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1.
Biomed Eng Online ; 22(1): 63, 2023 Jun 24.
Article in English | MEDLINE | ID: mdl-37355651

ABSTRACT

BACKGROUND: The underlying motivation of this work is to demonstrate that artificial muscle activity of known and unknown motion can be generated based on motion parameters, such as angular position, acceleration, and velocity of each joint (or the end-effector instead), which are similarly represented in our brains. This model is motivated by the known motion planning process in the central nervous system. That process incorporates the current body state from sensory systems and previous experiences, which might be represented as pre-learned inverse dynamics that generate associated muscle activity. METHODS: We develop a novel approach utilizing recurrent neural networks that are able to predict muscle activity of the upper limbs associated with complex 3D human arm motions. Therefore, motion parameters such as joint angle, velocity, acceleration, hand position, and orientation, serve as input for the models. In addition, these models are trained on multiple subjects (n=5 including , 3 male in the age of 26±2 years) and thus can generalize across individuals. In particular, we distinguish between a general model that has been trained on several subjects, a subject-specific model, and a specific fine-tuned model using a transfer learning approach to adapt the model to a new subject. Estimators such as mean square error MSE, correlation coefficient r, and coefficient of determination R2 are used to evaluate the goodness of fit. We additionally assess performance by developing a new score called the zero-line score. The present approach was compared with multiple other architectures. RESULTS: The presented approach predicts the muscle activity for previously through different subjects with remarkable high precision and generalizing nicely for new motions that have not been trained before. In an exhausting comparison, our recurrent network outperformed all other architectures. In addition, the high inter-subject variation of the recorded muscle activity was successfully handled using a transfer learning approach, resulting in a good fit for the muscle activity for a new subject. CONCLUSIONS: The ability of this approach to efficiently predict muscle activity contributes to the fundamental understanding of motion control. Furthermore, this approach has great potential for use in rehabilitation contexts, both as a therapeutic approach and as an assistive device. The predicted muscle activity can be utilized to guide functional electrical stimulation, allowing specific muscles to be targeted and potentially improving overall rehabilitation outcomes.


Subject(s)
Neural Networks, Computer , Upper Extremity , Humans , Male , Young Adult , Adult , Biomechanical Phenomena , Movement/physiology , Muscles , Electromyography/methods
2.
Sensors (Basel) ; 22(15)2022 Jul 29.
Article in English | MEDLINE | ID: mdl-35957260

ABSTRACT

A strong motion monitoring network records data that provide an excellent way to study how source, path, and site effects influence the ground motion, specifically in the near-source area. Such data are essential for updating seismic hazard maps and consequently building codes and earthquake-resistant design. This paper aims to present the Italian Strong Motion Network (RAN), describing its current status, employment, and further developments. It has 648 stations and is the result of a fruitful co-operation between the Italian government, regions, and local authorities. In fact, the network can be divided into three sub-networks: the Friuli Venezia Giulia Accelerometric Network, the Irpinia Seismic Network, and all the other stations. The Antelope software automatically collects, processes, and archives data in the data acquisition centre in Rome (Italy). The efficiency of the network on a daily basis is today more than 97%. The automatic and fast procedures that run in Antelope for the real-time strong motion data analysis are continuously improved at the University of Trieste: a large set of strong motion parameters and correspondent Ground Motion Prediction Equations allow ground shaking intensity maps to be provided for moderate to strong earthquakes occurring within the Italian territory. These maps and strong motion parameters are included in automatic reports generated for civil protection purposes.


Subject(s)
Earthquakes , Italy , Motion , Software
3.
Sensors (Basel) ; 21(16)2021 Aug 07.
Article in English | MEDLINE | ID: mdl-34450784

