Videofluoroscopic Investigation of Body Position on Articulatory Positioning

2014 ◽  
Vol 57 (4) ◽  
pp. 1135-1147 ◽  
Author(s):  
Youkyung Bae ◽  
Jamie L. Perry ◽  
David P. Kuehn

Purpose To quantitatively examine the effects of body position on the positioning of the epiglottis, tongue, and velum at rest and during speech. Method Videofluoroscopic data were obtained from 12 healthy adults in the supine and upright positions at rest and during speech while the participants produced 12 VCV sequences. The effects of body position, target sounds, and adjacent sounds on structural positioning and vowel formant structure were investigated. Results Velar retropositioning in the supine position was the most consistent pattern observed at rest. During speech, all structures, with varying degrees of adjustment, appeared to work against the gravitational pull, resulting in no significant narrowing in the oro- and nasopharyngeal regions while in the supine position. Minimal differences in the formant data between the body positions were also observed. Overall, structural positioning was significantly dependent on the target and adjacent sounds regardless of body position. Conclusions The present study demonstrated that structural positioning in response to gravity varied across individuals based on the type of activities being performed. With varying degrees of positional adjustment across different structures, fairly consistent articulatory positioning in the anterior–posterior dimension was maintained in different body positions during speech.

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Nicolas Hernandez Norager ◽  
Markus Harboe Olsen ◽  
Sarah Hornshoej Pedersen ◽  
Casper Schwartz Riedel ◽  
Marek Czosnyka ◽  
...  

Abstract Background Although widely used in the evaluation of the diseased, normal intracranial pressure and lumbar cerebrospinal fluid pressure remain sparsely documented. Intracranial pressure is different from lumbar cerebrospinal fluid pressure. In addition, intracranial pressure differs considerably according to the body position of the patient. Despite this, the current reference values do not distinguish between intracranial and lumbar cerebrospinal fluid pressures, and body position-dependent reference values do not exist. In this study, we aim to establish these reference values. Method A systematic search was conducted in MEDLINE, EMBASE, CENTRAL, and Web of Sciences. Methodological quality was assessed using an amended version of the Joanna Briggs Quality Appraisal Checklist. Intracranial pressure and lumbar cerebrospinal fluid pressure were independently evaluated and subdivided into body positions. Quantitative data were presented with mean ± SD, and 90% reference intervals. Results Thirty-six studies were included. Nine studies reported values for intracranial pressure, while 27 reported values for the lumbar cerebrospinal fluid pressure. Reference values for intracranial pressure were −  5.9 to 8.3 mmHg in the upright position and 0.9 to 16.3 mmHg in the supine position. Reference values for lumbar cerebrospinal fluid pressure were 7.2 to 16.8 mmHg and 5.7 to 15.5 mmHg in the lateral recumbent position and supine position, respectively. Conclusions This systematic review is the first to provide position-dependent reference values for intracranial pressure and lumbar cerebrospinal fluid pressure. Clinically applicable reference values for normal lumbar cerebrospinal fluid pressure were established, and are in accordance with previously used reference values. For intracranial pressure, this study strongly emphasizes the scarcity of normal pressure measures, and highlights the need for further research on the matter.


Author(s):  
Tijana Bojić ◽  
Zoran Matić ◽  
Mihajlo Stojković ◽  
Mirjana Platiša ◽  
Aleksandar Kalauzi ◽  
...  

