During a minimal invasive neurosurgery it is necessary to know precisely the 3D position of the surgical instruments and their relationship and interaction with the anatomy of the human brain. Today, ...on developing countries many surgeons still operate without 3D visual aids, managing instruments in the blind. With this idea we developed a new technique of Computer Assisted Surgery (CAS). We developed a new neuronavigator called Neuropanacea. It consists of our image processing software, the electromagnetic tracker for the localization of each one of the surgical instruments in the surgical room, and a personal computer (PC). The procedure for registration of these points captured using an electromagnetic tracker with the 3D space coordinates of the volume might be too complex. The main problem consists on finding the geometrical homogeneous transform to apply it to the acquired points with the electromagnetic tracker, and the registration of the fiducial markers visualized on the 3D volume. If we have the sorted correspondence of each one of the points in both systems, it is always possible to find a homogeneous transform into another system. However, in most of these cases we do not have this orderly set. One method to solve this problem is the iterative closest point (ICP). This work refers to the original algorithm of ICP. From this implementation we proposed two improvements for its correct convergence. The mean square error using the original algorithm was reduced from 2.1 ± 0.5 mm, to less than 0.5 mm.
Objetivos Validar la Escala para Evaluación de Síntomas Colaterales Extrapiramidales de Simpson-Angus en Colombia, usando una versión en lengua española. Métodos Estudio de validación de escala de ...medición, que constó de cuatro fases: traducción de la escala, estudio piloto, aplicación preliminar para análisis factorial, y análisis de validez, confiabilidad y sensibilidad al cambio del instrumento. Resultados La estructura factorial y la consistencia interna se evaluaron en 86 pacientes psiquiátricos hospitalizados. La confiabilidad test-retest e intervaluador se analizaron en una submuestra de 15 pacientes. El análisis de la validez de criterio concurrente se efectuó aplicando de manera simultánea las escalas de Simpson-Angus y la escala de Chouinard. La sensibilidad al cambio fue evaluada comparando las puntuaciones en dos momentos clínicamente diferentes en una submuestra de 20 pacientes. El análisis de factores principales mostró que la escala corresponde a una estructura unidimensional y dentro de esa estructura el signo de la Glabela aporta poco a la variabilidad total de la condición medida por la Escala. Los valores de confiabilidad test-retest, confiabilidad interevaluador, validez de criterio concurrente y sensibilidad al cambio fueron satisfactorios, con valores de estimadores de correlación superiores a 0,8 y niveles de precisión satisfactorios. Conclusiones La versión española adoptada en este estudio tiene adecuadas propiedades de medición del síndrome extrapiramidal inducido por neurolépticos y puede considerarse un instrumento de utilidad tanto en la práctica clínica como en investigación en Colombia. Sin embargo, una limitación importante puede ser su deficiencia para detectar dominios diferentes de la rigidez.
This paper presents the controller design and tests over a DC-AC converter used in an isolated photovoltaic (PV) system. The control stage is on a Boost converter and its effect takes place on a ...Voltage Source Inverter (VSI), to reach the DC-AC conversion essential in the PV system by a cascade connection of them. The digital controller was verified through tests in the simulation software Proteus®, obtaining satisfactory results related to the stability of the output voltage and a harmonic distortion lower than 6%, which indicates it is a viable control conversion system for a future real implementation in a PV installation.
Eccema numular: reporte de tres casos Casas-Barrera, María Alejandra; Ricardo-Soto, José William; Rolón- Cadena, Mariam Carolina ...
Revista de la Asociacion Colombiana de Dermatologia y Cirugia Dermatologica,
06/2019, Volume:
27, Issue:
1
Journal Article
Open access
El eccema numular es una dermatosis crónica y recidivante que se manifiesta con placas en forma de moneda, pruriginosas, de tamaño variable y bordes definidos, que evolucionan a placas liquenificadas ...y con descamación. A pesar de que se considera una enfermedad de adultos, existen reportes de caso de niños con eccema numular. Afecta a ambos sexos y las lesiones se presentan con mayor frecuencia en las extremidades, aunque pueden comprometer el tronco y el rostro.
La etiología de esta entidad es desconocida. Se considera una enfermedad multifactorial en la que intervienen fármacos, infecciones, alérgenos, irritantes, factores ambientales y factores emocionales, entre otros. Dado que la histopatología es inespecífica, el diagnóstico es eminentemente clínico.
