AR Marker Research Articles

Development and pilot validation of laser path anchor (LPA): A novel tool for augmented reality surgical navigation

Abstract Augmented reality navigation (ARN) enhances localization and operation by overlaying virtual guides onto realworld surgical fields. The study introduces a laser path anchor (LPA), a novel tool for ARN in surgery aimed at mitigating depth perception challenges. The LPA anchors the virtual planned path onto the physical laser beam, ensuring accurate puncture from any perspective. The tool consists of a rack, a primary laser emitter, an indicating laser emitter, and an AR marker with intrinsic and extrinsic properties validated through calibration and testing. Intrinsic validation involved measuring the parallelism between the indicating and primary laser using Cartesian graph screens. Extrinsic validation assessed the alignment and shortest distance between the virtual path and primary lasers. Results showed an angle deviation of 0.08° between the indicating and primary laser and 1.44° ± 0.47° between the virtual path and primary lasers, with a shortest distance of 7.60 mm ± 2.50 mm. The usability test demonstrated the LPA’s effectiveness in guiding needle insertions without altering the perspective or distracting the surgeon. Despite some limitations, the LPA enhances the user’s perception of linear objects and eliminates the need for perspective adjustments during puncture, warranting further development.

Abstract 3696: Liquid biopsy biomarker analysis during treatment with 177Lu-PSMA-617 in castrate resistant prostate cancer

Abstract Background: Prostate-Specific Membrane Antigen (PSMA) is a highly expressed prostate cancer (PCa) cell surface protein regulated by androgen receptor signaling and the target of the recently approved radioligand therapy 177Lu-PSMA-617. While some patients have dramatic responses to this therapy, rates of upfront or acquired resistance are high even in patients with PSMA-PET-avid disease, and better biomarkers of 177Lu PSMA-617 response and resistance are needed to select patients more effectively for this therapy. To address this need, we evaluated the relationship between longitudinal circulating tumor cell (CTC) androgen signaling and PSMA expression to 177Lu-PSMA-617 response or resistance in patients with metastatic prostate cancer. We leveraged a CTC androgen signaling signature that we have previously shown is prognostic for patients with metastatic prostate cancer treated with AR signaling inhibitors. Methods: Longitudinal blood samples were collected from 20 patients for circulating tumor cell (CTC) analysis at C1D1, C2D1, C4D1, and C6D1. CTCs were isolated with antibodies to EpCAM followed by parallel enumeration, analysis of cell surface expression of PSMA and RNA extraction for AR or neuroendocrine marker transcriptional profiling. Results: CTC samples were assessed for PSMA cell surface protein expression prior to treatment and on treatment. FOLH1 (PSMA) gene expression was detected from CTCs at baseline that persisted through treatment. Gene expression representative of AR pathway activation was present in 70% of the cohort at baseline and 50% of patients at C2D1. Concordant with these observations, no significant decrease in CTC number or PSMA protein expression was seen from baseline to C2D1. However, increased CTC AR pathway activation at C2D1 was associated with increased mean serum PSA (155 vs 21.93 ng/ml) and was associated with decreased duration of response. Conclusions: Improved tools to predict who will respond to 177Lu-PSMA-617 and detect early treatment resistance and disease progression are needed. Here, we show that persistent CTC burden, CTC AR signaling, and CTC PSMA expression are common early in treatment with 177Lu-PSMA-617 and may be associated with lower likelihood of clinical response. Further ongoing studies are needed to elucidate the relationship between these liquid biopsy results and clinical outcomes. Citation Format: Jamie M. Sperger, Marina N. Sharifi, Luke Nunamaker, Viridiana Carreno, Alex H. Chang, Shannon R. Reese, Charlotte Linebarger, Amy K. Taylor, Grace C. Bliitzer, John Floberg, Shuang G. Zhao, Joshua M. Lang. Liquid biopsy biomarker analysis during treatment with 177Lu-PSMA-617 in castrate resistant prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3696.

