3-dimensional Contour Research Articles

Development of a 3-Dimensional Back Contour Imaging System for Monitoring Scoliosis Progression in Children

Study DesignControl study. ObjectivesTo present a new surface topography system capable of taking 3-dimensional (3D) spine measurements, to establish baseline values for the measured parameters in a typically developing population, and to determine the intra-rater and inter-rater reproducibility of these parameters. Summary of Background DataCumulative exposure to radiation from diagnostic radiographs increases patient risk for cancer development. There is a need for noninvasive and non-radiographic tools to accurately and reproducibly measure spine deformity and track scoliosis progression. MethodsWe measured 10 typically developing subjects with the new Milwaukee Topography System, which is composed of 2 electromagnetic markers, an electronic processing unit, a handheld laser scanner, a software package, and a desktop computer. Two investigators separately scanned the same subjects multiple times, yielding a total of 4 scans per subject per investigator. We measured 17 3D back parameters in each scan. We performed a multivariate analysis of variances to test the hypothesis of no difference for all variables, measured intra-rater and inter-investigator reliability with intra-class correlation (ICC) coefficients, and calculated mean values. ResultsThere were highly reproducible ICC values between investigators for 6 parameters (ICC > 0.75), moderate ICC values for 8 parameters (0.75 > ICC > 0.4), and poor ICC values for 3 parameters (ICC < 0.4), all at p < .05. Intra-investigator ICCs were moderate to excellent for almost all parameters. ConclusionsThe Milwaukee Topography System can be used to monitor and measure 3D back contours in children. The 3D back parameters values measured in the typically developing population can be considered baseline values that can be compared with parameters measured in children with idiopathic scoliosis.

Orbitomaxillary Reconstruction Using the Layered Fibula Osteocutaneous Flap

To describe a surgical technique for total palatomaxillary and orbital reconstruction using a fibula osteocutaneous free flap in a layered fashion. Case series from a tertiary care facial plastic and reconstructive surgical practice including patients with postextirpative Brown 3a and 3b orbitopalatomaxillary defects undergoing immediate microvascular reconstruction. Application of the layered fibula free flap to composite maxillary defects permits single-stage, optimal reconstruction of contiguous orbitomaxillary defects, reconstitution of midface 3-dimensional contour, and restoration of the anterior alveolar arch with robust bone, thereby providing for potential sequential dental rehabilitation with osseointegrated implants. This technique demonstrates excellent long-term symmetry, support, function, and aesthetic contour. Although patients may need minor, adjunctive procedures, this technique is flexible in design and offers reliable outcomes with a minimum of morbidity. The fibula osteocutaneous free flap, because of its design flexibility and ability to provide structural support, is an excellent reconstructive option for total maxillary defects, including those that involve the orbit.

A Reappraisal of the Free Groin Flap in Aesthetic Craniofacial Reconstruction

Craniofacial defects are often associated with 3-dimensional volumetric contour deficiencies. The free groin flap was historically popular though technical limitations subsequently caused its use to fall from favor. We sought to determine if a role remained for the free groin flap in aesthetic craniofacial reconstruction. From May 2005 to July 2010, 15 patients had 18 consecutive free groin flaps performed by the senior surgeon at the R Adams Cowley Shock Trauma Center and the Johns Hopkins Medical Institute. Data collected included age, sex, operative date, etiology, defect size, recipient vessels, complications, donor-site closure, and follow-up time. Eighteen groin flaps were used for the patient cohort consisting of 10 males and 5 females (mean age, 26 years; range, 18-40 years) who underwent reconstruction necessitated by various oncologic, traumatic, infectious, and congenital etiologies. The average defect size was 7.3 × 6.3 cm (range, 3-10 × 1-10 cm). Seventeen flaps were based on the superficial circumflex iliac vessels and 1 on the superficial inferior epigastric vessels. Seventeen flaps used the superficial temporal artery and vein as the recipient vessels, and the remaining flap used the superior thyroid artery and retromandibular vein. Of the 18 flaps, 17 survived (94% survival rate). All donor sites were closed primarily. Follow-up time ranged from 6 to 60 months. The free groin flap is generally underused in the reconstruction of complex craniofacial facial defects. Its unique characteristics and minimal donor-site morbidity should prompt the reconstructive surgeon to retain the free groin flap in his or her armamentarium.

