Local Navigation Research Articles

Abstract A20: Hispanic patient navigation: An intervention to increase clinical trial participation

Abstract Background: Hispanics are the fastest-growing population in North Carolina and have unique health care needs related to culture and language. To meet their needs and address the historically low participation in cancer clinical trials, we developed a bilingual Hispanic Clinical Trial Navigator (HCTN) position to support Hispanic adult and pediatric patients treated at Wake Forest Baptist Comprehensive Cancer Center (WFBCCC). The HCTN is a novel approach to integrate culturally and linguistically competent navigation with support around clinical trial decision making. The purpose of this analysis was to evaluate the services provided during the program's first year and its impact on clinical trial participation. Methods: Retrospective data from 11/1/2015 to 10/31/2016 were obtained from a navigation database, WFBCCC cancer registry, and clinical trial system. Data are reported in the aggregate, and clinical trial participation rates were compared to data prior to the hiring of the HCTN (11/1/2014-10/31/2015). Results: There were 108 pediatric and adult patients navigated during the first year; 55 breast screening/diagnostic and 53 cancer treatment. The majority of patients were female (87%) with a mean age of 45 years. The most common diagnoses among treatment patients were breast (47%), hematologic (34%), and gastrointestinal (6%) malignancies. Major patient barriers identified include treatment logistics/transportation (87%), financial/insurance (70%) information/education (55%), and continuity of care (53%). In addition to education and referrals, the HCTN was able to remove potential barriers to trial participation through transportation assistance (31%), meal vouchers (21%), and parking validation (40%). In the year prior to the HCTN there were 88 newly diagnosed Hispanic patients with a clinical trial participation rate of 20% in treatment/non-treatment intervention studies. With HCTN navigation, clinical trial participation among Hispanic patients navigated was 34%. Conclusions: Our data indicate an initial success in increasing Hispanic participation in cancer clinical trials utilizing an HCTN. Navigation is now available in a majority of community cancer centers and is used as an opportunity to provide culturally and linguistically appropriate patient support around cancer and clinical trials. Placing HCTNs in cancer treatment settings could be a cost-effective and efficient method of providing navigation, while also facilitating state-of-the-art care through clinical trials. Opportunities exist for additional studies of navigation to increase clinical trial participation in underserved populations. Citation Format: Carla Strom, Kathryn E. Weaver, Jimmy Ruiz, Karen M. Winkfield. Hispanic patient navigation: An intervention to increase clinical trial participation [abstract]. In: Proceedings of the Tenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2017 Sep 25-28; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2018;27(7 Suppl):Abstract nr A20.

Mistie Problem and Correction Method of Single Channel Seismic Data in Shallow Sea

In processing and interpreting the shallow sea single channel or 2D seismic data, it is found that there are Mistie problems when the sections intersect. The existence of Mistie caused great inconvenience to our interpretation work, fine stratigraphic interpretation and amplitude mapping is required to do Mistie correction, therefore, the closure of seismic data is an indispensable work in processing. Through the analysis of Mistie problem of a shallow seismic area, it is resulted from the inaccuracy of navigation position and the tide, and the coordinate correction technique and tidal correction technique are used to correct the position inaccuracy and tidal effects. The correction result shows that the Mistie problem has been greatly improved.

Local and Global Navigation Maps for Safe UAV Flight

Local and Global Navigation Maps for Safe UAV Flight

Noise Immunity Analysis of LocataNet Navigation Receiver

The manuscript considers the problem of analyzing the reception characteristics of a pulse signal with intrapulse phase shift keying, used in local navigation systems such as LocataNet. Analytic formulas for the statistical characteristics of in-phase and quadrature correlators, a phase discriminator and standard errors of signal phase tracking are obtained. Noise immunity of signal acquisition and signal tracking modes is analysed. The manuscript shows that, at the same average energy of the pulse signal during the repetition period and the continuous phase-shifted signal at the same repetition period, the noise immunity of their reception both in search mode and in tracking mode is the same. Noise immunity of the received signals from LocataNet system is enhanced by increasing the navigation signal power at the receiver input.

