* Corresponding author. E-mail: pugliesi@curiango.ipen.br. Nuclear Instruments and Methods in Physics Research A 424 (1999) 248 — 251 Inspection of an artificial heart by the neutron radiography technique R. Pugliesi*, L.P. Geraldo, M.L.G. Andrade, M.O.Menezes, M.A.S. Pereira, M.J.S. Maizato  Instituto de Pesquisas Energe & ticas e Nucleares, IPEN/CNEN-SP, Divisa J o de Fı & sica Nuclear, TFF, Caixa Postal 11.049, Pinheiros, CEP 05422-970 Sa J o Paulo, SP, Brazil  Divisa J o de Bioengenharia, Instituto do Corac 7 a J o, Hospital das Clı & nicas, Sa J o Paulo, SP, Brazil Abstract The neutron radiography technique was employed to inspect an artificial heart prototype which is being developed to provide blood circulation for patients expecting heart transplant surgery. The radiographs have been obtained by the direct method with a gadolinium converter screen along with the double coated Kodak-AA emulsion film. The artificial heart consists of a flexible plastic membrane located inside a welded metallic cavity, which is employed for blood pumping purposes. The main objective of the present inspection was to identify possible damages in this plastic membrane, produced during the welding process of the metallic cavity. The obtained radiographs were digitized as well as analysed in a PC and the improved images clearly identify several damages in the plastic membrane, suggesting changes in the welding process.  1999 Elsevier Science B.V. All rights reserved. PACS: 81.70.Dw Keywords: Neutron radiography; Non-destructive testing technique 1. Introduction The neutron radiography technique is largely employed to inspect several types of hydrogen-rich substances such as oil, water, plastics, adhesives, even wrapped by thick metal layers. This property has provided possibilities of application of the tech- nique in a large number of areas, particularly in medical field [1,2]. The heart research institute-INCOR, in Sa  o Paulo, is developing an artificial heart prototype, to provide blood circulation assistance for cardiacal patients who are in urgent need for a heart transplant surgery. It was observed in the opera- tional tests that some of such hearts presented internal blood leakage and additional inspections were necessary in order to clarify this circulation failure. 0168-9002/99/$ — see front matter  1999 Elsevier Science B.V. All rights reserved. PII: S 0 1 6 8 - 9 0 0 2 ( 9 8 ) 0 1 2 5 3 - 4