Study on the Multi-Axis Motion Control Based on LabVIEW

On the basis of study on the key multi-axis motion control theories about acceleration &amp; deceleration control, numerical interpolation algorithm, device drivers and application design technologies based on LabVIEW, verified the feasibility through the 3-axis numerical milling platform developed by ourselves. The platform can also realize the simulation and practical verification about the demonstration teaching process of numerical control machining and 3-dimensional contour of the workpiece machined, and has the significant practical value.

Thoracodorsal Artery Scapular Tip Autogenous Transplant

To demonstrate that the 3 reconstructive advantages of the thoracodorsal artery scapular tip transplant (Tdast), a long pedicle, independently mobile tissue components, and the 3-dimensional nature of the scapular tip, will improve the quality and success of complex reconstructions by avoiding vein grafting, preventing the need for 2 separate transplants, and facilitating bony inset. Prospective case series. Tertiary care academic medical center. Twenty-one patients (male to female ratio, 16:5; mean age, 52 years) underwent reconstruction of the upper, middle, and lower face from 2001 through 2006. Indications for reconstruction were tumor ablation in 11 patients, secondary reconstruction in 4 patients, osteoradionecrosis in 4, and posttraumatic reconstruction in 2. Seventeen patients underwent radiation. All patients underwent harvest of an autogenous transplant of scapular tip bone and latissimus dorsi soft tissue based on the thoracodorsal artery. The mean bone length was 5.2 cm (range, 2.5-9.0 cm), and the mean cutaneous surface area was 68 cm² (range, 20-250 cm²). Reduction of vein grafting, avoidance of 2 transplants, use of the triangular shape of the scapular tip in reconstruction, complications, and shoulder function. The success rate of transplantation was 100%. The use of this transplant avoided vein grafting in 16 patients and the need for 2 separate transplants in 11 patients, and the 3-dimensional nature of the scapular tip facilitated inset in 13 patients. In 14 patients, more than 1 of these reconstructive advantages was achieved. In 6 patients, all 3 were accomplished. Eleven patients experienced a complication. The major complication rate was 33%, and the minor complication rate was 33%. The mean Constant-Murley test of shoulder function score was 87 of 100 (range, 74-100). The Tdast is an excellent choice for reconstruction in the head and neck as an alternative to procedures requiring vein grafting and multiple free tissue transplants, or in which the 3-dimensional contour of the scapular tip aids in reconstruction. The complication rate should be assessed in the context of the risk factors of the patient population and the outcome with respect to stable employment, increasing body mass index, and maintenance of shoulder function.

Position of Interbody Spacer in Transforaminal Lumbar Interbody Fusion: Effect on 3-dimensional Stability and Sagittal Lumbar Contour

Biomechanical study. To test 2 different intervertebral positions of a semilunar cage and their effects on 3-dimensional stability and segmental lordosis in a model of transforaminal lumbar interbody fusion (TLIF). In his original TLIF description, Harms recommended decortication of endplates, followed by placement of mesh cages in the middle-posterior intervertebral third. Subsequent studies presented conflicting recommendations: anterior placement of the spacer-cage for better load-sharing versus placement on the stronger posterolateral endplate regions. Six human lumbar spinal functional units were first tested intact. TLIF was performed using a semilunar poly-ether-ether-ketone cage randomly inserted in the anterior (TLIF-A) or posterior (TLIF-P) disc space. Pedicle screws and rods were added. Unconstrained pure moments in axial-torsion, lateral-bending (LB), and flexion-extension (FE) were applied under 0.05 Hz and +/-5 Nm sinusoidal waveform. Segmental motions were recorded. Range of motion (ROM) and neutral zone (NZ) were calculated. Pairwise comparisons were made using nonparametric Wilcoxon-matched pairs signed rank sum test with statistical significance set at P<0.05. TLIF-A and TLIF-P significantly decreased ROM (P<0.05) of the intact spinal functional unit, in FE and LB. In axial-torsion, decrease of ROM after TLIF procedures was not significant (P>0.05). Delta-ROM between TLIF-A and TLIF-P was not significant (P>0.05). TLIF-A and TLIF-P significantly decreased NZ in LB (P<0.05). In FE, TLIF-P significantly decreased NZ (P<0.05); TLIF-A showed a trend toward significance (P=0.09). Delta-NZ between TLIF-A and TLIF-P was not significant (P>0.05). Segmental lordosis of TLIF-A and TLIF-P on C-arm views showed angle differences within the range of measurement error of Cobb angles. Difference in ROM and NZ between anterior (TLIF-A) or posterior (TLIF-P) positions was not statistically significant. Similarly, both positions did not influence segmental lordosis.

