Qutb al-Din Shirazi in his commentary to Avicenna's "Qanoon" has clearly referred to Masihi as a physician who had been even more competent than Avicenna in his own time. He wrote other treatises on measles, on the plague, on the pulse, etc.
He was as his name indicates a christian Persian icon.
He died in a dust storm in the deserts of Khwarezmia in 1010.
Abu-Abdullah Muhammad ibn Īsa Māhānī 
