scholarly journals TRACKING OF HEAD POSITION RELATIVE TO THE SCREEN USING HEAD MOUNTED CAMERA / GALVOS POZICIJOS NUSTATYMAS EKRANO ATŽVILGIU NAUDOJANT ANT GALVOS PRITVIRTINTĄ KAMERĄ

2013 ◽  
Vol 5 (2) ◽  
pp. 65-69
Author(s):  
Evaldas Borcovas ◽  
Gintautas Daunys
Keyword(s):  
Block Diagram ◽  
Head Position ◽  
Optimal Parameters ◽  
Measuring Head ◽  
Positioning Systems ◽  
Head Positioning ◽  
Edge Detection Method ◽  
Orientation Parameters ◽  
Dual Core ◽  
Maximum Measurement

In this paper head position locating systems were analyzed. There were reviewed scientific articles with different proposed methods. The chosen system is with the camera located on the user head. The main parameters of the head positioning systems were analyzed. The procedure laid down in what order parameters are found. The diagram of the system and detail block diagram of the algorithm were provided. Realization of the algorithm used: edge detection method (Sobel), the adjustment algorithm (Subpixel). System is realized in Matlab and C# environment. Determine the optimal parameters for the algorithm execution. Execution of the algorithm in Matlab environment is 1.2 s and C # environment – 126 ms. During the examination of the longest executing algorithm segment, it was found that image filtering is carried out in 107 ms. It is noted that the uncertainty of the algorithm can be divided into static and measurement. The maximum static uncertainty while measuring head position parameters is 1.63 mm and orientation parameters – 0.16°. The maximum measurement uncertainty while measuring head position parameters is 4 mm and orientation parameters – 0.11°. Santrauka Nagrinėjamos galvos padėties pozicionavimo sistemos. Apžvelgti moksliniai straipsniai, kuriuose pateikiami įvairūs siūlomi metodai. Pasirinkta sistema, kai kamera pritvirtinama vartotojui ant galvos. Išskirti pagrindiniai galvos padėties nustatymo parametrai, nustatytas parametrų suradimo eiliškumas, pateikta sistemos schema ir detali algoritmo blokinė schema. Algoritmui įgyvendinti taikyti briaunų radimo (Sobel) ir algoritmo tikslinimo (Subpixel) metodai. Sistema įgyvendinta Matlab ir C# aplinkose. Nustatyti optimalūs algoritmo vykdymo parametrai. Naudojamo kompiuterio procesorius Intel Pentium dual core T4500 – 2,3 GHz. Vidutinis algoritmo veikimo laikas Matlab aplinkoje yra 1,2 s, o C# aplinkoje – 126 ms. Ištyrus algoritmo segmentų vykdymo laiką, pastebėta, kad ilgiausiai vykdomas vaizdo filtravimas – 107 ms. Parodyta, kad algoritmo neapibrėžtis galima suskirstyti į statines ir matavimo neapibrėžtis. Maksimali statinė neapibrėžtis, matuojant galvos pozicijos padėtį, yra 1,63 mm, matuojant orientacijos parametrus – 0,16°. Maksimali matavimo neapibrėžtis yra 4,0 mm, matuojant galvos padėties parametrus, ir 0,11° – orientacijos parametrus.

scholarly journals No benefit of flat head positioning in early moderate–severe acute ischaemic stroke: a HeadPoST study subgroup analysis

2020 ◽  
Vol 5 (4) ◽  
pp. 406-409
Author(s):  
Alejandro M Brunser ◽  
Menglu Ouyang ◽  
Hisatomi Arima ◽  
Pablo M Lavados ◽  
Thompson Robinson ◽  
...  
Keyword(s):  
Ischaemic Stroke ◽  
Acute Ischaemic Stroke ◽  
Subgroup Analysis ◽  
Head Position ◽  
National Institutes Of Health ◽  
Baseline Risk ◽  
Serious Adverse Event ◽  
Head Positioning ◽  
Registration Number ◽  
Stroke Trial