Локальная навигационная система для автоматического причаливания судна

This paper shows that it is necessary to solve the problem of accurate ship positioning to provide automatic ship berthing. It is impossible to solve this problem using global positioning systems since they do not provide the proper precision. The principles and methods of development of a local navigation system are discussed. The system operation is based on measurement of the distance between the antennas of radio equipment installed on a ship and at the quay. Microwave propagation analysis is used for distance measurements. It is followed by a homodyne procession of microwave signals and the phase difference measurements on low-frequency signals. The block diagram of the rangefinder and its operation principles are described. The main equations that determine functioning of the system are given. The procedure of the range finding by measuring the phase difference between signals is analyzed; some limitations of the method are shown. Some aspects of system operation concerning selection of its operating frequencies are discussed. It is shown that using the proposed block diagram gives possibility to create an effective local navigation system to provide automatic ship berthing.

Feasibility of A-mode ultrasound based intraoperative registration in computer-aided orthopedic surgery: A simulation and experimental study.

PurposeA fast and accurate intraoperative registration method is important for Computer-Aided Orthopedic Surgery (CAOS). A-mode ultrasound (US) is able to acquire bone surface data in a non-invasive manner. To utilize A-mode US in CAOS, a suitable registration algorithm is necessary with a small number of registration points and the presence of measurement errors. Therefore, we investigated the effects of (1) the number of registration points and (2) the Ultrasound Point Localization Error (UPLE) on the overall registration accuracy.MethodsWe proposed a new registration method (ICP-PS), including the Iterative Closest Points (ICP) algorithm and a Perturbation Search algorithm. This method enables to avoid getting stuck in the local minimum of ICP iterations and to find the adjacent global minimum. This registration method was subsequently validated in a numerical simulation and a cadaveric experiment using a 3D-tracked A-mode US system.ResultsThe results showed that ICP-PS outperformed the standard ICP algorithm. The registration accuracy improved with the addition of ultrasound registration points. In the numerical simulation, for 25 sample points with zero UPLE, the averaged registration error of ICP-PS reached 0.25 mm, while 1.71 mm for ICP, decreasing by 85.38%. In the cadaver experiment, using 25 registration points, ICP-PS achieved an RMSE of 2.81 mm relative to 5.84 mm for the ICP, decreasing by 51.88%.ConclusionsThe simulation approach provided a well-defined framework for estimating the necessary number of ultrasound registration points and acceptable level of UPLE for a given required level of accuracy for intraoperative registration in CAOS. ICP-PS method is suitable for A-mode US based intraoperative registration. This study would facilitate the application of A-mode US probe in registering the point cloud to a known shape model, which also has the potential for accurately estimating bone position and orientation for skeletal motion tracking and surgical navigation.

Research into the high-precision marine integrated navigation method using INS and star sensors based on time series forecasting BPNN

The integrated navigation method based on Inertial Navigation System (INS) and star sensor is a fully autonomous navigation technology. The algorithm employs navigation information from a star sensor as a benchmark to perform periodic recalibration of INS divergent position error. However, when Autonomous Underwater Vehicle (AUV) floats to the surface of the ocean, it displays a rocking motion, due to waves and other factors. This motion results in the star map acquired by star sensor appears trailing phenomenon. Thus, the navigation information obtained from star sensor cannot be used as benchmark information. To solve this problem, an integrated navigation method based on INS and star sensor using the Adaptive Differential Evolution Back Propagation Neural Network (ADE-BPNN) to predict carrier attitude is proposed in this paper. The ADE-BPNN time series forecasting technology enables the use of data describing the integrated navigation attitude over a period of time to predict the attitude of the carrier when a star map appears the trailing phenomenon. The effectiveness of this approach was demonstrated by simulation and experimental study. The results show that this approach can estimate the navigation errors of star sensor and INS. Therefore, the INS/star sensor integrated navigation accuracy is improved.

Implementation of the Navigate Your Health trial in the Brisbane Region to improve the health and wellbeing of children and young people in out of home care

