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Biomedical
7T  Head Coil
B1+ field in a 7T (300 MHz) birdcage coil.

 7 element spinal array tuned and matched at 3T
The 3T spinal array was tuned and matched,
the optimiser was used to reduce cross-coupling.
telemetry performance of folded helical dipole implant at 2.45 GHz
Telemetry performance at 2.45 GHz of an 
implant, which is injected into the fat layer
between a layer of skin and muscle.
SAR calculation for a mobile phone
SAR calculation from a mobile phone,
including the influence of user's hand.
RX antenna simulated with the Hugo anatomical model
Receive antenna for implant telemetry in
the MICS band, simulated with the
Hugo anatomical model

Introduction

Computational electromagnetics often plays a vital role in the development of biomedical technologies, where simulation offers valuable insight into the interactions of EM-fields inside or in the close proximity to the body. Due to the lossy nature of biological tissue, transmitter design typically focuses on ensuring that sufficient signal is radiated and not lost in the anatomical load, while complying to regulations that limit the specific absorption rate (SAR) and maximum thermal increase in the body.

FEKO offers a range of different methods which are suitable for these applications. While the MoM offers efficient and accurate solutions for most or all structures, FEM excels at simulation of complicated inhomogeneous dielectric geometries, such as human bodies. The hybridisation of these two methods, which comes at no extra cost in FEKO, is a natural choice for the biomedical simulations.

The MoM can be employed to design or analyse the performance of the radiating structure. Dielectric sheets or coatings can also be analysed efficiently, and a dielectric half space can be used to mimic an anatomical load as an intermediate simulation step. The final simulation of the radiator and detailed anatomical phantom can be analysed with the hybrid MoM/FEM, providing accurate field calculations inside the body.


Typical Applications

  • Hearing aids, body worn antennas and body area networks (BAN)
  • MRI and other microwave imaging technologies
  • Active and passive implants including pacemakers, neural implants, stents, and biosensors
  • Hyperthermia and RF tissue ablation
  • Dosimetry, SAR and safety analysis
  • Mobile phones, PDAs, tablets, Bluetooth headset and other mobile devices
  • Mobile phone base station compliance analysis
  • Calculation of RF fields inside automobiles


Specific Absorption Rate (SAR) Evaluation

FEKO has been thoroughly verified through measurements as well as comparisons to other CEM codes for field calculations inside dielectric volumes. Special routines have been implemented for the extraction of the spatial peak average SAR according to the ICNIRP compliance regulations. SAR averaging can also be calculated using parallel processing.


FEKO Phantom Model Database

A range of surface and volume mesh human body models are available at no extra cost to logged-in users in the support area.

The hybrid MoM/FEM is particularly suitable for cases where there is a free space region of arbitrary size between the antenna and the dielectric body, where the advantage is that the free space between the MoM region (antenna) and the FEM region (dielectric body) does not have to be discretised.

For some applications it may not be required to use anatomical phantoms. For example, SAR (Specific Absorption Rate) compliance regulations are typically based on generic phantoms filled with tissue simulating liquid. In this case the phantom load can be modelled in FEKO and simulated using either the MoM (SEP) or the FEM.

Articulated_human_SEP-1.jpg
Standing_human_FEM-1.jpg
Articulated_hand-1.jpg
IEEE_SAM_SEP_10mm-1.jpg
Articulated (parametric)    
Human (SEP and FEM)    
Articulated Hand (SEP)
   
IEEE Head (SEP)

 

VisibleHuman_full_model_8mm-1.jpgManStandingSlicedFrontView   
VisibleHuman_Head_and_shoulders_8mm-1.jpg   
VisibleHuman_Head_4mm-1.jpg   
IEEE_SAM_FEM_5mm-1.jpg   
Hugo_5media_8mm-1.jpg
Visible Human Full Model
(Inhomogeneous FEM)

Visible Human
Head and Shoulders
(Inhomogeneous FEM)

Visible Human Head
(Inhomogeneous FEM)

IEEE SAM
(Homogeneous FEM)

Hugo 4 organs (FEM)
Additional Information

Additional Information