Medical diagnostics using terahertz pulsed spectroscopy

Analysis and design of efficient passive components for the millimeter-wave and THz bands

“…The high absorption of THz energy by water implies high sensitivity to some diseases processes, and, although the strong absorption by water molecules causes low body penetration depth, this penetration seems to be enough for several kind of diagnostic purposes [60]. The use of THz-TDS has been observed as a powerful tool in studying teeth diseases [61], [62], skin diagnostics [63], [64], breast cancer diagnostic [65], [66], colon tissue cancers [67], or even ophthalmology [68].…”

“…Differences in THz spectra of healthy and diseased skin lead to appearance of contrast between healthy skin and sick tissues in parametrical images. Contrast is reported even in cases where the cancer lies at a small depth under the skin [60].…”

“…It is worth to mention Figure 2.15: T-ray imaging for medical applications 1. a) THz imaging of a human tooth revealing its interior structure and possible injuries [107]; b) Infiltrating carcinoma. Top image correspond to the photo of in vitro diseased skin and bottom image corresponds to the THz parametrical image of the cancer [60].…”

“…In fact, note that the environ- ments in which wire-type are though to operate do not contemplate a large number of bends, as much two or three. Consider for instance the case of scanning some inner tissues of the human body in order to get its spectral response (examples similar to those exposed in [60]- [68]). It could be foreseen wire-type structures prepared to be bent in such sections implementing the proposed designs 3 , and it seems apparently enough to provide two and as maximum three changes of direction if the access to the tissue is well provided.…”

“…Actually, extensive review of the literature indicates that there are three main attractive bands in general. First, one has the spectrum around 60 GHz, the [57][58][59][60][61][62][63][64] applications. Therefore, in this last case, although there is significant bandwidth to exploit, its uneven allocation and the proximity to the military bands may suppose a handicap in the future use.…”