High-speed Digital Video Recording Research Articles

The study of local mucociliary clearance of the middle nasal meatus in clinically healthy individuals and patients with foreign body in the maxillary sinus

Aim– to obtain the values of local mucociliary clearance (MCC) of the middle nasal meatus in normal conditions and in patients with foreign body in the maxillary sinuses.
 Material and methods.To assess the local MCC, we used the original method of modern high-speed digital video recording of the microscopic picture of the specimen, followed by its mathematical processing. The study included a group of rhinologically healthy individuals (60 people) and a group of patients with foreign body in the maxillary sinus (90 people).
 Results.We obtained the standard values of MCC in rhinologically healthy individuals (11.76 ± 3.01 Hz). In patients with foreign body in the maxillary sinuses, there was a correlation of the local MCC index with the severity of morphological changes, registered by computed tomography (CT), of the paranasal sinuses in the area of the middle nasal meatus and adjacent sinuses. Depending on the results of CT scanning, we identified 3 groups among the patients with foreign bodies in the maxillary sinuses – no morphological changes (CT1), changes outside the ostium (CT2) and pronounced morphological changes in the middle nasal meatus and surrounding paranasal sinuses (CT3). In the CT1 group the average values of the local MCC of the middle nasal meatus were 13.53 ± 2.46 Hz; in group CT2 – 11.71 ± 2.02 Hz; in the CT3 group – 6.84 ± 3.48 Hz. The differences in indicators in groups were statistically significant according to the Mann – Whitney test. The average value of the local MCC of the middle nasal meatus in patients without maxillary sinus mycetoma was 13.30 ± 2.91 Hz, in patients having maxillary sinus mycetoma – 10.74 ± 3.69 Hz; this difference was also statistically significant.

ASSESSMENT OF LOCAL MUCOCILIARY CLEARANCE OF THE MIDDLE NASAL MEATUS AFTER DIFFERENT TYPES OF SURGICAL ACCESS TO THE MAXILLARY SINUS

Abstract. The paper considers an original method for asessment the ciliar beating frequency (CBF) of the ciliated epithelium (mucociliary clearance) of the nasal mucosa using modern high-speed digital video recording of the microscopic picture of the brushed specimen, which followed by mathematical processing. This method used to study the local mucociliary clearance of the middle nasal meatus, which plays a key role in the modern understanding of the osteomeatal complex function. The normal values of the CBF of the middle nasal meatus in healthy individuals (11.76 ± 3.01 Hz) were determined. We studied the changes in the CBF of the ciliary epithelium of the middle nasal meatus with foreign bodies of the maxillary sinus. A correlation found between changes in the CBF of the ciliary epithelium of the middle nasal meatus and the CT changes in the region of the middle nasal meatus and paranasal sinuses. This also determined the effect of surgical trauma on the CBF of the middle nasal meatus and its changes in the early (up to 1 month) and late (1-6 months) following period. We clearly proved the dependence of the mucociliary clearance of the middle nasal meatus on the type of surgical access to the maxillary sinus during surgical interventions for foreign bodies of the maxillary sinus. We revealed certain advantages of transmaxillary and prelacrimal surgical access to the maxillary sinus over endonasal antrostomy during surgical interventions for foreign bodies of the maxillary sinus. Our data allow optimizing surgical interventions on the maxillary sinus with minimization of surgical trauma to the ciliary epithelium of the middle nasal passage and improving the functional and morphological results of surgical treatment of foreign bodies in the maxillary sinuses.

Investigation of Successful Eyedrop Instillation Rates and Analysis of Drop Positions Using High-speed Digital Video Recording System

We investigated the success rates of eyedrop instillation and the distance between the cornea and the dropper tip in 100 volunteers using high-speed digital video recording. Past eyedrop adherence studies assumed that instillation occurred without failure. The ideal distance between the cornea and dropper tip remained unclear, although the general estimate was approximately 2.54 cm (1 inch). This study was approved by the Institutional Review Boards of all participating medical institutions, and all volunteers provided written, informed consent. Successful instillation was defined as when 1 drop fell accurately into the eye on the first attempt. The instillation of ≥2 drops or drops delivered outside the eye was considered a failure. The distance between the eye and dropper tip was measured using still images from a paused digital video camera and a digital ruler. Forty percent of the volunteers instilled eyedrops without instructions from ophthalmologists, pharmacists, or other healthcare workers. When the images were analyzed, the success rate of the first instillation was 70.1%. When the eye was arbitrarily divided into 9 sections, most of the drop sites were the iris or the center of the eye. The distance between the dropper tip and cornea was 2.62±1.75 (median 2.20) cm. These results indicate that the generally recommended distance is usually followed. The successful instillation rate based on the distance from the dropper tip to the cornea was 77% at 1.6±0.88 cm and 54.9% at 4.8±1.25 cm.

