Navigation Assistance Research Articles

Incidence and risk factors associated with superior-segmented facet joint violation during minimal invasive lumbar interbody fusion

BACKGROUND CONTEXTThe trend of minimally invasive lumbar interbody fusion is increasing, and adjacent segmental degeneration (ASD) is one of the complications of the procedures in which facet joint violation (FJV) is a cause. FJVs can occur during percutaneous instrumentation. This study aimed to identify the risk factors that affect FJV during minimally invasive lumbar interbody fusion. PURPOSETo identify the risk factors for FJVs and the factors that have a strong impact on the violation. STUDY DESIGNRetrospective study. PATIENT SAMPLEPatients who underwent minimally invasive lumbar interbody fusion with percutaneous screw fixation between June 2018 and December 2019. OUTCOME MEASURESPrevalence of the FJV was reviewed by CT scans which obtained within 6 months after surgery, and the axial, coronal, and sagittal cuts of the scans were evaluated. The FJV was defined as the screw being visible in the facet joint in at least one plane of the CT scan. Radiographic parameters were measured using CT scans including diameters of the facet joints in the axial, coronal, and sagittal planes defined by the facet diameter. The facet angle (FA), the pedicle angle (PA), the screw-facet angle (SFA), the screw-endplate angle (SEA), and the superior margin of the facet joint in the sagittal plane (SD) differed from the head of the screw. At Last, the depth of back muscle was measured in the axial cut of the MRI. METHODSThis study analyzed 119 patients who underwent minimally invasive lumbar interbody fusion between June 2018 and December 2019. Facet joint violation at the uppermost level was examined using CT in all dimensions. Radiographic parameters (facet diameter, facet angle, pedicle angle, screw-facet angle, screw-endplate angle, and distance between the head of the screws and the facet) were measured. BMI, age, diagnosis, and navigation assistance were included in the study. Risk factors were analyzed to determine which factors had an effect on FJV, and the cut-off was calculated for each parameter. RESULTSThis study included 119 patients, with a mean age of 63 years. FJV occurred in 13/119 (10.9%) patients and 15/238 (6.3%) joints, respectively. No FJV occurred in 120 joints operated with navigation-assistance and 15/178 (8.4%) joints operated without navigation (p=.01). We found an increasing proportion of violations at more caudal levels: no violations occurred in eight patients with lumbar at L1 or L2, and 1/40 (2.5%), 7/158 (4.4%), and 7/32 (21.9%) of violations occurred at L3, L4, and L5, respectively (p=.01). The diameter of the facet in the axial cut, facet angle, screw facet angle, and distance between the head of the screw and facet were statistically significant in determining the increasing rate of FJV after multivariate analysis was performed (AROC=0.9486, p≤.05). The cutoff point for each radiographic parameter were diameter of facet in the axial ≥17.5 mm, diameter of facet in coronal plane ≥19.5 mm, facet angle ≥41.5o, screw-facet angle ≥39o, and distance between facet and the screw ≥-2.6 mm. The estimated probability of FJV was 96.9% when every parameter was greater than the cut-off point. CONCLUSIONSAn increase in the facet diameter in the axial plane, coronal plane, facet angle, screw facet angle, and the distance between the dome of the screw and facet are risk factors for FJV. Surgeons can avoid violations when radiographic considerations are done. Careful screw placement and good entry points for instrumentation may decrease the rate of facet violation.

Assisted Navigation Algorithm for Wireless Sensor Actuator and Robot Networks

Wireless Sensor, Actuator and Robot Networks (WSARNs) are made of mobile and static sensor nodes that interact in order to collaboratively perform specific tasks, such as supporting assisted navigation for mobile robotic nodes that carry out requested operations in hostile environments, where the human presence is impracticable. In this regard, it is worth noting that assisted navigation algorithms have a highly dynamic nature, and are implemented by sensor nodes that are characterized by limited transmission power and lean autonomy in terms of computing and memory capacity. This paper presents an improved version of the assisted navigation algorithm based on the concept of “credit field”. The main aim of the proposed algorithm is to reduce and balance the energy consumption among the static sensor nodes when running the algorithm to manage the presence of obstacles and adversary areas, thus extending the lifetime of WSARNs. The algorithm has been tested on a hybrid sensor network that employs Mica2 Motes as static sensor nodes and Lego Mindstorms robots integrated with a Stargate board developed by Crossbow as mobile nodes.

