伴随神经动作电流沿神经轴索则产生微弱磁场,测定这种磁场就可以无接触地测定神经活动的传导速度和方向。最初是wikswo用SQUID磁通计进行了测量,后来他又利用环形线圈和低噪声放大器等实现了这种测量。本文介绍了简化了的低噪声低输入阻抗放大器的制作,讨论了三种环形线圈的基础性工 A weak magnetic field is generated along the axon of the nerve accompanied by a nerve movement current, and the magnetic field can be measured contactlessly to determine the conduction velocity and direction of the nerve activity. Originally wikswo was measured with a SQUID magnetometer, which he later implemented using toroidal coils and low-noise amplifiers. This article describes the production of a simplified, low-noise, low-input impedance amplifier and discusses the basic workings of the three toroidal coils