Cardiorespiratory coupling (CRC), a set of cardiac and respiratory rhythms that optimise the body oxygenation and the adaptability of the cardiorespiratory system to the external and internal environment, is represented in the linear domain by coefficient Qpr, the number of heartbeats per respiratory cycle (1, 2). Slow 0.1Hz breathing in supine position (Supin01) and active standing (Stand) represent the states of maximal RRI vagal and sympathetic modulation, respectively, in physiological quiescence; standing with 0.1Hz breathing (stand01) is characterized by qualitatively specific pattern of CRC(3). The aim of our work was to investigate the Qpr in 4 states: supine position with spontaneous breathing (supin), stand, supin01and stand01. Methods: The ECG (RRI) and respiration signals were simultaneously recorded in 20 healthy human subjects in four conditions. Data acquisition and processing was performed as in (3). Results: Parameter Supin (mean95%CI) Stand (mean95%CI) Supin01 (mean95%CI) Stand01 (mean95%CI) RRI [s] 0.980.13 0.720.10 1.060.13 0.750.09 sd RRI [s] 0.060.02 0.040.02 0.090.03 0.070.02 BBI [s] 4.681.53 4.581.80 9.850.71 9.950.20 sdBBI [s] 1.110.69 1.351.29 1.440.94 1.060.44 Qpr 4.811.67 6.392.43 9.411.20 13.481.66 sdQpr 1.140.67 1.931.73 1.390.71 1.540.53 Table 1. Mean value and 95%CI of RRI, BBI and Qpr for 20 healthy subjects in four physiological states: Supin-supine position with spontaneous breathing, Stand- standing with spontaneous breathing, Supin01-supine position with 0.1Hz breathing, Stand01-standing with slow 0.1Hz breathing. Parameter Supin-Stand Supin-Supin01 Supin-Stand01 Supin01-Stand01 RRI 0.000 0.0 04 0.000 0.000 sd RRI 0.0 04 0.00 0 0.351 0.0 10 BBI 0.391 0.000 0.000 0.313 sdBBI 0.232 0.433 0.911 0.135 Qpr 0.0 00 0.000 0.000 0.000 sdQpr 0.0 06 0.370 0.0 33 0.191 Table 2. Probability values ​​(p) of statistically significant differences between different physiological states. Wilcoxon test on a sample of 20 subjects. Color-indicated statistically significant changes in values ​​(p <0.05) whose changes were related and discussed. - increase of mean value, -decrease of mean value. Our results show that Qpr is state dependent and that it increases with the behavioral task complexity. Postural change tunes Qpr by RRI modulation, while 0.1Hz breathing dominantly by the increase of BBI. Stand01 is characterized by concomitant adjustment of both RRI and BBI. These data imply that Qpr regulation is "loosely" and selectively coordinated in stand and supin01("dual control") while integrated in stand01 ("unitary control"(4)). Analogously to nonlinear CRC(3), Qpr is probably operated by hierarchically higher diencephalo-telencephalic autonomic networks. References: 1. Moser M et al, Biol Rhythm Res 1995;26(1):100-111. 2. Scholkmann F et al, Front Physiol 2019;10:371. 3. Matić Z et al, Front Physiol 2020;11:24. 4. Feldman JL et al, Annu Rev Physiol 1988;50,593606.


SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A163-A163
Author(s):  
Scott Schecter ◽  
Junjie Liu

Abstract Introduction Obstructive sleep apnea (OSA) is a heterogeneous disease dependent on many factors including the sleep stage and the body position. OSA is often more severe during the rapid eye movement (REM) sleep stage, a phenomenon known as REM predominance. Prior studies suggested associations of higher REM predominance of OSA with younger age, higher obesity, and lower adherence to continuous positive airway pressure (CPAP) therapy, but these studies had small cohort sizes. Here we leverage home-based sleep tests (HST) that estimate REM sleep and measure body position to study REM predominance in a larger cohort of OSA patients. Methods We retrospectively reviewed patients who took HST at our clinic using devices based on peripheral arterial tonometry (WatchPAT, Itamar Medical). The HST results included estimated REM sleep periods and measured body positions. Auto-titrating CPAP therapy was prescribed for the majority of OSA patients diagnosed by the HST. Our inclusion criteria were: apnea-hypopnea index (AHI) above 5 /hour, estimated REM sleep time above 30 minutes, oxygen saturation below 90% (T90) for less than 10 minutes, and successful retrieval of CPAP usage data. CPAP adherence was defined as the percentage of nights with CPAP usage above four hours, and REM predominance as the ratio between REM AHI and non-REM AHI. Additionally, the percentage of estimated sleep time in supine position was calculated. Results Among 292 consecutive patients whose HST were reviewed, 113 patients met the inclusion criteria. The 25th-75th percentile ranges of age, body mass index (BMI), AHI, REM predominance, CPAP adherence and supine sleep percentage were 36–56 years, 28.1–38.4 kg/m2, 8.9–25.9 /hour, 1.27–2.89, 40%-97% and 28%-72%, respectively. REM predominance was not associated with CPAP adherence (P &gt; 0.05), but was significantly associated with lower age, higher BMI, and higher supine sleep percentage (all P &lt; 0.01). Conclusion We found that REM-predominant OSA is relatively more prevalent not only in young and obese patients, but in patients who sleep relatively more in the supine position. This association of REM predominance with body position is a novel finding to our knowledge. Contrary to prior studies, we did not find association of REM predominance with adherence to CPAP therapy. Support (if any):


