Developing technology for imaging cancer tumors and sentinel lymph nodes utilizing sonic wave emission by magnetically stimulated particles

为了应用于通过磁刺激粒子发射声波的前哨淋巴结映射，我们开发了新的设备，该设备仅使用一个麦克风即可实现3D磁性粒子成像。它们是（1）兔耳反射器麦克风（BERM），其中麦克风安装在反射器的非对称位置上，并且分析了直接传播和由反射器反射的突发声波的脉冲响应。（2）随机路径全息声传感器，分析了突发超声波通过传声器头上随机分布的小孔（最大长度序列后）传播的脉冲响应。模拟实验证实了我们的新设备的工作原理。我们还开发了“两步配体交换反应”，通过该反应，我们成功地合成了具有窄尺寸分布的铁氧体珠;当它们的平均尺寸为20 nm时，它们显示出强烈的磁声效应，并且它们以高效率聚集在小鼠的第一淋巴结（伪前哨淋巴结）。

In order to apply to sentinel lymph node mapping by emission of acoustic waves by magnetically-stimulated particles, we developed new devices which will enable 3D magnetic particle imaging by using only one microphone. They are(1) Bunny ear Reflector Microphone(BERM) in which a microphone is mounted on a asymmetric position of a reflector and the impulse response of burst acoustic waves propagated directly and reflected by the reflector is analyzed. And(2)"Random Path Holophonic Sensor" in which the impulse response of burst ultrasonic waves propagated through the small apertures distributed randomly(after maximal-length sequences) on a microphone head is analyzed. Simulation experiments confirmed the operation principle of our new devices. We also developed "two-step ligand exchange reaction", by which we successfully synthesized ferrite beads with narrow size distribution ; when their average size was 20 nm they showed strong magneto-acoustic effect and they were accumulated at the first lymph nodes(pseudo sentinel lymph nodes) of a mouse at a high efficiency.