Correction to: An efficient object detection system for indoor assistance navigation using deep learning techniques

Correction to: An efficient object detection system for indoor assistance navigation using deep learning techniques

Path planning for assisting blind people in purposeful navigation

Blind <span>people present dificulties for reaching objects of interest in the daily life. In this sense, the integration of a path planning module for assisting blind people in purposeful navigation is noteworthy. In this work, we present an algorithm that leverages the high capability of an embedded computer with graphics processing unit (GPU) NVIDIA Jetson TX2 for computing optimal paths to objects of interest. The algorithm computes the optimal path to the objective, considering changes in the environment and changes in the position of the user. The algorithm is efficient for computing new paths when the environment changes by reusing parts of previous computations. In order to compare the performance, the algorithms were implemented and evaluated in MATLAB, C++ and CUDA, for different size of the grid and percentage of unknown obstacles. We found that the implementation on GPU has a speed up of 20 times W.R.T the implementation in C++ and more than 400 times W.R.T the implementation in MATLAB. These results boost us to integrate this module to our main system based on a stereo camera and a haptic belt and so provide to the user assistance in purposeful navigation at real time.</span>

Single Position Lateral Lumbar Interbody Fusion With Posterior Instrumentation Utilizing Computer Navigation and Robotic Assistance: Retrospective case review and surgical technique considerations

Study DesignRetrospective cohort study.ObjectiveTo determine safety and short-term outcomes of single-position lateral lumbar interbody fusion (LLIF) with bilateral posterior instrumentation and robotic assistance. The article also describes surgical technique considerations for the procedure.Methods20 patients underwent single-position LLIF with posterior instrumentation and robotic assistance. The patients were followed for a minimum of 3 months post-operatively.ResultsAverage operative time was 211 ± 34 minutes, average blood loss was 51.25 ± 17 cc’s, and average length of stay was 1.4 ± .75 days. There were no intraoperative complications, readmissions, revision surgeries, and no incidence of hardware malposition. Significant improvement in pain and ODI scores was noted at 3 month follow up.ConclusionsThe study demonstrated safety and short-term clinical efficacy of minimally invasive single-position lateral lumbar interbody fusion with bilateral posterior instrumentation utilizing robotic assistance and navigation. There are certain surgical technique considerations that must be followed to ensure optimal surgical workflow and predictable outcomes.

An evaluation of EfficientDet for object detection used for indoor robots assistance navigation

An evaluation of EfficientDet for object detection used for indoor robots assistance navigation

An efficient object detection system for indoor assistance navigation using deep learning techniques

An efficient object detection system for indoor assistance navigation using deep learning techniques

Individual Differences and Skill Training in Cognitive Mapping: How and Why People Differ.

Spatial ability plays important roles in academic learning and everyday activities. A type of spatial thinking that is of particular significance to people's daily lives is cognitive mapping, that is, the process of acquiring, representing, and using knowledge about spatial environments. However, the skill of cognitive mapping shows large individual differences, and the task of spatial orientation and navigation poses great difficulty for some people. In this article, I look at the motivation and findings in the research into spatial knowledge acquisition from an individual differences perspective. I also discuss major implications of the existence of large individual differences, particularly the possibility of improving cognitive mapping by training and adjusting navigation assistance to the wide variations in spatial aptitudes and preferences among people.

Complications associated with subaxial placement of pedicle screws versus lateral mass screws in the cervical spine: systematic review and meta-analysis comprising 1768 patients and 8636 screws.

Lateral mass screw (LMS) fixation for the treatment of subaxial cervical spine instability or deformity has been traditionally associated with few neurovascular complications. However, cervical pedicle screw (CPS) fixation has recently increased in popularity, especially with navigation assistance, because of the higher pullout strength of the pedicle screws. To their knowledge, the authors conducted the first meta-analysis comparing the complication rates during and/or after CPS and LMS placement for different pathologies causing cervical spine instability. A systematic literature search of PubMed and Embase from inception to January 12, 2021 was performed to identify studies reporting CPS and/or LMS-related complications. Complications were categorized into intraoperative and early postoperative (within 30days of surgery) and late postoperative (after 30days from surgery) complications. All studies that met the prespecified inclusion criteria were pooled and cumulatively analyzed. A total of 24 studies were conducted during the time frame of the search and comprising 1768 participants and 8636 subaxially placed screws met the inclusion criteria. The CPS group experienced significantly more postoperative C5 palsy (odds ratio [OR] = 3.48, 95% confidence interval [CI] = 1.27-9.53, p < 0.05). Otherwise, there were no significant differences between the LMS and CPS groups. There were no significant differences between the CPS and LMS groups in terms of neurovascular procedure-related complications other than significantly more C5 palsy in the CPS group.

