Limits...
Two 27 MHz Simple Inductive Loops, as Hyperthermia Treatment Applicators: Theoretical Analysis and Development.

Kouloulias V, Karanasiou I, Koutsoupidou M, Matsopoulos G, Kouvaris J, Uzunoglu N - Comput Math Methods Med (2015)

Bottom Line: The specific absorption rate (SAR) distributions were estimated from the respective local phantom temperature measurements.Comparisons of the theoretical, simulation, and experimental studies showed satisfying agreement.The penetration depth was measured theoretically and experimentally in the range of 2-3.5 cm.

View Article: PubMed Central - PubMed

Affiliation: 2nd Department of Radiology, ATTIKON University Hospital, Medical School, University of Athens, Rimini 1, Haidari, 124 64 Athens, Greece ; Microwave and Fiber Optics Laboratory, School of Electrical and Computer Engineering, Institute of Communication and Computer Systems, National Technical University of Athens, Heroon Polytechniou 9, 15780 Zografou, Greece ; 1st Department of Radiology, Aretaieion University Hospital, Medical School, University of Athens, Vassilissis Sofias 76, 115 28 Athens, Greece.

ABSTRACT

Background: Deep heating is still the main subject for research in hyperthermia treatment.

Aim: The purpose of this study was to develop and analyze a simple loop as a heating applicator.

Methods: The performance of two 27 MHz inductive loop antennas as potential applicators in hyperthermia treatment was studied theoretically as well as experimentally in phantoms. Two inductive loop antennas with radii 7 cm and 9 cm were designed, simulated, and constructed. The theoretical analysis was performed by using Green's function and Bessel's function technique. Experiments were performed with phantoms radiated by the aforementioned loop antennas.

Results: The specific absorption rate (SAR) distributions were estimated from the respective local phantom temperature measurements. Comparisons of the theoretical, simulation, and experimental studies showed satisfying agreement. The penetration depth was measured theoretically and experimentally in the range of 2-3.5 cm.

Conclusion: The theoretical and experimental analysis showed that current loops are efficient in the case where the peripheral heating of spherical tumor formation located at 2-3.5 cm depth is required.

No MeSH data available.


Related in: MedlinePlus

Internal detail of the cylindrical waveguide.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4663302&req=5

fig5: Internal detail of the cylindrical waveguide.

Mentions: For the construction of the phantom the transmission line theory was used, based on the measurements of the phantom's dielectric properties. Basically, the problem is the measurement of variables α and β which constitute the real and the imaginary part of the propagation constant (γ). For this purpose, the coaxial line method was used [15, 16]. The coaxial line had 42.5 cm length and 10 cm diameter and its internal details are depicted in Figure 5, where (E) is the signal input, (Δi) with i = 1 to 6 is the sampling, (Y) is the dielectric material, (T) is the termination of the line, and (A) is the reference measurement.


Two 27 MHz Simple Inductive Loops, as Hyperthermia Treatment Applicators: Theoretical Analysis and Development.

Kouloulias V, Karanasiou I, Koutsoupidou M, Matsopoulos G, Kouvaris J, Uzunoglu N - Comput Math Methods Med (2015)

Internal detail of the cylindrical waveguide.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4663302&req=5

fig5: Internal detail of the cylindrical waveguide.
Mentions: For the construction of the phantom the transmission line theory was used, based on the measurements of the phantom's dielectric properties. Basically, the problem is the measurement of variables α and β which constitute the real and the imaginary part of the propagation constant (γ). For this purpose, the coaxial line method was used [15, 16]. The coaxial line had 42.5 cm length and 10 cm diameter and its internal details are depicted in Figure 5, where (E) is the signal input, (Δi) with i = 1 to 6 is the sampling, (Y) is the dielectric material, (T) is the termination of the line, and (A) is the reference measurement.

Bottom Line: The specific absorption rate (SAR) distributions were estimated from the respective local phantom temperature measurements.Comparisons of the theoretical, simulation, and experimental studies showed satisfying agreement.The penetration depth was measured theoretically and experimentally in the range of 2-3.5 cm.

View Article: PubMed Central - PubMed

Affiliation: 2nd Department of Radiology, ATTIKON University Hospital, Medical School, University of Athens, Rimini 1, Haidari, 124 64 Athens, Greece ; Microwave and Fiber Optics Laboratory, School of Electrical and Computer Engineering, Institute of Communication and Computer Systems, National Technical University of Athens, Heroon Polytechniou 9, 15780 Zografou, Greece ; 1st Department of Radiology, Aretaieion University Hospital, Medical School, University of Athens, Vassilissis Sofias 76, 115 28 Athens, Greece.

ABSTRACT

Background: Deep heating is still the main subject for research in hyperthermia treatment.

Aim: The purpose of this study was to develop and analyze a simple loop as a heating applicator.

Methods: The performance of two 27 MHz inductive loop antennas as potential applicators in hyperthermia treatment was studied theoretically as well as experimentally in phantoms. Two inductive loop antennas with radii 7 cm and 9 cm were designed, simulated, and constructed. The theoretical analysis was performed by using Green's function and Bessel's function technique. Experiments were performed with phantoms radiated by the aforementioned loop antennas.

Results: The specific absorption rate (SAR) distributions were estimated from the respective local phantom temperature measurements. Comparisons of the theoretical, simulation, and experimental studies showed satisfying agreement. The penetration depth was measured theoretically and experimentally in the range of 2-3.5 cm.

Conclusion: The theoretical and experimental analysis showed that current loops are efficient in the case where the peripheral heating of spherical tumor formation located at 2-3.5 cm depth is required.

No MeSH data available.


Related in: MedlinePlus