You may wish to have your contribution take the form of a legacy or bequest, for which you should obtain proper advice.
A suitable clause in a Will to provide for a bequest would be on the following lines:

“I give and bequeath (free of all duty to the Otago Medical Research Foundation (Inc) the sum of $…………….. (or description of other property or assets) for research purposes that may relate to a diverse range of health problems including cancer and heart disease, AND I DECLARE that the receipt of the Secretaries or other proper officer thereof shall be a full and sufficient discharge to my Trustee for the said Legacy nor shall my Trustee be bound to see the application thereof.”