Hand-held Scanners Research Articles

Evaluation of handheld scanner for digitization of cartographic heritage

Researchers who use old maps to explore different historical periods and themes are often facing a serious problem in terms of unavailability of their digital copies that are of acceptable quality. The map collection of various heritage institution is mainly consisted of classic printed cartographic materials. The mentioned institutions usually have no capacity to digitize oversized archival items such as maps, due to lack of the appropriate equipment. The objective of this paper is to investigate an easy and cost-effective method for producing the digital versions of analogue maps, based on map scans captured using a hand-held scanner. Although handheld scanners are considered unsuitable for map scanning purposes, this paper seeks to explore the possibility of using these devices to produce the adequate georeferenced map image with a reasonable effort. The proposed method is compared with the common-used digitization procedure that involves conversion of hard-copy maps into the digital raster format using the large-format sheetfed scanner. The influence of ground control points quantity and transformation model type was also evaluated.Hand-held scanning resulted in an appropriate number of image files, covering the area of map sheet by overlapped narrow scan sections. The image mosaic was created and subjected to geometric quality assessments and statistical analysis. Results from georeferencing tests showed that the successful use of a hand-held scanner for the purpose of paper map conversion into digital format depends on the minimization of distortion effects using suitable geometric transformation method. If this approach is applied correctly, most users will be satisfied with the results obtained by hand-held scanning and will be able to correctly display the content of digitized cartographic material alongside other georeferenced digital data.

Performance Assessment of Reference Modelling Methods for Defect Evaluation in Asphalt Concrete.

The deterioration of road conditions and increasing repair deficits pose challenges for the maintenance of reliable road infrastructure, and thus threaten, for example, safety and the fluent flow of traffic. Improved and more efficient procedures for maintenance are required, and these require improved knowledge of road conditions, i.e., improved data. Three-dimensional mapping presents possibilities for large-scale collection of data on road surfaces and automatic evaluation of maintenance needs. However, the development and, specifically, evaluation of large-scale mobile methods requires reliable references. To evaluate possibilities for close-range, static, high-resolution, three-dimensional measurement of road surfaces for reference use, three measurement methods and five instrumentations are investigated: terrestrial laser scanning (TLS, Leica RTC360), photogrammetry using high-resolution professional-grade cameras (Nikon D800 and D810E), photogrammetry using an industrial camera (FLIR Grasshopper GS3-U3-120S6C-C), and structured-light handheld scanners Artec Leo and Faro Freestyle. High-resolution photogrammetry is established as reference based on laboratory measurements and point density. The instrumentations are compared against one another using cross-sections, point–point distances, and ability to obtain key metrics of defects, and a qualitative assessment of the processing procedures for each is carried out. It is found that photogrammetric models provide the highest resolutions (10–50 million points per m2) and photogrammetric and TLS approaches perform robustly in precision with consistent sub-millimeter offsets relative to one another, while handheld scanners perform relatively inconsistently. A discussion on the practical implications of using each of the examined instrumentations is presented.

A methodology for alignment of measured rail profiles in turnouts as a basis for reliable vehicle/track interaction simulations

For the development of condition monitoring algorithms for turnouts, an extensive dataset consisting of measurement and simulation results is required. The basis for reliable simulation results are precise and easy applicable measurement techniques of the turnout geometry, like 3D handheld scanners. The challenge in using the data from portable 3D scanners for vehicle/track interaction simulation lies in the correct alignment and preparation of the measured surface. In this paper, a methodology for pre-processing of 3D scanner measurement results is presented, based on turnout measurements with the device HandySCAN 700 from Creaform. Point cloud processing methods like Principal Component Analysis and Iterative Closest Point algorithm are used to align the measured surface to a reference frame. Interpolation of the measured points by CAD reference data is applied for repairing the profile sections due to missing surface points. Furthermore, comparisons were made regarding the quality of simulation results for different input sources. It can be shown that the results have a good quality agreement in respect of different profile measurements techniques. Thus, it could be shown, that the data from the portable 3D scanner can be used for multibody dynamic simulation after appropriate preparation with the presented method.

