Focused Ultrasound PC-6 Stimulation Effects on Blood Flow Volume, Skin Temperature, and Coldness of the Finger and Toe.

INTRODUCTION: Focused ultrasound can stimulate a specific point of tissue and can be a noninvasive method for acupoint stimulation. The aim of this study was to clarify the effects of acupoint stimulation by focused ultrasound on blood flow volume and coldness of the fingers and toes. MATERIALS AND METHODS: Forty healthy volunteers were included in this experiment. The blood flow volume and the skin temperature of a finger and toe were measured before and after stimulation of the pericardium 6 acupuncture point (PC-6) by focused ultrasound. Subjective coldness of the fingers and toes was also assessed using a visual analog scale (VAS) before and after stimulation. RESULTS: The maximum blood flow volumes of the finger and toe were significantly larger (p < 0.01) than those before stimulation. The maximum skin surface temperatures of the fingers were significantly higher (p < 0.01) than those before stimulation. The VAS scores for subjective coldness of the toes after stimulation were significantly higher (p < 0.01). CONCLUSION: The blood flow volume and skin temperature tended to increase after PC-6 stimulation. The VAS scores also indicated a tendency toward a warmer sensation in the toes after stimulation.

Brief effect of acupoint stimulation using focused ultrasound.

BACKGROUND: Acupuncture is used worldwide in medical treatment. However, needle insertion damages the skin and patients sometimes feel pain. To avoid such drawbacks, an acupoint stimulation device using focused ultrasound has been developed. Ultrasound stimulation does not damage the skin like acupuncture does because ultrasound can deliver vibration energy to soft tissues noninvasively. OBJECTIVES: The aim of this study was to clarify the effect of acupoint stimulation using focused ultrasound. SUBJECTS: Fifty (50) healthy volunteers (40 males and 10 females) were included in this experiment. DESIGN: Subjects were randomly assigned to two groups. LR-3 was stimulated bilaterally for 36 seconds by focused ultrasound and conventional acupuncture. Brachial artery blood flow volume was monitored by an ultrasound with an echo-tracking system. The hemodynamic parameters were measured before, during, and 30, 60, 180 seconds after stimulation. RESULTS: During stimulation, the blood flow volume of the acupuncture stimulation group decreased significantly (p<0.05) compared with resting value, but that of the focused ultrasound stimulation group did not decrease. Blood flow volume of both groups increased gradually and showed significant increase at 180 seconds after stimulation (p<0.05). CONCLUSIONS: Blood flow volume was increased significantly by both focused ultrasound stimulation and conventional acupuncture. Although a significant decrease of blood flow volume during acupuncture stimulation was observed, no such decrease was observed during ultrasound stimulation. Findings of the present study show that noninvasive stimulation of acupoints by focused ultrasound is as effective as conventional acupuncture in blood flow volume of the brachial artery.