NET WORTH: $1.55 billion +7%

LAST YEAR: $1.45 billion

AGE: 63

RESIDENCE: Los Angeles

SOURCE OF WEALTH: Surgical devices, investments

THE MONEY: Spinal surgeon and medical device inventor’s wealth built on more than $1.3 billion patent settlement from Medtronic for surgery innovations. Has gained from investments in energy and distressed real estate.

BUZZ: Windfall from Medtronic settlement provided inventor resources to encourage creative solutions to social needs, including animal welfare, medical research and environmental reclamation. Latest passion is promoting digital textbooks in college classrooms to lower costs for struggling students. Million Minds Foundation seeks to create library of low-cost and free digital textbooks. Michelson is owner of several rescue animals and is offering $25 million award for safe nonsurgical means to sterilize pets. Gary Karlin Michelson Charitable Foundation provides seed funding for promising medical innovators who can’t find money elsewhere. In Panama and Costa Rica, Michelson has planted more than 50 square miles of teak trees on former clear-cut rain forest. Continues to earn money through Karlin Asset Management investment vehicle. Made money during recession on oil and gas futures, and drilling rights. Was an early investor in distressed real estate and now makes bridge loans that enable developers to buy back higher-interest notes and loans and move forward on projects. Philadelphia native inspired to become surgeon after grandmother developed rare spinal condition. Holds 600 U.S. and foreign patents, many developed in garage lab after finishing his hospital rounds at Inglewood’s Centinela hospital.