Validation of a novel handheld 3D ultrasound system for imaging scoliosis - phantom study.

Use of 3D ultrasound (US) scanners to detect and monitor scoliosis have been validated. The Cobb angle, axial vertebral rotation, spinal flexibility, curvatures in the sagittal profile and the Cobb angle on the plane of maximum curvature (PMC) can be measured from coronal, transverse and sagittal planes of ultrasound images. However, traditional 3D ultrasound scanners are relatively bulky and expensive. 2D US handheld and low-cost scanners are widely available. To adapt the 2D scanners for scoliosis applications, a position and orientation system is integrated with the scanner. The objective of this study was to validate a newly developed 3D handheld US system to image the spine. The wireless handheld US scanner (C3-HD, Clarius, Canada) was selected because of its high resolution and availability of raw data. A wireless tracking system based on electromagnetic (G4 system, Polhemus, USA) was integrated with the Clarius ultrasound. During scanning, the ultrasound information was synchronized with the scanner's position and orientation by using custom developed software. Both information were streamed wirelessly to a laptop. Custom software reconstructed and displayed the 3D spinal image in real-time. A single 3D printed vertebra, two full plastic spine phantoms from T1-T12 vertebrae and a non-scoliotic volunteer were scanned. The 3D reconstruction process of a spine image was less than 3 seconds. The dimensional and the angle errors were 1 mm and 3°, respectively. This study demonstrated that a low-cost ($11,000 USD) handheld 3D ultrasound system was developed and validated. Clinical trials on subjects attending will be the next step.

Assessment of the reliability of hand-held surface scanner in the evaluation of adolescent idiopathic scoliosis.

Spinal deformities due to adolescent idiopathic scoliosis (AIS) result in impairment in the back surface topography. Sophisticated interventions are needed that address different aspects of deformity. The purpose of our study is to test the reliability of hand-held 3D scanners on the assessment of AIS. Forty-two AIS patients were included in our study. The back surfaces of the patients were scanned with the hand-held 3D scanner, while the patients were in the standing position with the arms hanging at the sides (P1), with the arms extended (P2), and forward bending position (P3). The acquired original image was superimposed with the mirror image. Root mean square (RMS) of the point-to-point distance was calculated, and the differences between the surfaces were determined. Correlation between RMS, Cobb, POTSI, scoliometer, radiographic rotations, TRACE results was calculated. A significant correlation coefficency (r) was found between the RMS and Cobb values in the thoracic (P1 = 0.80, P2 = 0.76, P3 = 0.71) and lumbal region (P1 = 0.56, P2 = 0.65, P3 = 0.63); between RMS and Raimondi in the thoracic (r, P1 = 0.80, P2 = 0.81, P3 = 0.78) and lumbar regions (P1 = 0.54, P2 = 0.64, P3 = 0.59); between RMS and scoliometer measurements in the thoracic (r, P1 = 0.58, P2 = 0.50, P3 = 0.41) and lumbar regions (P1 = 0.35, P2 = 0.41, P3 = 0.59); in thoracolumbar region between RMS and POTSI (P1 = 0.50, P2 = 0.25, P3= 0.36), between RMS and TRACE (P1 = 0.68, P2 = 0.5, P3 = 0.52), CONCLUSION: The hand-held scanners may contribute to gaining new insight into diagnosis and follow-up of AIS by its mobility that enables the acquisition of data in desired body position and place such as bedside or our patient clinics. Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.

Escáneres ópticos 3D de mano en ingeniería inversa

Data acquisition is a key part in any reverse engineering process. When measuring mechanical components, or any physical object, there are numerous methods to perform this phase, but handheld 3D scanners are among the most popular. Compared to static scanners, handheld scanners have the advantage of being easier to transport and use. The present article contains a brief description of reverse engineering and an analysis of the three technologies that make handheld 3D scanners possible. Examples of the most innovative devices within each category are included and the positioning methods of optical 3D scanners are discussed.This article aims to bring together the latest information on handheld optical scanners and their technologies in order to facilitate the choice of the most suitable method for each application.

