SOZO

The SOZO™ system utilizes multi-frequency bioimpedance spectroscopy, via hand and footplate electrodes, for noninvasive monitoring of extracellular fluid status in adult heart failure patients. Its methodology involves measuring impedance across 256 frequencies (3kHz-1000kHz), with data processed by the SOZOapp and SOZOhub to provide clinicians with actionable insights for fluid management.

The SOZO™ system is a noninvasive medical device intended for use by physicians to monitor fluid status in adult patients suffering from heart failure. It consists of a hand and footplate with stainless steel electrodes, which connects via Bluetooth to an Android tablet running the "SOZOapp." This app controls the hardware and transmits bioimpedance measurement data to a local hospital network database ("SOZOhub"). The device aims to assist clinicians in managing fluid problems by providing data that should be considered alongside other clinical information. The core technology of SOZO™ is bioimpedance analysis, where the patient makes contact with the electrodes for approximately 30 seconds. During this time, the system applies a small electrical current (200µA RMS) across 256 distinct frequencies, ranging logarithmically from 3kHz to 1000kHz. 'Drive' channels deliver this current, while 'sense' channels measure current, voltage, and phase angle to calculate impedance, resistance, and reactance. These parameters are then analyzed using established algorithms to determine extracellular fluid impedance levels for both the left and right sides of the body, which are presented to the clinician. Performance testing confirmed the device's electrical safety, EMC compatibility, software integrity, biocompatibility, and functional reliability, with comparative tests showing strong correlation (r > 0.99) with predicate systems.

AI Regulatory Concerns

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Jev reads the full FDA letter and returns calibrated concern probabilities per regulatory category. These are AI estimates, not regulatory advice.

• Q1. How does the SOZO™ system's measurement of extracellular fluid impedance correlate with established clinical markers of fluid overload or dehydration in heart failure patients (e.g., NT-proBNP, weight changes, clinical signs)?; What specific "established algorithms" are used to analyze the 256-frequency bioimpedance data, and how sensitive are these algorithms to variations in patient demographics (age, sex, ethnicity, BMI) or co-morbidities?; Beyond the reported strong correlation (r > 0.99) with predicate devices, what is the clinical impact of SOZO™'s multi-frequency approach (256 frequencies from 3kHz to 1000kHz) on the accuracy and reliability of fluid status assessment compared to single or fewer frequency devices?; How does the system account for, or instruct users to manage, potential confounders in bioimpedance measurements such as recent food/fluid intake, exercise, limb temperature, or electrode contact quality, especially in an outpatient or home setting?; What level of change in the SOZO™-derived impedance values is considered clinically significant for guiding therapeutic interventions in heart failure management, and what is the system's precision (reproducibility) for longitudinal monitoring?