Experiences with Medicaid Renewal and Reauthorization Policies in the Context of Child Health and Vaccine Coverage.

Difficulties complying with Medicaid recertification requirements may be responsible for a portion of Medicaid disenrollments and may impact access to preventive care. This study aimed to explore the barriers parents experienced renewing their child's Medicaid, how those barriers impact access to healthcare, and how changes in Medicaid policy can improve child health outcomes. To understand the barriers associated with Medicaid renewal, authors conducted in-depth interviews (N = 24) with racially and demographically diverse parents living in Baltimore. They found that administrative burden, lack of awareness regarding reauthorization, challenges with navigation assistance, and lack of access to the renewal system were crucial barriers to renewing Medicaid. Many participants identified negative impacts on child health outcomes resulting from lapses in coverage, including lack of healthcare access and missed immunizations. Drawing on these findings, the authors provide recommendations for streamlining and clarifying the Medicaid renewal process in Maryland, and the role of social work policy and practice in reducing barriers to renewal.

HikePal: A mobile exergame to motivate people with intellectual disabilities to do outdoor physical activities

People with intellectual disabilities often have a sedentary lifestyle that can lead to long-term issues like cardiovascular diseases, diabetes, obesity and depression. Although literature shows that the main reason for this is the lack of motivation to do physical activity, scarce research has been done in accessible apps to track and foster physical activities that address motivation. This paper presents HikePal, a game-inspired app to motivate individuals with intellectual disabilities to do physical activity outdoors. We have followed a design and creation research strategy using 1) semi-structured interviews with five experts (health care workers, special education experts and software engineers); 2) a focus group with an occupational therapist, a physical therapist and four software engineers; 3) a pilot user test with three individuals with intellectual disabilities and their caregivers. Having social interaction during the physical activity turned out to be a major motivational aspect of the system, whereas reward systems did not attract much of the users’ attention. Regarding the adapted navigational assistance, we found out that easy-to-read text, visual communication and street-level pictures were the key features to achieve successful and understandable guidance outdoors for people with intellectual disabilities. It proved useful to perform a test on the field and to refine the design guidelines in view of a forthcoming large-scale experimental test involving a larger number of persons with intellectual, sensory and motor disabilities.

Landmark information included in turn-by-turn instructions induce incidental acquisition of lasting route knowledge

ABSTRACT The augmentation of landmarks in auditory navigation instructions has been shown to improve incidental spatial knowledge acquisition during assisted navigation. Here, two driving simulator experiments are reported that replicated this effect even when adding a three-week delay between navigation and spatial tasks and varying the degree of detail in the provided landmark information. Performance in free- and cued-recall of landmarks and driving the route again without assistance demonstrated increased landmark and route knowledge when navigating with landmark-based compared to common GPS instructions. The results emphasize that adding auditory landmark references to existing navigation systems can potentiate processing of spatial features of the environment during every-day navigation.

Digital orthopedics technology leads the new development direction of arthroplasty

Digital orthopedics technology is a new interdisciplinary subject, known as the third technological wave in the field of orthopedics. The development direction of arthroplasty is focused on hoping to improve the long-term prognosis of patients by imitating more natural kinematics and optimizing implant positioning strategies. At present, various digital orthopedic technologies such as virtual reality technology, navigation assistance systems, and patient-specific instrumentation (PSI) and robot-assisted surgery in joint surgery are in full swing. In this article, relevant domestic and foreign literature were extensively reviewed and the author's own experiences were summarize, and the advantages, disadvantages, clinical efficacy and future prospects of the above-mentioned various technologies were evaluated too.