Ultrasonographic Assessment of Extravascular Lung Water in Hospitalized Patients Requiring Hemodialysis: A Prospective Observational Study

Introduction: Sonographic technologies can estimate extravascular lung water (EVLW) in hemodialysis (HD) patients. This study investigated the suitability of a handheld scanner in contrast to a portable scanner for quantifying EVLW in hospitalized patients requiring HD. Methods: In this prospective study, 54 hospitalized HD patients were enrolled. Bedside lung ultrasound was performed within 30 min before and after dialysis using handheld (phased array transducer, 1.7–3.8 MHz) and portable (curved probe, 5–2 MHz) ultrasound devices. Eight lung zones were scanned for total B-lines number (TBLN). The maximum diameter of inferior vena cava (IVC) was measured. We performed Passing-Bablok regression, Deming regression, Bland-Altman, and logistic regression analysis. Results: The 2 devices did not differ in measuring TBLN and IVC (p > 0.05), showing a high correlation (r = 0.92 and r = 0.51, respectively). Passing-Bablok regression had a slope of 1.11 and an intercept of 0 for TBLN, and the slope of Deming regression was 1.02 within the CI bands of 0.94 and 1.11 in the full cohort. TBLN was logarithmically transformed for Bland-Altman analysis, showing a bias of 0.06 (TBLN = 1.2) between devices. The slope and intercept of the Deming regression in IVC measurements were 0.77 and 0.46, respectively; Bland-Altman plot showed a bias of −0.07. Compared with predialysis, TBLN significantly (p < 0.001) decreased after dialysis, while IVC was unchanged (p = 0.16). Univariate analysis showed that cardiovascular disease (odds ratio [OR] 8.94 [2.13–61.96], p = 0.002), smoking history (OR 5.75 [1.8–20.46], p = 0.003), and right pleural effusion (OR 5.0 [1.2–25.99], p = 0.03) were strong predictors of EVLW indicated by TBLN ≥ 4. Conclusion: The lung and IVC findings obtained from handheld and portable ultrasound scanners are comparable and concordant. Cardiovascular disease and smoking history were strong predictors of EVLW. The use of TBLN to assess EVLW in hospitalized HD patients is feasible. Further studies are needed to determine if TBLN can help guide volume removal in HD patients.

Underground oil shale mine surveying using handheld mobile laser scanners

Underground oil shale mine surveying using handheld mobile laser scanners

An International, Multicenter Field Trial Comparison Between 3D-Printed and ICRC-Manufactured Transtibial Prosthetic Devices in Low-Income Countries

