Figure 2.

Hidden Markov model with only one observation. $\mathit{\pi }$ denotes the healthy starting state. Horizontal arcs represent the transitions from a state. ($\mathit{x}\left[t-1\right]$) to the state at the next time step ($\mathit{x}\left[t\right]$). The final state is then diagnosed (vertical arc, parametrized via sensitivity and specificity) and we observe $\mathit{z}$.