Pedestrian Lane Detection for Assistive Navigation of Vision-Impaired People: Survey and Experimental Evaluation

Pedestrian lane detection is one of the most crucial tasks in assistive navigation for vision-impaired people. It can provide information on walkable regions, help blind people stay on pedestrian lanes, and assist with obstacle detection. An accurate and real-time lane detection algorithm can improve travel safety and efficiency for the visually impaired. However, despite being an important task for assistive navigation systems, pedestrian lane detection in unstructured scenes has not attracted sufficient attention in the research community. Hence, this paper aims to provide a comprehensive review and an experimental evaluation of methods that can be applied for pedestrian lane detection, thereby laying a foundation for future researchers in this area. This study includes methods proposed for pedestrian lane detection, general road detection, and general semantic segmentation. We review these methods in two categories: traditional methods and deep learning methods. We perform an experimental evaluation of representative methods on a large benchmark dataset specifically created for pedestrian lane detection. We hope this paper can serve as an informative guide for researchers in the field of assistive navigation, and facilitate urgently-needed research for blind people.

Reliable Data Transmission Scheme for Perception Layer of Internet of Underwater Things (IoUT)

Internet of Underwater things (IoUT) is growing into one of the most important research interests since the last few decades. The primary objective of IoUT is to develop a worldwide network of smart underwater-interconnected objects. It has wide-ranging aquatic applications, including surveillance, pollution reduction, monitoring offshore oil and gas pipelines, disaster prevention, and navigation assistance, making it as important as a terrestrial communication system. The underwater communication channel poses unique acoustic communication challenges that suffer from long propagation delay, low bandwidth, multipath, and fading. IoUT significantly differs from the conventional Internet of Things (IoT) due to disparate environmental conditions under the ocean that require re-designing the underwater communication channel model. In addition to the challenges mentioned above, end-to-end delay and efficient energy utilization are also of great concern. Therefore, in this research paper, diverse attributes of underwater acoustic communication, including the speed of sound, transmission loss, absorption, and ambient noise, are analyzed to design a channel model for underwater communication. These environmental conditions also make underwater acoustic channels highly variable, so efficient resources, including bandwidth and power, are required. Adaptive modulation is proposed to make the communications system efficient by considering the distance between nodes and the signal-to-noise ratio as channel state information. The proposed channel model critically analyzed the CSI factors, results show efficient bandwidth utilization and appropriate power consumption for the well-suited route. The proposed research also aims to reduce end-to-end propagation delay by considering vertical angle-based shortest path (efficient route) in the Multilevel rotating priority MRP-routing algorithm.

Comparison of the Static and Dynamic Vibrotactile Interactive Perception of Walking Navigation Assistants for Limited Vision People

As an effective indication signal, vibration tactile has been widely studied. However, there is still a lack of comparative studies on the use of tactile interaction perception of both static vibration and dynamic vibration as direction indication signals for walking-assistance navigation products for the limited vision. Limited vision people have to perceive the travel environment through nonvisual senses. Besides, vibration and touch can reduce cognitive pressure in complex environments compared with auditory. This study aimed to compare the comprehensive interactive perception of direction indication by both static vibration and dynamic vibration in walking-assistance navigation products for limited vision people. In the tactile interaction perception experiment of static vibration and dynamic vibration, twenty-four participants were involved in the experiment. We measured the direction reaction time, the correct number of direction perceptions, and asked participants to evaluate the degree of perception and perceived comfort in each mode. It can be seen from the results that compared with the dynamic vibration, the static vibration had a higher correct perception numbers (F = 10.394, P = 0.006) and a shorter reaction time (F = 5.276, P = 0.038). And participants’ perception degree (F = 21.221, P < 0.001) and comfort degree (F = 47.692, P < 0.001) in static mode were higher than those in dynamic mode. In conclusion, the static vibration is superior to the dynamic vibration in terms of the comprehensive perception of direction indication. The static vibrotactile interactive perception is preferred as a direct indication signal in the walking-assistance navigation products for the limited vision.

