**6. Conclusions**

In this chapter, we dealt with ultra wideband sensing in medical engineering, i.e. using electromagnetic waves of large bandwidth for probing the human body and biological tissue. Sufficient penetration of the human body combined with antennas of manageable size were our major concern. Also, the frequency band from 1 GHz to 5…8 GHz turned out to be best suited for our purposes. By using active or dielectrically scaled antennas for this frequency range, they can be built sufficiently small. Wave propagation at these frequencies is mostly influenced by water, the most abundant component of biological tissue. The effect of salt becomes less detrimental above 1 GHz. Above 5…8 GHz, however, water absorption will drastically increase the propagation losses. The given frequency band also provides acceptable resolution for microwave imaging and ample micro-Doppler sensitivity.

ultraMEDIS – Ultra-Wideband Sensing in Medicine 315

This work was supported by the German Science Foundation (DFG) in the framework of the priority program UKoLoS (SPP 1202), project acronym ultraMEDIS. The authors appreciate the valuable contributions made by R. Herrmann, P. Rauschenbach and K. Schilling for sensor development, and helpful discussions; K. Borkowski and E. Hamatschek for electronic and mechanical component manufacturing; Ralf Stephan for his support in antenna design and measurement; Hartmut Günther and Stefan Barth for the manufacture of the ceramic antennas; Marina Sieler and Uwe Genatis for the galvanic metallization of the

[1] U. Pliquett, "Electricity and biology," in 11th International Biennial Baltic Electronics

[2] K. Nowak, W. Gross, K. Nicksch *et al.*, "Intraoperative lung edema monitoring by microwave reflectometry," *Interactive Cardiovascular and Thoracic Surgery*, pp. 540-544,

[3] J. Sachs, E. Zaikov, M. Helbig *et al.*, "Trapped Victim Detection by Pseudo-Noise Radar," in 2011 International Conference on Wireless Technologies for Humanitarian

[4] E. Zaikov, and J. Sachs, "UWB radar for detection and localization of trapped people,"

[5] J. Sachs, M. Helbig, R. Herrmann *et al.*, "Merkmalsextraktion und semantische Integration von Ultrabreitband-Sensoren zur Erkennung von Notfällen," in 3. Deutscher AAL-Kongress 2010 Assistenzsysteme im Dienste des Menschen, Berlin,

[6] R. Herrmann, J. Sachs, and F. Bonitz, "On benefits and challenges of person localization using ultra-wideband sensors," in Indoor Positioning and Indoor Navigation (IPIN),

[7] R. Herrmann, J. Sachs, K. Schilling *et al.*, "12-GHz Bandwidth M-Sequence Radar for Crack Detection and High Resolution Imaging," in International Conference on Ground

[8] R. Herrmann, "M-sequence based ultra-wideband radar and its application to crack detection in salt mines" PhD-Thesis, Faculty of Electrical Engineering and Information

[9] J. Sachs, "Ultra-Wideband Short-Range Sensing - Theory, Sensors, Applications", Berlin:

[10] M. A. Hein, C. Geyer, M. Helbig *et al.*, "Antennas for ultra-wideband medical sensor systems," in 3rd European Conference on Antennas and Propagation, EuCAP 2009,

[11] R.C. Hansen, "Fundamental Limitations in Antennas", in Proc. of the IEEE, vol. 69, n. 2,

Technology, Ilmenau University of Technology (Germany), Ilmenau, 2011.

Relief (ACWR 2011) Amritapuri, Kollam, Kerala, India, 2011, pp. 265-272.

*Ultra Wideband*, B. Lembrikov, ed., Rijeka, Croatia: Scivo, 2010.

2010 International Conference on, 2010, pp. 1-7.

Penetrating Radar (GPR), Birmingham, UK, 2008.

**Acknowledgement** 

**7. References** 

2011.

2010.

Wiley-VCH, 2012.

2009, pp. 1868-1872.

pp. 170-182, Feb. 1981

ceramic and MRI compatible antennas.

Conference, BEC 2008, pp. 11-20.

For experimental investigations, we exploited ultra-wideband pseudo-noise devices. They provide probing signals of very low power, thus avoiding damages to biological tissue. Furthermore, they provide sufficient dynamic range, measurement speed and short term stability for super resolution techniques of microwave imaging and weak-motion tracking.

We demonstrated medical applications of ultra-wideband sensing by three distinctive examples, each standing for a specific class of applications.


Remote or contact-based microwave imaging of inner organs or malignant tissue, for example the detection of breast tumors.
