A preliminary in vivo study of a method for measuring magneto-acoustic sonic source under electrical stimulation

Abstract

BACKGROUND: Stimulating current distribution in the tissue is unknown due to the complex distribution. OBJECTIVE: A preliminary in vivo measurement of the magneto-acoustic (MA) signal of the human finger is performed in this study. The approach for locating the magneto-acoustic source of the stimulating current is studied. METHODS: We use a lock-in amplifier to measure the MA signal under continuous wave electrical stimulation. The phase of the MA signal is used to extract the location of the sonic source. The experimental system is designed to measure the MA signal under electrical stimulation. RESULTS: Preliminary experiments results show that the amplitude precision is improved to less than 1 µPa. The sonic source is located with millimetre precision. CONCLUSIONS: We propose a new MA source-locating method with high measurement and location precision. This method will be significant to the study of the imaging and monitoring of the current distribution of electrical stimulation with high precision.

A Preliminary Study on Non-Invasive Detection of Electrical Stimulation Current Based on Magneto-Acoustic Effect

“…Compared with the current reports of simple one-dimensional sample MA sound source detection under electrical stimulation, the amplitude measurement accuracy is 10 −6 Pa magnitude [29]. In this study, the sound field measurement of pig brain tissue and two-dimensional samples with simulated skull brain tissue is carried out.…”

“…Therefore, the detection method of lock-in amplification is proposed to extract the magneto-acoustic signal with highprecision [27]- [29]. However, because lock-in amplification can only measure the amplitude and phase of magneto-acoustic signal, it is difficult to image the excitation current through limited data.…”

A Review on the Coupled Method of Using the Magnetic and Acoustic Fields for Biological Tissue Imaging

“…Based on this method, an in vivo measurement device was built in 2020, as shown in Fig. 4, to receive signals from human fingers [30] . Meanwhile, time-frequency characteristics of the image reconstruction based on the magneto-acoustic effect were analyzed, and a wave superposition method was proposed for sound sources based on the Green's function solution [31] .…”