## 2 State of the Art
### Related Work
\begin{table}
\begin{tabular}{|l|c|c|c|c|c|} \hline  & & & & \multicolumn{3}{c|}{**Network Segments**} \\ \cline{5-8}
**Project Name** & **Medical Area** & **Ubiquity Level** & & \\  & **Area** & **Ubiquity Level** & & & \\ \cline{5-8} [PERSON] _et al._ [2005–2006] [26, 27] & General purpose & Wide Area and self-monitoring & Z & WF,B, U & C \\ HealthGear [2006] [28] & Sleep & Self-monitoring & B & & \\ MERMOTH [2006] [29] & General purpose & Wide Area and self-monitoring & eT & WF & I \\  & & & & & \\ MyHeart [2006] [30] & Cardiac & Wide Area and self-monitoring & Wd & B & C \\ AUBADE [2006] [31] & Behavior & Controlled area & Wd & WF,B & \\ C. [PERSON] _et al._ [2006] [32] & Cardiac & Controlled area & Ws & Wd, & \\ SmartVest [2007] [33] & General purpose & Controlled area & Ws & U & \\ Human++ [2007] [34] & General purpose & Controlled area & Ws & U & \\ Personal Health Monitor [2007] [35] & General purpose & Wide Area and self-monitoring & B & & C \\ [PERSON] _et al._ [2008] [36] & Cardiac & Controlled area & 15.4 & & \\ [PERSON] et al. [2008] [37] & Cardiac & Wide Area & 15.4 & & C \\ MASN [2008] [38] & Cardiac & Controlled area & Wd & 15.4 & \\  & & Wide Area and self-monitoring & A & B, WF & C \\ HeartToGo [2009] [40] & Cardiac & Self-monitoring & Wd & B & \\ [PERSON] _et al._ [2009] [41] & Brain & Wide Area & Z & & I \\ [PERSON] _et al._ [2009] [42] & General purpose & Self-monitoring & eT & 15.4 & \\ [PERSON] _et al._ [2009] [43] & Falls & Wide Area & Z & & C \\ LOBIN [2010] (Study CASE) [44] & Cardiac & Controlled area & eT & 15.4 & I \\ [PERSON] _et al._ [2010] [45] & General purpose & Controlled area & MICS & WMTS & I \\ MEDISN [2010] [46] & General purpose & Controlled area & 15.4 & 15.4 & I \\ [PERSON] _et al._ [2011] [47] & Cardiac & Self-monitoring & B & WF & C \\ [PERSON] _et al._ [2011] [48] & Posture & Controlled area & Ws & & \\ [PERSON] _et al._ [2011] [49] & Posture & Controlled area & 15.4 & & \\ [PERSON] _et al._ [2011] [50] & Activity & Controlled area & 15.4 & & \\ [PERSON] _et al._ [2011] [51] & Cardiac & Wide Area & Wd & B & C \\ GeM-REM [2011] [52] & Cardiac & Wide Area & Ws & & C \\ [PERSON] _et al._ [2011] [53] & Sleep & Wide Area and self-monitoring & Wd & B & * \\ KNOWME [2012] [54] & Activity & Wide Area & B & & C \\ \hline \end{tabular}  
* B: Bluetooth; C: Cellular Network (e.g., GSM, GPRS; UMTS); eT: e-textile or integrated conductive yarns; I: Regular Internet connection (e.g., ADSL, cable); U: USB; Wd: Wired; WF: Wi-Fi; Ws: Wireless proprietary/not specified; Z: Zigbee; 15.4: IEEE 802.15.4; *: See appropriate table.  
\end{table} 
Table 2.  
In Table 2, systems are first classified according to the \"Medical Area\" they are designed for into broad sense categories. Specific target application can be found in the individual project descriptions. This classification criterion must not be used to get an impression of the medical field interest of the researchers on WHMS, since only those projects elaborating on the architecture and communications technologies have been considered. It is worthwhile to mention that projects belonging to the General Purpose and Cardiac categories have in common the monitoring of heart related physiological parameters. The distinction is made because projects assigned to the latter category are focused on such organ and only track heart related parameters while those assigned to the former also consider other kind of medical parameters to evaluate the overall health status. As previously stated in Section 1, an essential feature of WHMS is pervasiveness. Such a feature can appear in different flavors depending on the specific target application, justifying the classification criterion denominated as \"Ubiquity Level\". According to it, three categories can be distinguished, namely \"Controlled Area\", \"Wide Area\" and \"Self-Monitoring\". \"Controlled Area\" and \"Wide Area\" systems have in common the presence of medical specialists playing the role of information users.