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F del Pozo

Publications and source records attributed to F del Pozo.

29 records · Page 2Linked to original sources
PubMed1993

A pen-based system to support pre-operative data collection within an anaesthesia department.

This paper describes the design and implementation of a pen-based computer system for remote preoperative data collection. The system is envisaged to be used by anaesthesia staff at different hospital scenarios where pre-operative data are generated. Pen-based technology offers important advantages in terms of portability and human-computer interaction, as direct manipulation interfaces by direct pointing, and "notebook user interfaces metaphors". Being the human factors analysis and user interface design a vital stage to achieve the appropriate user acceptability, a methodology that integrates the "usability" evaluation from the earlier development stages was used. Additionally, the selection of a pen-based computer system as a portable device to be used by health care personnel allows to evaluate the appropriateness of this new technology for remote data collection within the hospital environment. The work presented is currently being realised under the Research Project "TANIT: Telematics in Anaesthesia and Intensive Care", within the "A.I.M.--Telematics in Health CARE" European Research Program.

Anesthesia Department, Hospital↗
PubMed1986

Behavior of neurons in the abducens nucleus of the alert cat--I. Motoneurons.

The activity of 53 antidromically identified abducens motoneurons was analyzed in alert cats during spontaneous and vestibular induced eye movements. Conduction velocities ranged from 13 to 70 m/s and all motoneurons increased their discharge rates with successive eye positions in the abducting direction. Motoneurons were recruited from -19 degrees to +7 degrees. Within the oculomotor range frequency saturation was never observed for any cell. The slope of rate-position (k) relationships ranged from 2 to 17.7 spikes/s/deg (n = 40, mean 8.7 +/- 2.5). Regression analysis showed that the rate-position plots could be fit by straight lines but in most cases exponential curves produced slightly better statistical fits. Steeper slopes suggest that successively larger increases in k are required for the lateral rectus muscle to maintain more eccentric fixations in the on direction. Interspike intervals for a constant eye position exhibited low variability (less than 3.5%) for fixations shorter than 1 s. Over longer periods, variability increased in proportion to the duration of the fixation in exponential-like fashion up to 14%. Abducens motoneurons showed considerable variability in frequency during repeated fixations of the same eye position. Discharge rates were found to depend upon both the direction of the previous eye movement and, more importantly, the animal's level of alertness. The rate-position regression lines for fixation periods after saccades in the on direction significantly differed in slopes (100%) and thresholds (20%) from those in the off direction. The observed static hysteresis in abducens motoneuron behavior was in opposite direction to that previously described for the mechanical properties of the lateral rectus. This suggests both neural and mechanical factors are significantly involved in determining final eye position. The animal's level of alertness was evaluated in this study by counting the number of saccadic movements/s occurring in "alert" (1 +/- 0.2 saccades/s), and "drowsy" (0.5 +/- 0.2 saccades/s) circumstances. Comparison of the rate-position regression lines between the two conditions showed a significant decrease in slopes (100%) and elevation of thresholds (70%). Discharge rate of abducens motoneurons increased abruptly 8.9 +/- 2.8 ms prior to saccades in the horizontal on direction, and decreased 14.8 +/- 4.05 m before saccades in the off direction. During purely vertical saccades the firing frequency of abducens motoneurons did not change. Burst frequency did not saturate during saccades, but increased with saccadic velocity in a linear fashion.(ABSTRACT TRUNCATED AT 400 WORDS)

Abducens Nerve↗
PubMed1986

Behavior of neurons in the abducens nucleus of the alert cat--II. Internuclear neurons.

