The effect of oro-naso-pharyngeal suction at birth on pulmonary mechanics is described in a random assigned controlled study of 40 normal term vaginally born infants. Twenty cases had their oro-naso-pharynx suctioned immediately after birth (S Group), whereas 20 were not suctioned in the neonatal period (NS Group). A computerized pneumotachographic system (MECVENT) was used for the assessment of respiratory mechanics (Dynamic Compliance (C. Dyn.) and Total Pulmonary Resistance (R) in inspiration and expiration at 10, 30 and 120 minutes after birth. In both groups the C. Dyn increased during the study period whereas the R decreased, mainly in the initial 30 minutes. No significant differences were observed between S and NS groups for any of the parameters of respiratory mechanics. The results obtained in this study provide no physiological basis to recommend routine airway suction at birth in normal, term, vaginally born infants.

A compact gaze tracker was developed by processing electrooculogram (EOG) signals taken from electrodes secured to an elastic head band. We confirmed that eye position is perceived by an observer in normal social interaction within 5°. We developed the prototype named PANTOJO after its pantographic potential to move a prosthetic eye following the healthy eye movements. We also confirmed that the EOG correlates with gaze angle. PANTOJO was implemented with a 1Hz to 20Hz bandwith, 66dB amplification and digital signal processing to output the position of the eye to within 2°. After initial calibration PANTOJO acts as a state machine, detecting and classifying eye movements according to saccades. A 75% success rate was achieved to detect transitions from discretized eye positions in 5° multiples from +40° to -40°. With its transport delay of 100 ms, update rate of 46Hz and an accuracy of 2.5° PANTOJO may prove to be a versatile gaze tracker for multiple applications, including communication devices for the disabled (e.g. tetraparesis), gait research or driving analysis in real life.

Monitoring intra-abdominal pressure (IAP) has become a standard in intensive care units. Correlation between the abdominal wall’s thickness (AWTh) and IAP has been reported previously. The abdominal wall can be modeled as a compound of parallel dielectric slabs; changes in their width have a direct effect on the reflection coefficient of the abdominal wall at microwave frequencies. This work describes the design of a reflectometry system and its proof-of-concept trial on five patients during laparoscopic surgery. The system complies with IEEE Std. C95.1-2005 concerning exposure of humans to microwave electromagnetic fields in controlled environments. The results putatively show an inverse correlation between IAP and the reflection coefficient, and a strong dependence on the body mass index. A better understanding of the dynamics in the changes of the AWTh (during intra-abdominal hypertension) will allow further development of a microwave-based technique for the continuous non-invasive indirect monitoring of IAP in critical patients.

An experimental stable model of an in vitro turtle brain (Chrysemys d'orbigny) was developed in order to compare electrographic activity (EEG) with transmembrane potentials. Two preparations were used: a whole intact hemisphere and a whole open hemisphere. The latter permitted easier impalement of cortical neurons through the ependymal surface. The EEG characteristics were similar to those described in turtles in vivo. The EEG was nonrhythmic (rhythmicity coefficient <0.40). The power spectrum presented a high energy band between 1 and 3 Hz, decreasing progressively towards the higher frequencies. Total power of the EEG was one order of magnitude greater than the system noise. Random large amplitude sharp waves (22–300 µV, 500–1,900 ms) were recorded spontaneously. Hypoxia produced an increase in frequency and amplitude of the large sharp waves, without modification of either EEG background activity or membrane potentials. Physostigmine provoked the disappearance of the large sharp waves, an effect reversed by atropine. The addition of TTX to the medium provoked the abolition of the EEG, although spikes and plateaus determined by Ca²⁺ conductances persisted. The power spectra band of maximum relative potency was 0.8–2.5 Hz for both EEG and slow membrane potentials.