Reprojection Error Analysis and Algorithm Optimization of Hand-Eye Calibration for Manipulator System.

The Euclidean distance error of calibration results cannot be calculated during the hand-eye calibration process of a manipulator because the true values of the hand-eye conversion matrix cannot be obtained. In this study, a new method for error analysis and algorithm optimization is presented. An error analysis of the method is carried out using a priori knowledge that the location of the augmented reality markers is fixed during the calibration process. The coordinates of the AR marker center point are reprojected onto the pixel coordinate system and then compared with the true pixel coordinates of the AR marker center point obtained by corner detection or manual labeling to obtain the Euclidean distance between the two coordinates as the basis for the error analysis. We then fine-tune the results of the hand-eye calibration algorithm to obtain the smallest reprojection error, thereby obtaining higher-precision calibration results. The experimental results show that, compared with the Tsai-Lenz algorithm, the optimized algorithm in this study reduces the average reprojection error by 44.43% and the average visual positioning error by 50.63%. Therefore, the proposed optimization method can significantly improve the accuracy of hand-eye calibration results.

A Leader-follower formation control of mobile robots by position-based visual servo method using fisheye camera

This paper presents a leader-follower formation control of multiple mobile robots by position-based method using a fisheye camera. A fisheye camera has a wide field of view and recognizes a wide range of objects. In this paper, the fisheye camera is first modeled on spherical coordinates and then a position estimation technique is proposed by using an AR marker based on the spherical model. This paper furthermore presents a method for estimating the velocity of a leader robot based on a disturbance observer using the obtained position information. The proposed techniques are combined with a formation control based on the virtual structure. In this paper, the formation controller and velocity estimator can be designed independently, and the stability analysis of the total system is performed by using Lyapunov theorem. The effectiveness of the proposed method is demonstrated by simulation and experiments using two real mobile robots.

High Accuracy and Wide Range Recognition of Micro AR Markers with Dynamic Camera Parameter Control

This paper presents a novel dynamic camera parameter control method for the position and posture estimation of highly miniaturized AR markers (micro AR markers) using a low-cost general camera. The proposed method captures images from the camera at each cycle and detects markers from these images. Subsequently, it performs iterative calculations of the marker’s position and posture to converge them to a specified accuracy while dynamically updating the camera’s zoom, focus, and other parameter values based on the detected marker’s depth distances. For a 10 mm square micro AR marker, the proposed system demonstrated recognition accuracy better than ±1.0% for depth distance and 2.5∘ for posture angle, with a maximum recognition range of 1.0 m. In addition, the iterative calculation time was 0.7 s for the initial detection of the marker. These experimental results indicate that the proposed method and system can be applied to the precise robotic handling of small objects at a low cost.

An Easy Snowpack Depth Evaluation Using Smartphone, Bluetooth Device, and Augmented Reality Marker of Open Computer Vision Package

An easy method to evaluate a remote place’s snowpack depth has been discussed for helping later-stage elderly persons’ life. The method of using a smartphone camera and an augmented reality marker (AR marker) has been investigated. The general smartphone with a high image resolution camera was used to observe snowpack depth in remote places and remote control the robot via Bluetooth device. And image processing using artificially integrated technology (AI technology) was adapted for detecting the AR markers and for evaluating the snowpack depth.

Real-World Task Realization by a Swarm System with a Robotic Hand and Possibility of AR Marker

Real-World Task Realization by a Swarm System with a Robotic Hand and Possibility of AR Marker

Electric Wheelchair Hybrid Operating System Coordinated with Working Range of a Robotic Arm

