(a) If permitted in the bond order, any required part of the proceeds from the sale of the revenue bonds may be used to:
(1) pay interest on the bonds during the period of the construction of a hospital facility to be provided through the issuance of the bonds;
(2) pay operation and maintenance expenses of the facility to the extent and for the time specified in the bond order; and
(3) create reserves for the payment of the principal of and interest on the bonds.
(b) The bond proceeds may be invested until needed to the extent and in the manner provided by the bond order.