BackgroundAlthough the Head Positioning in acute Stroke Trial (HeadPoST) showed no effect of the flat head position (FP; vs sitting up head position (SUP)) on functional outcome, we hypothesised that it could still offer benefits if commenced early in those with acute ischaemic stroke (AIS) of at least moderate severity.MethodsSubgroup analysis of HeadPoST in participants with National Institutes of Health Stroke Scale (NIHSS) scores ≥7, ≥10 and ≥14, randomised to FP or SUP <4.5 hours of AIS onset on functional outcomes defined by a shift in scores on the modified Rankin scale (mRS) and death/disability (mRS scores 3–6), and any cardiovascular serious adverse event. Logistic regression analyses were undertaken adjusted for study design and baseline risk factors.ResultsThere was no significant differential treatment effect in patient subgroups defined by increasing baseline NIHSS scores: adjusted OR and 95% CI for ordinal shift and binary (3–6) mRS scores: for NIHSS ≥7 (n=867) 0.92 (0.67 to 1.25) and 0.74 (0.52 to 1.04); NIHSS ≥ 10 (n=606) 0.80 (0.58 to 1.10) and 0.77 (0.49 to 1.19); NIHSS ≥14 (n=378) 0.82 (0.54 to 1.24) and 1.22 (0.69 to 2.14).ConclusionsEarly FP had no significant effect in patients with moderate–severe AIS.Trial registration numberNCT02162017.

Head and Bottle Angles Achieved by Patients During High-Volume Sinonasal Irrigations

2019 ◽  
Vol 33 (3) ◽  
pp. 302-309
Author(s):  
Zachary H. Griggs ◽  
Amy M. Williams ◽  
John R. Craig
Keyword(s):  
High Volume ◽  
Head Position ◽  
Lateral View ◽  
Frontal View ◽  
Video Cameras ◽  
Institutional Review ◽  
Head Positioning ◽  
Henry Ford ◽  
Head Positions ◽  
Average Angle

Background Certain head positions can optimize topical irrigation distribution to specific sinuses. No studies have assessed whether patients attain these positions when irrigating. Objective The purpose of this study was to assess head and bottle angles achieved when patients irrigate based on instructions from an irrigation device or from a Rhinologist. Methods Study approval was obtained from Henry Ford Health System’s Institutional Review Board (10604). Forty-two patients with various rhinologic conditions were equally divided into groups based on irrigation instruction type: pictoral instructions from an irrigation device or written/verbal instructions from a Rhinologist. Both groups’ instructions directed nose-to-floor head positioning. Simulating home irrigations, patients irrigated 120 mL of saline into each naris using 240 mL squeeze bottles. Frontal and lateral views were captured using video cameras. On frontal view, angles were measured between (1) nasal dorsum (ND) and bottle tip (BT; n = 84) and (2) ND and vertical (V; n = 84). On lateral view, angles were measured between (1) line from nasion-to-pogonion (NTP) and horizontal (H) (n = 73) and (2) NTP and BT (n = 73). Results On lateral view, average angle between NTP and H was 20.0° (standard deviation [SD] = 13.1, 95% confidence interval [CI] = 17.0–23.0) and between NTP and BT was 59.4° (SD = 15.8, 95% CI = 55.8–63.1). On frontal view, average angle between ND and V was 9.5° (SD = 19.5, 95% CI = 5.3–13.6) and between ND and BT was 24.5° (SD = 12.0, 95% CI = 21.9–27.0). There were no significant angle differences between sides or instruction types. Conclusion When instructed to irrigate in the nose-to-floor head position, patients achieved a head position uprotated 20° on lateral view and vertex rotated 10° away from the side of irrigation on frontal view.

Nano-and Micro-Actuations of Hard Disk’s Head Positioning System: Precision Control and Evaluation

2006 ◽  
Author(s):  
Y. Han ◽  
H. S. Tzou
Keyword(s):  
Controller Design ◽  
Lateral Displacement ◽  
Hard Disk Drives ◽  
Pole Placement ◽  
Flying Height ◽  
Positioning System ◽  
Positioning Systems ◽  
Height Control ◽  
Micro Actuator ◽  
Head Positioning

A new piezoelectric micro-actuator with 2-dimensional control, i.e., a track following control and a flying height control, of the head positioning system for high-density hard disk drives (HDD) was previously developed in our lab. In this study, control algorithms for the new 2-degree-of freedom (DOF) micro-actuator are developed to independently control the lateral displacement and the transverse deflection to against various disturbances and system uncertainties. The structure of the piezoelectric micro-actuator is reviewed briefly. Then, the overall control strategy for the micro-actuator system is discussed. Next, controller design schemes for each DOF are presented. The pole placement method is used to design controllers. To obtain compensation for overshoot and settling time, pole and zero locations are carefully chosen. First, the control law is defined for the disturbance rejection. Second, the estimator is designed for noise reduction. Lastly, the reference input is added for the command following. Simulation results show that the proposed controllers in the closed-loop system provide good stability, and compensate for disturbances and noises. The data suggest that the proposed micro-actuator control system considerably improves track following and flying height control of head positioning systems in highdensity HDDs.