ABSTRACT

Current knowledge about tectonic plate movement is widely applied in numerous scientific fields; however, questions still remain to be answered. In this study, the focus is on the determination and analysis of the parameters that describe tectonic plate movement, i.e., the position (Φ and Λ) of the rotation pole and angular rotation speed (ω). The study was based on observational material, namely the positions and velocities of the GNSS stations in the International Terrestrial Reference Frame 2014 (ITRF2014), and based on these data, the motion parameters of five major tectonic plates were determined. All calculations were performed using software based on a least squares adjustment procedure that was developed by the author. The following results were obtained: for the African plate, Φ = 49.15 ± 0.10°, Λ = -80.82 ± 0.30°, and ω = 0.267 ± 0.001°/Ma; for the Australian plate, Φ = 32.94 ± 0.05°, Λ = 37.70 ± 0.12°, and ω = 0.624 ± 0.001°/Ma; for the South American plate, Φ = -19.03 ± 0.20°, Λ = -119.78 ± 0.39°, and ω = 0.117 ± 0.001°/Ma; for the Pacific plate, Φ = -62.45 ± 0.07°, Λ = 111.01 ± 0.14°, and ω = 0.667 ± 0.001°/Ma; and for the Antarctic plate, Φ = 61.54 ± 0.30°, Λ = -123.01 ± 0.49°, and ω = 0.241 ± 0.003°/Ma. Then, the results were compared with the geological plate motion model NNR-MORVEL56 and the geodetic model ITRF2014 PMM, with good agreement. In the study, a new approach is proposed for determining plate motion parameters, namely the sequential method. This method allows one to optimize the data by determining the minimum number of stations required for a stable solution and by identifying the stations that negatively affect the quality of the solution and increase the formal errors of the determined parameters. It was found that the stability of the solutions of the Φ, Λ, and ω parameters varied depending on the parameters and the individual tectonic plates.

4.
Zhonghua Nan Ke Xue ; 26(10): 895-899, 2020 Nov.
Article in Chinese | MEDLINE | ID: mdl-33382220

ABSTRACT

OBJECTIVE: To investigate the application of the self-made semen quality control (QC) product in internal QC of computer-assisted sperm analysis (CASA). METHODS: CASA was calibrated with high- and low-concentration commercially available semen QC product and meanwhile 15 samples of self-made mixed semen QC product were placed in 75 cryotubes containing liquid nitrogen, followed by CASA of the concentration, motility, curvilinear velocity (VCL), straight line velocity (VSL), average path velocity (VAP), linearity (LIN), wobble (WOB) and straightness (STR) of the sperm using standard procedures and 50 days of continuous monitoring. The Makler counting plate was used to measure the concentration and motility of the self-made sperm. RESULTS: The coefficients of variation (CV) of the commercially available semen QC product at high and low concentrations were 6.18% and 7.85%, respectively. CASA showed that the concentration of the self-made QC product was (25.97 ± 1.41) ×106/ml, with a CV of 5.42%, and the sperm motility, VCL, VSL, VAP, LIN, WOB and STR were (22.15 ± 1.75)% (CV = 7.9%), (59.18 ± 2.05) µm/s (CV = 3.46%), (26.79 ± 1.2) µm/s (CV = 4.48%), (34.98 ± 1.4) µm/s (CV = 4.01%), 46.81 ± 1.55 (CV = 3.3%), 60.52 ± 1.3 (CV = 2.15%) and 76.46 ± 1.98 (CV = 2.59%), respectively. The concentration and motility of the self-made sperm detected with the Makler counting plate were (34.39 ± 2.37) ×106/ml (CV = 6.89%) and (38.04 ± 1.69)% (CV = 4.44%), respectively. Levey-Jennings QC charts were plotted for the indicators using the means and standard deviation. CONCLUSIONS: The self-made internal QC product by liquid nitrogen cryopreservation is feasible and effective for monitoring the accuracy and precision of CASA-derived sperm concentration and motion parameters, and it has a smaller CV than the commercially available QC product in measuring sperm concentration.


Subject(s)
Quality Control , Semen Analysis/methods , Semen Analysis/standards , Sperm Motility , Computers , Humans , Male , Spermatozoa
5.
Sensors (Basel) ; 20(21)2020 Oct 25.
Article in English | MEDLINE | ID: mdl-33113827

