Sensor, gas analyzer and method for measuring concentration of at least one respiratory gas component

A gas analyzer for measuring a concentration of at least one respiratory gas component in a breathing gas, which concentration is varying during a breathing cycle having an inspiration phase, an expiration phase and a phase between the inspiration and expiration, the gas analyzer comprising:

• an airway adapter comprising a sampling cell configured to allow the breathing gas flow, at least one optical component configured to guide radiation, wherein the optical component is in direct or indirect contact with the respiratory gas inside the sampling cell, a first port configured to deliver respiratory gas to the sampling cell, and a second port configured to remove respiratory gas from the sampling cell;
• a sensor connectable to the airway adapter, the sensor comprising at least one radiation source configured to emit radiation towards the at least one optical component, at least one radiation sensing detector configured to receive for radiation and provide a signal indicative of the concentration of the at least one respiratory gas component, an electronics board configured to receive and process the signal from the at least one radiation sensing detector to determine the concentration of the at least one respiratory gas component, and an energy storage device configured to supply energy to the at least one radiation source;
• wherein the electronics board is configured to choose from among at least a first and a second mode of energy supply to the at least one radiation source, wherein the first mode is an operation mode configured to allow sufficient energy supply to the at least one radiation source needed for subsequent concentration determination within at least one phase of the breathing cycle, and the second mode is a rest mode configured to allow reduced energy supply to the at least one radiation source compared to the operation mode to limit radiation for saving energy of the energy storage device within the breathing cycle, when reduced accuracy in concentration determination is acceptable.

A method for measuring a concentration of at least one respiratory gas component in a breathing gas, which concentration is varying during a breathing cycle having an inspiration phase, an expiration phase and a phase between the inspiration and expiration, the method comprising:

• emitting radiation by at least one radiation source towards at least one optical component one of in direct and indirect contact with the respiratory gas inside a sampling cell, receiving the radiation by at least one radiation sensing detector and providing from the at least one radiation sensing detector a signal indicative of the concentration of the at least one respiratory gas component;
• receiving the signal from the at least one radiation sensing detector and processing the signal in an electronics board to determine the concentration of the at least one respiratory gas component;
• supplying energy from an energy storage device to the at least one radiation source;
• and
• wherein the method further comprises choosing the electronics board from among at least a first and a second mode of energy supply to the at least one radiation source, wherein the first mode is an operation mode configured to allow sufficient energy supply to the at least one radiation source needed for subsequent concentration determination within at least one phase of the breathing cycle, and the second mode is a rest mode configured to allow reduced energy supply to the at least one radiation source compared to the operation mode to limit radiation for saving energy of the energy storage device within the breathing cycle.