Gallo Joseph A, Draper David O, Brody Lori Thein, Fellingham Gilbert W
Rocky Mountain University of Health Professions Graduate Program in Sports Research, Provo, UT, USA.
J Orthop Sports Phys Ther. 2004 Jul;34(7):395-401. doi: 10.2519/jospt.2004.34.7.395.
A repeated-measure crossover design was used. The independent variable was the type of ultrasound (pulsed or continuous) and the dependent variable was intramuscular temperature.
To compare changes in intramuscular temperature resulting from the use of pulsed ultrasound versus continuous ultrasound with an equivalent spatial average temporal average (SATA) intensity.
There is a lack of research on the heat-generating capabilities of pulsed ultrasound within human muscle.
The subjects were 16 healthy volunteers (mean age +/- SD, 21.3 +/- 2.5 years). Each subject was treated with pulsed ultrasound (3 MHz, 1.0 W/cm2, 50% duty cycle, for 10 minutes) and continuous ultrasound (3 MHz, 0.5 W/cm2, for 10 minutes) during a single testing session. Tissue temperature returned to baseline and stabilized between treatments and treatment order was randomized. Tissue temperature was measured every 30 seconds using a 26-gauge needle microprobe inserted at a depth of 2 cm in the left medial gastrocnemius muscle. Data were analyzed using a linear mixed model.
Treatment with continuous ultrasound produced a mean (+/-SD) temperature increase of 2.8 degrees C +/- 0.8 degrees C above baseline. Treatment with pulsed ultrasound produced a mean (+/-SD) temperature increase of 2.8 degrees C +/- 0.7 degrees C above baseline. Statistical analysis revealed no significant differences in either the extent or rate of temperature increases between the 2 modes of ultrasound application.
Pulsed ultrasound (3 MHz, 1.0 W/cm2, 50% duty cycle, for 10 minutes) produces similar intramuscular temperature increases as continuous ultrasound (3 MHz, 0.5 W/cm2, for 10 minutes) at a 2-cm depth in the human gastrocnemius. Spatial average temporal average intensity is an important consideration when selecting pulsed ultrasound parameters intended to deliver nonthermal effects.
采用重复测量交叉设计。自变量为超声类型（脉冲式或连续式），因变量为肌肉内温度。
比较使用脉冲超声与连续超声且空间平均时间平均（SATA）强度相等时肌肉内温度的变化。
关于脉冲超声在人体肌肉中产生热量的能力缺乏研究。
受试者为16名健康志愿者（平均年龄±标准差，21.3±2.5岁）。在单次测试过程中，每位受试者分别接受脉冲超声（3兆赫，1.0瓦/平方厘米，占空比50%，持续10分钟）和连续超声（3兆赫，0.5瓦/平方厘米，持续10分钟）治疗。两次治疗之间组织温度恢复至基线并稳定，治疗顺序随机。使用26号针式微探头在左内侧腓肠肌2厘米深处每30秒测量一次组织温度。数据采用线性混合模型进行分析。
连续超声治疗后平均（±标准差）温度比基线升高2.8℃±0.8℃。脉冲超声治疗后平均（±标准差）温度比基线升高2.8℃±0.7℃。统计分析显示，两种超声应用模式在温度升高程度或速率上均无显著差异。
在人体腓肠肌2厘米深处，脉冲超声（3兆赫，1.0瓦/平方厘米，占空比50%，持续10分钟）与连续超声（3兆赫，0.5瓦/平方厘米，持续10分钟）产生的肌肉内温度升高相似。在选择旨在产生非热效应的脉冲超声参数时，空间平均时间平均强度是一个重要考虑因素。
