Central venous catheters (CVC) are commonly used in clinical practice to improve a patient's quality of life. Unfortunately, there is an intrinsic risk of acquiring an infection related to microbial biofilm formation inside the catheter lumen. It has been estimated that 80 % of all human bacterial infections are biofilm-associated. Additionally, 50 % of all nosocomial infections are associated with indwelling devices. Bloodstream infections account for 30-40 % of all cases of severe sepsis and septic shock, and are major causes of morbidity and mortality. Diagnosis of bloodstream infections must be performed promptly so that adequate antimicrobial therapy can be started and patient outcome improved. An ideal diagnostic technology would identify the infecting organism(s) in a timely manner, so that appropriate pathogen-driven therapy could begin promptly. Unfortunately, despite the essential information it provides, blood culture, the gold standard, largely fails in this purpose because time is lost waiting for bacterial or fungal growth. This work presents a new design of a venous access port that allows the monitoring of the inner reservoir surface by means of an impedimetric biosensor. An ad-hoc electronic system was designed to manage the sensor and to allow communication with the external receiver. Historic data recorded and stored in the device was used as the reference value for the detection of bacterial biofilm. The RF communication system sends an alarm signal to the external receiver when a microbial colonization of the port occurs. The successful in vitro analysis of the biosensor, the electronics and the antenna of the new indwelling device prototype are shown. The experimental conditions were selected in each case as the closest to the clinical working conditions for the smart central venous catheter (SCVC) testing. The results of this work allow a new generation of this kind of device that could potentially provide more efficient treatments for catheter-related infections.

No abstract

No abstract

New advances in biosensor and electronic technologies will merge in new health assistance paradigms strongly based on the remote Biomonitoring. Biomedical circuit and systems have much to say on this, as for example the central venous catheters (CVC). Central venous catheters are commonly used in clinical practice to improve a patient's quality of life. Nevertheless, there remains a large risk of infection associated with microbial biofilm (about 80% of all human bacterial infections). The standardization bodies, the radiofrequency devices and the biosensor technology are taking their positions, and the integration of all that effort is the work proposed in this paper. An ultra-low power active medical implant is presented for in-body monitoring of Electrical Bioimpedances (EBI) based sensors. A detailed and exhaustive lifetime evaluation has been done based on two typical monitoring parameters: the frequency of the internal sensor measuring and the frequency of external communication requests. The results show up to 20 months lifetime powered with a 50mA coin-cell battery.