Medical procedures and therapies are often faced by the same challenge: accurately measuring and controlling lowest flow rates down to the microlitre-per-hour range. In most of these cases, the outcome of the therapy, along with the well-being or even the survival of the patient, strongly rely on reliable and continuous drug administration in such low-flow regimes. While various countermeasures have been evaluated and introduced, there is still room for improvement and for new technologies to be established. One novel development with tremendous potential in many applications – such as for ambulatory infusions, in peadiatrics and neonatology, or for continuous urine flow measurements – is a single-use liquid flow sensor that is able to measure lowest flow rates and detect common failure modes quickly and reliably.

Small flow rates for delicate care

In pediatrics and neonatology, the little and vulnerable patients receive a lot of special care and attention, not only from the nursing staff, clinicians and their parents, but also from the medical industry. In this context, flow rates of 1ml/h or lower are typical due to the patients’ low body weights. Consequentially, the known and inherent issues of the current infusion technology (start-up delays, flow-discontinuation and dependence on hydrostatic pressure) may have even more detrimental effects on the therapy outcome.

Single-use liquid flow sensors, integrated into infusion sets, will enable medical devices to accurately monitor administered flow rates, and detect common failure modes quickly and reliably.

Administration of life-saving drugs with a short half-life, such as adrenalin, must not be delayed or discontinued by the infusion technology in question. However, this happens frequently due to the compliance of the tubing and syringe plunger, the movement and vertical displacement of syringe pumps during transport of the patient, or the loading of a new syringe into the pumping device.

The fluidic balance of a child or a neonate has to be observed and calculated on a daily basis. The sum of any fluid injected or ingested, be it drugs or nutrition, and the excreted fluid is not only critical to the well-being of the child, but also limited. Single-use liquid flow sensors, integrated into infusion sets, will enable medical devices to not only accurately monitor the administered flow rates, but also to detect the above-mentioned common failure modes quickly and reliably.

Freeing-up time

By using a single-use liquid flow sensor, important measurement data and vital signs could be acquired and stored automatically in the electronic patient data management system. This solves the issue of timeconsuming, inaccurate and cumbersome hand-written medical charts, and allows the timely detection of adverse effects. The data would furthermore be easily available for a retrospective analysis. Above all, it would free-up the time of the nursing staff so it could be spent on other tasks that require personal attention.

Many medical applications can be revolutionised or enabled by using the LD20, the single-use liquid flow sensor from Sensirion. The LD20 combines Sensirion’s proven liquid flow sensing technology in a single-use, cost-optimised design for high-volume applications in the medical, life sciences or food industry. The LD20 sensors provide a bidirectional measurement of flow rates from below 1ml/h up to 1000ml/h, while still reliably detecting common failure modes – such as occlusion, free flow or air bubbles – with unprecedented speed and sensitivity.