Electric wheelchair-mounted robotic arms can help patients with disabilities to perform their activities in daily living (ADL). Joysticks or keypads are commonly used as the operating interface of Wheelchair-mounted robotic arms. Under different scenarios, some patients with upper limb disabilities such as finger contracture cannot operate such interfaces smoothly. Recently, manual interfaces for different symptoms to operate the wheelchair-mounted robotic arms are being developed. However, the stop the wheelchairs in an appropriate position for the robotic arm grasping task is still not easy. To reduce the individual’s burden in operating wheelchair in narrow spaces and to ensure that the chair always stops within the working range of a robotic arm, we propose here an operating system for an electric wheelchair that can automatically drive itself to within the working range of a robotic arm by capturing the position of an AR marker via a chair-mounted camera. Meanwhile, the system includes an error correction model to correct the wheelchair’s moving error. Finally, we demonstrate the effectiveness of the proposed system by running the wheelchair and simulating the robotic arm through several courses.

Utilizing Marker to Integrate Augmented Reality in Furniture Using Unity 3D

The development of technology has had an effect on online shopping, whilst the use of Augmented Reality technology has provided customers a new method to see things in their actual context, particularly large and heavy products like furniture. Customer satisfaction, scheduling constraints, and the inability to picture the actual product are cited as problems. Augmented Reality is a three-dimensional technology that enables people to see and comprehend the actual environment while being surrounded by virtual objects. In other words, augmented reality comprises of computer-generated three-dimensional images that link the virtual world to the actual world. Finding from research papers has shown two types of AR application for furniture, which is marker based and markerless. Virtual Furniture, a project developed using Unity 3D, Google Cloud database and C# programming language is an AR marker based application. This application will further help furniture industry businesses to assist customers in visualizing an object in a real environment before purchasing it.

Smart Attendance System Using AR Marker

Abstract: In the current scenario smartphones play a vital role in our daily life, In fact they are a part of our lives. Smartphones can now handle the majority of problems fast and easily. Every person's life has been made simpler and easier as a result of it.Basically this paper focuses on the problem which is faced by the faculties and students during the process of attendance and there are more chances of proxies in the traditional method (using pen and papers). The paper proposed a system that will use AR Marker technology and handle the problem for recording the attendance of the students in school and colleges. The suggested system consists of two applications: one for creating the AR Marker by entering class information via faculty, and another for scanning the QR code via students. The teacher will generate the QR code and present it to the students using a projector, after which the students will simply open the second app and scan the QR code to get their attendance. The Smart Attendance System is cost effective because it does not rely on biometric devices which are expensive. The paper explains how the system authenticates students' identities in order to prevent fraudulent registrations. By changing the QR code every five to ten seconds and just for five minutes, the system is able to reduce the proxy level. If any student fails to show up for class, the professor may display the QR code again. The system is in charge of managing and evaluating all students' attendance. In addition, the system will save the attendance data in XLS and CSV files for future use. Keyword: Smart Attendance System, AR Marker, Attendance System using QR Code, Software as a Service .

Correction of 3D-SLAM Self-Positioning with AR Markers for Mobile Manipulation Tasks

In the conventional, Simultaneous Localization and Mapping (SLAM), it is difficult to calculate the camera movement using the image features in the environment with less features. To cope with this problem, we address this research proposes a method coordinating SLAM and AR marker recognition in a featureless space. We assume a processing/inspection work of a large structure by a mobile manipulator. We use a depth sensor that executes 3D-SLAM in the horizontal direction and an RBG camera that recognizes AR markers in the overhead direction, and show real-time detection of errors that occur during SLAM execution using AR markers.

Position and Orientation Control of a Mobile Robot based on Robust Marker Position Estimation using a Sphere Camera

- This paper describes position and orientation control of a mobile robot using a sphere camera. While a sphere camera has a wider field of view than a normal camera, the field of view is distorted. Therefore, image recognition is performed by compensating for this distortion. The control of a mobile robot using this sphere camera enables better localization estimation, distance recognition, and object recognition than with a normal camera. In this paper, we propose a position estimation method using markers with color invariants that are robust to illumination. We use a hybrid marker system that employs a circle marker and an AR marker. We demonstrate the effectiveness of our method by conducting experiments on position control of a two-wheel mobile robot using the sphere camera and marker recognition.

