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J M Del Castillo

Publications and source records attributed to J M Del Castillo.

8 recordsLinked to original sources
PubMed2005

Application of singular spectrum analysis to the smoothing of raw kinematic signals.

Motion capture systems currently used in biomechanical analysis introduce systematic measurement errors that appear in the form of noise in recorded displacement signals. The noise is unacceptably amplified when differentiating displacements to obtain velocities and accelerations. To avoid this phenomenon, it is necessary to smooth the displacement signal prior to differentiation in order to eliminate the noise introduced by the experimental system. The use of singular spectrum analysis (SSA) is presented in this paper as an alternative to traditional digital filtering methods. SSA is a novel non-parametric technique based on principles of multivariate statistics. The original time series is decomposed into a number of additive time series, each of which can be easily identified as being part of the modulated signal, or as being part of the random noise. Several examples that demonstrate the superiority of this technique over other methods used in biomechanical analysis are presented in this paper.

Acceleration↗
PubMed2000

Long-term follow-up of pregnant women after percutaneous mitral valvuloplasty.

The aim of this study was to evaluate long-term clinical follow-up and echocardiographic data on pregnant patients with mitral stenosis who underwent percutaneous mitral valvuloplasty (PMV) in our center and the development of their infants. PMV has proven to be an effective alternative to treat pregnant patients with mitral stenosis. However, long-term outcome of these patients, as well as the potential harmful effects caused by radiation on their infants, still awaits to be determined. From January 1988 to February 1999, 30 pregnant women (mean gestational duration, 24.95 +/- 5.59 weeks) underwent PMV. Twenty-three (77%) were subsequently followed by a medical interview during 5.33 +/- 3.12 years. Clinical variables such as NYHA functional class (FC), the need of a repeat PMV or surgical procedure, the presence of embolic events, and mortality rate were evaluated during follow-up. Mitral valve area, mean transmitral gradient, and the presence of mitral regurgitation were also assessed by Doppler echocardiography. Clinical data on the development of the infants were obtained from the assistant pediatricians. All patients were in NYHA FC III or IV before the procedure. During follow-up, 91% of them were in FC I and II. Two patients (9%) who had remained in FC III underwent a repeat successful PMV; no further surgery was required. There were no embolic events or death related to the procedure. Echocardiography showed an initial increase in mitral valve area from 1.14 +/- 0.22 cm(2) to 2.01 +/- 0.21 cm+/- (P < 0.0001). During long-term follow-up, it decreased to a mean of 1.75 +/- 0.24 cm(2) (P < 0. 0001). Initial transmitral valve gradient decreased from 17.73 +/- 4. 56 mm Hg to 5.91 +/- 1.80 mm Hg (P = 0.0001) and 8.95 +/- 3.58 (P = 0.002) during long-term follow-up. Twenty one children (96%), aged 4. 91 +/- 2.8 years, showed normal growth and development, and no clinical abnormalities were observed. These favorable long-term results suggests PVM to be the procedure of choice to treat pregnant women with mitral stenosis who remain in FC III or IV despite adequate medical therapy. No harmful effects due to the use of radiation were observed in the children.

Adolescent↗
PubMed1993

[Echocardiographic relation criteria. A new selection method for mitral valvotomy with balloon catheter].

PURPOSE: To find out new subjects that could be useful to select patients between 9 and 12 points, according to Block's Criteria, to mitral balloon valvotomy. METHODS: One hundred and forty patients underwent mitral balloon valvotomy. Among them, 29 (21%) had between 9 and 12 points. These patients were divided into two groups: group A-patients with mitral valve area > or = 1.5cm2, immediately after balloon valvotomy and in the follow-up period; group B-patients with mitral valve area < 1.5cm2 immediately after or during the follow-up period, patients with severe mitral regurgitation after the procedure and patients who died in the follow-up period. All patients were analyzed by echocardiographic relation criteria (ERC): calcification + subvalvar disease/thickness + mobility. Each one was quantified from 1 to 4 points according to the degree of valvular disease. RESULTS: Group A was composed of 17 (51%) and group B 12 (41%) patients. The variables age, sex, previous mitral commissurotomy and atrial fibrillation did not show difference between groups. In group A mitral valve area (cm2) increased from 1.15 +/- 0.25 to 1.97 +/- 0.26 (p < 0.00001) keeping stable during the follow-up period. In group B percutaneous mitral balloon valvotomy resulted in an increase from 1.26 +/- 0.19 to 1.77 +/- 0.16 (p < 0.00001), however, there was an important decrease in the follow-up period to 1.34 +/- 0.15 (p < 0.00001). The ERC showed that all group A patients had a relation < 1. However, in group B, 10 patients (83%), the relation was > or = 1, and in only 2 patients (17%) was < 1 (p < 0.00001). CONCLUSION: The group of patients between 9 and 12 points in the Block's criteria is heterogenic, therefore, each case might be evaluated individually and the echocardiographic relation criteria should be used in order to select these patients to the procedure.