ABSTRACT

The article is the fourth part of our research program concerning an analysis of tectonic plates' motion parameters that is based on an observation campaign of an array of satellite techniques: SLR, DORIS, VLBI, and now GNSS. In this paper, based on the International Terrestrial Reference Frame 2014 (ITRF2014) for observations and using the GNSS technique, the Eurasian tectonic plate motion was analyzed and the plate motion parameters Φ, Λ (the position of the rotation pole), and ω (the angular rotation speed) were adjusted. Approximately 1000 station positions and velocities globally were obtained from the GNSS campaign over a 21-year time interval and used in ITRF2014. Due to the large number of data generated using this technique, the analyses were conducted separately for each tectonic plate. These baseline data were divided into a number of parts related to the Eurasian plate, and are shown in this paper. The tectonic plate model was analyzed on the basis of approximately 130 GNSS station positions. A large number of estimated station positions allowed a detailed study to be undertaken. Stations that agree with the plate motion were selected and plate parameters were estimated with high accuracy. In addition, stations which did not agree with the tectonic plate motion were identified and removed. In the current paper, the influence of the number and location of stations on the computed values and accuracy of the tectonic plate motion parameters is discussed. Four calculation scenarios are examined. Each scenario contains 30 stations for the common solution of the European and Asiatic part of the Eurasian plate. The maximum difference between the four calculation scenarios is 0.31° for the Φ parameter and 0.24° for the Λ parameter, indicating that it is at the level of the value of the formal error. The ω parameter has the same value for all the scenarios. The final stage of the analysis is the estimation of parameters Φ, Λ, and ω based on all of the 120 stations used in the four calculation scenarios (i.e., scenario 1 + scenario 2 + scenario 3 + scenario 4). The following results are obtained: Φ = 54.81° ± 0.37°, Λ = 261.04° ± 0.48°, and ω = 0.2585°/Ma ± 0.0025°/Ma. The results of the analysis are compared with the APKIM2005 model and another solution based on the GNSS technique, and a good agreement is found.

6.
National Journal of Andrology ; (12): 895-899, 2020.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-880288

ABSTRACT

Objective@#To investigate the application of the self-made semen quality control (QC) product in internal QC of computer-assisted sperm analysis (CASA).@*METHODS@#CASA was calibrated with high- and low-concentration commercially available semen QC product and meanwhile 15 samples of self-made mixed semen QC product were placed in 75 cryotubes containing liquid nitrogen, followed by CASA of the concentration, motility, curvilinear velocity (VCL), straight line velocity (VSL), average path velocity (VAP), linearity (LIN), wobble (WOB) and straightness (STR) of the sperm using standard procedures and 50 days of continuous monitoring. The Makler counting plate was used to measure the concentration and motility of the self-made sperm.@*RESULTS@#The coefficients of variation (CV) of the commercially available semen QC product at high and low concentrations were 6.18% and 7.85%, respectively. CASA showed that the concentration of the self-made QC product was (25.97 ± 1.41) ×10⁶/ml, with a CV of 5.42%, and the sperm motility, VCL, VSL, VAP, LIN, WOB and STR were (22.15 ± 1.75)% (CV = 7.9%), (59.18 ± 2.05) μm/s (CV = 3.46%), (26.79 ± 1.2) μm/s (CV = 4.48%), (34.98 ± 1.4) μm/s (CV = 4.01%), 46.81 ± 1.55 (CV = 3.3%), 60.52 ± 1.3 (CV = 2.15%) and 76.46 ± 1.98 (CV = 2.59%), respectively. The concentration and motility of the self-made sperm detected with the Makler counting plate were (34.39 ± 2.37) ×10⁶/ml (CV = 6.89%) and (38.04 ± 1.69)% (CV = 4.44%), respectively. Levey-Jennings QC charts were plotted for the indicators using the means and standard deviation.@*CONCLUSIONS@#The self-made internal QC product by liquid nitrogen cryopreservation is feasible and effective for monitoring the accuracy and precision of CASA-derived sperm concentration and motion parameters, and it has a smaller CV than the commercially available QC product in measuring sperm concentration.


