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Biomedical subjects

L M Gallo

Publications and source records attributed to L M Gallo.

24 records · Page 2Linked to original sources
PubMed1995

A new method for three-dimensional reconstruction and animation of the temporomandibular joint.

The aim of this project was to develop a new method for the three-dimensional reconstruction and animation of the temporomandibular joint (TMJ). Magnetic resonance (MR) tomograms of the TMJ were combined, using an extraorally placed reference system, with jaw motion data, recorded with six degrees of freedom, by means of the opto-electronic tracking system Jaws-3D. The three-dimensional reconstruction of the TMJ was calculated and animated on a graphics workstation by means of kinematic transformations. A subject without any past or present history of myoarthropathies of the masticatory system, performed jaw opening and closing and chewed chewing gum. The animation provided a three-dimensional visualisation of the movements of the entire condyle within the fossa. The condyle-fossa distance was computed for every condylar point and represented by shading the surface of the condyle with pseudo-colours. The position of the minimum distance between condyle and fossa was calculated and displayed in a plane graph representing the condylar surface.

Humans↗
PubMed1994

Precision of the jaw tracking system JAWS-3D.

The purpose of this study was to measure, under laboratory conditions, the noise level of the optoelectronic jaw-tracking system JAWS-3D, which records the movement of the whole mandible from extraorally placed landmarks. Also, an assessment was made of its accuracy in measuring positions, angles, and velocities. The results showed that the accuracy of JAWS-3D decreased when the distance between the recorded point and the extraoral landmarks increased. The path of a point near to the landmarks was estimated with an error of 0.11%, whereas the error increased to 1.33% when the point was far from the landmarks. The maximum error in angle computation was 0.7 degrees. The velocities calculated by JAWS-3D corresponded closely to the actual ones: mean error of 3 mm/s for velocities up to 80 mm/s. Thereafter, the error increased to reach 26 mm/s at a speed of 210 mm/s.

Artifacts↗
PubMed1993

Power spectral analysis of temporomandibular joint sounds in asymptomatic subjects.

Very little has been done to quantify temporomandibular joint (TMJ) sound amplitudes and background noise and to determine the spectrum from healthy TMJs. Thus, the aim of this study was to record acoustically the sounds emitted by healthy TMJs with and without mandibular movements, for determination of baseline spectra. TMJ sounds were recorded bilaterally from 40 subjects with healthy joints by means of a self-developed recording system using miniature capacitor microphones inserted into the earpieces of a medical stethoscope placed in the meatus of the auditory canal. The recordings were performed without mandibular movements and during three consecutive opening and closing movements. The signals were high-pass-filtered at 50 Hz, low-pass-filtered at 2 kHz, and analyzed by fast Fourier transform computation on a 1024-point window (fs = 5 kHz). The linearly weighted average baseline spectrum recorded without motion showed maximum values of 31 dBSPL (sound pressure level) with a standard error of +2 to -3 dB. The linearly weighted average movement spectrum had a peak of 66 dBSPL at 156 Hz and decreased almost linearly by about 40 dB/decade to 25 dBSPL at 2000 Hz with a standard error of +/- 2 dB. Thus, the TMJ sound spectrum of mandibular movements in asymptomatic subjects differed at low frequencies by up to 35 dB from the baseline spectrum in absence of motion.

Adolescent↗
PubMed1992

Long-term results of varicocelectomy.

Between 1983 and 1985, 257 infertile men were examined for any present varicocele by means of the Doppler sonography, telethermography and palpation. Based on these findings, the spermiogram and the infertility history, high ligation of the spermatic vein was indicated in 89 patients with varicocele and a median duration of infertility of 36 months (6-88 months). Postoperative sperm examinations have shown a significant improvement in sperm count and morphology, but not in motility. The most significant drop was observed in germ cell concentration from 1.68 to 1.06 mio/ml (p less than 0.025 Wilcoxon signed rank sum test). The follow-up examination 6 years after the beginning of the study has shown that only 56 out of the 89 patients underwent surgery, whereas 33 patients refrained from it. Pregnancy rates were 42% (23 out of 55, 1 patient lost to follow-up) in the operated group and 45% (14 out of 31, 2 patients lost to follow-up) in the nonoperated group. The comparison of the two graphs showing pregnancy incidence clearly demonstrates that pregnancies in the nonoperated group occur earlier than in the operated group; it has to be noted, however, that several patients only refrained from being operated on because pregnancy had occurred before surgery was planned. On the one hand, our study confirms other authors' results, i.e. that pregnancy rates in the nonoperated group are relatively high despite present varicocele. On the other hand, the operated group achieved practically the same high pregnancy rate when monitored over a longer period of time.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