Self-Localization of Outdoor Autonomous Flight Drone Using Point Cloud with AR Marker Information Generated using SfM and ORB-SLAM

Self-Localization of Outdoor Autonomous Flight Drone Using Point Cloud with AR Marker Information Generated using SfM and ORB-SLAM

Transparent Manipulators Accomplished with RGB-D Sensor, AR Marker, and Color Correction Algorithm

Transparent Manipulators Accomplished with RGB-D Sensor, AR Marker, and Color Correction Algorithm

Development of augmented reality in the basic physics practicum module

This research aims to design and develop a media lab in the form of Augmented Reality applications that are used in basic physics lab module. AR applications work with a tracking system and the reconstruction of the 2D marker contained in the experimental module to display 3D video animation. The method used in this research is the development of software includes the stages of collecting and analyzing the needs, do the design and manufacturing applications, validation and testing by the user, and revision. Results of the assessment by the AR application validator media and materials are respectively 80% and 85% in the predicate is valid and may be used after minor revisions. The results of trials by students as the user indicates that the 2D marker on lab module was initially less obvious and less sensitive at the time of scanning. However, after the revision of the 2D marker on lab module, 2D AR marker was sufficiently clear and sensitive at the time of scanning so that AR can help the general practical implementation and the AR content to support the practical implementation. The results showed that the development of AR applications had been successfully carried out and the AR application can function well with the scan time 1-1.5 second at a distance of 10-20 cm and successfully used in the experimental module at an angle of <900, with the result that, AR applications in basic physics practicum module as the media are supporting practicum implementation

Improvement of Performance of Navigation System for Supporting Independence Rehabilitation of Wheelchair - Bed Transfer

The purpose of this research is to improve the position and angle estimation accuracy of the wheelchair guide system for Hemiplegic patients. The wheelchair guide system aims to assist the patients to transfer between their wheelchair and bed. This system prompts properly to user depending on the situation as same as care worker. Therefore, the system is developed to prompt the measured position and angle of wheelchair. The position estimator uses an AR marker to detect the wheelchair position. However, its estimation is contaminated by measurement noises and sometimes fails because the marker is out of the camera’s field of view. To improve the estimation of position and moving direction, we introduce the kinematic model of the wheelchair and utilize the Extended Kalman Filter with the model. In this paper, we describe the self-position estimation method of the navigation system and AR marker, with the estimation method using Kalman Filter.

Measurement of Displacement of AR Marker in Augmented Reality Odometry Calibration System

Measurement of Displacement of AR Marker in Augmented Reality Odometry Calibration System

Managing Piping Parts Efficiently Using “AR Marker” Technology Based on Results of Field Test

Managing Piping Parts Efficiently Using “AR Marker” Technology Based on Results of Field Test

Imperceptible AR Markers for Near-Screen Mobile Interaction

Owing to the pervasive use of displays and smartphones, mobile interactions with display screens have gained attention within the advertising and gaming industries as well as in human-computer interaction research. Communication through QR code-like markers and localization via AR markers are common examples of such interactions. However, these visible markers interfere with the display content; this problem is critical for localization over a wide range of interactions, and fewer markers result in less reliability and accuracy. Although some studies have addressed this issue, few have focused on near-screen interaction without additional hardware. To address this problem, we propose an easy-to-install localization method that uses an array of AR markers, which are made imperceptible to the human eye through chromaticity vibration at 30 Hz. We mainly focus on applications, such as digital signage, where users point their smartphones at the display content. Through four evaluations, we confirm that the pointing error is within 1 mm, and that the proposed system works, when the distance between the screen and smartphone is 4-24 times the size of the AR marker. In addition, we establish that our system is robust against rotation. Finally, we present two potential application scenarios, advertising and navigation.

Task generation with Node-RED system and travel experiment of a mobile robot using AR marker

Task generation with Node-RED system and travel experiment of a mobile robot using AR marker