Abstract: A breath-sample contained (100) comprising an inlet (102) for receiving a breath sample, a wall (104) at least partially defining a chamber (106) for containing the breath sample, and a valve (110) between the inlet (102) and the chamber (106). The valve (110) is in fluid communication with the inlet (102) and the chamber (106), and is configurable between at least a first open configuration (110a) for flow of breath sample from the inlet (102) to the chamber (106) up to a first flow rate, and a second open configuration (110b) for flow of breath sample from the inlet (102) to the chamber (106) at a second flow rate greater than the first flow rate. Once the valve (110) has been configured in the second open configuration (110b), the valve (110) cannot then reconfigure itself to the first open configuration (110a).

Abstract: In examples, there is a device for converting ammonia (NH3) in a human breath sample to nitric oxide (NO). The device comprises a tube and a heater. The tube comprises an inlet, an outlet, and a wall defining an internal surface of the tube and an external surface of the tube. The wall comprises substantially the same material along a thickness from the internal surface of the tube to the external surface of the tube. The material is catalytic for conversion of ammonia to nitric oxide. The heater is configured to heat the wall.

Abstract: In examples, there is a method comprising receiving an esophageal gas sample at a nitric oxide sensor, the nitric oxide sensor generating a signal indicative of the amount of nitric oxide in the esophageal gas sample, the nitric oxide sensor outputting the signal, and, based on the signal, determining the amount of nitric oxide in the esophageal gas sample.

Abstract: A gas sensor device which is connectable to a portable electronic device, and to associated methods. The gas sensor device includes a sensor adapted to detect a gas of interest in exhaled breath of a subject and provide an output signal which is dependent upon the concentration of gas detected, and an interface of the gas sensor device communicates with the portable electronic device. The gas sensor device may be connectable to the portable electronic device via an audio jack.