Continuous Monitoring of Anaesthetics Concentration to Control Anaesthesia Delivery

Politecnico di Torino & EPFL Joint Research project

Contacts:

Simone AiassaPhD student, Politecnico di Torino-DET, EPFL-IC-LSI (simone.aiassa@polito.it)
Sandro Carrara Dr MER, EPFL-IC-LSI (sandro.carrara@epfl.ch)
Danilo Demarchi, Professor, Politecnico di Torino-DET

Motivation

Every year, 30,000 people undergo anaesthesia and remain awake, feeling pain, many more are put into uselessly deep or prolonged chemical coma. Proper anaesthesia requires the achievement of a certain concentration of drugs. Today, prediction errors in control models reach 25% due to the patients diversity. The continuous monitoring of anaesthetic would contribute to better individualization of patients management.

Conventional system to monitor the Depth of Ananesthesia (DOA), such as Bi-Spectral Index (BIS), show some limitations due to high inter-patient variability and the usage of predictive models. The Therapeutic Drug Monitoring (TDM) can measure the actual drug concentration in the patient, allowing a dynamic adjustment of the anaesthetic infusion to meet personal requirements. Nowadays, no commercially-available system is able to exploit a real-time point-of-care anaesthetic monitoring, due to the lack of technologies capable to read anaesthetics and possible to be integrated into a simple object. Electrochemical investigation can be adopted to measure the therapeutic compounds (Propofol, Midazolam, and Paracetamol), in particular, Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV) are highly attractive due to fast measurements, multi sensing, and high sensitivity.

Goal

The aim of the project is the development of a fully portable bio-sensor for automatic continuous monitoring of infused drug in patient’s blood for improved anaesthesiology practice. We envision a portable intelligent syringe to monitor the delivery of anaesthetic compounds during surgery:

  • Needle: bio-sensor (electrochemical cell);
  • Chamber: electronic sensor interface (quasi-digital, bio-inspired driver and read-out);
  • Plunger: intelligent wireless interface (custom digital architecture).

The system requires to be portable, low cost, small, and low power, the sampling must be autonomous, intelligent, and on-line.

Concept of the proposed system: the portable syringe provides to the anaesthesiologist in real-time the concentration of the drugs infused in the patient under anaesthesia.

Acknowledgement

This work is supported by Politecnico di Torino and Compagnia di San Paolo under the initiative Joint research projects with top universities.