Introduction

Respiratory asynchrony is a condition experienced by subjects that suffer from limited autonomous respiratory capability and receive ventilation support that does not match their needs in terms of duration, volume and flow. Given the large variability of asynchronies, the problem is often under-diagnosed due to the difficulty in its recognition and shortage of specialists. The invention concerns a new characterization for patient-ventilator asynchronies, focused exclusively on flow and pressure evolution. The invention also relates to a method, based on such characterization, for automatic detection of asynchronies.

Technical features

Asynchronies are usually detected by observing a patient’s bedside time-flow and time-pressure graphs. Oesophageal pressure and Electrical Activity of diaphragm signal (EAdi) waveforms can also be used to detect asynchronies, but they are semi-invasive and require strict calibration, the accuracy of the signal is affected by several variables and specific skills for the interpretation of tracings are required. In the characterization object of the invention any respiratory cycle corresponds to a loop cycle in the pressure-flow space and asynchronies, which represent work overloads for the overall patient-ventilator system due to impedance in the respiratory activity, appear as small loops decorating the breath loop cycle which are automatically detected and measured by specific algorithm, starting from flow and pressure data normally provided by ventilators and without need for additional devices to be applied to the patient. The system can work in real-time and with any ventilator currently used in Intensive Care Units.

Possible Applications

• Mechanical ventilation in Intensive Care Units.

Advantages

• Better ventilation: identification of asynchronies helps setting proper ventilation;
• Automatic: detection of asynchronies is completely automatic, with possibility to alert physicians;
• Non invasive: no additional devices on patients are needed (e.g. oesophageal catheter);
• Suitable for every mechanical ventilator;
• Low-cost device.