ABSTRACT Introduction The gap between the needs of individuals with amputation and access to prosthetists in low-income countries (LICs) is significant. Training new personnel to bridge this gap would exceed the current output of all prosthetic and orthotic programs globally. Strategies are needed to increase the productivity of existing prosthetists in order to serve more patients. Emerging technologies such as 3D scanning, modeling, and printing have been investigated for their ability to decrease the manufacturing time for prosthetic devices; however, few studies have compared the efficacy of 3D-printed devices to traditionally manufactured (e.g., International Committee of the Red Cross [ICRC]) devices. Studies that previously compared these two methods were limited by low population size and restricted timeframes. The purpose of this study was to gather evidence comparing the efficacy of 3D-printed and ICRC transtibial prostheses in large patient populations in LICs over time. Materials and Methods A total of 61participants between the ages of 5 and 25 completed this study's 8-week trial. Participants were recruited from four clinical sites in Uganda, Tanzania, and Cambodia. Ethics approval was obtained from each of the four clinical sites before study initiation. Consent was obtained from each participant before study enrolment. The participants' residual limbs were 3D scanned by local prosthetists using hand-held 3D scanners. Prosthetists digitally rectified the 3D scanned models using Canfit and NiaFit 3D modeling software. The rectified models were fabricated using 3D printers. 3D-printed devices were lined with foam liners and coupled to standard ICRC pylons and feet. Participants used the 3D-printed sockets for 4 weeks, then returned to the clinic to complete a 28-question Likert scale questionnaire, assessing their experiences with their 3D-printed devices. Surveys were based on the Prosthesis Evaluation Questionnaire. Participants were then given a new transtibial prosthetic device manufactured using traditional ICRC methods and instructed to use this device for 4 weeks. They then returned to the clinic to complete the questionnaire as aforementioned. Responses from both surveys were assessed using a two-tailed Student t-test (P &lt; 0.05). Results Data from the Tanzania Training Centre for Orthopaedic Technologists (n = 10) indicated that their users rated ICRC devices significantly higher in categories measuring stability, including ability to walk, walking up steep slopes and stairs, walking on slippery surfaces, overall fit, comfort while standing, and texture of the device. In contrast, participant data from Comprehensive Rehabilitation Services in Uganda (n = 25), Cambodian School of Prosthetics and Orthotics (n = 10), and Comprehensive Community Based Rehabilitation in Tanzania (n = 16) showed no significant differences across all measured outcomes. Conclusions This is the first study to compare and contrast the efficacy of 3D-printed and ICRC transtibial prosthetic devices across geographic locations in LICs with a large study population. Results demonstrate that, in general, 3D-printed devices were rated comparably to ICRC. This result was consistent at three of four clinical trial sites. Further studies will be required to elucidate the rating differences observed at the fourth site.

Deep-Learning Image Reconstruction for Real-Time Photoacoustic System.

Recent advances in photoacoustic (PA) imaging have enabled detailed images of microvascular structure and quantitative measurement of blood oxygenation or perfusion. Standard reconstruction methods for PA imaging are based on solving an inverse problem using appropriate signal and system models. For handheld scanners, however, the ill-posed conditions of limited detection view and bandwidth yield low image contrast and severe structure loss in most instances. In this paper, we propose a practical reconstruction method based on a deep convolutional neural network (CNN) to overcome those problems. It is designed for real-time clinical applications and trained by large-scale synthetic data mimicking typical microvessel networks. Experimental results using synthetic and real datasets confirm that the deep-learning approach provides superior reconstructions compared to conventional methods.

Comparison of Backpack, Handheld, Under-Canopy UAV, and Above-Canopy UAV Laser Scanning for Field Reference Data Collection in Boreal Forests

In this work, we compared six emerging mobile laser scanning (MLS) technologies for field reference data collection at the individual tree level in boreal forest conditions. The systems under study were an in-house developed AKHKA-R3 backpack laser scanner, a handheld Zeb-Horizon laser scanner, an under-canopy UAV (Unmanned Aircraft Vehicle) laser scanning system, and three above-canopy UAV laser scanning systems providing point clouds with varying point densities. To assess the performance of the methods for automated measurements of diameter at breast height (DBH), stem curve, tree height and stem volume, we utilized all of the six systems to collect point cloud data on two 32 m-by-32 m test sites classified as sparse (n = 42 trees) and obstructed (n = 43 trees). To analyze the data collected with the two ground-based MLS systems and the under-canopy UAV system, we used a workflow based on our recent work featuring simultaneous localization and mapping (SLAM) technology, a stem arc detection algorithm, and an iterative arc matching algorithm. This workflow enabled us to obtain accurate stem diameter estimates from the point cloud data despite a small but relevant time-dependent drift in the SLAM-corrected trajectory of the scanner. We found out that the ground-based MLS systems and the under-canopy UAV system could be used to measure the stem diameter (DBH) with a root mean square error (RMSE) of 2–8%, whereas the stem curve measurements had an RMSE of 2–15% that depended on the system and the measurement height. Furthermore, the backpack and handheld scanners could be employed for sufficiently accurate tree height measurements (RMSE = 2–10%) in order to estimate the stem volumes of individual trees with an RMSE of approximately 10%. A similar accuracy was obtained when combining stem curves estimated with the under-canopy UAV system and tree heights extracted with an above-canopy flying laser scanning unit. Importantly, the volume estimation error of these three MLS systems was found to be of the same level as the error corresponding to manual field measurements on the two test sites. To analyze point cloud data collected with the three above-canopy flying UAV systems, we used a random forest model trained on field reference data collected from nearby plots. Using the random forest model, we were able to estimate the DBH of individual trees with an RMSE of 10–20%, the tree height with an RMSE of 2–8%, and the stem volume with an RMSE of 20–50%. Our results indicate that ground-based and under-canopy MLS systems provide a promising approach for field reference data collection at the individual tree level, whereas the accuracy of above-canopy UAV laser scanning systems is not yet sufficient for predicting stem attributes of individual trees for field reference data with a high accuracy.

