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1.
Long-Ho Chau Wenfeng Liang Florence Wing Ki Cheung Wing Keung Liu Wen Jung Li Shih-Chi Chen Gwo-Bin Lee 《PloS one》2013,8(1)
The use of optical dielectrophoresis (ODEP) to manipulate microparticles and biological cells has become increasingly popular due to its tremendous flexibility in providing reconfigurable electrode patterns and flow channels. ODEP enables the parallel and free manipulation of small particles on a photoconductive surface on which light is projected, thus eliminating the need for complex electrode design and fabrication processes. In this paper, we demonstrate that mouse cells comprising melan-a cells, RAW 267.4 macrophage cells, peripheral white blood cells and lymphocytes, can be manipulated in an opto-electrokinetics (OEK) device with appropriate DEP parameters. Our OEK device generates a non-rotating electric field and exerts a localized DEP force on optical electrodes. Hitherto, we are the first group to report that among all the cells investigated, melan-a cells, lymphocytes and white blood cells were found to undergo self-rotation in the device in the presence of a DEP force. The rotational speed of the cells depended on the voltage and frequency applied and the cells'' distance from the optical center. We discuss a possible mechanism for explaining this new observation of induced self-rotation based on the physical properties of cells. We believe that this rotation phenomenon can be used to identify cell type and to elucidate the dielectric and physical properties of cells. 相似文献
2.
Robert Hetzel Kurt Wüthrich Johann Deisenhofer Robert Huber 《European biophysics journal : EBJ》1976,2(2):159-180
Summary The molecular conformation of the basic pancreatic trypsin inhibitor (BPTI) is known in considerable detail from both X-ray studies in single crystals and NMR studies in solution. The NMR experiments showed that the aromatic rings of the phenylalanyl and tyrosyl residues can undergo rapid rotational motions about the C-C bond. The present paper describes a model investigation of the mechanistic aspects of these intramolecular rotational motions. From calculations of the conformational energies for molecular species derived from the X-ray structure by rotations of individual aromatic rings, it was apparent that the rotational motions of the aromatics could only be understood in a flexible structure. Flexibility was simulated by allowing the protein to relax to an energetically favorable conformation for each of the different rotation states of the aromatic rings. It was then of particular interest to investigate how the perturbations caused by different rotation states of the aromatic rings were propagated in the protein structure. It was found that the rotation axes C-C were only slightly affected (
120°). The most sizeable perturbations are caused by through space interactions with nearby atoms, which move away from the ring center and thus release the steric hindrance opposing the rotational motions. The values for the energy barriers obtained from the energy minimization are of the same order of magnitude as those measured by NMR. 相似文献
3.
To investigate myosin II function in cell movement within a cell mass, we imaged green fluorescent protein-myosin heavy chain (GFP-MHC) cells moving within the tight mound of Dictyostelium discoideum. In the posterior cortex of cells undergoing rotational motion around the center of the mound, GFP-MHC cyclically formed a "C," which converted to a spot as the cell retracted its rear. Consistent with an important role for myosin in rotation, cells failed to rotate when they lacked the myosin II heavy chain (MHC-) or when they contained predominantly monomeric myosin II (3xAsp). In cells lacking the myosin II regulatory light chain (RLC-), rotation was impaired and eventually ceased. These rotational defects reflect a mechanical problem in the 3xAsp and RLC- cells, because these mutants exhibited proper rotational guidance cues. MHC- cells exhibited disorganized and erratic rotational guidance cues, suggesting a requirement for the MHC in organizing these signals. However, the MHC- cells also exhibited mechanical defects in rotation, because they still moved aberrantly when seeded into wild-type mounds with proper rotational guidance cues. The mechanical defects in rotation may be mediated by the C-to-spot, because RLC- cells exhibited a defective C-to-spot, including a slower C-to-spot transition, consistent with this mutant's slower rotational velocity. 相似文献
4.
The sensory weighting model is a general model of sensory integration that consists of three processing layers. First, each
sensor provides the central nervous system (CNS) with information regarding a specific physical variable. Due to sensor dynamics,
this measure is only reliable for the frequency range over which the sensor is accurate. Therefore, we hypothesize that the
CNS improves on the reliability of the individual sensor outside this frequency range by using information from other sensors,
a process referred to as “frequency completion.” Frequency completion uses internal models of sensory dynamics. This “improved”
sensory signal is designated as the “sensory estimate” of the physical variable. Second, before being combined, information
with different physical meanings is first transformed into a common representation; sensory estimates are converted to intermediate
estimates. This conversion uses internal models of body dynamics and physical relationships. Third, several sensory systems
may provide information about the same physical variable (e.g., semicircular canals and vision both measure self-rotation).