Localized Elevation of Shear Stress Is Related to Coronary Plaque Rupture: A 3-Dimensional Intravascular Ultrasound Study With In-Vivo Color Mapping of Shear Stress Distribution

The purpose of the present study was to assess the relationship between shear stress distribution and coronary plaque rupture by means of a new color-mapping program of shear stress with 3-dimensional intravascular ultrasound (IVUS). Various in-vitro studies have demonstrated that shear stress of the vascular lumen is one of the important determinants of coronary plaque vulnerability. However, the in-vivo relationship between shear stress and plaque rupture is still unclear. In the present study, 3-dimensional IVUS was used to obtain spatial information on luminal geometry from 20 patients with acute coronary syndrome having a distinct ulcerative lesion. These 3-dimensional contours for each lumen were first reconstructed into mesh polygons, and then analyzed by means of a program for calculating the fluid dynamics. The flow was considered to be a constant laminar one. Then, colorized mappings of the distribution of the streamline, blood pressure, and shear stress were performed. The original luminal contour for each ruptured lesion was obtained by smoothing and extrapolation. All patients had a coronary plaque rupture in the proximal or top portion of the plaque hill. In the color mapping, localized elevation of blood pressure and shear stress could be observed on each plaque surface. The shear stress concentration was frequently correlated with the plaque rupture site (kappa = 0.79). Although the absolute value of shear stress is not sufficient to directly provoke mechanical destruction of the fibrous cap, localized high shear stress might be a trigger of fibrous cap rupture.

Distance, shape and more: recognition of object features during active electrolocation in a weakly electric fish

In the absence of light, the weakly electric fish Gnathonemus petersii detects and distinguishes objects in the environment through active electrolocation. In order to test which features of an object the fish use under these conditions to discriminate between differently shaped objects, we trained eight individuals in a food-rewarded, two-alternative, forced-choice procedure. All fish learned to discriminate between two objects of different shapes and volumes. When new object combinations were offered in non-rewarded test trials, fish preferred those objects that resembled the one they had been trained to (S+) and avoided objects resembling the one that had not been rewarded (S-). For a decision, fish paid attention to the relative differences between the two objects they had to discriminate. For discrimination, fish used several object features, the most important ones being volume, material and shape. The importance of shape was demonstrated by reducing the objects to their 3-dimensional contours, which sufficed for the fish to distinguish differently shaped objects. Our results also showed that fish attended strongly to the feature ;volume', because all individuals tended to avoid the larger one of two objects. When confronted with metal versus plastic objects, all fish avoided metal and preferred plastic objects, irrespective of training. In addition to volume, material and shape, fish attended to additional parameters, such as corners or rounded edges. When confronted with two unknown objects, fish weighed up the positive and negative properties of these novel objects and based their decision on the outcome of this comparison. Our results suggest that fish are able to link and assemble local features of an electrolocation pattern to construct a representation of an object, suggesting that some form of a feature extraction mechanism enables them to solve a complex object recognition task.

