Wearable Tissue Oximetry During Arm Cuff Occlusion, Walking, and Standing Tests in Outpatients With Chronic Heart Failure

This prospective, single-center, observational pilot study evaluated an investigational wearable tissue oximeter (NIRSense Argus Oximetry System, also called Envello Core) in adult outpatients with chronic heart failure in New York Heart Association (NYHA) class I, II, or III at Jackson Heart Clinic in Jackson, Mississippi. During one routine clinic visit, participants wore three adhesive optical sensors, on the forearm, the thigh, and the sternum, while completing three standard tests: a blood pressure cuff occlusion of the arm (vascular occlusion test), a six-minute walk test, and a change from lying down to standing. The sensors use near-infrared spectroscopy to record changes in tissue oxygenation. The study compared tissue oxygenation responses across NYHA classes and with standard clinical measures (blood pressure, pulse rate, pulse oximetry, and walk distance). Participation added about 30 minutes to the visit, with no follow-up. Fifty participants were enrolled. No treatment decisions were based on the study device.