Subject(s)
Humans , Male , Computers , Quality Control , Semen Analysis/standards , Sperm Motility , Spermatozoa
7.
Sensors (Basel) ; 20(1)2019 Dec 18.
Article in English | MEDLINE | ID: mdl-31861305

ABSTRACT

Vibration induces a micro-Doppler effect, which contains crucial motion information and features of the micro-motion target. However, the traditional radar can only acquire micro-motion information in the radial direction. The multi-channel radar is capable of acquiring actual micro-motion information in a three-dimensional space, including amplitude, frequency, and three-dimensional direction of vibration. Moreover, the high-accuracy parameter estimation can be achieved in the terahertz band. In this paper, a method for three-dimensional micro-motion feature exaction and parameter estimation is proposed, including a phase-derived-range algorithm, interference, and auto-correlation. Meanwhile, to prove feasibility of the method, the results of simulations and experiment based on a 0.22 THz multi-channel radar system are presented after theoretical analyses.

8.
Sensors (Basel) ; 19(8)2019 Apr 22.
Article in English | MEDLINE | ID: mdl-31013644

ABSTRACT

Techniques for measuring the position and orientation of an object from corresponding images are based on the principles of epipolar geometry in the computer vision and photogrammetric fields. Contributing to their importance, many different approaches have been developed in computer vision, increasing the automation of the pure photogrammetric processes. The aim of this paper is to evaluate the main differences between photogrammetric and computer vision approaches for the pose estimation of an object from image sequences, and how these have to be considered in the choice of processing technique when using a single camera. The use of a single camera in consumer electronics has enormously increased, even though most 3D user interfaces require additional devices to sense 3D motion for their input. In this regard, using a monocular camera to determine 3D motion is unique. However, we argue that relative pose estimations from monocular image sequences have not been studied thoroughly by comparing both photogrammetry and computer vision methods. To estimate motion parameters characterized by 3D rotation and 3D translations, estimation methods developed in the computer vision and photogrammetric fields are implemented. This paper describes a mathematical motion model for the proposed approaches, by differentiating their geometric properties and estimations of the motion parameters. A precision analysis is conducted to investigate the main characteristics of the methods in both fields. The results of the comparison indicate the differences between the estimations in both fields, in terms of accuracy and the test dataset. We show that homography-based approaches are more accurate than essential-matrix or relative orientation-based approaches under noisy conditions.

9.
Chemosphere ; 214: 791-800, 2019 Jan.
Article in English | MEDLINE | ID: mdl-30296767

ABSTRACT

BACKGROUND: Exposure to high levels of metals/metalloids may impair semen quality. Computer-aided sperm analysis (CASA) can be used for kinematic analysis of spermatozoa, which provides additional insights into sperm motion characteristics. OBJECTIVE: To explore the associations of urinary and seminal plasma metal/metalloid concentrations with CASA motion parameters and assess the degree of correspondence between the two sample types. METHODS: Eighteen metals/metalloids in seminal plasma and repeated urine samples were determined among 746 men recruited from a reproductive center. We assessed their associations with 6 CASA motion parameters [i.e., straight-line velocity (VSL), curvilinear velocity (VCL), average path velocity (VAP), linearity (LIN), straightness (STR) and amplitude head displacement (ALH)] using multivariable linear regression models. RESULTS: We found significantly inverse dose-dependent relationships between seminal plasma arsenic (As) and VSL, VCL and VAP, between seminal plasma selenium (Se) and VSL and VAP, between seminal plasma zinc (Zn) and STR and LIN, and between seminal plasma manganese (Mn) and LIN in single-metal models [all false discovery rate (FDR) adjusted P for trend < 0.05]. These dose-response relationships remained statistically significant based on multiple-metal models and restricted cubic spline functions. Metal/metalloid concentrations in urine poorly predicted the same-day seminal plasma concentrations [coefficient of determination (R2) < 0.15]. We didn't find any significant associations between urinary metal/metalloid concentrations and the CASA motion parameters. CONCLUSION: Exposure to high levels of As, Se, Mn and Zn may impair sperm motion capacity. Concentrations of metals/metalloids in spot urine samples cannot accurately predict same-day seminal plasma exposure levels.