The Sales Impact of Using Handheld Scanners: Evidence from the Field

Anecdotal evidence is mixed regarding whether handheld scanners used in stores increase or decrease consumer sales. This article reports on three field studies, supported by eye-tracking technology and matched sales receipts, as well as two laboratory studies that show that handheld scanner use increases sales, notably through unplanned, healthier, and impulsive purchases. The findings highlight that these effects may be limited by factors such as not having a budget; for those without a budget, use of scanners can decrease sales. Building on embodied cognition and cognitive appraisal theories, the authors predict that scanners, as a bodily extension, influence sales through both cognitive (shelf attention, perceived control) and affective (number of products touched, shopping experience) mechanisms. The results offer implications for retailers considering whether to integrate scanners into their store environments.

Nanobubble Mediated Gene Delivery in Conjunction With a Hand-Held Ultrasound Scanner.

Recent research has revealed that nanobubbles (NBs) can be an effective tool for gene transfection in conjunction with therapeutic ultrasound (US). However, an approach to apply commercially available hand-held diagnostic US scanners for this purpose has not been evaluated as of now. In the present study, we first compared in vitro, the efficiency of gene transfer (pCMV-Luciferase) with lipid-based and albumin-based NBs irradiated by therapeutic US (1MHz, 5.0 W/cm2) in oral squamous carcinoma cell line HSC-2. Secondly, we similarly examined if gene transfer in mice is possible using a clinical hand-held US scanner (2.3MHz, MI 1.0). Results showed that lipid-based NBs induced more gene transfection compared to albumin-based NBs, in vitro. Furthermore, significant gene transfer was also obtained in mice liver with lipid-based NBs. Sub-micro sized bubbles proved to be a powerful gene transfer reagent in combination with conventional hand-held ultrasonic diagnostic device.

Pilot Implementation of Falsified Medicines Directive in Hospital Pharmacy to Develop Best Practices for Medicine Decommissioning Process.

Background: The introduction of a medicines verification and decommissioning system into the hospital pharmacy may result in an increased workload for pharmacy staff. The pilot implementation allows us to understand all the implications of the process, optimize process workflows, and estimate the time and cost of implementation. Methods: All the packages received at the hospital pharmacy had a 2D data matrix codes and were scanned. We analyzed the time needed to unpack a variety of products, scan them, and receive the notification. Results: In total, 144 packages were scanned at an average time of 3.05 s, with most (86.9%) under 4 s. Manual decommissioning using handheld scanners was less efficient than the automated solution tested and resulted in an additional 0.4 full-time equivalent hours per million packages per year. The pattern and total time of manual scanning depended not only on the quantity but also the size of the package and type of packing. Conclusions: This evaluation of scanning performance allows optimizing the process at operational, technical, and resource levels for medicine verification and decommissioning.

