If I remember correctly he was structuring a derivative contract based on life expectancy/actual life time. The goal was to hedge risks between health insurers and life insurance policies.

Life insurance policies policies want to offset the risk of a group dying prematurely in the defined time window and health insurance companies want to offset risk a group of people living long but with signifiant health problems.

At the time it didn't go anywhere because some folks dubbed it "Death Derivatives" and he was working on it at the mortgage crisis was unfolding.