Adult↗
PubMed1992

Echocardiographic long-term evaluation of percutaneous balloon mitral valvotomy.

Percutaneous balloon mitral valvotomy (BMV) is an alternative therapeutic method for patients with mitral stenosis. We studied 62 patients (56 females, mean age 36.4 years) who underwent balloon mitral valvotomy. Five patients were pregnant and in New York Heart Association Functional Class IV. Doppler echocardiographic studies were performed prior to the procedure, and at 7 days, 6 months, 12 months, and 24 months after the procedure. We studied the following parameters: echo-score by the sum of valvular mobility, thickening, and calcification, and subvalvular disease, graded from 1 to 4; and mitral valve area (MVA) and mitral pressure gradient (MPG) by Doppler echocardiography. The patients were separated into two groups: group I with an echo-score less than or equal to 8 (40 patients), and group II with an echo-score greater than or equal to 9 (22 patients). Mitral valve area and MPG were compared with hemodynamics through the correlation coefficient and linear regression. Comparison between groups I and II was performed using the unpaired Student's t-test. Follow-up of MVA and MPG was analyzed by analysis of variance. The Student's t-test did not show any significant difference between MVA and MPG before balloon mitral valvotomy. There was significant decrease of MVA in group II (P less than 0.01) in the last three studies. There was significant increase in MPG in group II (P less than 0.01) in every postvalvotomy study. The analysis of variance of group I showed statistical increase of the MVA, and significant decrease of the MPG after BMV. The analysis of variance of group II showed significant increase in MVA and significant decrease in MPG between the pre- and the first postvalvotomy study. There was significant decrease (P less than 0.01) in MVA, and increase in MPG in the three postvalvotomy studies. Complications included mitral regurgitation, residual interatrial communication, pericardial effusion due to an atrial wall perforation, and peripheral embolization. Atrial fibrillation did not significantly alter the results of BMV. Results were considered positive when MVA was greater than 1.5 cm 2 and area increase was greater than 25%. Patients with an echo-score less than or equal to 8 (group I) benefit from BMV, with a positive predictive value greater than 78%. In pregnant patients the symptomatology was alleviated by BMV, without any signs of fetal compromise.

Adolescent↗
PubMed1989

[Doppler echocardiographic evaluation of heart transplantation].

In order to evaluate major Doppler-Echocardiographic parameters for the diagnosis of acute cardiac allograft rejection episodes a serial of 54 Doppler Echocardiograms were performed simultaneously with endomyocardial biopsy in five patients (mean age = 40.2 y/o). Measurements included: right and left chambers diameters, left ventricular (LV) myocardial diastolic thickness, LV systolic function parameters, LV mass, LV volume/mass ratio, LV isovolumic relaxation time, mitral flow peak velocities and pressure half-time. Episodes with acute rejection histopathologic findings, Billingham class III or IV, were associated to increase in LV free wall thickness and LV mass (p less than 0,005) as well as decreased isovolumic relaxation time and pressure half-time (p less than 0,001). Left ventricular systolic function parameters and heart rate were no different comparing rejection and no rejection episodes. However, in each patient, progressive lower values of LV ejection fraction were associated to higher incidence of acute rejection episodes. Isovolumic relaxation time increased promptly following immunosuppressive therapy. Thus, Doppler Echocardiography is a reliable method for early detection of acute cardiac allograft rejection and monitoring of the cardiac transplant recipient.

Adult↗
PubMedDate not supplied

Effect of topical cyclosporin A on Thygeson's superficial punctate keratitis.

Thygeson's superficial punctate keratitis (Thygeson's SPK) is a distinct clinical entity, characterized by round conglomerates of discrete, granular, white-gray, fine intraepithelial dots without conjunctival involvement. The only effective treatment with regard to relieving symptoms and diminishing lesions has been topical corticosteroids, but their prolonged use can be associated with severe side-effects. The purpose of this study is to present the long-term results of the use of 2% topical cyclosporin A in olive oil in Thygeson's SPK. Eight patients diagnosed as having Thygeson's SPK were included. All the patients were treated with 2% cyclosporin dissolved in olive oil four times a day for three months, and two times a day for one month before withdrawing therapy. The follow-up period ranged from twelve to twenty-five months. The number of corneal lesions varied between 5 and 15 before treatment. After cyclosporin treatment, no corneal lesion was observed and the cornea remained clear after the follow-up period. In conclusion, 2% cyclosporin in olive oil is a safe alternative to corticosteroids in the treatment of Thygeson's SPK, and resulted in satisfactory control of the condition.

Administration, Topical↗