Jose Luis Vargas

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The recording of auditory brainstem response (ABR) at high stimulation rates is of great interest in audiology. It allows a more accurate diagnosis of certain pathologies at an early stage and the study of different mechanisms of adaptation. This paper proposes a methodology, which we will refer to as randomized stimulation and averaging (RSA) that allows(More)
OBJECTIVES The stimulation levels programmed in cochlear implant systems are affected by an evolution since the first switch-on of the processor. This study was designed to evaluate the changes in stimulation levels over time and the relationship between post-implantation physiological changes and with the hearing experience provided by the continuous use(More)
The recording of auditory brainstem response (ABR) signals is a common measure applied to assess hearing impairments. However, most of the available commercial devices able to record ABR signals can be unaffordable for many medical centers because of their cost and low flexibility. This paper describes a system that allows the recording of high quality ABR.(More)
The recording of the auditory brainstem response (ABR) is used worldwide for hearing screening purposes. In this process, a precise estimation of the most relevant components is essential for an accurate interpretation of these signals. This evaluation is usually carried out subjectively by an audiologist. However, the use of automatic methods for this(More)
A highly efficient and regioselective synthesis of 1,2-dihydroquinolines via a multicomponent reaction between an aniline and two ketones is described. This reaction was catalyzed by magnesium bromide and carried out under solvent-free conditions. When the reaction was performed by using 3-substituted anilines and nonsymmetrically substituted ketones,(More)
Randomized stimulation and averaging (RSA) allows auditory evoked potentials (AEPs) to be recorded at high stimulation rates. This method does not perform deconvolution and must therefore deal with interference derived from overlapping transient evoked responses. This paper analyzes the effects of this interference on auditory brainstem responses (ABRs) and(More)
Recording auditory evoked responses (AER) is done not only in hospitals and clinics worldwide to detect hearing impairments and estimate hearing thresholds, but also in research centers to understand and model the mechanisms involved in the process of hearing. This paper describes a high-performance, flexible, and inexpensive AER recording system. A full(More)
Intraoperatory awakening or awareness can be defined as recovering of conscience during general anesthesia. We report such a case happened in a 11 year-old boy during a hypospadias repair. After anesthetic education he related intraoperatory conscience without pain, anxiety, displeasing symptoms or long-term psychoconductal distress. We remark(More)
Seventy-three patients were studied with a discordant atrioventricular connexion (ages 3 months to 46 years). In 58 the diagnosis was proved by angiography and in the other 15 at necropsy. Forty-eight had usual atrial arrangement and 25 mirror-image atria. Fifty-two patients had ventriculo-arterial discordance, 13 double outlet right ventricle, 4(More)
UNLABELLED Twenty three cases with impairment of greater than 40% of DLCO were studied in a search of frequency, severity and pathophysiological mechanisms of PAH. Hemodinamic studies, pulmonary angiography (PA), lung scan (LS), lung biopsies (LB) were performed. The venous admixture was estimated and expressed as percentage ratio of the cardiac output(More)