Navigate Your Health is a place-based, co-designed model that will improve the health and wellbeing of children in out-of-home care (OOHC) in the Brisbane Region. The model defines the process and pathways for initial health screening, subsequent comprehensive health and developmental assessments, the provision of ongoing healthcare needs, and will be supported by the creation of four individual Health Navigator positions. Research consistently shows that children and young people in care are likely to have poorer health and wellbeing outcomes than those who are not in care, including poorer physical, developmental, behavioural and mental/emotional health. The Queensland Child Protection Commission of Inquiry report highlighted that children and young people in the care system also have higher rates of earlier onset of sexual activity, higher rates of sexually transmitted infections and higher rates of earlier pregnancy and parenting. Since late 2016, Children’s Health Queensland (CHQ), Department of Communities, Child Safety and Disability Services’ Brisbane Region, and Brisbane Aboriginal and Torres Strait Islander Community Health Service (Brisbane ATSICHS) have jointly led a co-design process with partners – including non-government agencies, Primary Health Networks (PHNs), children and young people and foster carers. Stakeholders contributed their vast experience and expertise to assist in the development of a best practice model. The proposed elements of the model include: Health Screening: Children and young people will receive a preliminary health check, followed by a comprehensive health and developmental assessment covering the domains of physical, developmental and mental/emotional health. Referral coordination: The most appropriate pathways for the child/young person will be determined - dependent on the outcome of the preliminary and comprehensive assessments, age, cultural status, disability status, care and health history. Referrals to required services or additional assessments are progressed and will be monitored to ensure the timeliness of follow up and the development of a Health Management Plan. Health care coordination: Children and young peoples’ healthcare will continue to progress in an integrated way, and in line with the recommendations of their Health Management Plan. A higher emphasis and priority for meeting their healthcare needs is in place and Child Safety Officers (CSOs) are provided with support in healthcare coordination. Change to be implemented: The trial implementation of a place-based, co-designed response in Brisbane that will deliver improved health outcomes for children and young people in OOHC Funding for four Health Navigator roles to support the trial The use of the Navigate Your Healthmodel as outlined above The Health Navigators will have capacity to be co-located between existing CHQ facilities and Child Safety Service Centres on an as needs basis to assist in development of relationships with Health and Child Safety staff, and to establish professional linkages. Fostering partnerships with PHNs and Brisbane ATSICHS will also enable flexibility for Health Navigators to co-locate with these services, as required. Evaluation of Navigate Your Healthwill encompass three outcome categories: implementation, clinical and economic outcomes.

Cycling of oxyanion-forming trace elements in groundwaters from a freshwater deltaic marsh

Pore waters and surface waters were collected from a freshwater system in southeastern Louisiana to investigate the geochemical cycling of oxyanion-forming trace elements (i.e., Mo, W, As, V). A small bayou (Bayou Fortier) receives input from a connecting lake (Lac des Allemands) and groundwater input at the head approximately 5 km directly south of the Mississippi River. Marsh groundwaters exchange with bayou surface water but are otherwise relatively isolated from outside hydrologic forcings, such as tides, storms, and effects from local navigation canals. Rather, redox processes in the marsh groundwaters appear to drive changes in trace element concentrations. Elevated dissolved S(-II) concentrations in marsh groundwaters suggest greater reducing conditions in the late fall and winter as compared to the spring and late summer. The data suggest that reducing conditions in marsh groundwaters initiate the dissolution of Fe(III)/Mn(IV) oxide/hydroxide minerals, which releases adsorbed and/or co-precipitated trace elements into solution. Once in solution, the fate of these elements is determined by complexation with aqueous species and precipitation with iron sulfide minerals. The trace elements remain soluble in the presence of Fe(III)- and SO42-- reducing conditions, suggesting that either kinetic limitations or complexation with aqueous ligands obfuscates the correlation between V and Mo sequestration in sediments with reducing or euxinic conditions.

Improved polar inertial navigation algorithm based on pseudo INS mechanization

From the perspective of global inertial navigation system (INS), an improved inertial navigation algorithm is proposed to solve the navigation problem in polar regions. The implementation of navigation system is achieved with two executive units, navigation calculation (NC) unit and parameter transformation (PT) unit. The NC unit is executed autonomously with pseudo INS mechanization under the spherical Earth model. The pseudo INS mechanization is established with the pseudo-Earth frame, which is a generalized Earth frame and is reconstructed based on the switching position selected properly with the motion range of vehicle. Then, the smooth switching of navigation frame and the intrinsic unity of navigation algorithm can be achieved, thereby further unifying the polar navigation algorithm for both strapdown INS and platform INS in a brief form in global regions. On the other hand, the PT units are employed to correct and transform navigation parameters to a corresponding coordinate system with ellipsoidal Earth model and can be conducted simultaneously in parallel, thereby ensuring the navigation accuracy and communicating with other local navigation systems conveniently. Theoretical analysis and numerical results indicate the validity of the proposed algorithm.

