ITBM-RBM最新文献

In this paper a new algorithm for detection of suspicious mass area from mammographic images is presented. It uses histogram modification enhancement technique and a segmentation method based on minimization of inertia sum. The histogram modification filter is designed so as to be able to enhance disease patterns of suspected masses by cleaning up unrelated background clutters. Segmentation is then performed on the enhanced-image to localize the suspected mass areas using minimisation of inertia sum of images intensity classes. The proposed algorithm was tested on a database of 32 mammogramms provided by Gynaeco-obstetric and pediatric hospital of Yaoundé on which masses had previously been localised by experienced radiologists. Results show that the algorithm is able to identify masses in all cases presented with a sensibility of 94% approximately. In addition, we found out that sizes and edges of masses detected are similar to those marked by radiologists. Furthermore in some cases, we could detect some hidden masses that the radiologists were not able to mark out.

Different hypertonic solutions are employed during cardiac surgery. Indications of two of them are linked with the molecule itself. It is sodium bicarbonate and glucose. The first indication of mannitol et hypertonic saline solutions is the hyper osmolarity. The solutions of 4.2 and 8.4% bicarbonate allow the correction of a metabolic acidosis when the cause does not be rapidly treated. The 30% glucose solution is used with high dose of insulin and with potassium to enhance the myocardial function. The 10 or 20% solution of mannitol is added to the prime solution of CPB circuit to increase the osmolality. Mannitol is also a scavenger of free radicals produce during CPB when heart reperfusion and hyperoxie. Originally the “small volume resuscitation”, the 7.5% hypertonic saline solution is little employed during cardiac surgery. It enhances the myocardial inotropisme and decreases the systemic vascular resistances. It acts against the hydria leak from intravascular sector to the interstitial sector with a decrease of post CPB oedema. Hypertonic saline and glucose 30% solutions proprieties are particularly evolved.

The ocular hypertension (elevation of the intraocular pressure — IOP —) is widespread in the industrialized countries. Its consequences can lead to complete blindness. That is why it is the subject of an attentive surveillance, notably with risky (glaucomatous) patients. Ophthalmologists currently use aplanation tonometers whose utilization induces multiple constraints: (local anaesthesia, additional instrumentations required, …). Our aim was to propose an investigative method both atraumatic and ambulatory. We designed an original device that, putting to profit a physical relation between frequency of mechanical vibration of the ocular globe and the intraocular pressure, combines vibrometry by laser interferometry and spectral analysis of a mechanical impulse transmitted to the eye by a micro hammer located on the temporal edge of the orbital socket. After having scrupulously confirmed that the luminous energy delivered to the eye by the laser source was in agreement with the authorized security norms, we led a survey clinic on 25 patients to test the innocuity and the reliability of this device and to value the reproducibility of measurements. The obtained results are very encouraging: the expressed discomfort is comparable the one felt during analogous sight-testings. Reliability is good (18% of failure in recorded measurements) and the intra individual reproducibility, expressed by the coefficient of interrelationship intraclass, outlines a value qualified of very good (R > 0.93). These first results encourage us to pursue our works to succeed in establishing an correlation between the measured value (the resonance frequency of the eye-ball) and the supervised one (the intraocular pressure).

L'objectif de cette étude est de simuler les résultats cliniques à long terme de l'arthroplastie totale de la hanche et d'identifier les causes biomécaniques des différents résultats observés. L'étude est fondée sur des modèles éléments finis construits à partir d'une base de données d'images cliniques. Le calcul a combiné l'analyse des contraintes–déformations des modèles avec un algorithme de remodelage osseux. Une étude paramétrique, suivant différents facteurs biomécaniques, a été menée. Les patients ont été répartis en trois groupes en fonction des résultats de l'opération à long terme. Les résultats des simulations ont été comparés avec les images des patients 14 ans après leur opération. Les conclusions de l'étude montrent que les résultats à long terme dépendent non seulement des facteurs biomécaniques considérés mais également de la combinaison de ces facteurs.

Biological tissues are mainly constituted of soft matter. This very particular state, neither liquid, nor gaseous, nor solid, leads for simulation to the use of mathematical models more and more complex. Moreover, these tissues are arranged in multi-layer way, they are anisotropic and they have not mechanical linear properties. The evaluation of the interface pressures by traditional methods leads to measurement errors. FORSAFE is a sensor of the pressure between newborn's head and forceps allowing to limit hazards due to bad positioning and too important tightening of the forceps during the delivery. It is based on an original bio-inspired method reproducing the touch sense by micropalpations.

Sound envelope considered as amplitude modulation contains relevant information about speech intelligibility. Hewitt and Meddis developed an auditory pathway model that codes amplitude modulation. It was extended to a multi channel one. Inferior colliculus response to amplitude-modulated white noise is compared with the response to amplitude-modulated tone in terms of firing rate and synchronisation index. The carrier signal does not affect single characteristic frequency unit. This result lets us propose a more complete structure to be explored.

The use of volatile anesthetics during CPB is still not frequent in France. The use of volatile anesthetics has however some advantages compared with intravenous anesthesia especially in terms of myocardial protection. We reported our experience in 759 patients operated with isoflurane (642) or sevoflurane (117). The volatile anesthetics were used for the maintenance of anesthesia and stabilisation of arterial pressure even during CPB and allowed an early extubation.