Thinly sliced

A collaboration of US and Swedish researchers presents, for the first time, radio frequency (RF) reliability studies of fully integrated complimentary metal-oxide-semiconductor (CMOS) radio frequency integrated circuits (RFICs), important for designing next generation wireless communication applications, especially those that are based on ultra-thin flexible packages. Mitra et al. have a wide spread of research areas, including such topics as communications radar, hand-held medical scanners and portable weapon scanning technology. It is, however, their research into CMOS RFICs that lead to the present paper. Mastery of CMOS technology, with its small chip size, is thought to be crucial for the continued miniaturisation of circuits, with the world of nanoelectronics providing a potential gateway to the next generation of highly integrated multifunctional devices, circuits and systems. The Radio Frequency Integrated Circuits (RFIC) Lab members at North Dakota State University. (From Left) Arka Biswas, Chitralekha Biswas, Dipankar Mitra (in the back), and Babak Hamidi. RFIC Characterisation Set-up at NDSU. The ‘thinning-down’ of integrated circuits is one step towards mastering CMOS technology, with thinner and more lightweight circuitry providing more efficient and cost-effective solutions for various applications, including wireless communications, wearable and flexible electronics and Internet of Things (IoT) devices. One of the biggest challenges for realisation of flexible and ultra-thin ICs is the effect die-substrate thinning has on the RF performance of the IC. It was this problem that triggered Mitra et al. into producing the RF reliability studies presented in Electronics Letters. Thinning of the die-substrate, the small block of semiconducting material upon which a circuit is built, is one of the main contributors to performance degradation for RFICs, whilst also being the most important for producing thinner and more flexible circuitry. In their work, Mitra et al. use a voltage-controlled oscillator (VCO) to measure the effects of die-substrate thickness on the RF performance of the IC, including frequency range, RF output power variation, phase noise variation and DC parameters. The usual thickness of die-substrate for CMOS circuits as between 250–300 micrometres. Mitra et al. used a 250 µm thickness VCO as a test case, and then thinned down the die-substrate to 50 µm, 35 µm and 25 µm. They found that deviations of frequency and output power are within 1% and 1 dB respectively, with DC parameters also shown to be fairly similar for the different substrate thicknesses. The sensitivity to phase noise when thinning down was found to be significant, which confirms the well-known fact that phase noise sensitivity increases due to leakage. Flexible electronics is changing the way we make and use electronics. Many existing applications, such as wireless communication, wearable electronics, and healthcare monitoring require flexibility to promote more efficient and cost-effective solutions. Development of these flexible electronics is driving progress in the field, which enables futuristic applications such as a network of IoT devices and connected, smart cities. Several initiatives from governments and industry have also contributed to the progress and it is now estimated that the market for flexible electronics will reach $300 billion by 2028, with expected growth from $29 billion in 2017 to over $63 billion in 2023 for printed, flexible and organic electronics alone. The high-performance of CMOS electronics will be critical to this growth in flexible electronics, as a great number of current and future electronics rely on the fast communication and computation they can provide.

Use of a flexible optical fibre bundle to interrogate a Fabry-Perot sensor for photoacoustic imaging.

Photoacoustic imaging systems based on a Fabry Perot (FP) ultrasound sensor that is read-out by scanning a free-space laser beam over its surface can provide high resolution photoacoustic images. However, this type of free-space scanning usually requires a bulky 2-axis galvanometer based scanner that is not conducive to the realization of a lightweight compact imaging head. It is also unsuitable for endoscopic applications that may require complex and flexible access. To address these limitations, the use of a flexible, coherent fibre bundle to interrogate the FP sensor has been investigated. A laboratory set-up comprising an x-y scanner, a commercially available, 1.35 mm diameter, 18,000 core flexible fibre bundle with a custom-designed telecentric optical relay at its distal end was used. Measurements of the optical and acoustic performance of the FP sensor were made and compared to that obtained using a conventional free-space FP based scanner. Spatial variations in acoustic sensitivity were greater and the SNR lower with the fibre bundle implementation but high quality photoacoustic images could still be obtained. 3D images of phantoms and ex vivo tissues with a spatial resolution and fidelity consistent with a free-space scanner were acquired. By demonstrating the feasibility of interrogating the FP sensor with a flexible fibre bundle, this study advances the realization of compact hand-held clinical scanners and flexible endoscopic devices based on the FP sensing concept.

