Tides Of Change - Paperbackby Mark Tochen (Author) Tides of Change is a collection of poetry by Mark Tochen, a retired pediatrician and life long writer. This book is dedicated to Mark's wife Dr. Helen Tochen, a pediatrician, hematologist, and blood bank specialist throughout a distinguished medical career. Helen is Mark's mainstay and the mother of their two children. She was diagnosed with Alzheimer's syndrome in 2016, and this book of poetry was written to honor Helen and