Cognition-Driven Navigation Assistive System for Emergency Indoor Wayfinding (Cogdna): Proof of Concept and Evidence

Cognition-Driven Navigation Assistive System for Emergency Indoor Wayfinding (Cogdna): Proof of Concept and Evidence

Smart Glasses and Augmented Reality: Empowering Maintenance Personnel in Industrial Settings

The efficient maintenance and servicing of industrial equipment are crucial for the smooth operation of manufacturing facilities. However, maintenance personnel often encounter challenges in locating and addressing specific issues, such as equipment jams, within complex systems. Despite the presence of SCADA or HMI systems that can indicate the existence of a fault, identifying the exact location of the issue within the system remains a significant hurdle. This research aims to explore the development and implementation of smart glasses integrated with augmented reality (AR) technology to provide maintenance personnel with real-time, location-based navigation assistance within industrial environments. By leveraging AR, the proposed smart glass software will function as a navigational tool, guiding users directly to the precise location of equipment faults, resembling "Google Maps" for industrial maintenance. This research seeks to investigate the potential impact of AR-assisted navigation on the efficiency and effectiveness of maintenance activities, particularly in complex industrial settings. Furthermore, the study will address the usability, user acceptance, and technical feasibility of integrating AR technology into maintenance processes, ultimately contributing to the advancement of smart maintenance solutions in industrial settings.

Evaluating predictability in outdoor mobility: A potential pathway to personalized assistance for people with dementia

AbstractBackgroundPeople with dementia (PwD) often become lost, which is commonly attributed to spatial disorientation, one of the earliest symptoms of dementia, particularly of the Alzheimer’s disease type. Spatial disorientation can limit a person's ability to navigate in an outdoor environment. As a result, PwD experience outdoor mobility decline, which, in turn, can have a negative impact on their cognitive functions. Thus, enabling safe outdoor mobility is important for dementia research. Artificial Intelligence (AI) methods in conjunction with Global Positioning System (GPS) data show great potential for supporting the outdoor mobility needs of PwD. The objective of this work is to evaluate the extent to which we can predict future destinations of PwD by learning from their past mobility habits.MethodEight cognitively‐intact older adults (CTL) and seven older adults with dementia completed four weeks of GPS recording. Each participant’s stops and trips were extracted from their trajectories. We determined the predictability of each participant’s mobility patterns using three approaches. First, we assumed each stop is visited with equal probability, thus, disregarding temporal aspects of travel. Next, we built on the previous approach by including stop visitation probability, thus, capturing the heterogeneity of visitations. Finally, to capture the full spatiotemporal characteristics of mobility, we added in‐depth temporal characteristics including the visitation frequency, the order in which the stops were visited, and the time spent at each stop.ResultRelying solely on the spatial dimension of mobility yielded no predictive power across the two groups. Adding the heterogeneity of visitation patterns, we observed an increase in the predictability power; PwD displayed a trend toward higher predictability compared to the CTLs, but the student’s t‐test did not reach statistical significance (0.833±0.085vs.0.768±0.029, t(13)=‐2.06, p=0.06; d=‐1.07). Finally, relying on full spatiotemporal characteristics, a 4‐week record of mobility patterns displayed 95% (SD=2%) and 92% (SD=1%) predictability among PwD and CTLs, respectively. This value was significantly higher among PwD, t(13) = ‐3.39, p&lt;.01; d=‐1.75.ConclusionOur findings offer new perspectives on the predictive mobility models based on GPS data and AI that can be used to provide personalized assistance for outdoor navigation of people with dementia.

Optimal Staffing for Vessel Traffic Service Operators: A Case Study of Yeosu VTS.

Vessel traffic volume and vessel traffic service (VTS) operator workloads are increasing with the expansion of global maritime trade, contributing to marine accidents by causing difficulties in providing timely services. Therefore, it is essential to have sufficient VTS operators considering the vessel traffic volume and near-miss cases. However, no quantitative method for determining the optimal number of workstations, which is necessary for calculating the VTS operator staffing level, has yet been proposed. This paper proposes a new, microscopic approach for calculating the number of workstations from vessel trajectories and voice recording communication data between VTS operators and navigators. The vessel trajectory data are preprocessed to interpolate different intervals. The proposed method consists of three modules: Information services, navigational assistance services, and traffic organization service. The developed model was applied to the Yeosu VTS in Korea. Another workstation should be added to the current workstation based on the proposed method. The results showed that even without annual statistical data, a reasonable VTS operator staffing level could be calculated. The proposed approach helps prevent vessel accidents by providing timely services even if the vessel traffic is congested if VTS operators are deployed to a sufficient number of workstations.