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 for Mark to be her spokesman with family and friends. The poems make a narrative of love and loss, of fifty years of marriage vows renewed daily, and of Mark and Helen's unwavering and clear devotion to each other. Helen is Mark's Muse; she is his source of joy and love, a constant companion, the woman who reads his heart with the gift of perfect understanding.