost benefit analysis of airspace changes. It is crucial that communities can understand the full health impacts of the proposals.

The Evolution of Minimally Invasive Spine Tumor Resection and Stabilization: From K-Wires to Navigated One-Step Screws.

Minimization of the surgical approaches to spinal extradural metastases resection and stabilization was advocated by the 2012 Oncological Guidelines for Spinal Metastases Management. Minimally invasive approaches to spine oncology surgery (MISS) are continually advancing. This paper will describe the evolution of minimally invasive surgical techniques for the resection of metastatic spinal lesions and stabilization in a single institute. A retrospective analysis of patients who underwent minimally invasive extradural spinal metastases resection during the years 2013-2019 by a single surgeon was performed. Medical records, imaging studies, operative reports, rates of screw misplacement, operative time and estimated blood loss were reviewed. Detailed description of the surgical technique is provided. Of 138 patients operated for extradural spinal tumors during the study years, 19 patients were treated in a minimally invasive approach and met the inclusion criteria for this study. The mortality rate was significantly improved over the years with accordance of improve selection criteria to better prognosis patients. The surgical technique has evolved over the study years from fluoroscopy to intraoperative 3D imaging and navigation guidance and from k-wire screw insertion technique to one-step screws. Minimally invasive spinal tumor surgery is an evolving technique. The adoption of assistive devices such as intraoperative 3D imaging and one-step screw insertion systems was safe and efficient. Oncologic patients may particularly benefit from the minimization of surgical decompression and fusion in light of the frailty of this population and the mitigated postoperative outcomes associated with MIS oncological procedures.

Patient-specific Cardio-respiratory Motion Prediction in X-ray Angiography using LSTM Networks

Objective. To develop a novel patient-specific cardio-respiratory motion prediction approach for X-ray angiography time series based on a simple long short-term memory (LSTM) model. Approach. The cardio-respiratory motion behavior in an X-ray image sequence was represented as a sequence of 2D affine transformation matrices, which provide the displacement information of contrasted moving objects (arteries and medical devices) in a sequence. The displacement information includes translation, rotation, shearing, and scaling in 2D. A many-to-many LSTM model was developed to predict 2D transformation parameters in matrix form for future frames based on previously generated images. The method was developed with 64 simulated phantom datasets (pediatric and adult patients) using a realistic cardio-respiratory motion simulator (XCAT) and was validated using 10 different patient X-ray angiography sequences. Main results. Using this method we achieved less than 1 mm prediction error for complex cardio-respiratory motion prediction. The following mean prediction error values were recorded over all the simulated sequences: 0.39 mm (for both motions), 0.33 mm (for only cardiac motion), and 0.47 mm (for only respiratory motion). The mean prediction error for the patient dataset was 0.58 mm. Significance. This study paves the road for a patient-specific cardio-respiratory motion prediction model, which might improve navigation guidance during cardiac interventions.

Highlights from the Detroit SID Vehicle Display Symposium and Exposition

Highlights from the Detroit SID Vehicle Display Symposium and Exposition

Design and Implementation of Tour Guide Robot for Red Education Base

This article focuses on the development of red tourism and the construction of red education bases, and designs a tour guide robot that combines with the Internet of Things for guiding and promoting red education bases. The motion control part of this design is completed by STM32, and the control system adopts the ROS (Robot Operating System) framework, achieving functions such as map construction, path planning, navigation, obstacle avoidance, and voice guidance. The robot also implements the Internet of Things to improve human-machine interaction and user experience.

Autonomous Navigation and People Guidance by a Mobile Robot

Autonomous Navigation and People Guidance by a Mobile Robot

Parameter Identification of a PN-Guided Incoming Missile Using an Improved Multiple-Model Mechanism

An active defense against an incoming missile requires information of it, including a guidance law parameter and a first-order lateral time constant. To this end, assuming that a missile with a proportional navigation (PN) guidance law attempts to attack an aerial target with bang-bang evasive maneuvers, a parameter identification model based on the gated recurrent unit (GRU) neural network is built in this paper. The analytic identification solutions for the guidance law parameter and the first-order lateral time constant are derived. The inputs of the identification model are available kinematic information between the aircraft and the missile, while the outputs contain the regression results of missile parameters. To increase the training speed and the identification accuracy of the Model, an output processing method called improved multiplemodel mechanism (IMMM) is proposed in this paper. The effectiveness of IMMM and the performance of the established model are demonstrated through numerical simulations under various engagement scenarios.

Investigation of the Performance Characteristics of the Angle-based Proportional Navigation Guidance Law

Guidance commands generated by the proportional navigation guidance (PNG) law which constitutes the most popular one among the guidance laws applied on the guidance munition fired against predetermined targets are in the form of linear acceleration or angular speed as dictated by the relevant engagement geometry. As a result of the studies in which notable linear acceleration- and angle-based guidance laws are compared, it is seen the lateral acceleration values obtained with the PNG law occur in a lower level than the results of the angle-based guidance laws. However, the angle-based guidance laws lead to lower final miss distances. In this study, the PNG law is so adapted that it yields angle-based guidance commands and then it is applied upon a short-range air-to-surface missile against a maneuvering surface target as well as the velocity pursuit guidance law that is nothing but a version of PNG law, linear homing guidance law, and body pursuit guidance law. After the computer simulations, it is observed that the angle-based PNG law produces smaller final miss distances compared to its original form. The resulting lateral accelerations are in admissible levels. Also, the engagement duration values with the target happen to be almost the same.