Damping of vibration of the car suspension at resonance

2021 ◽  
pp. 3-8
Author(s):  
Keyword(s):  
Mathematical Model ◽  
Block Diagram ◽  
Vibration Absorber ◽  
Optimal Parameters ◽  
Dynamic Vibration Absorber ◽  
Vibration Absorption ◽  
Dynamic Vibration ◽  
Car Suspension ◽  
Dynamic Damping ◽  
Dynamic Absorber

A block diagram of the device has been developed, which is based on the principle of dynamic vibration absorption. The design of a dynamic absorber of car suspension vibrations is considered. A mathematical model of a car suspension with a dynamic vibration absorber and the results of its numerical simulation are presented. The analysis of the results obtained makes it possible to determine the optimal parameters of the device for a dynamic vibration absorber. Keywords: suspension, car, dynamic, damping, vibration, mathematical, model, analysis, parameters

Abstract 448: Strain Rate Dependent Myosin Head Position Changes During Relaxation

2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Weikang Ma ◽  
Melissa J Bukowski ◽  
Alexandra R Matus ◽  
Thomas C Irving ◽  
Charles S Chung
Keyword(s):  
Strain Rate ◽  
Thin Filament ◽  
Myosin Head ◽  
Thick Filament ◽  
Calcium Sensitivity ◽  
Head Position ◽  
Mechanical Control ◽  
Myocardial Relaxation ◽  
Rate Dependent ◽  
Head Positioning

Impaired cardiac relaxation is present in nearly all cases of heart failure and possibly in up to 25% of the asymptomatic population. Myocardial relaxation is known to be biochemically modified by the calcium reuptake rate, thin filament calcium sensitivity, and crossbridge kinetics. Mechanical regulation of relaxation was thought to be regulated via afterload, but we have recently shown that a lengthening strain was sufficient to modify relaxation. Further, the relaxation rate is actually dependent on the strain rate, a relationship that we termed Mechanical Control of Relaxation. Computational modeling suggests that myosin detachment is a key mechanism underlying Mechanical Control of Regulation, but to date, no experimental evidence for this was available. The objective of this study was to determine if myosin head position changed in response to lengthening strains during relaxation. Intact cardiac trabeculae were mounted within the beamline of the Biophysical Collaborative Access Team (BioCAT) beamline at the Advanced Photon Source at Argonne National Laboratories. The trabeculae were paced and load-clamps were performed during time-resolved imaging of the equatorial axis, which primarily reflects myosin head positioning. Activation (pacing) caused the myosin head localization to shift from the thick filament to near the thin filament (increased I 1,1 /I 1,0 ratio). During stretch, there was a transient decline of the I 1,1 /I 1,0 ratio which recovered until relaxation was complete, when the ratio again reduced indicating myosin returned to the thick filament. These preliminary data suggest that Mechanical Control of Relaxation is caused by perturbations in myosin, but the late-diastolic kinetics suggests that the strain-rate dependent detachment does not lead to immediate deactivation of myosin heads. Modifications of myosin ATPase properties may reveal more specific regulatory targets, which may provide new insight and targets for treating impaired myocardial relaxation.

The Hardware Design of Partial Discharge On-Line Monitoring System in High Voltage Cable

2014 ◽  
Vol 672-674 ◽  
pp. 822-826
Author(s):  
Zhen Hao Wang ◽  
Dan Pang ◽  
Xi Lin Zhang ◽  
Yi Zhou ◽  
Xiao Juan Han
Keyword(s):  
Power Management ◽  
Block Diagram ◽  
Partial Discharge ◽  
Positioning System ◽  
Positioning Systems ◽  
Xlpe Cable ◽  
Processing Module ◽  
On Line ◽  
Discharge Monitoring ◽  
And Control

This article is one of the series of papers about research and development of partial discharge monitoring and positioning systems in cross-linked polyethylene(XLPE) cable. We discuss the design of hardware principle diagram which belongs to partial discharge on-line monitoring and positioning system in XLPE cable in terms of the system block diagram, power management module and control processing module and so on, the operation effect of partial discharge on-line monitoring and positioning system in XLPE cable shows the correctness and effectiveness of the above methods.