The activity of 43 antidromically identified abducens internuclear neurons with conduction velocities ranging from 14 to 54 m/s was analyzed in alert cats during spontaneous and vestibular induced eye movements. The discharge rate of internuclear neurons significantly increased with successive adducting positions of the contralateral eye. Slopes of rate-position (k) relationships ranged from 3.1 to 17.9 spikes/deg (mean 12.01 +/- 3.1). Threshold ranged from -19 degrees to +3 degrees. Frequency saturation was never observed for any internuclear neuron within the oculomotor range. Although straight lines were selected to illustrate the rate-position relationships, exponential curves always provided the best statistical fit demonstrating that an enhancement in frequency potentiation (k) must accompany more eccentric fixations in the on direction. Internuclear neurons showed a low variability in firing rate (less than 3.0%) for fixations less than 1 s. Variability increased with both longer and repeated fixations of the same eye position. Discharge rates were found to depend upon both the direction of the preceding eye movement and the animal's level of alertness. Separate regression lines of rate-position relations following saccades in the on and off directions differed significantly in slope (100%), but not threshold. The observed static hysteresis in an identified non-motoneuron shows this property to be in a central neural circuit prior to the extraocular motoneuron. The slopes (k) of rate-position plots for all internuclear neurons decreased significantly (100%) when level of alertness changed from "alert" (1 +/- 0.2 saccades/s) to "drowsy" (0.5 +/- 0.2 saccades/s). Thresholds, however, were not significantly altered. Discharge rate of abducens internuclear neurons increased abruptly 10.4 +/- 2.5 ms preceding saccades in the on direction, and decreased 20.5 +/- 7.8 ms before saccades in the off direction. Internuclear neuronal activity was not affected by pure vertical saccades. During on direction saccades, firing frequency did not saturate, but increased with velocity in a linear fashion. Exponential functions often fit the data better due to the difference in slopes of rate-velocity plots for on vs off direction saccades. Slopes (rs) of rate-velocity regression lines during spontaneous saccades ranged from 0.99 to 4.10 spikes/s/deg/s (mean 2.16 +/- 0.93). During saccades in the off direction activity always decreased, but it seldom ceased. Rate-velocity regression lines measured during the fast phase of vestibular nystagmus (rsv = 2.09 +/- 0.88) showed no significant differences from rs slopes in 82% of the cases.(ABSTRACT TRUNCATED AT 400 WORDS)

Abducens Nerve↗
PubMed1986

[Choledochal cyst. Presentation of 5 cases in childhood].

Five cases of choledochal cyst diagnosed from 1976 to 1983 are presented. Four patients began in the neonatal period as a cholestatic syndrome resembling biliary atresia and one patient began later on as a cholangitis. It is important for diagnosis the use of ultrasounds and radionuclide hepatobiliary. Clinical course depends on early diagnosis and treatment, because there is often an atresia of the common hepatic duct associated.

Bile Ducts↗
PubMed1982

Toward chronobiologic pattern discrimination of the risk of developing breast cancer and other diseases.

With a view of the prevention as well as treatment of cancer and other diseases, it is important to quantify health positively and on an individual basis by chronobiologic methods. These include the assessment of the characteristics of certain circadian, circannual and other endocrine rhythms and trends, for the recognition of risk (prior to the occurrence of a given disease) by an alteration of the same rhythm characteristics and even by a time-specified single sample. With this aim in mind, a small number of selected (rather than randomly picked) women of 3 age groups was extensively sampled for 12 plasma hormones around the clock and the calendar, in 2 geographic locations. Such data revealed correlations of the familial risk of developing breast cancer with the circannual amplitudes of circulating prolactin and TSH. The risk of several other conditions was also correlated with hormonal rhythm characteristics; for example, the risk of developing diseases associated with a high blood pressure was correlated with the circannual amplitude of plasma aldosterone. The mapping of circannual characteristics, however, is time-consuming and costly and may not be warranted as a first step, for example when a physician is not in a position to wait for a year to make a diagnosis. With the possibility in mind that sampling requirements may be reduced to one or at most two samples, a chronobiologic pattern discrimination analysis was undertaken on the original data from young adults. The results are presented to indicate the method and to suggest the singling-out of certain variables for further testing on a larger, properly stratified and randomized sample, rather than as definitive results. Different classifiers and different corresponding reference values from variables that undergo circadian and circannual rhythms may perhaps withstand the test (and, with Vergil, the tooth) of time. If so, reference values that are time-specified may well prove to be a sine qua non in the assessment of certain neuroendocrine aspects of developing certain diseases, including breast cancer.

Adolescent↗
PubMed1976

Ultradian rhythms in the mobility and behavior of rhesus monkeys.

