| Popis: |
In a previous work we have demonstrated that the transcutaneous neuromuscular electrical stimulation of the muscles of the leg in the human increases largely the arterial femoral blood flow. This elevated flow is stable during the stimulation. The present work deals with the influence of the frequency of the stimulation on the level of this hyperaemia. The neuromuscular electrical stimulation is applied to the internal and external branches of the sciatic nerve in order to stimulate the whole muscles of the leg and the foot. The stimulus is yielded by a Compex stimulator for seven minutes with frequencies in random order between 3 and 15 Hz. The intensity of the current (mean: 31 mA) is set up at such a level to increase blood flow by at least 100% at 5 Hz. The femoral arterial flow velocity and the pulsatility index are assessed during the last minute of the stimulation by a duplex ultrasound method. The peripheral vascular resistance is calculated on the base of the femoral blood flow and the mean arterial pressure. Seven healthy volunteers are studied (6 males and one female, aged 26.9 years, +/- 6.9). The haemodynamic variables are recorded at rest (table I). We observe a linear increase of the blood flow with increasing frequencies of stimulation (181% of the rest value at 3 Hz and 276% at 9 Hz) (fig. 1).(ABSTRACT TRUNCATED AT 250 WORDS) |
