  The quantum Ito formula has so far been proved for regular (bounded) quantum
semimartingales We give three different extensions to classes of essentially
self-adjoint (unbounded) quantum semimartingales.
  The first extension is to quantum semimartingales whose integrands have chaos
matrices controlled by certain scalar matrices
  The second extension is to perturbations of classical, possibly unbounded,
quantum semimartingales by bounded quantum semimartingales
  The third extension is obtained by perturbing an essentially self-adjoint
quantum semimartingale satisfying the quantum Duhamel formula by a regular
quantum semimartingle.