Therefore, we hypothesize that the “central estimate” of a physical variable is computed as a weighted sum of all available
intermediate estimates of this physical variable, a process referred to as “multicue weighted averaging.” The resulting central
estimate is fed back to the first two layers. The sensory weighting model is applied to three-dimensional (3D) visual–vestibular
interactions and their associated eye movements and perceptual responses. The model inputs are 3D angular and translational
stimuli. The sensory inputs are the 3D sensory signals coming from the semicircular canals, otolith organs, and the visual
system. The angular and translational components of visual movement are assumed to be available as separate stimuli measured
by the visual system using retinal slip and image deformation. In addition, both tonic (“regular”) and phasic (“irregular”)
otolithic afferents are implemented. Whereas neither tonic nor phasic otolithic afferents distinguish gravity from linear
acceleration, the model uses tonic afferents to estimate gravity and phasic afferents to estimate linear acceleration. The
model outputs are the internal estimates of physical motion variables and 3D slow-phase eye movements. The model also includes
a smooth pursuit module. The model matches eye responses and perceptual effects measured during various motion paradigms in
darkness (e.g., centered and eccentric yaw rotation about an earth-vertical axis, yaw rotation about an earth-horizontal axis)
and with visual cues (e.g., stabilized visual stimulation or optokinetic stimulation).
Received: 20 September 2000 / Accepted in revised form: 28 September 2001 相似文献
5.
Background
The aim of this study was to observe the rotation patterns at the papillary muscle plane in the Left Ventricle(LV) with normal subjects using two-dimensional speckle tracking imaging(2D-STI).Methods
We acquired standard of the basal, the papillary muscle and the apical short-axis images of the LV in 64 subjects to estimate the LV rotation motion by 2D-STI. The rotational degrees at the papillary muscle short-axis plane were measured at 15 different time points in the analysis of two heart cycles.Results
There were counterclockwise rotation, clockwise rotation, and counterclockwise to clockwise rotation at the papillary muscle plane in the LV with normal subjects, respectively. The ROC analysis of the rotational degrees was performed at the papillary muscle short-axis plane at the peak LV torsion for predicting whether the turnaround point of twist to untwist motion pattern was located at the papillary muscle level. Sensitivity and specificity were 97% and 67%, respectively, with a cut-off value of 0.34°, and an area under the ROC curve of 0.8. At the peak LV torsion, there was no correlation between the rotational degrees at the papillary muscle short-axis plane and the LVEF in the normal subjects(r = 0.000, p = 0.998).Conclusions
In the study, we conclude that there were three rotation patterns at the papillary muscle short-axis levels, and the transition from basal clockwise rotation to apical counterclockwise rotation is located at the papillary muscle level. 相似文献6.
We employ an optimal solution to both the shape from motion problem and the related problem of the estimation of self-movement on a purely optical basis to deduce practical rules of thumb for the limits of the optic flow information content in the presence of perturbation of the motion parallax field. The results are illustrated and verified by means of a computer simulation.The results allow estimates of the accuracy of depth and egomotion estimates as a function of the accuracy of data sampling and the width of field of view, as well as estimates of the interaction between rotational and translational components of the movement. 相似文献
7.
