TY - JOUR T1 - Real-time continuous measurement of lactate through a minimally invasive microneedle patch: a phase I clinical study JF - BMJ Innovations JO - BMJ Innov SP - 87 LP - 94 DO - 10.1136/bmjinnov-2021-000864 VL - 8 IS - 2 AU - Damien K Ming AU - Saylee Jangam AU - Sally A N Gowers AU - Richard Wilson AU - David M E Freeman AU - Martyn G Boutelle AU - Anthony E G Cass AU - Danny O’Hare AU - Alison H Holmes Y1 - 2022/04/01 UR - http://innovations.bmj.com/content/8/2/87.abstract N2 - Introduction Determination of blood lactate levels supports decision-making in a range of medical conditions. Invasive blood-sampling and laboratory access are often required, and measurements provide a static profile at each instance. We conducted a phase I clinical study validating performance of a microneedle patch for minimally invasive, continuous lactate measurement in healthy volunteers.Methods Five healthy adult participants wore a solid microneedle biosensor patch on their forearms and undertook aerobic exercise for 30 min. The microneedle biosensor quantifies lactate concentrations in interstitial fluid within the dermis continuously and in real-time. Outputs were captured as sensor current and compared with lactate concentrations from venous blood and microdialysis.Results The biosensor was well-tolerated. Participants generated a median peak venous lactate of 9.25 mmol/L (IQR 6.73–10.71). Microdialysate concentrations of lactate closely correlated with blood. Microneedle biosensor current followed venous lactate concentrations and dynamics, with good agreement seen in all participants. There was an estimated lag-time of 5 min (IQR −4 to 11 min) between microneedle and blood lactate measurements.Conclusion This study provides first-in-human data on use of a minimally invasive microneedle patch for continuous lactate measurement, providing dynamic monitoring. This low-cost platform offers distinct advantages to frequent blood sampling in a wide range of clinical settings, especially where access to laboratory services is limited or blood sampling is infeasible. Implementation of this technology in healthcare settings could support personalised decision-making in a variety of hospital and community settings.Trial registration number NCT04238611.Data are available upon reasonable request. Data is available upon request to the corresponding author. ER -