Subject(s)
Dimenhydrinate/chemistry , Metalloids/urine , Semen Analysis/methods , Semen/chemistry , Humans , Male , Spermatozoa/physiology
10.
Sensors (Basel) ; 18(4)2018 Mar 30.
Article in English | MEDLINE | ID: mdl-29601511

ABSTRACT

In order to tackle the inaccurate step length measurement of people with different heights and in different motion states, a height-adaptive method of step length measurement based on motion parameters is proposed in this paper. This method takes people's height, stride frequency, and changing accelerometer output while walking into integrated consideration, and builds a dynamic and parameterized model of their step length. In this study, these parameters were calibrated with thirty sets of experiment data from people with different heights and in different motion states, which were then verified experimentally by motion data of randomly selected subjects, regardless of speed and height. The experiment results indicate that the height-adaptive step length measurement was realized, thus eliminating the influence of height exerted on step length measurement.

11.
J Surg Educ ; 75(2): 516-526, 2018.
Article in English | MEDLINE | ID: mdl-28864265

ABSTRACT

OBJECTIVE: To investigate the effect of motion parameter feedback on laparoscopic basic skill acquisition and retention during a standardized box training curriculum. DESIGN: A Lap-X Hybrid laparoscopic simulator was designed to provide individual and continuous motion parameter feedback in a dry box trainer setting. In a prospective controlled trial, surgical novices were randomized into 2 groups (regular box group, n = 18, and Hybrid group, n = 18) to undergo an identical 5-day training program. In each group, 7 standardized tasks on laparoscopic basic skills were completed twice a day on 4 consecutive days in fixed pairs. Additionally, each participant performed a simulated standard laparoscopic cholecystectomy before (day 1) and after training (day 5) on a LAP Mentor II virtual reality (VR) trainer, allowing an independent control of skill progress in both groups. A follow-up assessment of skill retention was performed after 6 weeks with repetition of both the box tasks and VR cholecystectomy. SETTING: Muenster University Hospital Training Center, Muenster, Germany. PARTICIPANTS: Medical students without previous surgical experience. RESULTS: Laparoscopic skills in both groups improved significantly during the training period, measured by the overall task performance time. The 6 week follow-up showed comparable skill retention in both groups. Evaluation of the VR cholecystectomies demonstrated significant decrease of operation time (p < 0.01), path length of the left and right instrument, and the number of movements of the left and right instruments for the Hybrid group (all p < 0.001), compared to the box group. Similar results were found at the assessment of skill retention. CONCLUSION: Simulation training on both trainers enables reliable acquisition of laparoscopic basic skills. Furthermore, individual and continuous motion feedback improves laparoscopic skill enhancement significantly in several aspects. Thus, training systems with feedback of motion parameters should be considered to achieve long-term improvement of motion economy among surgical trainees.


Subject(s)
Cholecystectomy, Laparoscopic/education , Clinical Competence , Laparoscopy/education , Motor Skills , Simulation Training/methods , Time and Motion Studies , Chi-Square Distribution , Feedback , Female , Germany , Hospitals, University , Humans , Learning Curve , Male , Operative Time , Prospective Studies , Retention, Psychology , Statistics, Nonparametric , Task Performance and Analysis
12.
International Eye Science ; (12): 2285-2288, 2018.
Article in Bi | WPRIM (Western Pacific) | ID: wpr-688332

ABSTRACT

@#AIM: To observe the binocular motion parameters of children and adolescents with myopia anisometropia, and to investigate the influence of myopia anisometropia in children and adolescents on binocular motion parameters. <p>METHODS: A case-control study was conducted. From September 2014 to May 2016, 82 cases of children aged 7 to 14 who were admitted to the University-Town Hospital of Chongqing Medical University were involved. There were 47 emmetropic children as the control group and 35 myopic anisometropic children as the experimental group. We measured the diopter, separated lateral phoria at distance(5m)and near(40cm), gradient and computational AC/A ratios, accommodative function, as well as accommodative function,including fused cross cylinder(FCC), negative relative accommodation/ positive relative accommodation(NRA/PRA), AMP and accommodation facility(AF). <p>RESULTS: The separated lateral phoria at distance(5m)and near(40cm), FCC, PRA, gradient and computational AC/A ratios had significant different between two groups(<i>P</i><0.05). Between two groups, AF, NRA had no significant difference found, the same as difference between the detected AMP and minimum normal AMP(<i>P</i>>0.05). <p>CONCLUSION: Myopia anisometropia in children and adolescents had a significant effect on separated lateral phoria at distance(5m)and near(40cm), FCC, PRA, gradient and computational AC/A ratios.

