Electromagnetic–Acoustic Sensing for Biomedical Applications

Abstract

This paper reviews the theories and applications of electromagnetic–acoustic (EMA) techniques (covering light-induced photoacoustic, microwave-induced thermoacoustic, magnetic-modulated thermoacoustic, and X-ray-induced thermoacoustic) belonging to the more general area of electromagnetic (EM) hybrid techniques. The theories cover excitation of high-power EM field (laser, microwave, magnetic field, and X-ray) and subsequent acoustic wave generation. The applications of EMA methods include structural imaging, blood flowmetry, thermometry, dosimetry for radiation therapy, hemoglobin oxygen saturation (SO2) sensing, fingerprint imaging and sensing, glucose sensing, pH sensing, etc. Several other EM-related acoustic methods, including magnetoacoustic, magnetomotive ultrasound, and magnetomotive photoacoustic are also described. It is believed that EMA has great potential in both pre-clinical research and medical practice.

Photoacoustic molecular imaging using combined acupuncture and gold nanorods as a composite contrast agent

“…[1][2][3][4][5][6][7] This in vivo brain functional imaging technique has the following unique advantages: (1) it is an noninvasive imaging mode which is conducted in accordance with ethical principles; (2) animals can maintain normal physiological activity during imaging; (3) it has adequate spatial resolution (up to tens of m), temporary resolution (up to tens of ms) and limited depth of penetration (up to several mm, with intact scalp) in monitoring the brain; (4) it provides high-resolution functional information, such as hemoglobin and blood oxygenation levels relevant to describing physiology and pathology. 6,[8][9][10][11][12][13][14][15][16][17][18][19][20] PAT of small animal brain has successfully been implemented. 3,[8][9][10][11][12][13] In these studies, PAT was used for mapping the microvascular network of a mouse brain with the hemodynamic activities when the scalp and skull were intact.…”

“…6,[8][9][10][11][12][13][14][15][16][17][18][19][20] PAT of small animal brain has successfully been implemented. 3,[8][9][10][11][12][13] In these studies, PAT was used for mapping the microvascular network of a mouse brain with the hemodynamic activities when the scalp and skull were intact. 8,[10][11][12][13] Resting-state functional connectivity (RSFC) has been studied in the mouse brain using PAT.…”

“…3,[8][9][10][11][12][13] In these studies, PAT was used for mapping the microvascular network of a mouse brain with the hemodynamic activities when the scalp and skull were intact. 8,[10][11][12][13] Resting-state functional connectivity (RSFC) has been studied in the mouse brain using PAT. 8,11 PAT was able to detect connectivity between di®erent functional regions and even between sub-regions.…”

Electromagnetic Medical Sensing

“…This Special Issue also includes three reviews. Two of them discuss glucose sensing and monitoring: non-invasive electromagnetic sensing of glucose [7], and invasive to minimally-invasive to non-invasive techniques, devices and sensors for glucose monitoring [8], whereas the third review investigates electromagnetic–acoustic biomedical sensing [9].…”

“…The paper [9] reviews the theories and applications of different electromagnetic-acoustic techniques. The investigated techniques include light-induced, microwave-induced, thermo-acoustic, magnetic-modulated thermo-acoustic, and X-ray-induced thermo-acoustic methods.…”