Multi-GNSS high-rate RTK, PPP and novel direct phase observation processing method: application to precise dynamic displacement detection

This paper provides the methodology and performance assessment of multi-GNSS signal processing for the detection of small-scale high-rate dynamic displacements. For this purpose, we used methods of relative (RTK) and absolute positioning (PPP), and a novel direct signal processing approach. The first two methods are recognized as providing accurate information on position in many navigation and surveying applications. The latter is an innovative method for dynamic displacement determination with the use of GNSS phase signal processing. This method is based on the developed functional model with parametrized epoch-wise topocentric relative coordinates derived from filtered GNSS observations. Current regular kinematic PPP positioning, as well as medium/long range RTK, may not offer coordinate estimates with subcentimeter precision. Thus, extended processing strategies of absolute and relative GNSS positioning have been developed and applied for displacement detection. The study also aimed to comparatively analyze the developed methods as well as to analyze the impact of combined GPS and BDS processing and the dependence of the results of the relative methods on the baseline length. All the methods were implemented with in-house developed software allowing for high-rate precise GNSS positioning and signal processing. The phase and pseudorange observations collected with a rate of 50 Hz during the field test served as the experiment’s data set. The displacements at the rover station were triggered in the horizontal plane using a device which was designed and constructed to ensure a periodic motion of GNSS antenna with an amplitude of ~3 cm and a frequency of ~4.5 Hz. Finally, a medium range RTK, PPP, and direct phase observation processing method demonstrated the capability of providing reliable and consistent results with the precision of the determined dynamic displacements at the millimeter level. Specifically, the research shows that the standard deviation of the displacement residuals obtained as the difference between a benchmark-ultra-short baseline RTK solution and selected scenarios ranged between 1.1 and 3.4 mm. At the same time, the differences in the mean amplitude of the oscillations derived from the established scenarios did not exceed 1.3 mm, whereas the frequency of the motion detected with the use of Fourier transformation was the same.

Safe Local Navigation for Visually Impaired Users With a Time-of-Flight and Haptic Feedback Device.

This paper presents ALVU (Array of Lidars and Vibrotactile Units), a contactless, intuitive, hands-free, and discreet wearable device that allows visually impaired users to detect low- and high-hanging obstacles, as well as physical boundaries in their immediate environment. The solution allows for safe local navigation in both confined and open spaces by enabling the user to distinguish free space from obstacles. The device presented is composed of two parts: a sensor belt and a haptic strap. The sensor belt is an array of time-of-flight distance sensors worn around the front of a user's waist, and the pulses of infrared light provide reliable and accurate measurements of the distances between the user and surrounding obstacles or surfaces. The haptic strap communicates the measured distances through an array of vibratory motors worn around the user's upper abdomen, providing haptic feedback. The linear vibration motors are combined with a point-loaded pretensioned applicator to transmit isolated vibrations to the user. We validated the device's capability in an extensive user study entailing 162 trials with 12 blind users. Users wearing the device successfully walked through hallways, avoided obstacles, and detected staircases.

Разностно-дальномерный метод определения координат потребителя применительно к построению локальных беззапросных систем навигации

Satellite navigation systems are the de-facto standard of navigation systems; however, the scope of their application is limited to an open terrain in which a sufficient number of navigation satellite signals are observed. At the same time, the development of navigation systems for enclosed spaces is a topical issue for a number of practical applications. Existing solutions that allow satellite radio navigation systems to be used in enclosed premises have a number of significant shortcomings. This circumstance generates the need of searching for alternative approaches to construction of indoor navigation systems. They differ from each other in complexity and achieved navigation accuracy. One of promising lines in constructing local radio navigation systems involves the use of ultra wide-band signals. The article considers the development of a precise non- enquiry range-difference local indoor navigation system on the basis of ultra wide-band radio modules.

Проблемы локализации навигационно-связной аппаратуры. Состояние дел с разработкой отечественных приемников и модулей локальных систем навигации

Проблемы локализации навигационно-связной аппаратуры. Состояние дел с разработкой отечественных приемников и модулей локальных систем навигации

A Study on Align Process Improvement for K-MLRS Launchers and Position Navigation Unit

A Study on Align Process Improvement for K-MLRS Launchers and Position Navigation Unit