Author(s):  
F. Riva ◽  
U. Buck ◽  
K. Buße ◽  
R. Hermsen ◽  
E. J. A. T. Mattijssen ◽  
...  

AbstractThis study explores the magnitude of two sources of error that are introduced when extracorporeal bullet trajectories are based on post-mortem computed tomography (PMCT) and/or surface scanning of a body. The first source of error is caused by an altered gravitational pull on soft tissue, which is introduced when a body is scanned in another position than it had when hit. The second source of error is introduced when scanned images are translated into a virtual representation of the victim’s body. To study the combined magnitude of these errors, virtual shooting trajectories with known vertical angles through five “victims” (live test persons) were simulated. The positions of the simulated wounds on the bodies were marked, with the victims in upright positions. Next, the victims were scanned in supine position, using 3D surface scanning, similar to a body’s position when scanned during a PMCT. Seven experts, used to working with 3D data, were asked to determine the bullet trajectories based on the virtual representations of the bodies. The errors between the known and determined trajectories were analysed and discussed. The results of this study give a feel for the magnitude of the introduced errors and can be used to reconstruct actual shooting incidents using PMCT data.


Author(s):  
Fernanda Mottin Refinetti ◽  
Ricardo Drews ◽  
Umberto Cesar Corrêa ◽  
Flavio Henrique Bastos

Crustaceana ◽  
2013 ◽  
Vol 86 (13-14) ◽  
pp. 1695-1710 ◽  
Author(s):  
Susan E. Allen ◽  
A. G. Lewis

Locomotor appendage-body relationships were used to examine whether swimming or reduction in sinking rate is the more important function in the second nauplius and copepodid stages of Lepeophtheirus salmonis (Krøyer, 1837). Except for the similarity in swimming appendage surface areas without setae, the appendages of the two stages are morphologically distinct. Although the nauplius is smaller than the copepodid it has long slender appendages that, with setae, provide greater total surface area than the paddle-shaped copepodid thoracic legs. Copepodid thoracic legs are more similar to those used for swimming by planktonic copepods although with more limited propulsion capability. Naupliar appendages project from the body while copepodid appendages can be folded against the ventral surface, improving hydrodynamic flow as well as body position after attachment to a host. Both copepodid and naupliar appendages are of sufficient size that they should provide escape velocities of more than 100 mm ⋅ s−1. The nature and display of the naupliar appendages suggest they could be used to reduce sinking rate by as much as 64%, reducing the need to swim to maintain a suitable location in the water. Although copepodid thoracic legs could reduce sinking rate by over 40%, their position on the ventral surface and the nature of other appendages suggests a more important use, for orientation and attachment once a host is located.