Multifractality in the peripheral cardiovascular system from pointwise holder exponents of laser Doppler flowmetry signals 下载免费PDF全文
Humeau A Chapeau-Blondeau F Rousseau D Tartas M Fromy B Abraham P 《Biophysical journal》2007,93(12):L59-L61
We study the dynamics of skin laser Doppler flowmetry signals giving a peripheral view of the cardiovascular system. The analysis of Hölder exponents reveals that the experimental signals are weakly multifractal for young healthy subjects at rest. We implement the same analysis on data generated by a standard theoretical model of the cardiovascular system based on nonlinear coupled oscillators with linear couplings and fluctuations. We show that the theoretical model, although it captures basic features of the dynamics, is not complex enough to reflect the multifractal irregularities of microvascular mechanisms.In clinical and physiological investigations, the cardiovascular system dynamics can be considered from a central or from a peripheral point of view. Heart-beat interval sequences, reflecting a central view of the human cardiovascular system, have been analyzed and the results have shown that they display multifractal properties for healthy subjects (1). A peripheral view of the cardiovascular system dynamics is possible by studying microvascular blood flow signals given by the laser Doppler flowmetry technique (2). These signals have complex dynamics, with fractal structures and chaos (3,4). However, are these data, reflecting the underlying mechanisms acting at the microscopic level of the human physiology, as irregular as those giving a central view point of the system dynamics? Is a single fractal exponent sufficient to characterize them? Moreover, a set of nonlinear coupled oscillators has recently been proposed as a standard theoretical model of the cardiovascular system (5–8). Is the dynamics of the corresponding simulated data close to the one of real cardiovascular signals?Herein we report that skin laser Doppler flowmetry signals display multifractal properties on young healthy subjects at rest. By estimating Hölder exponents of signals recorded on the finger, we show that the dynamics of peripheral signals can be irregular, as central data are. We also conclude that the use of a standard theoretical model of the cardiovascular system, based on five nonlinear coupled oscillators with linear couplings and fluctuations, is not complex enough to model the multifractal properties of the cardiovascular system. To our knowledge, it is the first time that multifractality of experimental and simulated laser Doppler flowmetry signals is studied.The rapid changes in a time series are called singularities and a characterization of their strength is obtained with the Hölder exponents (9). When a broad range of exponents is found, signals are considered as multifractal. A narrow range implies monofractality. One of the most widely used monofractal signal models is the fractional Brownian motion. In opposition, multifractal signals are more complex and inhomogeneous. The multifractal formalism has been established to account for the statistical scaling properties of time series observed in various physical situations. A singularity spectrum D(h) of a signal is the function that gives, for a fixed h, the Hausdorff dimension of the set of points x where the Hölder exponent h(x) is equal to h. The Hölder exponent h(x0) of a function f at the point x0 is the highest h value so that f is Lipschitz at x0. There exists a constant C and a polynomial Pn(x) of order n so that for all x in a neighborhood of x0 we have (10,11)(1)The Hölder exponent measures the degree of irregularity of f at the point x0.We analyze experimental skin laser Doppler flowmetry signals reflecting microvascular blood flow. The signals are recorded with a frequency sampling of 20 Hz on the finger of seven young healthy people between 20 and 35 years old (12). A laser Doppler flowmetry signal is shown in Fig. 1. For each recording, 15,601 pointwise Hölder exponents are taken into account. They are computed with a parametric generalized quadratic variation based estimation method (13). Open in a separate windowFIGURE 1Skin laser Doppler flowmetry signal recorded on a young healthy subject at rest.For the skin laser Doppler flowmetry signals, we find a minimum Hölder exponent of 0.56, a maximum of 0.71, a mean value of 0.63, and a standard deviation of 0.03 (average values over seven signals). The difference between the minimum and maximum Hölder exponents is therefore of 0.15. An example of Hölder exponent time series is shown in Fig. 2. To compare the results with known mono and multifractal data, we generate a fractional Brownian motion (monofractal signal) and a multifractional Brownian motion (multifractal signal) (14). For each data, 15,601 pointwise Hölder exponents are taken into account. Open in a separate windowFIGURE 2Hölder exponents for a skin laser Doppler flowmetry signal recorded on a young healthy subject at rest.
