Development and validation of a measurement system for continuously monitoring postoperative reservoir levels

AbstractFollowing cardiac surgical procedures, multiple drainage systems remain in place inside the patient ’s chest to prevent the development of pericardial effusion or pneumothorax. Therefore, postoperative bleeding must be diligently observed. Currently, observation of the exudate rate is performed through periodical visual inspection of the reservoir. To improve postoperative monitoring, a measurem ent system based on load cells was developed to automatically detect bleeding rates. A reservoir retaining bracket was instrumented with a load cell. The signal was digitized by a microcontroller and then processed and displayed on customized software written in LabView. In cases where bleeding rate s reach critical levels, the device will automatically sound an alarm. Additionally, the bleeding rate is displayed on the screen with the status of the alarm, as well as the fluid level of the reservoir. These data are all logged to a file. The measurement system has been validated for gain stabili ty and drift, as well as for sensor accuracy, with different in vitro examinations. Additionally, performance of the measurement device was tested in a clinical pilot study on patients recovering from cardiac surgical procedures. The in vitro investigation showed that the monitoring device had excel lent gain and drift stability, as well as sensor accuracy, with a resolution of 2.6 mL/h for the bleeding rate. During the clinical examination, bleeding rates of all patients were correc...
Source: Australasian Physical and Engineering Sciences in Medicine - Category: Biomedical Engineering Source Type: research