  The heavy-quark expansion for inclusive semi-leptonic B decays introduces
$\bar{\Lambda}$ and $\lambda_1$, which are matrix elements in heavy-quark
effective field theory. We review how they can be obtained from an analysis of
the heavy quark mass dependence of heavy-light meson masses in lattice QCD. We
present preliminary results for the bottom quark mass, $m_b$, using
$\bar{\Lambda}$ and $\lambda_1$ for the $B_s$ meson from a 2+1 sea-flavor
unquenched calculation.
