Analysis of specific absorption rate in biological tissue surrounding transcutaneous transformer for an artificial heart

Externally-coupled transcutaneous energy transmission for a ventricular assist device-Miniaturization of ferrite core and evaluation of biological effects around the transformer

“…The ECTT is assumed to be attached to the body. The biological tissue has three layers: skin (a thickness of 3 mm), fat (a thickness of 5 mm), and muscle (100 × 100 × 100 mm 3 )he authors previously studied how electromagnetism influences biological tissue using the ECTT as a function of the dimensions (primary and secondary coil are also together) [5]. However, electromagnetic influences on biological tissue are the electrical insulation, the secondary coil had a silicone coating with a thickness of 3.5 mm [12].…”

“…We have developed a transcutaneous energy transmission (TET) system, which transfers energy via electromagnetic induction between two coils of a transcutaneous transformer placed on each side of the skin over the pectoralis major muscle [2][3][4]. As one of several possible methods, the externally-coupled transcutaneous transformer (ECTT) is studied in this paper [5][6][7]. However, the ferrite cores of the ECTT in conventional studies are too large.…”

“…Moreover, the authors have studied how electromagnetism influences biological tissue via the ECTT. For example, the thermal effects caused by electromagnetic waves and the specific absorption rate (SAR) surrounding the ECTT were studied using a homogeneous biological tissue model [5,8]. However, the electromagnetic influences on biological tissue, which are called dosimetry estimations, were not evaluated using detailed human body models but were instead evaluated using a simple calculation.…”

“…In this paper, we evaluated how the electromagnetism influences the biological tissue from the ECTT as a function of the dimensions of the cross-sectional area of ferrite cores designed from both conventional studies and a version scaled down by 0.45[5]. The large model had outer and inner diameters of 38.0 and 22.0 mm, respectively; a thickness of 14 mm; and a cross-sectional area of 112.0 mm 2 .…”

Analysis of Current Density and Specific Absorption Rate in Biological Tissue Surrounding Transcutaneous Transformer for an Artificial Heart

“…These indices have the basic restrictions defined by the International Commission on nonionizing radiation protection (ICNIRP) [14]. Therefore, the authors have studied the thermal effect caused by electromagnetic waves and have analyzed SAR surrounding an externally coupled type of transformer via the transmission-line modeling (TLM) method at a frequency of only 100 kHz [15]. The evaluations of SAR and current density surrounding an air-core transcutaneous transformer have not been investigated and safe transmission conditions have not been known.…”