In vivo Monitoring by EIT for the Pig’s Bleeding after Liver Injury

Abstract

Many reasons, such as traffic accident, abdomen post-operation, etc., may cause intraperitoneal bleeding. To further demonstrate the feasibility of non-invasive monitoring of EIT for intraperitoneal bleeding, pig’s bleeding model of liver injury was made. The pig’s liver was hurt by puncture needle manually so that the internal autobleeding process is continuous and nature, which resembles the clinical bleeding process of abdominal organ injuries.

Totally 5 cases of 3 month old pig’s bleeding of liver injury were monitored by EIT. In the experiments, 16 electrodes were placed around the skin-prepared abdomen, an alternating current (1mA, 50KHz) was applied on polar driven pattern, and the improved back-projection algorithm was used for image reconstruction. The EIT system imaged at 1 frame per second. The monitor time lasted about 40~120 minutes till the subject was dying or dead of hemorrhoea. After paunching each pig, the total bleeding volume was measured and it ranged from 450~870ml.

The imaging results show that after liver injury, the bleeding area in EIT images become redder and larger gradually with the bleeding process going on, indicating EIT could monitor the development of the pig’s liver bleeding dynamically and noninvasively.