Evaluation of mucociliary clearance in the postoperative period after a maxillary sinus surgery

Objectives - evaluation of the local function of the mucociliary clearance (MCC) in the postoperative period in patients with foreign bodies in the maxillary sinuses, who have undergone various surgical treatment. Material and methods. Using an original analysis technique for highspeed digital video recording of a microscopic picture of a specimen, obtained by brush biopsy from specific regions of the nasal cavity and paranasal sinus under endoscopic control, the MCC of the nasal mucosa was evaluated in the control group (n=60) and in the group of patients, who received various surgery (n=60) of maxillary sinuses. Results. We obtained the data on persistent and apparent local MCC disorders in the field of the surgical intervention in the postoperative period. Conclusion. Surgical interventions with access not in the area of the natural ostium of the maxillary sinus are more gentle, since they do not injure the mucociliary clearance in the key region - the ostium.

Childhood physical activity body contact risk: feasibility of a novel technique for objective measurements of impact speed, frequency, and intentionality.

Children at risk for bleeding injuries are restricted from body contact during physical activity but current recommendations are based on expert opinion. Evaluate high-speed digital video recording as an objective measure of body contact risk during physical activity. Observational study of physical activities among healthy children, grouped according to participation in teams (vs. individual) and on their perceived risk of injury (high/low). High speed digital video recordings documented the collision target (floor/ground/ice, people, wall, equipment), estimated speed, and impact rates for team and individual activities, with and without expected body contact. Among 348 participating children (3-16 years, 51% female), 32% to 78% experienced at least one contact. Impact type varied significantly (chi-square, p < 0.001) by activity category. Unstructured and Team high risk activity impacts were primarily with the floor/ground, whereas Individual low risk activities were characterized by equipment impacts. Impact speeds were typically 1.0 to 2.1 m s(-1) . Higher impact speeds occurred during instructional classes (2.1 m s(-1) ), unstructured free swim (1.9 m s(-1) ) and ball hockey (1.7 m s(-1) ). Impact rates were higher during Team high risk and Team low risk sports (3.0 and 1.8 impacts per minute, respectively) compared to Individual (high or low risk) or Unstructured activities (0.2-0.3 impacts per minute). High speed video recordings of childhood physical activity are a feasible method for characterizing the frequency, type, direction and speed of impacts. Quantifying the impacts that occur during childhood physical activity could inform the guidelines for physical activity participation among children with identified bleeding risks.

Perpendicular Pull‐Out Force of Locking Versus Non‐Locking Plates in Thin Cortical Bone Using a Canine Mandibular Ramus Model

To compare the holding strength of a conventional plate-screw construct with a locking plate-screw construct in the thin cortical bone of the canine mandibular ramus. Mechanical study. Paired cadaveric canine mandibles (n = 10 pairs). Perpendicular pull-out testing was performed on 2.0-mm limited-contact dynamic compression plate (LC-DCP)-screw constructs and 2.0-mm string-of-pearls (SOP) plate-screw constructs applied to the ramus of the canine mandible. Pull-out force was applied perpendicular to the long axis of the plates. Construct stiffness and load at failure were determined from load-displacement curves and method of failure was determined from high speed digital video recordings. A paired t-test was used to compare mean construct stiffness and load at failure between groups. SOP plate-screw constructs had a significantly higher mean construct stiffness and load at failure than did LC-DCP-screw constructs. LC-DCP constructs failed by screw pull-out while bone slicing and fracture were prominent mechanisms of failure for SOP constructs. SOP plate-screw constructs sustained a significantly higher perpendicular load at failure than did LC-DCP-screw constructs.

Effects of Acetazolamide on Infantile Nystagmus Syndrome Waveforms: Comparisons to Contact Lenses and Convergence in a Well-Studied Subject

Aim:To determine if acetazolamide, an effective treatment for certain inherited channelopathies, has therapeutic effects on infantile nystagmus syndrome (INS) in a well-studied subject, compare them to other therapies in the same subject and to tenotomy and reattachment (T&R) in other subjects.Methods:Eye-movement data were taken using a high-speed digital video recording system. Nystagmus waveforms were analyzed by applying an eXpanded Nystagmus Acuity Function (NAFX) at different gaze angles and determining the Longest Foveation Domain (LFD).Results:Acetazolamide improved foveation by both a 59.7% increase in the peak value of the NAFX function (from 0.395 to 0.580) and a 70% broadening of the NAFX vs Gaze Angle curve (the LFD increased from 20° to 34°). The resulting U-shaped improvement in the percent NAFX vs Gaze Angle curve, varied from ~60% near the NAFX peak to over 1000% laterally. The therapeutic improvements in NAFX from acetazolamide (similar to T&R) were intermediate between those of soft contact lenses and convergence, the latter was best; for LFD improvements, acetazolamide and contact lenses were equivalent and less effective than convergence. Computer simulations suggested that damping the central oscillation driving INS was insufficient to produce the foveation improvements and increased NAFX values.Conclusion:Acetazolamide resulted in improved-foveation INS waveforms over a broadened range of gaze angles, probably acting at more than one site. This raises the question of whether hereditary INS involves an inherited channelopathy, and whether other agents with known effects on ion channels should be investigated as therapy for this condition.