Recent trends in energy and nutrient content of take-home food and beverage purchases in Great Britain: an analysis of 225 million food and beverage purchases over 6 years

IntroductionIn recent years, there has been an increased focus on developing a coherent obesity policy in the UK, which has led to various national policy initiatives aimed at improving population...

INCREASING TRACKING ROBUSTNESS FOR LOW-COMPLEXITY REAL-TIME RECONSTRUCTIONS WITH HANDHELD OPTICAL SCANNERS

Abstract. By offering fast and flexible solutions to create 3D models, handheld scanners are currently under the focus of many research activities in various 3D data processing fields. The real-time constraint is still challenging to achieve especially when it comes with concurrent needs, such as level of accuracy in the data acquisition, easiness of recovering from scanning interruptions or loop closure abilities... Among them, object/scene tracking quality is one of the most critical. In this work, we describe two issues that affects its performance, focusing on the robustness of the process. Specifically, we encounter such issues at to two different steps while moving through the working pipeline of a prototype handheld scanner, i.e. (1) the data pre-processing before running a pairwise alignment between a frame and the model representation, called key-frame, and (2) the temporal and quality criteria that govern key-frame updates. Our approach simply consists in substituting the use of a rigid (uniform) pattern for sampling, with a random distribution of points. We then implement an adaptive statistical method to select suitable timing steps for key-frames refreshing, comparing this solution with a previous static one based on regular updating rate. We run experiments on a dataset created with our own scanner and we show that the adoption of such alternatives reduce the number of tracking failures, consequently increasing the robustness of the system, improving the quality of the alignments and preserving the real-time behavior of the device.

Исследование ручных трёхмерных лазерных сканеров

The authors consider hand-held laser scanners, as a new photogrammetric tool for obtaining three-dimensional models of objects. The principle of their work and the newest optical systems based on various sensors measuring the depth of space are described in detail. The method of simultaneous navigation and mapping (SLAM) used for combining single scans into point cloud is outlined. The formulated tasks and methods for performing studies of the DotProduct (USA) hand-held laser scanner DPI?8X based on a test site survey are presented. The accuracy requirements for determining the coordinates of polygon points are given. The essence of the performed experimental research of the DPI?8X scanner is described, including scanning of a test object at various scanner distances, shooting a test polygon from various scanner positions and building point cloud, repeatedly shooting the same area of the polygon to check the stability of the scanner. The data on the assessment of accuracy and analysis of research results are given. Fields of applying hand-held laser scanners, their advantages and disadvantages are identified.

Evaluation of holding handheld scanner on muscle activity, heart rate variability, and model accuracy in industrial applications

PurposeThe capabilities of handheld scanners have been investigated previously in different applications, without considering its impact on the accuracy of model, heart rate variability (HRV), subjective measurements, and worker muscular activity. The present study aims to evaluate the impact of using two handheld scanners, elevation, and orientation of object that is scanned on the basis of aforementioned parameters. Design/methodology/approachTo achieve these objectives, electromyographic measurements of six muscles were obtained. Moreover, dependent variables include; NASA task load index (NASA-TLX) as a subjective measure, HRV, and accuracy of the model; while, the scanner-type (laser versus white light scanner), target orientation (0° versus 45°), and elevation (50 cm versus 80 cm table height) were the independent variables. FindingsThe results of the within-subject design indicated that a light scanner exhibited less accurate performance, lower cardiac cost, less subjective NASA-TLX, and less task execution time than the laser scanner. Originality/valueWhen using the laser scanner, to reduce muscle contraction and decrease the subjective NASA-TLX, the target elevation and orientation angle with respect to the horizontal plane must be 80 cm and 45°, respectively. However, when using the light scanner, to reduce muscle contraction and the subjective NASA-TLX, the target elevation and orientation angle with respect to the horizontal plane must be 50 cm and 0°, respectively. Furthermore, cardiac rhythms were less stressed when using the laser scanner at a 50 cm target elevation and light scanner at an 80 cm target elevation.