Open in a separate windowWe next compare the range of the Hölder exponents computed above with the range of exponents obtained from simulated laser Doppler flowmetry data. Simulated signals are computed with a standard theoretical model of the cardiovascular system based on five nonlinear coupled oscillators reflecting the heart beats, respiration, myogenic, neurogenic, and endothelial related metabolic activities (i = 1–5, respectively) (5–8,15). This model has been proposed after analyses of several cardiovascular data that have shown the presence of well-defined spectral peaks (implying the presence of oscillatory processes), amplitude and frequency modulation, as well as synchronization effects in the cardiovascular system (5–8,16). The basic unit in the model is written as (5–8)(2)(3)with(4)where x and y are vectors of oscillator state variables, αi, ai, and ωi are constants, gxi(x) and gyi(y) are linear coupling vectors. The preliminary simulations of the model restricted to the cardio-respiratory interactions suggest that there is a mixture of linear and parametric couplings, but that the linear couplings seem to dominate (5). Moreover, Stefanovska et al. (5) and McClintock and Stefanovska (16) show that it is essential to take into account the influence of stochastic effects resulting from the (unmodeled) rest of the system. Herein we use linear couplings and fluctuations. To model the latter, the characteristic angular frequencies of the cardiac, respiratory, myogenic, neurogenic, and endothelial related metabolic activities are written as(5)where fi_s are the characteristic frequencies, ρ is a constant, and ζi(t) is a white Gaussian noise with mean 0 and variance 1. The blood flow is then computed as(6)with the same frequency sampling as the real signals (20 Hz). We choose the model parameters (Eqs. 2–6), as well as the level of fluctuations, to obtain a good match between the power spectra of the simulated data and of a real signal. Both spectra show a broad peak at ∼1 Hz, reflecting the cardiac activity, and contain much noise in the highest frequencies. In what follows, simulated signals passed through the same processing chain as real signals for the computation of the Hölder exponents: 15,601 Hölder exponents are determined.The analysis of the Hölder exponents from the simulated data demonstrates that, even if their range is near the one obtained for the Hölder exponents of real laser Doppler flowmetry recordings (see and2),2), the Hölder exponents of the simulated data are higher than those of the real signals. The Hölder exponents of the simulated data are always >1, whereas those of the real signals are always <1. This is also true when an attenuated or an amplified version of the simulated time series is analyzed. The simulated signals are therefore differentiable whereas the real ones are not and are thus much more irregular.
Open in a separate windowThis study is the first multifractal analysis of laser Doppler flowmetry signals. It indicates a weak multifractal behavior of peripheral blood flow signals, for young healthy subjects at rest. The laser Doppler flowmetry time series show irregularities that can be characterized by a range of noninteger Hölder exponents. This contributes to a quantitative assessment of the complexity of the data recorded from peripheral locations where intricate interactions at the microcirculation level take place. This is the first time that multifractality of peripheral blood flow signals is shown. A study conducted on heart-beat interval sequences of healthy human subjects has demonstrated that, at this more central level of the cardiovascular system, multifractal properties are observed too (1). Data from both peripheral and central levels of the human cardiovascular system thus display multifractal properties for young healthy subjects. Further work is now needed to investigate whether pathologies that affect the microcirculation, such as diabetes, modify the signals dynamics.Previous studies conducted on the standard theoretical model of the cardiovascular system based on five coupled oscillators have shown that the model has the ability to capture relevant properties of the cardiovascular dynamics, like the presence of oscillatory processes with modulation and synchronization effects (5–8,16). In addition, the power spectra of the simulated data and of the experimental signals display a similar structure: a peak at ∼1 Hz due to the cardiac activity and noise in the high frequency band. However, the difference between the value of the Hölder exponents found for the real and for the simulated data leads to the conclusion that the model of the five oscillators using linear couplings and fluctuations is not adequate to reproduce the irregularity properties of the underlying mechanisms acting at the microvascular level.Our results may offer some guidelines for the construction of more complex mathematical models of laser Doppler flowmetry signals that could better reflect the irregularities of real data and provide relevant physiological information. This will become possible by finding more adequate parameters and couplings in the nonlinear coupled oscillators'' system. The fitting of singularity spectrum from simulated data to the one from real signals could be a possible approach. 相似文献
TABLE 1
Value for the minimum, maximum, range, mean, and standard deviation of the Hölder exponents computed for skin laser Doppler flowmetry (LDF) signals (average value computed over seven signals), for a monofractal signal (fBm), and for a multifractal signal (mBm)Signal | Minimum value | Maximum value | Range | Mean value | Standard deviation |
---|---|---|---|---|---|
LDF | 0.56 | 0.71 | 0.15 | 0.63 | 0.03 |
fBm | 0.47 | 0.55 | 0.08 | 0.51 | 0.02 |
mBm | 0.29 | 0.71 | 0.42 | 0.52 | 0.13 |
TABLE 2
Value for the minimum, maximum, range, mean, and standard deviation of the Hölder exponents computed for a laser Doppler flowmetry signal simulated with five nonlinear coupled oscillatorsSignal | Minimum value | Maximum value | Range | Mean value | Standard deviation |
---|---|---|---|---|---|
Simulated signal | 1.23 | 1.37 | 0.13 | 1.28 | 0.02 |
8.
