A study of the spectral analysis of the electrogastrography has been mad in man in a non-invasive condition: normal subjects in two groups: young and old subjects (n = 72) were compared with gastric cancers (n = 42) and ulcerous (n = 22) subjects. Morning recording (10-11 h a.m.), in fasting conditions, were repeated every three successive days. In normal subjects, the mean frequency of the spectral gastric component is very stable (2.8 +/- 0.2 cycles per min), whatever be the sex, the age of the body weight. In normal subjects, the mean spectral amplitude (y) varied with the derivation: in derivation 3-6 (according to the antro-pyloric axis) is the greatest amplitude (y = 52 +/- 22 microV). In the cancerous condition, the range of the frequencies increases, but the mean frequency does not change (2.8 +/- 0.3 cycles per min). However, in 7 cancerous subjects the frequencies (x) fell beyond the limits of the population with an (x) being either less than or equal to 2.4 or greater than or equal to 3.2 cycles per min. In a great proportion (forty-seven per cent) of the cancerous subjects, an important and significant increase of amplitude is recorded (at least in one derivation). In these cases, the location of the cancer is the cardia, the fundus or the pylorus. The amplitudes fall significantly beyond those observed in ulcerous patients. The possible explanations of these variations and the applications to the future monitoring of patients are discussed.

1) The present paper concerns the relationship between localization and extension of gastric cancers and the spectral characteristics of the EGG in 73 subjects (32 women and 41 men). 2) The recordings were made in the morning (during 1 h) on fastened patients. Three sets of bipolar cutaneous electrodes were placed on the abdomen around the pyloric radiological projection taken for axis (radius 7 cm; angle 60 degrees); sampling period for analysis is 1 per sec. The spectrum is computed (FFT) for 256 samples in each channel. 3) In the control subjects (n = 72: 24 women and 48 men), the "normal characteristics" of the peak EGG are the following: frequency: 2.89 +/- 0.2 c/min; amplitude 40 +/- 20 microV (2-5 derivation), whatever the age. 4) In the cancerous subjects significative increase of the mean spectral component amplitude of the gastric frequency was always found in all different localizations. However, this criterion of amplitude was missing for the corpus localization. 5) The process of infiltration of the wall was accompanied by a significative decrease of the mean frequency. But in ulcerous, vegetant or stenosant cases the frequency was not affected in contrast with the amplitude. 6) In extensive cases the decrease of the frequency was more important. If in several cases (early cancers, mucous cancers of the lesser or greater curvature), no significative abnormality of the spectrum was observed, abnormalities are frequent in cardiac, fundic and antral neoplasies.

A standardised application of electrogastrography (EGG) using spectral analysis was used in 182 subjects (72 normals, 74 cancerous and 36 ulcerous) in a large range of the aging (10 to 70 years). The conditions of derivations from the abdominal surface electrodes (n = 6) are following: bipolar distance 14 cm around the pyloric point at 0 degrees (antrum axis), 60 degrees and 120 degrees. In fasting situation in normal subjects the gastric frequency (N) and the spectral amplitude (Y) of the most energetic component of EGG was 2.89 +/- 0.2 c/min for N and 54 +/- 44 microV for Y in antropyloric axis. In the cancerous group a significative increase of mean amplitude is observed (P = 0.01). On the contrary any mean change of frequency was observed (2.89 +/- 0.3 c/min). The individual comparison with normal parameters leads to following selection: neoplasia, n = 42/74 cases (57%); ulcer, n = 13/36 (36%); however 7/72 normal subjects (10%) fall in this abnormal class as false positive. After an ingestion of tea (120 ml) giving a volumetric stimulation, the modifications of frequency are not significative contrary to the amplitude increase. Finally, the association of one or two abnormalities leads to the following percentages: 66% in cancerous, 45% in ulcerous and 23% in normal subjects. Thus a better proportion of abnormalities was observed in cancerous subjects with the stimulation but this procedure may lead to an increase of false abnormality in the non-neoplastic subjects.