The presence of ultradian rhythms in the mobility and behavior of rhesus monkeys was explored in eleven animals equipped with mobility FM transmitters and placed alone or in pairs in laboratory cage situated in a sound proof, temperature controlled room, with food and water ad libitum. After an habituation period of 3 to 7 days, telemetric recordings of the mobility of the animals showed ultradian rhythms with a periodicity of 70 min during the daily 12-h light period. During the corresponding 12-h dark period, there were two dominant cycles of 103-144 min and 48 min respectively. Restriction of food and water to 1h/day did not change the duration of these cycles, and the presence of random noise also had little effect. Spontaneous behavior occurred in regular sequences within each cycle. Social relationships were found to affect rhythmicity of behavior, since pairs of monkeys synchronized their cycles. The lever press response recorded during auto-shaping showed the same rhythmicity found in mobility, demonstrating the influence of ultradian rhythms on learned behavior.

Animals↗
PubMedDate not supplied

Telemedicine for diabetes care: the DIABTel approach towards diabetes telecare.

Telemedicine is modifying classical health care by providing effective solutions to an increasing number of new situations. This article summarizes the potential benefits made available by this technology in diabetes care, and describes in detail how the new DIABTel Telemedicine Service complements the daily care of diabetic patients. The basic functions of the telemedicine system include telemonitoring of patient's blood glucose data and self-management actions, and remote care from doctors to diabetic patients. The system's architecture comprises two main components: the Medical Workstation, a PC-based system to be used by physicians and nurses in Diabetes Day Centre units in hospitals, and the Patient Unit, a palmtop-computer to be used by patients in their day to day activities. Both components, in an integrated approach, offer tools to doctors and patients for data collection and management, viewing and interpretation modules, data/message exchange services and an interactive glucose/insulin simulator for educational purposes. The DIABTel telemedicine diabetes care procedure aims: (1) to improve communication of the patient with the hospital-based diabetologist, in between the patient's visits to the clinic; (2) to allow doctors to assess the patient's condition on a frequent basis (every week); (3) to help patients with management in the daily care of diabetes, and (4) to provide patients with a service of 'supervised autonomy', to increase patient's independence without decreasing the necessary continual support and supervision from the doctor. Finally, we discuss the practical problems, limitations and vital issues regarding implementation of the telemedicine service.

Blood Glucose Self-Monitoring↗
PubMedDate not supplied

DIABNET: a qualitative model-based advisory system for therapy planning in gestational diabetes.

An intelligent decision support system for the analysis of home monitoring data and therapy planning in gestational diabetes is presented. The paper describes the integration of qualitative and quantitative reasoning modules within the DIABNET advisory system. The system kernel is a qualitative model of the physiological processes involved in the glucose metabolism of this type of diabetic patient. A causal probabilistic network (CPN) has been used to represent the qualitative model in order to manage uncertain and missing monitoring data. The DIABNET inputs are the patient's available ambulatory monitoring data, and the output is a dietary and insulin therapy adjustment that includes initiation of insulin therapy, quantitative insulin dose changes and qualitative diet and schedule modifications. Over periods of up to seven days, monitoring data are analysed by the CPN to detect any diet or insulin therapy items which may require modification. The qualitative insulin needs are translated into a quantitative proposal in line with the characteristics of the patient and the modification strategies usually used by doctors. The first evaluation of the system has been accomplished, the encouraging results of which are also presented.

Blood Glucose Self-Monitoring↗
PubMedDate not supplied

Chronobiologic pattern discrimination of plasma hormones, notably DHEA-S and TSH, classifies an expansive personality.

Methods of chronobiologic pattern discrimination, a "monotest' involving the leave-one-out technique and a "maximin distance' algorithm for cluster analysis, along with stepwise discriminant analysis procedures and correlation techniques are used in the search for classifiers of personality. By these methods, chronoendocrine relations of an expansive personality are explored in data sampled around the clock in 4 seasons on 10 North American and 3 Japanese women. Of 12 plasma hormones determined in each season, DHEA-S shows a time-dependent relation to an expansive, egocentric personality assessed by an abbreviated version of the Minnesota Multiphasic Personality Inventory; time-dependent co-classifiers are TSH, LH, prolactin and cortisol. Cost-effective recommendations for sampling are thus proposed for further tests of endocrine factors classifying for an expansive personality and, perhaps, classifying also for any associated vulnerability or risk state.

Adolescent↗