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Abstract: SA-PO350

The Application of a Wearable Diffuse Reflectance Spectroscopy Monitor in the Assessment of Volume in Haemodialysis Patients

Session Information

Category: Dialysis

  • 701 Dialysis: Hemodialysis and Frequent Dialysis


  • Sandys, Vicki K., Royal College of Surgeons in Ireland, Dublin, Ireland
  • Bhat, Lavleen, Royal College of Surgeons in Ireland, Dublin, Ireland
  • Ninan, Anna, Royal College of Surgeons in Ireland, Dublin, Ireland
  • Edwards, Colin, Royal College of Surgeons in Ireland, Dublin, Ireland
  • Sexton, Donal J., The University of Dublin Trinity College, Dublin, Ireland
  • O'Seaghdha, Conall M., Royal College of Surgeons in Ireland, Dublin, Ireland

Group or Team Name

  • Haemodialysis Outcomes & Patient Empowerment group

The 2019 Kidney Health Initiative identified a need for solutions addressing fluid management in-between dialysis sessions. We aimed to assess the validity and reproducibility of a wearable hydration monitor in maintenance dialysis patients.


Prospective, single-arm observational study on 20 haemodialysis patients between January-June 2021 in a single haemodialysis centre. Participants wore a prototype wearable infrared spectroscopy device on their forearm during dialysis and nocturnally, termed the Sixty device. Bioimpedance measurements were performed 4 times using the body composition monitor (BCM) over 3 weeks. Sixty outputs a scale concordant with hydration level whereby 1 is euvolemia. Values in kg are calculated from this scale. Sixty measurements were compared with the BCM overhydration (OH) index pre and post dialysis and with standard haemodialysis parameters.


12 out of 20 patients had usable data. 55% female, 80% white. Mean age was 52 ± 12.4 years. The overall accuracy for predicting pre-dialysis categories of fluid status using Sixty was 0.56 [κ = 0.01; 95% CI -0.39 – 0.42]. The accuracy for the prediction of post-dialysis categories of volume status was low [accuracy= 0.33, κ= 0.07; 95% CI= -0.14 to 0.27]. Agreement using Bland-Altman plots is shown in Figure 1. Sixty outputs at the start and end of dialysis were weakly correlated with pre and post dialysis weights (r= 0.27 and r= 0.27, respectively), as well as weight loss during dialysis (r= 0.31), but not ultrafiltration volume (r= 0.12). There was no difference between the change in Sixty readings during an overnight session, and the change in Sixty readings during a dialysis session [mean difference 0.09kg, t(39)= 0.38, p= 0.71].


A prototype wearable infrared spectroscopy device was unable to accurately assess changes in fluid status during or between dialysis sessions. In the future, hardware development and advances in photonics may enable the tracking of interdialytic fluid status.


  • Commercial Support – Enteprise Ireland Disruptive Technologies Innovation Fund grant DTIF 2019_86