AbstractFirst results of the comparison between the electrical activity of taenia coli and circular muscle are described. Experimental techniques consisted in recording electrical activity for 83 h in 12 patients during the post-operative period after cholecystectomy. Bipolar wire electrodes were surgically inserted in each muscle of the transverse colon's median portion. Statistical treatment leads to the principal conclusion as follows:- Whatever type of muscles we have investigated, always could be found slow rhythmic components (called electro-control activity, ECA) in frequency ranges of 1-5 c/min and 9-12 c/min.- Major part of taenia coli ECA is in frequency range between 1-5 c/min. ECA in this frequency range can be found in 21% of circular ECA, 23% of taenia coli ECA and 9% of common ECA (% means percents of total recording time).- Higher frequencies are found in 7% of circular ECA, 4% of taenia coli ECA and 3% of common ECA.- Using long time constant (more than 2 s) the bursts of spikes (10-50 μV...

Electrical activity of the colon was investigated in the postoperative period in 12 patients, 1 to 6 days after cholecystectomy. The polygraphic records are obtained during 2 hours each day late in the morning (10-12 h) in a preprandial situation from serosal implantation of bipolar copper wires inserted into each circular and longitudinal layer in narrow portion of the middle part of the transverse colon. The time presence diagrams was built up after recognition of the basic patterns activity previously definite by Sarna as follows: Electro-Control-Activity, with it slow waves (ECA), Electro-Response-Activity (ERA) with Discrete bursts (DERA) or Continuous ones (CERA). In the former postoperative period 1 to 3 days ECA is present with a low range frequency 1-5 c/min. The higher frequency (10-12 c/min) activity arises sporadically, in this case associated with DERA bursts. From the 4th day all activities ECA and DERA increase significantly. The continuous response activity CERA may be observed in all periods but more frequently from the 3rd day with the same mean duration (12.4 +/- 1.85 s for the circular fibers and 21.6 +/- 2.56 s for the longitudinal ones); the predominance of longitudinal activity duration is significative (p = .001). The complex CEC (26-40 c/min) associated with CERA is observed only in 3% of the time recording. Thus after the onset of colonic motility with DERA and CERA in the 3th day, the normalization is obtain the 6th day with the predominant rythm of 1-2 c/min.

First results of the comparison between the electrical activity of taenia coli and circular muscle are described. Experimental techniques consisted in recording electrical activity for 83 h in 12 patients during the post-operative period after cholecystectomy. Bipolar wire electrodes were surgically inserted in each muscle of the transverse colon's median portion. Statistical treatment leads to the principal conclusion as follows: Whatever type of muscles we have investigated, always could be found slow rhythmic components (called electro-control activity, ECA) in frequency ranges of 1-5 c/min and 9-12 c/min. Major part of taenia coli ECA is in frequency range between 1-5 c/min. ECA in this frequency range can be found in 21% of circular ECA, 23% of taenia coli ECA and 9% of common ECA (% means percents of total recording time). Higher frequencies are found in 7% of circular ECA, 4% of taenia coli ECA and 3% of common ECA. Using long time constant (more than 2 s) the bursts of spikes (10-50 microV) meaning active responses are always accompanied with slower components of important amplitude (greater than or equal to 100 microV): In the discrete mode of activity (DERA) short bursts (during 1-2.5 s) always follow the ECA, whereas in the continuous mode of activity (CERA) mostly longlasting bursts (up to 30 s) could be found. The bursts represent 14% of total time, namely in 8% of longitudinal ECA, 4% of circular ECA and 2% of common ECA. ECA of taenia coli in the case of common ECA is always prolonged. Typical slow waves of greater amplitude (greater than or equal to 500 microV) different from ECA are frequently recorded probably due the intensive contractile process.

The exigencies of quickly developing economics and of managing the growth of knowledge and available technologies give the educational task a particular urgency. Such a problem, generally felt in that areas presenting a high technological change rate, is particularly relevant in an always more computerized society, whereas the capability of educating users of social and industrial computer based system means to manage the change. Informatics, so, plays an important role not only as subject of didactical curricula but, over all, in designing and controlling the educational intervention and in realizing the connection between the scientific production and the socio-economic system. Besides evidentiating such problematics, this paper describes some realized products representing the operative tools useful to the implementation of instructional processes in Informatics, in a theoretical context that takes into consideration two models: the learning process model and the educational system one.

A method to overcome the limitations of the “sliding-scale” technique for the ADC statistical equalization is proposed.