Research also included dissection and of the failure modes of explanted pacemakers of any manufacturer. Most failures were due to an internal short circuit of one of the cells of the multicell battery due to the growth of metallic dendrites; or the result of water vapour diffusing though the epoxy resin encapsulation. The only suitable cell available at the time was the mercuric oxide-zinc cell, so the battery problems remained. In 1967 Telectronics commenced research into the technologies which could allow hermetic sealing of the pacemaker to preclude water vapour penetration and, as an interim measure contracted AWM a subsidiary of Amalgamated Wireless Australia Limited (AWA) to develop integrated circuits for the electronics. These early integrated circuits were developed by David R Money who later joined Telectronics and later still led development of the cochlear implant for the profoundly deaf. The circuits were analogue type, housed in hermetically sealed ceramic military 'flat packs' with redundant double gold bonding of the terminations. The IC's were first used in the model P7 of 1969.