Producion of Nanoparticle Assemblies by Electro-Spraying and Freeze-Drying of Colloids: A New Method to Resolve Handling Problem of Nanoparticles

To resolve handling problem of nanoparticles , due to their small size, a new methodology of electro-spray ing and freeze-drying was developed for colloidal nanoparticles of silica and titania to transform them to solid macro-scale nanoparticle assemblies. The assemblies were then redispersed in an aqueous system to investigate the effect of formulation of original solutions and the process parameters on reversibility of the system to a stabilised colloidal condition. The electro-spraying was employed to control the size of droplets and consequently the size of nanoparticle assemblies in the freeze-drying. High speed digital video recording of the spray process revealed that within a narrow range of voltage, the size of droplets reduced sharply to a minimum value, where a narrow size distribution was obtained. Non-destructive structural analysis of the freeze-dried nanoparticle assemblies using X-ray micro-tomography represented different structures of the nanoparticle assemblies depending on type of nanoparticles. The stability analysis of redispersed nanoparticles in water (using centrifugal stability analyser) and their size distribution (obtained by nano-sizer) showed different stability conditions. These conditions were affected by physicochemic al properties of nanoparticle assemblies and process parameters. In terms of titania, it was found that with an appropriate formulation of PEG solution (as binder of assemblies) and optimum size of the nanoparticle assemblies it was possible to produce assemblies having adequate strength and good re-dispersion properties.

Application of background oriented schlieren for quantitative measurements of shock waves from explosions

This paper describes application of a background oriented schlieren technique in order to obtain quantitative measurements of shock waves from explosions by processing high speed digital video recordings. The technique is illustrated by an analysis of two explosions, a high explosive test and a hydrogen gas explosion test. The visualization of the shock front is utilized to calculate the shock Mach number, leading to a predicted shock front pressure. For high explosives the method agreed quite well with a standard curve for side-on shock pressures. In the case of the gas explosion test we can also show that the shock front is non-spherical. It should be possible to develop this technique to investigate external blast waves and external explosions from vented gas explosions in more details.

Combustion of levitated titanium particles in air

Combustion of titanium particles in air is of interest for applications to pyrotechnic countermeasures against chemical or bacteriological pollution, synthesis of nanoscale titania, and fire/explosion safety in metallurgical and SHS technologies. In this work, combustion of single titanium particles is studied using electrodynamic balance (levitation) and laser ignition. High-speed digital video recording and a photomultiplier are used for diagnostics. Based on the obtained data, empirical formulas are proposed for the dependence of the burning time on the initial particle size. Thermodynamic calculations are made to support the conclusions based on experimental data. The particle burning time is estimated using a simplified mathematical model for diffusion-controlled combustion. Comparison of the estimates with the experimental results suggests that oxygen diffusion in the gas phase plays a major role in the combustion mechanism of 100-μm or larger titanium particles in air, while kinetics become more important for smaller sizes.

Powered control mechanisms contributing to dynamically stable swimming in porcupine puffers (Teleostei: Diodon holocanthus)

Balances of multiple varying forces must be the basis for the unusually great dynamic stability of swimming pufferfishes. We used high-speed digital video recordings to study biomechanics and kinematics of rectilinear swimming at different speeds of five porcupine puffers in a water tunnel. We measured critical swimming speeds (U crit ); fin biomechanics, kinematics, and coordination; recoil movements; and gait changes. Major propulsors were pectoral fins at lower speeds; dorsal, anal, and caudal fins at higher speeds. Precise coordination of fin movements produced small recoil movements at speeds below U crit . The unusual body shape probably contributes to unconscious stability control.

Observations of Barnacle Detachment from Silicones using High-Speed Video

ABSTRACT The detachment of barnacles (under shear and tensile loads) from silicone was investigated with the aid of high-speed digital video recording. A handheld probe was used to apply loads to the shells of barnacles attached to three clear silicone-elastomer coatings of known thickness applied to glass plates. The tests were performed in the laboratory in air and underwater. Representative data are presented as a qualitative description of separation at the barnacle adhesive–silicone interface. Detailed examination of adhesive separation during detachment provided new insight into the nature of a marine biological adhesive on a low modulus, artificial surface. The visible response of the barnacle adhesive on silicone under external shear and tensile loading was suggestive of the viscous fingering seen in Saffman–Taylor instabilities. Complex branching separation occurred in rapid progression, usually within 100 ms. The results suggest that the barnacle adhesive exhibits rheological responses of a viscous material at the interface with silicone surfaces. Additional experiments with time-lapse photography demonstrated that the adhesive was stable underwater but became dehydrated or coalesced when exposed directly to air. A simple model of the adhesive system of a barnacle in contact with silicone based upon Balanus eburneus is proposed to assist in the development of a more complete understanding of barnacle adhesion.