A feasability study of color flow doppler vectorization for automated blood flow monitoring.

An ongoing issue in vascular medicine is the measure of the blood flow. Catheterization remains the gold standard measurement method, although non-invasive techniques are an area of intense research. We hereby present a computational method for real-time measurement of the blood flow from color flow Doppler data, with a focus on simplicity and monitoring instead of diagnostics. We then analyze the performance of a proof-of-principle software implementation. We imagined a geometrical model geared towards blood flow computation from a color flow Doppler signal, and we developed a software implementation requiring only a standard diagnostic ultrasound device. Detection performance was evaluated by computing flow and its determinants (flow speed, vessel area, and ultrasound beam angle of incidence) on purposely designed synthetic and phantom-based arterial flow simulations. Flow was appropriately detected in all cases. Errors on synthetic images ranged from nonexistent to substantial depending on experimental conditions. Mean errors on measurements from our phantom flow simulation ranged from 1.2 to 40.2% for angle estimation, and from 3.2 to 25.3% for real-time flow estimation. This study is a proof of concept showing that accurate measurement can be done from automated color flow Doppler signal extraction, providing the industry the opportunity for further optimization using raw ultrasound data.

[Suicidal children and adolescents]. / Enfants et adolescents suicidants.

BACKGROUND: Psychiatric evaluation of suicide attempters is necessary in order to define aspects of primary and secondary prevention of suicidal behavior. POPULATION AND METHODS: All the 80 children and adolescents (66 girls and 14 boys) admitted from September 1989 to September 1992 in a pediatric hospital for suicide attempt have been included in this study. Their mean age was 13 yr 10 mo +/- 1.4 and 81% of them were more than 13 years of age. Evaluation included a structured interview and a scale assessing general psychopathology. RESULTS: Risk factors included previous psychiatric history in the patient (47%), family history of psychiatric disturbances in 33% of the mothers, 15% of the fathers and 13% in both. Recent modification in familial composition was seen in one third of cases and chronic difficulties in parent/child interaction in 92%. A relationship between the non impulsivity of the suicidal gesture, psychiatric history and depression diagnosed at the time of evaluation was also recognized. CONCLUSIONS: Knowledge of these risk factors should help to prevent and treat some aspects of suicidal behavior.