Luis Joseph, Park Eun Joo, Meyer Richard J, Smith Nadine Barrie
Graduate Program in Acoustics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
J Acoust Soc Am. 2007 Oct;122(4):2022-30. doi: 10.1121/1.2769980.
Circular cymbal ultrasound arrays have been shown to be effective in delivering therapeutic levels of insulin in rats, rabbits, and pigs. To improve delivery efficiency, a rectangular cymbal design was desired in order to achieve a broader spatial intensity field without increasing the size of the device or the spatial-peak temporal-peak intensity (I(SPTP)). With a similar intensity (50 mWcm(2)), the goal was to determine if the 3x1 rectangular cymbal array could perform significantly better than the 3x3 circular array for glucose reduction in hyperglycemic rabbits. Rabbit experiments were performed using three groups: nonsonicated control (n=3), ultrasound exposure using a circular cymbal array (n=3), and ultrasound exposure using a rectangular cymbal array (n=3). Rabbits were anesthetized and a water tight reservoir that held the insulin was fastened on the rabbit's thigh. At the beginning of the experiment and every 15 min for 90 min, the blood glucose level was determined. For comparison between individual rabbits, the absolute level is normalized by subtracting out the baseline in order to arrive at the change in glucose level. For the control group, the normalized glucose level increased (more hyperglycemic) to +80.0+/-28.8 mgdl (mean+/-SEM). Using the circular array, the glucose level decreased to -146.7+/-17.8 mgdl at 90 min. However, using the rectangular cymbal array, the glucose decreased faster and to a level of -200.8+/-5.9 mgdl after 90 min. These results indicated the feasibility of the rectangular cymbal array as an improved device for drug delivery.
圆形钹式超声阵列已被证明在向大鼠、兔子和猪体内输送治疗剂量的胰岛素方面是有效的。为了提高输送效率，需要一种矩形钹式设计，以便在不增加设备尺寸或空间峰值时间峰值强度（I(SPTP)）的情况下实现更宽的空间强度场。在强度相似（50 mW/cm²）的情况下，目标是确定3×1矩形钹式阵列在降低高血糖兔子的血糖方面是否能比3×3圆形阵列表现得明显更好。使用三组兔子进行实验：未进行超声处理的对照组（n = 3）、使用圆形钹式阵列进行超声照射的组（n = 3）以及使用矩形钹式阵列进行超声照射的组（n = 3）。兔子被麻醉后，将装有胰岛素的防水储液器固定在兔子大腿上。在实验开始时以及之后的90分钟内每隔15分钟测定一次血糖水平。为了在个体兔子之间进行比较，通过减去基线来对绝对水平进行归一化，以得出血糖水平的变化。对于对照组，归一化后的血糖水平升高（血糖更高）至 +80.0±28.8 mg/dl（平均值±标准误）。使用圆形阵列时，90分钟时血糖水平降至 -146.7±17.8 mg/dl。然而，使用矩形钹式阵列时，血糖下降得更快，90分钟后降至 -200.8±5.9 mg/dl。这些结果表明矩形钹式阵列作为一种改进的药物输送装置的可行性。
