In-vivo detection of bleeding simulated in a Peritoneal dialysis model using a hemiarray EIT configuration

Abstract

A new method to image and quantify intra-abdominal hemorrhage (IAH) using electrical impedance tomography (EIT) was tested. We proposed an electrode hemi-array placed exclusively on the anterior abdomen to monitor a supine patient for IAH without complicating concurrent traumatic injuries. Peritoneal dialysis (PD) was used as a model for IAH to assess the in vivo performance of the hemi-array. Using the EPack 2 data acquisition system, EIT measurements were recorded before, during, and after the administration of dialysate. Simultaneously, the amount of dialysate was recorded, synchronous to the EIT measurements, to be used as a control. Tomographic images of impedance change were reconstructed using a weighted, sensitivity-based method and then post-processed to obtain a quantitative estimate of the total dialysate administered. Our preliminary study included two subjects, one male and one female, each participating for two sessions, spaced about six months apart. Data collected from these sessions indicate that with a realized in vivo SNR of about 35dB the EPack 2 can detect accumulations larger than about 100mL with a quantification uncertainty of about +/- 50mL. Using these data we have developed new algorithms that can automatically detect the onset of bleeding in less than two minutes. This method shows promise for automated detection of other pathologies, e.g. ascites, and is adaptable for use on other anatomy including the skull, and pelvis.