Filling the Periorbital Hollows With Hyaluronic Acid Gel: Initial Experience With 244 Injections

To review our initial experience using hyaluronic acid gel (Restylane) as a filler to treat the periorbital hollows. This is a retrospective, anecdotal case review of 244 cosmetic hyaluronic acid gel injections in 155 patients. An average volume of 0.9 ml per injection session was used in an individualized pattern that variably included the orbital rim hollow, zygomatic hollow, septal confluence hollow, and eyebrow and cheek fat pad. To achieve smooth contours, a layered, feathered threading technique was used, placing the filler deep to the orbicularis. Hyaluronidase injections were used in 11% of patients at follow-up visits to "dissolve" some of the filler to reduce contour irregularities. One hundred eight of 121 (89%) patients with follow-up visits were satisfied with the cosmetic improvement after hyaluronic acid gel injections. For maintenance, the interval to second injection averaged 6.5 months. Side effects included lumps or contour irregularities (11%), bruising (10%), color change (7%), and fluid (15%). Twelve patients were unsatisfied and were not interested in additional injections: 5 with malar fluid, 3 with lumpy irregularity, and 3 with color change. Complex 3-dimensional contours and thin skin over bone render periorbital filling difficult. However, with individualized planning and with care taken to create smooth, feathered contours, it is possible to achieve acceptable improvement. We found that most patients considered themselves improved cosmetically, despite occasional side effects including contour irregularity or lumps, bruising, color change, and fluid accumulation. Patients with very thin skin, preexisting color problems, or preexisting eyelid fluid may not be good candidates for periorbital filling with hyaluronic acid gel. The effect of the filler is temporary, of course, and we counsel patients to anticipate maintenance injections at 6- to 12-month intervals.

Joint cosmological parameters forecast from CFHTLS-cosmic shear and CMB data

We present a prospective analysis of a combined cosmic shear and cosmic microwave background data sets, focusing on a Canada France Hawaii Telescope Legacy Survey (CFHTLS) type lensing survey and the current WMAP-1 year and CBI data. We investigate the parameter degeneracies and error estimates of a seven parameter model, for the lensing alone as well as for the combined experiments. The analysis is performed using a Monte Carlo Markov Chain calculation, allowing for a more realistic estimate of errors and degeneracies than a Fisher matrix approach. After a detailed discussion of the relevant statistical techniques, the set of the most relevant 2 and 3-dimensional lensing contours are given. It is shown that the combined cosmic shear and CMB is particularly efficient to break some parameter degeneracies. The principal component directions are computed and it is found that the most orthogonal contours between the two experiments are for the parameter pairs , and , where ns and are, respectively, the slope of the primordial mass power spectrum and the running of the spectral index. It is shown, under the assumption of perfectely controlled systematics, that an improvement of a factor of 2 is expected on the running of the spectral index from the combined data sets. Forecasts for error improvements from a wide field space telescope lensing survey are also given.