Los tratamientos farmacológicos más usados y reportados involucran corticoides tópicos de mediana y gran potencia, asociados a emolientes y antihistamínicos. Sin embargo, hay reportes de casos en los que se han usado inmunomoduladores e inmunosupresores, especialmente en los casos graves y de difícil manejo.
The implications of the American College of Cardiology/American Heart Association (ACC/AHA) lesion classification in patients with in-stent restenosis (ISR) are unknown.
Four hundred fifty patients ...included in the RIBS randomized study were analyzed. A centralized core laboratory assessed ISR classifications including ACC/AHA, the classification of Mehran et al (
Circulation 1999;100:1872-8), diffuse/focal, and a new quantitative ISR index (lesion length/stent length). Logistic regression models were constructed for prespecified outcome measures including (1) unsatisfactory acute results and (2) recurrent restenosis rate.
Complex (B2/C) lesions (78%) more frequently obtained unsatisfactory acute results (20% vs 8%,
P = .007), smaller minimal lumen diameter after the procedure (2.45 ± 0.5 vs 2.73 ± 0.5 mm,
P = .001) and at follow-up (1.48 ± 0.8 vs 1.94 ± 0.8 mm,
P = .0001), and had a higher restenosis rate (43 vs 24%,
P = .001) than simple (A/B1) lesions. On logistic regression analysis, all classification schemes were useful to predict unsatisfactory initial results (area under the curve: 0.63, 0.61, 0.59, and 0.62) and recurrent restenosis (area under the curve: 0.60, 0.64, 0.61, and 0.63). The predictive ability of these schemes persisted despite adjustment for potential confounders. Although the ACC/AHA classification was a better predictor of acute results, the classification of Mehran was superior to predict restenosis.
The ACC/AHA classification provides a useful tool to determine acute procedural results and the long-term angiographic outcome of patients with ISR.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
This randomized trial compared repeat stenting with balloon angioplasty (BA) in patients with in-stent restenosis (ISR).
Stent restenosis constitutes a therapeutic challenge. Repeat coronary ...interventions are currently used in this setting, but the recurrence risk remains high.
We randomly assigned 450 patients with ISR to elective stent implantation (224 patients) or conventional BA (226 patients). Primary end point was recurrent restenosis rate at six months. Secondary end points included minimal lumen diameter (MLD), prespecified subgroup analyses, and a composite of major adverse events.
Procedural success was similar in both groups, but in-hospital complications were more frequent in the balloon group. After the procedure MLD was larger in the stent group (2.77 ± 0.4 vs. 2.25 ± 0.5 mm, p < 0.001). At follow-up, MLD was larger after stenting when the in-lesion site was considered (1.69 ± 0.8 vs. 1.54 ± 0.7 mm, p = 0.046). However, the binary restenosis rate (38% stent group, 39% balloon group) was similar with the two strategies. One-year event-free survival (follow-up 100%) was also similar in both groups (77% stent vs. 71% balloon, p = 0.19). Nevertheless, in the prespecified subgroup of patients with large vessels (≥3 mm) the restenosis rate (27% vs. 49%, p = 0.007) and the event-free survival (84% vs. 62%, p = 0.002) were better after repeat stenting.
In patients with ISR, repeat coronary stenting provided better initial angiographic results but failed to improve restenosis rate and clinical outcome when compared with BA. However, in patients with large vessels coronary stenting improved the long-term clinical and angiographic outcome.
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Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The study was aimed at validating the Simpson-Angus scale for neuroleptic-induced extrapyramidal syndrome in Colombia, using a Spanish version of the scale.
The scale was validated in four steps: ...translating the scale, pilot study, preliminary use for factorial analysis and analysis of validity, reliability and sensitivity to change.
Factorial structure and internal consistency were evaluated in 86 psychiatric inpatients. Test-retest and inter-rater reliability were evaluated in a 15-patient subgroup. Concurrent validity was analysed by simultaneously applying Simpson-Angus and Chouinard scales. Sensitivity to change was evaluated by comparing the scores of two different clinical points in a 20-patient subgroup. Main factor analysis revealed that the scale has a one-dimensional structure; the Glabella tap did not contribute towards total variability of the condition measured for the scale. Test-retest and inter-rater reliability values, concurrent validity and sensitivity to change were good. Correlation estimation scores were above 0.8 and accuracy levels were also good.
The Spanish version of the SA scale, adapted for this study, is suitable for assessing neuroleptic-induced extrapyramidal syndrome; it would be a useful instrument in both clinical practice and research settings in Colombia. However, an important limitation could be its lack of detecting any domain different to that of rigidity.
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