Theoretical Investigation of Ultra-WideBand (UWB) Penetration Through Biological Tissues
S Han-Oh1*, E Oh2, (1) Johns Hopkins University, Baltimore, MD, (2) U.S. Naval Research Lab, Washington, D.C.SU-E-J-62 Sunday 3:00PM - 6:00PM Room: Exhibit Hall
Purpose: The UWB is a radio-frequency electromagnetic pulse with width around nanosecond encompassing 3.1-10.6 GHz frequencies. The UWB is currently used in remote sensing as through-the-wall imaging technology. To develop this technology into through-the-body tumor-detection technology, first, we theoretically investigate whether the UWB pulses can penetrate through human tissues such as skin, muscle, bone, fat, and lung. Specifically we want to calculate which frequencies can penetrate deeper through human tissues.
Methods:We theoretically relate the complex permittivity with the complex index of refraction and obtain the reflection and transmission coefficients for skin, muscle, bone, fat, and lung. We use an experimentally-measured complex permittivity from the published source¹ as input to our numerical model. We calculate 1/e penetration depth, which is equivalent to 36.7% of initial radar power, for each frequency, from air to each tissue as an indicator of penetration capability of the UWB.
Results:Our results show that lower UWB frequency (3 GHz) is better at penetrating through the human tissues than higher frequency (10 GHz). We find 1/e penetration depth for human skin, muscle, fat, bone, and lung to be 4.45, 4.67, 0.49, 2.61, and 2.38 cm for 3 GHz, respectively. At 10 GHz, the 1/e penetration depths are reduced significantly to 0.17, 0.13, 0.33, 0.21, 0.19 cm, respectively. This result indicates that it is better to design a UWB radar system with higher power at lower frequencies.
Conclusion:We find that lower frequencies of the UWB can penetrate deeper into human tissues. This result will be used to design a future experiment for further investigation of the UWB radar as a new modality for lung-tumor detection.
1. Gabriel et al. The dielectric properties of biological tissues: I. Literature survey Phys. Med. Biol. 41(11) 2231-2249