V. D. Pustovitov 《Plasma Physics Reports》2013,39(3):199-208
A method is proposed for stability analysis of the locked and rotating resistive wall modes (RWMs) in tokamaks. The method is based on the relations describing the balance of energy permeating through the vessel wall. This is a natural extension of the traditional energy approach to the plasma stability tasks which allows incorporation of the energy outflow (absent in the classical energy principle) and its dissipation in the wall. The proposed method covers the locked and rotating modes with a complex growth rate. Its efficiency is proved by derivation of a general dispersion relation for such modes with further reduction to particular consequences for slow and fast RWMs. It is shown that in the latter case, when the skin depth becomes smaller than the wall thickness, the mode rotation essentially amplifies its damping, weakening and even suppressing the instability. This effect was earlier found in the frame of the slab model [V. D. Pustovitov, Phys. Plasmas 19, 062503 (2012)]. Here, it is confirmed with equations valid for toroidal geometry, which are obtained as a supplement to the standard energy principle. The presented results predict strong rotational stabilization of the fast RWMs, which occurs at the mode rotation frequency above a critical level. The estimates are given to allow comparison of these predictions with experimental results. 相似文献
9.
Leslie R. Landrum 《Brittonia》1991,43(3):199-200
The following new combinations are made:Myrteola phylicoides (Benth.) Landrum,Myrteola phylicoides var.glabrata (Berg) Landrum,Myrceugenia alpigena var.fuliginea (Berg) Landrum,Myrceugenia ovata var.regnelliana (Berg) Landrum, andMyrceugenia pilotantha var.nothorufa (Legrand) Landrum. 相似文献
10.
Fangjun Bao Hao Chen Ye Yu Jiguo Yu Shi Zhou Jing Wang QinMei Wang Ahmed Elsheikh 《PloS one》2013,8(8)
Purpose
To investigate the bilateral symmetry of the global corneal topography in normal corneas with a wide range of curvature, astigmatism and thickness valuesDesign
Cross-Sectional StudyMethods
Topography images were recorded for the anterior and posterior surfaces of 342 participants using a Pentacam. Elevation data were fitted to a general quadratic model that considered both translational and rotational displacements. Comparisons between fellow corneas of estimates of corneal shape parameters (elevation, radius in two main directions, Rx and Ry, and corresponding shape factors, Qx and Qy) and corneal position parameters (translational displacements: x0, y0 and z0, and rotational displacements: α, β and γ) were statistically analyzed.Results
The general quadratic model provided average RMS of fit errors with the topography data of 1.7±0.6 µm and 5.7±1.3 µm in anterior and posterior corneal surfaces. The comparisons showed highly significant bilateral correlations with the differences between fellow corneas in Rx, Ry, Qx and Qy of anterior and posterior surfaces remaining insignificantly different from zero. Bilateral differences in elevation measurements at randomly-selected points in both corneal central and peripheral areas indicated strong mirror symmetry between fellow corneas. The mean geometric center (x0, y0, z0) of both right and left corneas was located on the temporal side and inferior-temporal side of the apex in anterior and posterior topography map, respectively. Rotational displacement angle α along X axis had similar distributions in bilateral corneas, while rotation angle β along Y axis showed both eyes tilting towards the nasal side. Further, rotation angle γ along Z axis, which is related to corneal astigmatism, showed clear mirror symmetry.Conclusions
Analysis of corneal topography demonstrated strong and statistically-significant mirror symmetry between bilateral corneas. This characteristic could help in detection of pathological abnormalities, disease diagnosis, measurement validation and surgery planning. 相似文献11.
