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This study focused on measuring examinees' muscle activities during mammography positioning using surface electromyography. Muscle activities were measured in three women (40-50s) in two-view mammography (MLO: mediolateral oblique, CC: craniocaudal). The muscles measured were the sternocleidomastoid, biceps, trapezius, and gastrocnemius, selected based on the visual analogue scale reported by Sharp et al. We used a multi-purpose portable bio-amplifier (Polymate AP1000) to assess the muscle activities. The results showed that the trapezius in right MLO and sternocleidomastoid in right CC were active in all three subjects. This suggests that the muscles directly related to mammography positioning are highly active. In addition, the gastrocnemius was active throughout the mammography. The biceps and gastrocnemius were also active in at least one of the three women. We believe that quantitative assessment of muscle activities during mammography positioning will contribute to the improvement of pain-reduction programs in mammography.

The aims of this paper are to make clear the characteristics of sympathetic skin response(SSR) wave. The records of SSR wave were obtained using a DC servo-amplifier with the frequency response of DC to 30 Hz and drift level of 10 microV/10 min. The SSR from the palm of 10 normal control subjects(6 males and 4 females, age range 21-25 yrs) were elicited by electrical stimulation of the median nerve at upper arm. The results that the peak latency and the duration of SSR were approximately 6.32 +/- 2.5 s and 47.5 +/- 7.5 s respectively were obtained experimentally with the amplifier, though the results of AC recordings with time constant of 0.3 s were about 1.0 s and 2.0 s respectively. It can be considered that exact peak latency and duration of SSR are much longer than those data of previous studies. These findings suggest that electric stimulation should be applied at longer intervals than 60 s for rejection of the remaining potential level of SSR and the habituation.

When agonists are ionophoretically applied to the neuromuscular junction using a short current pulse, the effect of stray capacity and the change of resistance of the ejecting micropipette on the output current has to be considered. The present paper describes an apparatus that was devised using OP-amplifiers so that the apparent stray capacity was remarkably reduced, and the amount of the output currents was in proportion to the input voltage of the short pulse even if the resistance of the micropipette changed markedly during the experiments.

Images are very useful to obtain diagnostic informations in medical fields. Also by superimposing two or three images obtained from the same patient, various informations, for example a degree of overlapping and anatomical land mark, which can not be found in only one image, can be often found. In this paper characteristics of our trial color television system for the purpose of superimposing X-ray images and/or radionuclide images are described. This color television system, superimposing two images in each different color consists of two monochromatic vidicon cameras and 20 inches conventional color television in which only two simple video amplifier circuits are added. Signals from vidicon cameras are amplified about 40 dB and are directly applied to cathode terminals of color CRT in the television. This system is very simple and economical color displays, and enhance a degree of overlapping and displacement between images. As one of typical clinical applications, pancreas images were superimposed in color by this method. As a result, size and position of pancreas was enhanced. Also X-ray image and radionuclide image were superimposed to find exactly the position of tumors. Furthermore this system was very useful for color display of multinuclides scintigraphy.