Correction of spinal deformities by extension and pressure was one of Avicenna's methods which remained in use for centuries. This refined apparatus was shown in famous surgical textbook by Johann Scultetus (1679). Abu 'Ali al-Husayn ibn 'Abd Allah ibn Sina (980-1037), commonly known as Ibn Sina or by his Latinized name Avicenna, was a Persian polymath, who wrote almost 450 treatises on a wide range of subjects, of which around 240 have survived. His most famous works are The Book of Healing, a vast philosophical and scientific encyclopedia, and The Canon of Medicine, which was a standard medical text at many medieval universities.