We employ iSimp available in https://research.bioinformatics.udel.edu/isimp/
Peng,Y., Tudor,C., Torii,M., Wu,C.H., Vijay-Shanker,K. (2012) iSimp: A Sentence Simplification System for Biomedical Text. In Proceedings of the 2012 IEEE International Conference on Bioinformatics and Biomedicine. 211-216.