Static state hemodynamic variables estimation model for the moving-actuator type total artificial heart. Part II - Aortic pressure estimation.

Aortic pressure (AoP) estimation is a very important study for the artificial heart. In this paper, we developed a AoP estimation model for the moving-actuator type total artificial heart (MH-TAH) that was being developed at Seoul National University Hospital. The proposed model is simple and provides beat-by-beat mean AoP estimation. Moreover, it uses non-invasively acquired signals. Model parameters were adjusted with in vitro data by least mean square (LMS) algorithm. Results showed that the proposed scheme gives a mean estimation error of about 8 (mmHg). This ensures the suitability of the proposed model. The proposed approach can also be applied to the model setup of pulmonary arterial pressure (PAP) estimation by using the symmetric characteristics between AoP and PAP.

Double-contrast radiographic assessment of lupus-associated enteropathy.

PURPOSE: To describe the double-contrast radiographic features of lupus-associated enteropathy. MATERIALS AND METHODS: Six patients with systemic lupus erythematosus involving the small bowel were assessed by double-contrast radiography of the duodenum and small intestine, with reference to clinical manifestations and jejunoscopic findings. RESULTS: Lupus-associated enteropathy could be categorized into two types: acute onset enteritis in four patients and protein-losing enteropathy with hyperlipidaemia in two patients. The former group presented with irregular thickening and spiculation in the folds of the multiple segments of the duodenum to the terminal ileum, and they were frequently accompanied by thumbprinting, suggestive of ischaemic change. The latter group was characterized by mildly thickened folds with multiple submucosal nodules in the upper portion of the jejunum. In one patient from this group, jejunal biopsy demonstrated lymphangiectasia. Both groups were successfully treated by high-dose prednisolone. Follow-up radiography in the former group showed a complete improvement within 2-7 weeks, whereas radiographic abnormalities in the latter remained even after 2 months. CONCLUSIONS: Lupus-associated enteropathy cases may be divisible into two types; an acute ischaemic enteritis type and a protein-losing enteropathy type, each presenting distinct radiographic features.