An efficiency algorithm on Gaussian mixture UKF for BDS/INS navigation system

To further improve the performance of UKF (Unscented Kalman Filter) algorithm used in BDS/SINS (BeiDou Navigation Satellite System/Strap down Inertial Navigation System), an improved GM-UKF (Gaussian Mixture Unscented Kalman Filter) considering non-Gaussian distribution is discussed in this paper. This new algorithm using SVD (Singular Value Decomposition) is proposed to alternative covariance square root calculation in UKF sigma point production. And to end the rapidly increasing number of Gaussian distributions, PDF (Probability Density Function) re-approximation is conducted. In principle this efficiency algorithm proposed here can achieve higher computational speed compared with traditional GM-UKF. And simulation experiment result show that, compared with UKF and GM-UKF algorithm, new algorithm implemented in BDS/SINS tightly integrated navigation system is suitable for handling nonlinear/non-Gaussian integrated navigation position calculation, for its lower computational complexity with high accuracy.

Data protection in radio channels of local differential satellite navigation subsystems

We consider data protection in radio channels of control–correction stations of the GLONASS/GPS local differential subsystem of the river on inland waterways of Russia under the influence of mutual and industrial noise. Based on the investigation of coefficients of the relative sensitivity to variations in the parameters and structure of signals and noise and on the required bit error rate of the element-by-element receiving of digital messages, we introduce estimate criteria for the noise-immunity and functional stability of radio channels. We provide methods to compute the noiseimmunity and functional stability of radio channels. We investigate the variational–parametrical sensitivity of the range size of a control–correction station to variations in parameters of the mutual and industrial noise, as well as its variational–functional sensitivity to variations in the frequency–time structure of the signal and the mutual noise. We find that the parameter variations in industrial noise provide the most sensitive influence on the size of the range of control–correction stations.

Optimization of potential field parameters using genetic algorithm

This paper addresses a metaheuristics approach to optimize the parameters of the potential fields (PF) method. This method is an important algorithm and is primarily used for local navigation problems. However, estimating the appropriate parameters is essential for safe and smooth navigation. For instance, complex scenarios that include long and thin corridors or cluttered environments having numerous obstacles require reliable parameter estimation. Accordingly, the genetic algorithm is utilized to estimate the appropriate algorithms to overcome conventional navigation problems based on the PF method. The experimental results verify the reliability and efficiency of the proposed approach.
 Keywords: Path planning, potential fields (PF) method, genetic algorithm (GA), DEAP, robot navigation, parameter optimization.

Single-axis rotation/azimuth-motion insulation inertial navigation control system with FOGs

Rotation modulation technology could effectively improve the accuracy of the inertial navigation system (INS) by compensating for the biases of the inertial sensors automatically. However, the carrier angular motion and rotation control error could reduce the rotation modulation effect and then decrease the navigation accuracy. To address this problem, for the single-axis rotation INS, a novel rotation control scheme is presented. The control scheme employs the fiber optic gyros to control the inertial measurement unit (IMU) rotation angular velocity so that the INS with both rotation modulation and azimuth motion insulation functions. Furthermore, in order to reduce the control error, this study adopts two ways: optimizing the control strategy and shortening the delay time. The former way is to control the IMU rotating about the z-axis of the platform frame with respect to the navigation frame, rather than the up-axis of the navigation frame. The latter way is to apply interrupt mode rather than inquiry mode to complete the data transfer between the navigation and the control processors. The simulation and experimental results demonstrate that: the proposed method would not only realize the rotation modulation of the biases of the inertial sensors, but also achieve the insulation of the azimuth motion. The steady-state control error of the control system is less than 10" and the overshoot control error is less than 50". Compared to the traditional SRINS, the navigation position error in the single-axis rotation/azimuth-motion insulation INS could reduce 50% in some navigation application.

New fault-tolerant federated Kalman filters for integrated navigation

PurposeThe purpose of this paper is to achieve accurate integrated navigation results for the unmanned aerial vehicle (UAV) systems even in the presence of possible navigation faults in the subsystems of the federated Kalman filter.Design/methodology/approachThe federated Kalman filter is modified from two aspects to get accurate navigation results under abnormity. First, time-variant vector distribution coefficients trading off the navigation accuracy and the observability degree of each state component are computed to replace the traditional scalar coefficients. Second, a fault-tolerant filter is proposed as the local navigation filter.FindingsSimulations for the navigation of a UAV system show that the proposed method can be applied for accurate navigation purpose even in the presence of subsystem navigation faults.Originality/valueNew fault-tolerant federated Kalman filters for integrated navigation are presented to achieve accurate navigation solutions.