P0941 HIGH-RESOLUTION ESOPHAGEAL MANOMETRY (HRM) WITH TOPOGRAPHIC PLOTTING IN PRE-TERM AND TERM NEONATES

Introduction: HRM uses closely spaced recording sites and axial data interpolation to better visualize time and space relationships of pressure data. These techniques in adults and older children reveal that esophageal peristalsis is comprised of a chain of 3 contraction segments, 1 in striated muscle and 2 in the smooth-muscle region, that culminates in lower esophageal sphincter contraction. The 2nd segment (proximal smooth-muscle esophageal body) appears to be at least in part under cholinergic control and important in the peristaltic pump. HRM has not been applied to neonates to see if segmental contraction characteristics are seen in this group. Methods: HRM was used to study 5 full-term neonates (gestational age 37–41 wk; post-delivery age 0–7 d) and 7 pre-term neonates (gestational age 30–36 wk; age 3–24 d). Subjects were intubated with a 9-lumen (2.25 mm OD) perfused catheter with recording sites at 1-cm intervals, and data were acquired with a system designed specifically for HRM (MMS, Enschede, Holland). Small volume water swallows were used when possible. 3-dimensional topographic contour plots and cines of axial wave propagation were examined to detect peristaltic characteristics and recurring contraction segments. Results: The techniques were successful in each case, and peristaltic events were easily identified on topographic plots and cine review despite expected artefact - even if not clearly recognized on conventional tracings. In full-term neonates the 2nd segment was well developed and consistently present in all subjects; the 1st and 3rd were seen intermittently in 4 subjects. Complete peristaltic sequences were present in 47.6±15.3% of swallows. The 2nd segment was also consistently evident in pre-term neonates of >34 wks gestational development or 32 wks gestation plus >3wks age. Only fragments of peristalsis and no well-defined segments were seen in 2 subjects with 30–31 wks gestation plus 9–16 d age. These youngest subjects had no completed peristalses whereas the other pre-term subjects had 43.4±5.8% completed peristalses and resembled the full-term neonates (p=0.8). Conclusion: HRM with topographic plotting simplifies the identification of peristaltic events in neonates because of their similarity to the stereotypical chain of contraction segments in older subjects. The segments cannot be identified in subjects with <32 wks gestational development with <3 wks of post-delivery age, suggesting that the maturation of this process occurs near term. The prominent, early development of the 2nd contraction segment may reflect the importance of this region for its pro-clearance protective effects.

Brain potentials elicited by matching global and occluded 3-dimensional contours

Subjects were instructed to match 3-dimensional forms while event-related potentials (ERPs) were recorded to explore the relationship between visual completion and conflict processing. Sequentially presented paired stimuli (S1 and S2) were identical in condition I, while in condition II the images were of the same contour, but S2 contained an invisible portion, and in condition III S1 and S2 were of different contours. Subjects indicated if stimuli were physically identical or contour similar in two separate sessions. Following the onset of S2, ERP components P100, N150, and LPC were recorded in all conditions. N150 was enhanced in condition II in both sessions, and N270 was elicited in conditions II and III. N150 is related to visual completion, while N270 is related to the evaluation of information discrepancy, belonging to independent systems.

Triple-Flap Technique for Reconstruction of Large Nasal Defects

Triple-Flap Technique for Reconstruction of Large Nasal Defects

Decomposition products of N, N′-disalicylidene-1,2-propanediamine adsorbed on 304 stainless steel

The compound, N, N′-disalicylidene-1,2-propanediamine, is commonly added to jet fuels to counteract the catalysis of thermally induced autoxidation by certain dissolved metals. The behavior of the metal deactivator additive (MDA) in thermally stressed jet fuel has raised questions on whether it decomposes after coming into contact with hot metal surfaces within the aircraft fuel system. Temperature programmed desorption (TPD) was performed to detect decomposition products of MDA on the 304SS surface. A method of scanning a relatively large mass range during desorption was developed to acquire 3-dimensional contour TPD (CTPD) plots of adsorbed species on the surface. Compounds with molecular masses of 107, 133, 232 and 290 were detected and their structures proposed. Conventional TPD spectra of selected molecular masses were then taken as a function of exposure. Mechanistic pathways for decomposition of MDA and formation of new compounds on the surfaces are proposed.

Changes in skin redness, pigmentation, echostructure, thickness, and surface contour after 1 pulsed dye laser treatment of port-wine stains in children.

The pulsed dye laser is the treatment of choice for children with port-wine stains (PWSs). Evaluation of treatment outcome and adverse effects is traditionally based on subjective clinical scoring systems. We intend to objectify treatment results and adverse reactions after 1 treatment with the pulsed dye laser. A before-and-after trial using skin reflectance to detect changes in skin redness and pigmentation, ultrasonography to evaluate changes in echostructure and skin thickness, and 3-dimensional surface contour analysis to detect changes in surface texture. Twelve children with PWSs. A university dermatological department. The skin reflectance-determined change in skin redness correlated with the clinical response (r = 0.46, P < .002). The percentage of reflectance-determined lightening was equal for pink, red, and dark red PWSs (median, 42.9%). Skin pigmentation increased after laser treatment (P < .007). Ultrasonography revealed lower dermal echogenicity of preoperative PWSs than of postoperative PWSs (P < .007) and healthy skin (P < .001). An increase in echogenicity reflected a decrease in the dermal water (blood) content. Variations were found in the dermal localization of the PWS. Skin thickness was significantly higher in the PWS before treatment than after (P < .001). The preoperative lesional thickness correlated inversely with the ultrasound-assessed treatment response (r = 0.35, P < .04). The surface contour parameters decreased significantly after laser treatment, indicating a flattening of the skin surface. The contour changes correlated positively with treatment response. By clinical evaluation, no hypopigmentation or texture changes were detected. The evaluation of treatment outcome and adverse effects is refined by the use of skin reflectance, ultrasonographic, and surface contour analysis.

