gitated elements, 5-interdigitated elements and 13- interdigitated elements. Hence, this briefs us to design the antenna with various numbers of elements to achieve broadband to narrow band applications [Boby, Prajapati, Rathinasamy, Mukherjee, & Mondal (2022)]. 12.11 EXPERIMENTAL ANALYSIS THROUGH THZ SPECTROSCOPY AND IMAGING THz science with existing technologies has achieved a remarkable progress in med- ical diagnostics experimentally. The early detection and diagnosis of several diseases can be achieved using THz spectroscopy and imaging techniques. Among many pos- sibilities, two of the techniques of blood sugar measurement and tumor-cancer detec- tion are described below. 12.11.1 A NON-INVASIVE BLOOD SUGAR MEASUREMENT METHOD Non-invasive blood sugar measurement is possible using a THz time domain spectro- scopic technique through which diabetes can be diagnosed. In this investigation, sub-THz radiation (around 0.1THz) has been used because of its lower absorption of water in glu- cose solution. The concentration of glucose in the blood can be identified using reflect- ance measurement for measuring the blood glucose through this non-invasive technique. Detector (SBD) Horn antenna PTFE lens (f=84 @60 GHz) PTFE film Peristaltic pump Oscillator Flow cell Solution Thermostat bath FIGURE 12.17 Schematic diagram of the optical configuration showing the sub-THz reflection measurement system for measuring the glucose in blood using a non-invasive technique. Terahertz Antenna in Future Healthcare Informatics Figure 12.17 shows the schematic diagram of the optical configuration showing the sub-THz reflection measurement system for measuring the glucose in blood using a non-invasive technique. The semiconductor oscillator device emits THz radiation which is focused by a polytetrafluoroethylene (PTFE) lens to the flow cell. The blood sample is circulated onto the flow cell using a peristaltic pump. Hence, another PTFE lens focuses the THz beam after reflection from the flow cell. Finally, the reflected THz is detected 