Smartphone-based Indoor Navigation for Guidance in Finding Location Buildings Using Measured WiFi-RSSI

This study investigates a Wi-Fi-based indoor navigation system to determine building locations. The system was developed using the fingerprint method from the Received Signal Strength Indication (RSSI) of each Access Point (AP). The main components of a smartphone-based system use data from Wi-Fi and the Global Positioning System (GPS). The system developed for navigation is designed and implemented as an element of a dynamic, seamless mobility planning and building location route guidance application. Building map data is collected from Google Map data and enhanced by coloring the geographic location of buildings displayed on mobile devices. Navigational aids collected from sensors provide trip orientation and position updates. The approach of measuring the distance between known positions is compared to those displayed in the application with the haversine formula to measure the accuracy of the position displayed. A series of experiments were conducted in the Politeknik Negeri Semarang area, Indonesia. The experiment results showed that the Wi-Fi-based indoor positioning system was accurate within 7.050 meters of the error for that location, thus proving the system's usefulness for determining the location of buildings in the campus area. The measurement has not adopted the maximum APs placement for signal coverage and strength, only using the existing APs positions. The temperature nor humidity was neither measured in each area where the AP was installed, which is discussed later. This system can help visitors without asking, even though they have only visited once.

Innovative C-Arm-Free Navigation Technique for Posterior Spinal Fixation for Atlantoaxial Subluxation: A Technical Note.

Study design: Technical note. Objectives: To present a novel C-arm-free technique guided by navigation to insert and place a C1 lateral mass screw. Background and Objectives: Atlantoaxial subluxation (AAS) is a relatively common sequelae in patients with rheumatoid arthritis (RA) and upper cervical trauma. If they present with severe symptoms, surgical intervention such as posterior fusion is indicated. The established treatment for AAS is fixation with a C1 lateral mass screw and C2 pedicle screw (modified Goel technique) to achieve bony fusion. However, this technique requires fluoroscopy for C1 screw insertion. To avoid exposing the operating team to radiation, we present here a novel C-arm-free C1 lateral mass screw insertion technique for AAS. Materials and Methods: A 67-year-old man was referred to our hospital with neck pain, quadriparesis, and clumsiness and numbness of both upper and lower limbs. He had undergone C3-6 posterior fusion previously in another hospital. In physical examination, he had severe muscle weakness of bilateral upper limbs and hypoesthesia of all four limbs. He had hyper-reflexia of bilateral lower limbs and pollakiuria. His Japanese orthopedic score was 8 points out of 17. Preoperative radiograms showed AAS with an atlantodental interval (ADI) of 7 mm. MRI indicated retro-odontoid pseudotumor and severe spinal cord compression at the C1-2 level. The patient underwent posterior atlantoaxial fixation under navigation guidance. To prevent epidural bleeding during the insertion and placement of a C1 lateral mass screw, we have here defined a novel screw insertion technique. Results: The surgical time was clocked as 127 min and blood loss was 100 mL. There were no complications per-operatively or in the postoperative period. The patient showed almost full recovery (JOA 16/17) at two months follow-up and a solid bony fusion was noticed in the radiograms at one year follow-up. Conclusions: This novel surgical procedure and C1 lateral mas screw placement technique is a practical and safe method in recent advances of AAS treatment. Procedurally, the technique helps prevent epidural bleeding from the screw entry point and also allows for proper C1 screw insertion under navigation guidance without exposing surgeons and staff to the risk of fluoroscopic radiation.

Air-Ground Integrated Mobile Edge Computing in Vehicular Visual Sensor Networks

In the vehicular visual sensor networks, multiple vehicles with on-board cameras capture visual observations of the environment while moving along their trajectories and the 3-D map is jointly estimated to provide guidance for real-time navigation. Due to high mobility of vehicles and heavy computation burden of 3-D map estimation, the cooperative vehicular visual sensing is latency-critical and computation-intensive, and thus suitable to be solved by edge computing. This article designs an air-ground integrated mobile edge computing (MEC) framework for the vehicular visual sensor networks, in which parallel computation is implemented by the vehicles locally and also partially offloaded to the edge server on the unmanned aerial vehicle (UAV), and our aim is to minimize the total latency of the network through the optimization of the UAV trajectory and the offloading ratios of vehicles. To characterize the motion, sensing, computation, and communication processes in the network, the timeline includes two periods, with the motion period for motion and sensing and the service period for computation and communication, where the service period is divided into several stages with the latency models for computation or communication in each stage. Then we propose a dynamic alternate trajectory design and partial offloading scheduling algorithm for the air-ground integrated MEC in the vehicular visual sensor networks. Numerical results verify the effectiveness of our scheme in terms of latency and also show the impacts of computation burden, computation capability, and communication condition on performance.