Relationship between the affected ear in benign paroxysmal positional vertigo and habitual head-lying side during bedrest

2006 ◽  
Vol 120 (7) ◽  
pp. 534-536 ◽  
Author(s):  
B Ö Çakir ◽  
İ Ercan ◽  
Z A Çakir ◽  
Ş Civelek ◽  
S Turgut
Keyword(s):  
Benign Paroxysmal Positional Vertigo ◽  
Prospective Trial ◽  
Head Position ◽  
Posterior Semicircular Canal ◽  
Positional Vertigo ◽  
Head Positioning ◽  
Falling Asleep ◽  
The Right ◽  
Lateral Head ◽  
Paroxysmal Positional Vertigo

Objective: To assess the association between the habitual head position during bedrest and the affected ear in benign paroxysmal positional vertigo (BPPV).Study design: Prospective trial of patients with active BPPV of the posterior semicircular canal, confirmed on physical examination.Methods: Seventy-five patients were asked to explain the head position and lying side they were accustomed to before falling asleep in bed.Results: Fifty patients (67 per cent) habitually adopted a lateral head position during bedrest. The ear affected by BPPV was found to be consistent with the head-lying side during bedrest in 43 cases (86 per cent) (29 cases for the right ear and 14 cases for the left ear).Conclusion: Habitual lateral head-positioning during bedrest can be a major factor leading to the development of BPPV in the ipsilateral ear.

scholarly journals Determining Optimal Parameters of Regular Microrelief Formed on the End Surfaces of Rotary Bodies

Algorithms ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 46
Author(s):  
Volodymyr Dzyura ◽  
Pavlo Maruschak ◽  
Olegas Prentkovskis
Keyword(s):  
Block Diagram ◽  
Geometric Parameters ◽  
Geometrical Parameters ◽  
Optimal Parameters ◽  
Center Of Rotation ◽  
Optimal Value ◽  
Different Types ◽  
The Relationship ◽  
Overlap Area

The analytical dependences for determining the overlap area of V-shaped grooves of partially regular microrelief shifted by an angular pitch of 0.5° are established. The V-shaped grooves are formed on the end surface of the rotary body by vibration. In addition, the intersection between groove elements can be of different types. The relationship between the geometric parameters of V-shaped grooves and their location is determined. The influence of geometrical parameters of grooves on the overlap area is established depending on their location. Measures are proposed to ensure that the burnishing area is the same at different distances from the center of rotation of the rotary body end surface on which the partially regular microrelief is formed. A graph showing the dependence of the overlap area of two grooves on the axial pitch between them is constructed, and a block diagram of the algorithm for determining the optimal value of the axial pitch is developed.

scholarly journals ADVANCED TIE FEATURE MATCHING FOR THE REGISTRATION OF MOBILE MAPPING IMAGING DATA AND AERIAL IMAGERY

2016 ◽  
Vol XLI-B1 ◽  
pp. 617-623
Author(s):  
P. Jende ◽  
M. Peter ◽  
M. Gerke ◽  
G. Vosselman
Keyword(s):  
Urban Areas ◽  
Template Matching ◽  
Feature Detection ◽  
Feature Matching ◽  
Aerial Imagery ◽  
Exterior Orientation ◽  
Mobile Mapping ◽  
Positioning Systems ◽  
Matching Techniques ◽  
Orientation Parameters

Mobile Mapping’s ability to acquire high-resolution ground data is opposing unreliable localisation capabilities of satellite-based positioning systems in urban areas. Buildings shape canyons impeding a direct line-of-sight to navigation satellites resulting in a deficiency to accurately estimate the mobile platform’s position. Consequently, acquired data products’ positioning quality is considerably diminished. This issue has been widely addressed in the literature and research projects. However, a consistent compliance of sub-decimetre accuracy as well as a correction of errors in height remain unsolved. <br><br> We propose a novel approach to enhance Mobile Mapping (MM) image orientation based on the utilisation of highly accurate orientation parameters derived from aerial imagery. In addition to that, the diminished exterior orientation parameters of the MM platform will be utilised as they enable the application of accurate matching techniques needed to derive reliable tie information. This tie information will then be used within an adjustment solution to correct affected MM data. <br><br> This paper presents an advanced feature matching procedure as a prerequisite to the aforementioned orientation update. MM data is ortho-projected to gain a higher resemblance to aerial nadir data simplifying the images’ geometry for matching. By utilising MM exterior orientation parameters, search windows may be used in conjunction with a selective keypoint detection and template matching. Originating from different sensor systems, however, difficulties arise with respect to changes in illumination, radiometry and a different original perspective. To respond to these challenges for feature detection, the procedure relies on detecting keypoints in only one image. <br><br> Initial tests indicate a considerable improvement in comparison to classic detector/descriptor approaches in this particular matching scenario. This method leads to a significant reduction of outliers due to the limited availability of putative matches and the utilisation of templates instead of feature descriptors. In our experiments discussed in this paper, typical urban scenes have been used for evaluating the proposed method. Even though no additional outlier removal techniques have been used, our method yields almost 90% of correct correspondences. However, repetitive image patterns may still induce ambiguities which cannot be fully averted by this technique. Hence and besides, possible advancements will be briefly presented.

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