Low-cost flow meter innovation will improve fluid management in hospital patients with the aim of improving healthcare outcomes.
When you imagine a patient in a hospital bed you will probably picture an intravenous (IV) drip as part of the scene. Between 80 and 90% of hospital inpatients will receive an infusion of one or more intravenous fluids during their stay.
For some, such as those on a nil by mouth regime, all fluid in and out of the body will be managed by a combination of IV infusion and catheterisation.
Managing the fluid intake and output – known as fluid balance – is an important component of hospital care. Staff need to be able to monitor the rate of fluid intake and output accurately to ensure optimal fluid balance.
Patients who don't receive sufficient fluids risk dehydration and severe complications such as Acute Kidney Injury. Those who receive too much can experience hypervolemia, potentially leading to congestive heart failure.
Current technology lags behind this need. NICE guidelines estimate that as many as 1 in 5 patients who receive IV fluids and electrolytes suffer a complication or morbidity due to errors in their use.
Key to this is difficulty in accurately measuring flow rate. The flow rate of traditional gravity IV sets is measured by counting drips – which is both time consuming and inaccurate due to droplet variability and human error.
Flomark, founded by experienced industrial designer Jonathan West and James Kinross, Reader in Surgery at Imperial, has developed a low-cost solution to this problem, the Flomark™ - a sterile, single-use flow meter that integrates with standard gravity IV sets and provides a simple visual indicator of flow rate. The device incorporates a float – a little red ball – and a visual scale showing millilitres per hour.
This innovation has helped it secure £300,000 from investors including Imperial College Enterprise Fund and the British Design Fund as part of a broader funding round intended to fuel the commercial launch and sales of the Flomark® device.
The founders were inspired to develop the Flomark® having observed that the quality of fluid management technology was low in comparison to the importance to patient safety of getting it right.
James Kinross, FRCS, PhD, Reader in General Surgery, Department of Surgery and Cancer, said: "Effective fluid management is critical for preventing complications such as hypovolemia or fluid overload, which can significantly impact patient outcomes. Our new device offers clinicians precise, reliable control over fluid delivery, supporting safer, more responsive care at the bedside."
Following an Innovate UK Smart Grant completed in 2024, the company has also developed a prototype electronic regulator device which tracks the position of the float in the flow meter, providing accurate control of flow rate that compensates for changes in pressure and resistance.
Jonathan West, CEO of Flomark, said:
"Our ultimate aim is to develop a solution offering live fluid balance information. Using the flow meter and regulator together for input, and similar devices measuring urine output, we will be able in the future to offer really accurate data for fluid management, improving patient outcomes and reducing the time burden on clinical and hospital staff of manually monitoring fluids."
