2022 · Mouzakis — Quantification of dissolved H₂ and continuous monitoring of hydrogen-rich water for haemodialysis applications: An experimental study
Super-Abstract
This study validated a contactless electrochemical sensor for continuously measuring dissolved hydrogen concentrations in physiological solutions relevant to haemodialysis. The sensor showed a linear relationship between applied H₂ content and equilibrium concentration, though calibration differences between sensors and temperature sensitivity require attention. This is an in-vitro instrumentation study — no patients or animals were involved. (The International Journal of Artificial Organs, 2022.)
Commentary
Hydrogen-enriched dialysate is an emerging approach to reduce the oxidative and inflammatory burden in patients with end-stage renal disease (ESRD) undergoing chronic haemodialysis. A critical prerequisite for this application is a reliable, real-time method to verify and control H₂ concentrations in the dialysate circuit. Measuring dissolved H₂ in a closed fluid loop continuously — without sampling — is technically challenging. This paper tests a novel contactless sensor (Pureron Japan Co., Ltd) by assembling an in-vitro circuit with physiological solutions and cross-validating against an oxygen sensor via partial pressure readings. The linear response characteristic (H₂ in gas mixture proportional to dissolved concentration at equilibrium) is encouraging for practical use. Two limitations are identified: relatively long response time and sensor-to-sensor variability that may require recalibration. Neither limitation is described as prohibitive for haemodialysis applications. This is purely an instrumentation validation study — it does not report clinical outcomes, patient data, or new H₂ biological effects.
Key quotes
- „The relationship between the applied H2 content in the gaseous mixture and the H2 concentration value at equilibrium is linear.“ — the key technical finding enabling reliable dosimetry
- „the hydrogen monitoring system has a rather long response time, and its readings seem to slightly diverge from sensor to sensor as well as at different temperatures.“ — identified limitations requiring calibration attention
- „a standardised measuring method to determine the levels of hydrogen in dialysate and subsequently in blood is required.“ — the unmet need motivating this engineering work
Our assessment
A technical in-vitro validation study for H₂ measurement instrumentation in a dialysis-relevant context. This is engineering groundwork, not a clinical or biological study. No patient outcomes are assessed. The findings support the feasibility of real-time H₂ monitoring in haemodialysis circuits, which is a prerequisite for safe clinical use — but the clinical benefits of H₂-enriched dialysate themselves must be evaluated separately.
Study design
- Type: in-vitro instrumentation validation study · Model: experimental circuit with physiological solutions (no animals, no patients) · H₂ delivery: gaseous H₂ introduced into test circuit at defined concentrations; sensor measures dissolved H₂
- Result: linear H₂ dose–response in solution confirmed; sensor response time longer than ideal; slight sensor-to-sensor variability observed; cross-validation with oxygen partial-pressure sensor successful
Abstract
The prevalence of oxidative and inflammatory stress in end-stage renal disease (ESRD) patients has often been associated with chronic haemodialysis therapies. Over the past decades, several reports have shown the potential of hydrogen molecule as an antioxidant in the treatment of various medical conditions in animal models, as well as in pilot studies with human patients. Recently, a hydrogen-enriched dialysate solution has been introduced, holding promise in reducing the oxidative and/or inflammatory complications arising during haemodialysis. To this end, a standardised measuring method to determine the levels of hydrogen in dialysate and subsequently in blood is required. This study explores the possibility of quantifying hydrogen concentration using a novel contactless sensor that detects dissolved hydrogen in liquids. An experimental circuit is assembled to validate the sensitivity and accuracy of the hydrogen monitoring system (Pureron Japan Co., Ltd) through in vitro investigations with physiological solutions. Measurements of dissolved molecular hydrogen concentration are corroborated by an established oxygen sensor providing continuous partial pressure readings. The relationship between the applied H2 content in the gaseous mixture and the H2 concentration value at equilibrium is linear. At the same time, the hydrogen monitoring system has a rather long response time, and its readings seem to slightly diverge from sensor to sensor as well as at different temperatures. For this reason, a sensor recalibration might be necessary, which could become part of the product's ongoing development. Nevertheless, the aforementioned minor deficiencies can be mostly considered negligible in applications such as haemodialysis.
Source & links
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