13.
Int J Comput Assist Radiol Surg ; 11(9): 1599-610, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27492067

ABSTRACT

PURPOSE: Optical colonoscopy is a prominent procedure by which clinicians examine the surface of the colon for cancerous polyps using a flexible colonoscope. One of the main concerns regarding the quality of the colonoscopy is to ensure that the whole colonic surface has been inspected for abnormalities. In this paper, we aim at estimating areas that have not been covered thoroughly by providing a map from the internal colon surface. METHODS: Camera parameters were estimated using optical flow between consecutive colonoscopy frames. A cylinder model was fitted to the colon structure using 3D pseudo stereo vision and projected into each frame. A circumferential band from the cylinder was extracted to unroll the internal colon surface (band image). By registering these band images, drift in estimating camera motion could be reduced, and a visibility map of the colon surface could be generated, revealing uncovered areas by the colonoscope. Hidden areas behind haustral folds were ignored in this study. The method was validated on simulated and actual colonoscopy videos. The realistic simulated videos were generated using a colonoscopy simulator with known ground truth, and the actual colonoscopy videos were manually assessed by a clinical expert. RESULTS: The proposed method obtained a sensitivity and precision of 98 and 96 % for detecting the number of uncovered areas on simulated data, whereas validation on real videos showed a sensitivity and precision of 96 and 78 %, respectively. Error in camera motion drift could be reduced by almost 50 % using results from band image registration. CONCLUSION: Using a simple cylindrical model for the colon and reducing drift by registering band images allows for the generation of visibility maps. The current results also suggest that the provided feedback through the visibility map could enhance clinicians' awareness of uncovered areas, which in return could reduce the probability of missing polyps.


Subject(s)
Colon/diagnostic imaging , Colonic Polyps/diagnosis , Colonoscopy/methods , Imaging, Three-Dimensional , Video Recording , Colonoscopes , Equipment Design , Humans
14.
J Xray Sci Technol ; 24(4): 599-613, 2016 05 17.
Article in English | MEDLINE | ID: mdl-27198924

ABSTRACT

PURPOSE: A motion algorithm has been developed to extract length, CT number level and motion amplitude of a mobile target from cone-beam CT (CBCT) images. MATERIALS AND METHODS: The algorithm uses three measurable parameters: Apparent length and blurred CT number distribution of a mobile target obtained from CBCT images to determine length, CT-number value of the stationary target, and motion amplitude. The predictions of this algorithm are tested with mobile targets having different well-known sizes that are made from tissue-equivalent gel which is inserted into a thorax phantom. The phantom moves sinusoidally in one-direction to simulate respiratory motion using eight amplitudes ranging 0-20 mm. RESULTS: Using this motion algorithm, three unknown parameters are extracted that include: Length of the target, CT number level, speed or motion amplitude for the mobile targets from CBCT images. The motion algorithm solves for the three unknown parameters using measured length, CT number level and gradient for a well-defined mobile target obtained from CBCT images. The motion model agrees with the measured lengths which are dependent on the target length and motion amplitude. The gradient of the CT number distribution of the mobile target is dependent on the stationary CT number level, the target length and motion amplitude. Motion frequency and phase do not affect the elongation and CT number distribution of the mobile target and could not be determined. CONCLUSION: A motion algorithm has been developed to extract three parameters that include length, CT number level and motion amplitude or speed of mobile targets directly from reconstructed CBCT images without prior knowledge of the stationary target parameters. This algorithm provides alternative to 4D-CBCT without requirement of motion tracking and sorting of the images into different breathing phases. The motion model developed here works well for tumors that have simple shapes, high contrast relative to surrounding tissues and move nearly in regular motion pattern that can be approximated with a simple sinusoidal function. This algorithm has potential applications in diagnostic CT imaging and radiotherapy in terms of motion management.