Tactile sensing of 3-dimensional surface features

SummaryRobots will require some form of proximity sensing in order to perform many delicate exploration, assembly and manipulation tasks. This paper describes a novel articulated tactile probe which can locate and accurately measure the 3-dimensional surface contours of small objects. Although lacking the speed of data acquisition possible with vision and other non-contact sensors, the resulting data is easily processed to give useful information about an object.

Contour maps of auscultatory percussion in healthy subjects and patients with large intrapulmonary lesions

Auscultatory percussion of the chest is a clinical examination method that has been purported to detect intrapulmonary masses by their effect on transmission of the percussion note to the posterior chest. Recent findings from this laboratory suggested that the sound of sternal percussion may actually travel through the chest cage and not the lung parenchyma. To investigate this possibility further, we recorded the sound produced by sternal percussion at 63 evenly spaced points over the posterior chest wall of 3 healthy subjects and 4 patients with large, discrete intrathoracic lesions in the right upper lobe (2 patients), left lower lobe, and left upper lobe (1 patient each). We constructed 3-dimensional contour maps of the indices of sound amplitude and frequency to view graphically the pattern of distribution of the sound. Examination of the maps revealed areas of increased amplitude in the zones of projection of some osseous structures, especially the scapulae, both in the healthy subjects and patients. No disturbances in the pattern reflecting the presence of mediastinal structures or intrathoracic lesions were found despite the existence of deeply situated lung masses as large as 10 cm in diameter. These findings support the argument that the sound of sternal percussion travels to the posterior chest predominantly through chest wall structures.

Draw 2D, draw 3D: MOPAC 2- and 3-dimensional graphical output written using the PHIGS graphics standard

Programs, written in graPHIGS, to display 2- and 3-dimensional contour plots of orbital density of molecular orbitals are described and included on disk. The 3D image is created by “stack plotting” 2-dimensional slices of the molecular orbital density. Features including zoom, xyz-rotation, writing pixel images to a file and superposition of stick plots of the molecule on the orbital contours.

Better Accuracy from Sidescan Records: The Object-Chord Method

Sidescan Sonar has become a widely used and often indispensable tool for seafloor engineering and survey activities in the oil industry This acoustic technique has the ability to create a wide and continuous 'picture' of the 3-dimensional seafloor features and contours, and therefore permits quick and economical acquisition of seafloor information which is not readily available through other types of acoustic instrumentation. The accuracy of mapped objects interpreted from this method has been limited by the fact that the fish is towed a distance from the vessel and its position is affected by different sea states and current conditions resulting in different feathering angles and layback distances. Some present interpretation techniques do take into account the uncertain feathering angles of the fish, but they assume no errors in both the layback distances. The object-chord method takes into account both the feathering angle and layback errors and in certain circumstances, due to good field practices, eliminates them, resulting in more accurate positions mapped.

Furcation topography of the maxillary and mandibular first molars.

The objective of the present study was to describe the topography of the furcation area of the maxillary and mandibular first molars. By using a photogrammetric method, the furcation areas of extracted teeth were plotted to obtain 3-dimensional contour maps. By comparing the individual 10 drawings of the maxillary and mandibular first molars, respectively, some morphological characteristics of the furcation areas could be described. Accordingly, the study showed the complexity of the furcation areas with presence of a number of small ridges, peaks and pits forming a mixture of convexities and concavities.