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R Quiniou

Publications and source records attributed to R Quiniou.

2 recordsLinked to original sources

Temporal abstraction and inductive logic programming for arrhythmia recognition from electrocardiograms.

This paper proposes a novel approach to cardiac arrhythmia recognition from electrocardiograms (ECGs). ECGs record the electrical activity of the heart and are used to diagnose many heart disorders. The numerical ECG is first temporally abstracted into series of time-stamped events. Temporal abstraction makes use of artificial neural networks to extract interesting waves and their features from the input signals. A temporal reasoner called a chronicle recogniser processes such series in order to discover temporal patterns called chronicles which can be related to cardiac arrhythmias. Generally, it is difficult to elicit an accurate set of chronicles from a doctor. Thus, we propose to learn automatically from symbolic ECG examples the chronicles discriminating the arrhythmias belonging to some specific subset. Since temporal relationships are of major importance, inductive logic programming (ILP) is the tool of choice as it enables first-order relational learning. The approach has been evaluated on real ECGs taken from the MIT-BIH database. The performance of the different modules as well as the efficiency of the whole system is presented. The results are rather good and demonstrate that integrating numerical techniques for low level perception and symbolic techniques for high level classification is very valuable.

Algorithms↗

[Urinary iodide determination by X-ray fluorescence].

Urinary iodide measurement has been carried out by X-ray-fluorescence, either directly on urinary solution, or after matrix concentration. Proportionality between emitted XK alpha rays of iodine and iodide mass in standards has been observed on a large scale, ranging up to 400 micrograms. With an exciting-1.11 GBq (241(95) Am)-radioactive source, 0.44 microgram are detected for solid matrix, and 0.9 microgram/ml for iodide in solution for 10 mn measuring time. So direct measurement on solution can be applied only to high excreted iodide. For normal range iodide determination is performed after anionic resin concentration (on 100 ml or 200 ml). For tracing, Na I131 is employed. The binding ratio is strongly depending on flow, resin weight, and associate urinary anionic components. On 20 healthy subjects, normal range value is 53 +/- 22 micrograms/l (m +/- s.d.). Comparative study with an electrochemical method showed fluorescence iodide values are lower than the former. The proposed method is very simple, one or two steps (function of iodide content). As no interfered Rx has been observed in the Rx iodide region, the authors can ascertain that accurate values are observed by X-ray fluorescence. In case of high iodide content, this methods allows to distinguish urinary iodide versus total urinary iodine, when performing solution and matrix concentration studies on the urinary batch.

Humans↗