Cynthia M Lester McCully John Bacher Rhonda P MacAllister Emilie A Steffen-Smith Kadharbatcha Saleem Marvin L Thomas rd Rafael Cruz Katherine E Warren 《Comparative medicine》2015,65(1):77-82
Rapid, serial, and humane collection of cerebrospinal fluid (CSF) in nonhuman primates (NHP) is an essential element of numerous research studies and is currently accomplished via two different models. The CSF reservoir model (FR) combines a catheter in the 4th ventricle with a flexible silastic reservoir to permit circulating CSF flow. The CSF lateral port model (LP) consists of a lateral ventricular catheter and an IV port that provides static access to CSF and volume restrictions on sample collection. The FR model is associated with an intensive, prolonged recovery and frequent postsurgical hydrocephalus and nonpatency, whereas the LP model is associated with an easier recovery. To maximize the advantages of both systems, we developed the CSF lateral reservoir model (LR), which combines the beneficial features of the 2 previous models but avoids their limitations by using a reservoir for circulating CSF flow combined with catheter placement in the lateral ventricle. Nine adult male rhesus monkeys were utilized in this study. Pre-surgical MRI was performed to determine the coordinates of the lateral ventricle and location of choroid plexus (CP). The coordinates were determined to avoid the CP and major blood vessels. The predetermined coordinates were 100% accurate, according to MRI validation. The LR system functioned successfully in 67% of cases for 221 d, and 44% remain functional at 426 to 510 d postoperatively. Compared with established models, our LR model markedly reduced postoperative complications and recovery time. Development of the LR model was successful in rhesus macaques and is a useful alternative to the FR and LP methods of CSF collection from nonhuman primates.Abbreviations: CP, choroid plexus; FR, CSF 4th ventricular reservoir model; LP, CSF lateral port model; LR, CSF lateral reservoir model; SER, successful establishment rateSerial ventricular CSF sampling in NHP is a frequent and critical requirement for a wide variety of studies and is predominantly accomplished by using either of 2 models. The 4th ventricle (FR) model, previously referred to as an Ommaya reservoir,6 and lateral port (LP) models2 are closed, indwelling, subcutaneous systems that allow for serial, rapid, and humane collection of CSF, as well as intraventricular drug administration, in unanesthetized and restrained NHP.The FR model (Figure 1 A) consists of a catheter that is placed in the 4th ventricle and attached to a silastic reservoir that is implanted subcutaneously over the occipital bone. The silastic reservoir is depressed repetitively prior to and after sampling to circulate the CSF throughout the ventricles and catheter system to provide an unbiased sample without volume loss to dead space. The reservoir is accessed percutaneously to obtain a CSF sample via aspiration or to administer drug. The FR model initially was developed in 19776 and continues to be used for pharmacokinetic studies. This system continues to demonstrate a low rate of successful establishment, but once established, the FR model remains patent for prolonged periods without evidence of neurologic sequelae or bleeding from the choroid plexus (CP) in rhesus macaques. The decreased establishment rate of this model is attributed, at least in part, to postsurgical development of hydrocephalus, given that the catheter, which is routed through the aqueduct of Magendie to the 4th ventricle, can obstruct the flow of CSF. In addition, maintaining catheter patency is problematic due to CP bleeding during the recovery period. Postsurgical care and recovery after creating the FR are extensive, frequently requiring prolonged analgesics and steroid administration, with many days needed for complete recovery.Open in a separate windowFigure 1.Evolution of CSF ventricular models, with flow dynamics. (A) Sagittal diagram of original FR (Ommaya) model, with placement in the 4th ventricle. Developed in 1977. Arrows indicate the circulating flow of CSF. (B) Original LP model, with catheter placement in the lateral ventricle and attachment to an IV access port. Developed in 1990. Arrows indicate the static, unidirectional flow of CSF. (C) The LR model, a composite of the 2 earlier CSF models. Arrows indicate the circulating flow of CSF.The LP model (Figure 1 B) consists of a catheter that is implanted in the lateral ventricle and attached to a subcutaneous intravenous access port. The port is accessed percutaneously to obtain the CSF sample or to administer a drug. The LP is a static model, because the CSF is not circulated or mixed through the ventricles, and CSF is obtained via unidirectional flow. The LP model was developed in 1990 for intrathecal drug administration3 and has been used subsequently for CSF collection4 by several investigators. CSF sampling with the LP model is restrictive: the volume of the system (that is, the dead space) must be removed at each collection to obtain an unbiased sample, collection is accomplished via gravitational flow and not aspiration, and the collection frequency is dependent on the rate of CSF replacement. In addition, the potential for sample contamination from blood due to CP bleeding remains problematic for the duration of LP implantation. However, the use of the lateral ventricle avoids the postsurgical complication of hydrocephalus. This system demonstrated a high rate of successful establishment with a reduction in the necessary analgesic and steroid administration as well as days to complete recovery, as compared with the FR model. Analysis of our clinical records from 2003 to 2013 revealed a successful establishment rate (SER) of 39% for the FR model; 33% of these systems remained functional for 3 to 7.5 y (Successful establishment rate (%)
Duration
4 mo 1 y or more No. of days No. of months No. of years LP (n = 11) 91 82 1075 35.3 2.9 LR (n = 9) 67 44 292.9 9.6 0.8 FR (n = 18) 39 33 637.6 21.0 1.8