2017 ◽  
Vol 284 (1852) ◽  
pp. 20170359 ◽  
Author(s):  
Arjun Nair ◽  
Christy Nguyen ◽  
Matthew J. McHenry

An escape response is a rapid manoeuvre used by prey to evade predators. Performing this manoeuvre at greater speed, in a favourable direction, or from a longer distance have been hypothesized to enhance the survival of prey, but these ideas are difficult to test experimentally. We examined how prey survival depends on escape kinematics through a novel combination of experimentation and mathematical modelling. This approach focused on zebrafish ( Danio rerio ) larvae under predation by adults and juveniles of the same species. High-speed three-dimensional kinematics were used to track the body position of prey and predator and to determine the probability of behavioural actions by both fish. These measurements provided the basis for an agent-based probabilistic model that simulated the trajectories of the animals. Predictions of survivorship by this model were found by Monte Carlo simulations to agree with our observations and we examined how these predictions varied by changing individual model parameters. Contrary to expectation, we found that survival may not be improved by increasing the speed or altering the direction of the escape. Rather, zebrafish larvae operate with sufficiently high locomotor performance due to the relatively slow approach and limited range of suction feeding by fish predators. We did find that survival was enhanced when prey responded from a greater distance. This is an ability that depends on the capacity of the visual and lateral line systems to detect a looming threat. Therefore, performance in sensing, and not locomotion, is decisive for improving the survival of larval fish prey. These results offer a framework for understanding the evolution of predator–prey strategy that may inform prey survival in a broad diversity of animals.


2018 ◽  
Vol 32 (11) ◽  
pp. 961-975 ◽  
Author(s):  
Jessica Battisto ◽  
Katharina V. Echt ◽  
Steven L. Wolf ◽  
Paul Weiss ◽  
Madeleine E. Hackney

Author(s):  
Rahul Subramanian ◽  
Naga Venkata Rakesh ◽  
Robert F. Beck

Accurate prediction of the roll response is of significant practical relevance not only for ships but also ship type offshore structures such as FPSOs, FLNGs and FSRUs. This paper presents a new body-exact scheme that is introduced into a nonlinear direct time-domain based strip theory formulation to study the roll response of a vessel subjected to moderately large amplitude incident waves. The free surface boundary conditions are transferred onto a representative incident wave surface at each station. The body boundary condition is satisfied on the instantaneous wetted surface of the body below this surface. This new scheme allows capturing nonlinear higher order fluid loads arising from the radiated and wave diffraction components. The Froude-Krylov and hydrostatic loads are computed on the intersection surface of the exact body position and incident wave field. The key advantage of the methodology is that it improves prediction of nonlinear hydrodynamic loads while keeping the additional computational cost small. Physical model tests have been carried out to validate the computational model. Fairly good agreement is seen. Comparisons of the force components with fully linear and body-nonlinear models help in bringing out the improvements due to the new formulation.


1978 ◽  
Vol 45 (4) ◽  
pp. 581-589 ◽  
Author(s):  
V. P. Vellody ◽  
M. Nassery ◽  
W. S. Druz ◽  
J. T. Sharp

With a linearized respiratory magnetometer, measurements of anteroposterior and lateral diameters of both the rib cage and the abdomen were made at functional residual capacity and continuously during tidal breathing. Twenty-five subjects with normal respiratory systems were studied in the sitting, supine, lateral decubitus, and prone body positions. When subjects changed from sitting to supine position anteroposterior diameters of both rib cage and abdomen decreased while their lateral diameters increased. Both anteroposterior and lateral tidal excursions of the rib cage decreased; those of the abdomen increased. When subjects turned from supine to lateral decubitus position both anteroposterior diameters increased and the lateral diameters decreased. This was associated with an increase in both lateral excursions and a decrease in the abdominal anteroposterior excursions. Diameters and tidal excursions in the prone position resembled those in the supine position. Diameter changes could be explained by gravitational effects. Differences in tidal excursions accompanying body position change were probably related to 1) differences in the distribution of respiratory muscle force, 2) differences in the activity or mechanical advantage of various inspiratory muscles, and 3) local compliance changes in parts of the rib cage and abdomen.


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