The recent definitions on intra-abdominal pressure (IAP), intra-abdominal volume (IAV) and abdominal compliance (C ab ) are a step forward in understanding these important concepts. They help our understanding of the pathophysiology, aetiology, prognosis, and treatment of patients with low C ab . However, there is still a relatively poor understanding of the different methods used to measure IAP, IAV and C ab and how certain conditions may affect the results. This review will give a concise overview of the different methods to

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Maintaining an appropriate inventory of packaged blood products is a critical part of modern medicine. Consequently, the assessment of red blood cell (RBC) functionality is instrumental for the monitoring of the quality of stored RBC (sRBC) in the blood bank. We present a comprehensive study of sRBC lesion kinetics in SAGM (saline, adenine, glucose, mannitol) solution, using microwave dielectric spectroscopy (0.5-50 GHz) and cell deformability. As part of the research, we have isolated the microwave dielectric response of cytoplasmic water in sRBC. The extracted dielectric parameters are sensitive to the age of the cells and, in particular, to the critical moment of transition from discocyte to echinocyte. From the analysis of the dielectric relaxation as a function of storage-duration, we postulate that the behavior is rooted in the delicate interplay between bound and bulk water in the cellular interior. In particular, the microwave dielectric response reflects the moment when the continuous diffusion of oxygen to the cell and the oxygenation of hemoglobin affects the role played by water in the maintenance of cell integrity. These results open a possible new avenue for the noninvasive inspection of stored red blood cells, permitting a true inventory system for the modern blood bank.

Monitoring intra-abdominal pressure (IAP) has become a standard in intensive care units. Correlation between the abdominal wall's thickness (AWTh) and IAP has been reported previously. The abdominal wall can be modeled as a compound of parallel dielectric slabs; changes in their width have a direct effect on the reflection coefficient of the abdominal wall at microwave frequencies. This work describes the design of a reflectometry system and its proof-of-concept trial on five patients during laparoscopic surgery. The system complies with IEEE Std. C95.1-2005 concerning exposure of humans to microwave electromagnetic fields in controlled environments. The results putatively show an inverse correlation between IAP and the reflection coefficient, and a strong dependence on the body mass index. A better understanding of the dynamics in the changes of the AWTh (during intra-abdominal hypertension) will allow further development of a microwave-based technique for the continuous non-invasive indirect monitoring of IAP in critical patients.