Subject(s)
Algorithms , Cone-Beam Computed Tomography/methods , Image Processing, Computer-Assisted/methods , Models, Biological , Humans , Lung/diagnostic imaging , Lung/physiology , Movement , Phantoms, Imaging
15.
Accid Anal Prev ; 81: 251-9, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25846494

ABSTRACT

Drowsy/distracted driving has become one of the leading causes of traffic crash. Only certain particular drowsy/distracted driving behaviors have been studied by previous studies, which are mainly based on dedicated sensor devices such as bio and visual sensors. The objective of this study is to extract the common features for identifying drowsy/distracted driving through a set of common vehicle motion parameters. An intelligent vehicle was used to collect vehicle motion parameters. Fifty licensed drivers (37 males and 13 females, M=32.5 years, SD=6.2) were recruited to carry out road experiments in Wuhan, China and collecting vehicle motion data under four driving scenarios including talking, watching roadside, drinking and under the influence of drowsiness. For the first scenario, the drivers were exposed to a set of questions and asked to repeat a few sentences that had been proved valid in inducing driving distraction. Watching roadside, drinking and driving under drowsiness were assessed by an observer and self-reporting from the drivers. The common features of vehicle motions under four types of drowsy/distracted driving were analyzed using descriptive statistics and then Wilcoxon rank sum test. The results indicated that there was a significant difference of lateral acceleration rates and yaw rate acceleration between "normal driving" and drowsy/distracted driving. Study results also shown that, under drowsy/distracted driving, the lateral acceleration rates and yaw rate acceleration were significantly larger from the normal driving. The lateral acceleration rates were shown to suddenly increase or decrease by more than 2.0m/s(3) and the yaw rate acceleration by more than 2.5°/s(2). The standard deviation of acceleration rate (SDA) and standard deviation of yaw rate acceleration (SDY) were identified to as the common features of vehicle motion for distinguishing the drowsy/distracted driving from the normal driving. In order to identify a time window for effectively extracting the two common features, a double-window method was used and the optimized "Parent Window" and "Child Window" were found to be 55s and 6s, respectively. The study results can be used to develop a driving assistant system, which can warn drivers when any one of the four types of drowsy/distracted driving is detected.


Subject(s)
Accidents, Traffic/prevention & control , Accidents, Traffic/psychology , Attention , Automobile Driving/psychology , Orientation , Psychomotor Performance , Sleep Stages , Acceleration , Adult , Child , China , Female , Humans , Male , Middle Aged , Reference Values , Statistics, Nonparametric , Young Adult
16.
Asian-Australas J Anim Sci ; 27(10): 1417-25, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25178293

ABSTRACT

The selection of morphologically normal spermatozoa is critical to obtain high breeding performances in boar breeding farms and artificial insemination (AI) centers. Parameters for the selection of semen mainly include total sperm motility, concentration, and morphology. However, these primary parameters are often not reliable for discriminating between normal and abnormal, non-fertilizable spermatozoa. The present study was designed to compare the motion characteristics, fertilization ability using in vitro fertilization (IVF), and acrosome formation of the semen from boars having low (boar number 2012) and normal (boar number 2004 and 2023) breeding performances. The ultimate goal was to identify additional simple and easy criteria for the selection of normal sperm. There was no significant difference between boar 2004 and boar 2023 sperm total motility in computer assisted sperm analysis. However, boar number 2012 semen presented a significantly reduced population of rapid moving spermatozoa and an increased population of slow moving spermatozoa compared to boar numbers 2004 and 2023. Analysis of detailed motion characteristics revealed that sperm from boar number 2012 had significantly reduced motility in progressiveness, average path velocity, straight-line velocity (VSL), curvilinear velocity (VCL), straightness, and linearity. The assessment of the fertilizing ability by IVF also showed that sperm from boar number 2012 showed a fertility rate of 3.4%, whereas sperm from boar number 2023 had a fertility rate of 75.45%. Interestingly, most of the sperm nuclei were found on the peripheral area of the oocytes, suggesting that the sperm from boar number 2012 lacked penetration ability into the oocyte zonapellucida. The acrosome formation analysis using Pisum sativum agglutinin staining demonstrated that the sperm from boar number 2012 had a defect in acrosome formation. Consequently, primary parameters for selecting semen before AI such as motility are not sufficient to select normal and fertilizable spermatozoa. In conclusion, the present study suggests that the acrosome staining and detailed motion characteristics such as progressiveness, VCL, and VSL should be included in determining semen quality together with primary parameters for successful AI and high breeding performance in the swine industry.

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