New lung function measure ΔR is able to detect airway obstruction with high sensitivity and specificity and is suitable for use in lung function testing in young children.

Tracking of the within-breath changes of respiratory mechanics using the forced oscillation technique may provide outcomes that characterise the dynamic behaviour of the airways during normal breathing.We measured respiratory resistance () and reactance () at 8 Hz in 55 chronic obstructive pulmonary disease (COPD) patients and 20 healthy controls, and evaluated and as functions of gas flow (') and volume () during normal breathing cycles. In 12 COPD patients, additional measurements were made at continuous positive airway pressure (CPAP) levels of 4, 8, 14 and 20 hPa.The and' and relationships displayed a variety of loop patterns, allowing characterisation of physiological and pathological processes. The main outcomes emerging from the within-breath analysis were the loop area (AXV) quantifying expiratory flow limitation, and the tidal change in during inspiration (Δ) reflecting alteration in lung inhomogeneity in COPD. With increasing CPAP, AXV and Δ approached the normal ranges, although with a large variability between individuals, whereas mean remained unchanged.Within-breath tracking of and allows an improved assessment of expiratory flow limitation and functional inhomogeneity in COPD; thereby it may help identify the physiological phenotypes of COPD and determine the optimal level of respiratory support.

Noninvasive measurement of Zrs can be made in neonates during natural sleep with a high success rate, even in the first hours of life.

The Arduino platform is widely used in education of physics to perform a number of different measurements. Teachers and students can build their own instruments using various sensors, the analogue-to-digital converter of the Arduino board and code to calculate and display the result. In several cases this can mean incautious reproduction of what can be found on the Internet and an indepth understanding can be missing. Here we thoroughly analyse a frequently used resistance measurement method and show demonstration experiments as well to make it clear. Construction of the OhmmeterA wide range of experiments and solutions are shown where sensors and the Arduino platform are used to teach physics efficiently and attractively while the cost is kept very low [1][2][3][4][5]. Sensors have an output (voltage, current, resistance, capacitance, inductance) that can be handled by electronics.Since an analogue-to-digital converter (A/D converter, ADC) has voltage input, some circuitry is needed to convert the sensor's output into voltage that fits in the input range of the ADC. Like in any measurement, a reference is required. The Arduino board's ADC accepts an input voltage in the range from 0 V to VREF, where VREF is the reference voltage. Digital sensors incorporate all of these plus a digital data interface.The simplest way to measure resistance is to build a voltage divider which has an output voltage that depends on the unknown resistance, see figure 1. This is the common method applied in Arduino Ohmmeter projects published on the Internet.

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