Quality of martensitic stainless steel type AISI-420 utilized in the manufacture surgical implements

Até o presente momento, o aço inoxidável martensítico do tipo AISI-420 é muito utilizado na confecção de ferramentas cirúrgicas. Tais ferramentas vêm apresentando corrosão prematura, identificada após processo de limpeza e esterilização, perda de corte e/ou quebra durante os processos cirúrgicos. Esse trabalho avalia esse aço sobre à composição química, dureza, microestrutura e resistência à corrosão por pite em solução de detergente enzimático diluída em água por polarização cíclica anódica. Essa mistura é utilizada na limpeza das ferramentas que são submersas por 2h nessa solução antes da lavagem e esterilização. Os resultados mostram aços com microestrutura composta de martensita com fase ferrita e impurezas. Os referidos aços apresentam baixos valores de potencial de pite em comparação aos aços com microestrutura totalmente martensítica que possuem maiores valores.Until now the martensitic stainless steel type AISI-420 is widely used in the manufacture of surgical implements. These implements present premature corrosion problems identified after cleaning, , sterilization and cutting edge loss and/or rupture during the surgical processes. This study evaluates the steel as to the chemical composition, hardness, microstructure and pitting corrosion resistance in a solution of enzyme detergent diluted in water by anodic cyclic polarization. This mixture is used in the cleaning of surgical implements that are submerged in this solution for 2 h before cleaning and sterilization. The results show steels with martensite microstructures in the ferrite phase, together wth impurities. These presented low pitting potential values in compariston to steels with a fully martensitic microstructure.Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)CNPqFAPES

Podometry: a critical evaluation of its use in Hansen's disease

The aim of this paper is to evaluate the effectiveness of podometry to measure the pressure developed over the feet and the value of these findings to help in the prevention of the plantar neuropathic ulcer in patients bearing Hansen's disease. We evaluated 13 patients with impaired plantar pain and touch sensations and 17 normal patients. All the patients were submitted to static evaluation using the podometer. The system employed was the "Midcapteur" commercial podometer composed of a platform for acquisition of analogic data capable of registering the segmental pressures applied to the feet. These data are read by a 386 IBM/PC compatible computer that registers the graphic patterns obtained from the pressures developed and also calculates the modes of pressure distribution in the four quadrants of the foot. These data obtained by means of static podometry were compared to the clinical evaluation of pain and touch sensation of the feet in hansenian patients. The results demonstrate that podometery is an efficient method for evaluating the pressure in impaired feet in Hansen's disease and is a progression of neuropathic ulcer; it is sensitive in the identification of the spots of increased pressure in anesthetic and anomalous areas, asymmetries and in correlating the presence of ulcers with increased pressure