Validation of a Wearable Bioimpedance Sensor for Hydration Monitoring (VAMOS)

Validation of a Wearable Bioimpedance Sensor for Non-Invasive Monitoring of Hydration Status

The purpose of the project is to validate the performance of a wearable bioimpedance sensor (Re:Balans®) for monitoring hydration status. The study includes hospitalized patients aged 65 years or older who are admitted to the hospital with suspected dehydration. Data will be collected continuously throughout the hospital stay using one sensor placed on the back, one on the upper arm, and one on the front of the thigh. Sensor measurements will be compared with multiple reference methods for assessing hydration status, including blood tests, body weight and fluid balance charts. Agreement with these reference measures will form the basis for the performance evaluation.

The anticipated benefit of the project is the validation of a novel, user-friendly, and non-invasive tool for hydration monitoring, with the aim of improving patient care, preventing complications, and reducing the need for hospital readmissions.

Study Overview

• Status: Not yet recruiting
• Conditions: Dehydration; Hypovolemia
• Intervention / Treatment: Device: Bioimpedance sensor

Detailed Description

The study aims to evaluate how well a wearable bioimpedance sensor (Re:Balans®) tracks changes in hydration status in hospitalized patients. The objective is to validate the sensor's ability to provide continuous, non-invasive monitoring of fluid balance, which may improve the management and treatment of patients at risk of dehydration or fluid overload. Such a solution could also help reduce the need for hospital admissions and in-person follow-up visits.

The investigation is designed as a prospective cohort study in which patients are followed throughout their hospital stay, typically lasting 3-7 days. Participants will wear three sensors, placed on the upper back, upper arm, and anterior thigh. The sensors automatically perform measurements every minute during the study period.

At baseline and during daily follow-up visits, several assessments of hydration status will be performed. These include body weight measurements, blood tests, and whole-body bioimpedance measurements. In a subgroup of patients, ultrasound assessment of the inferior vena cava will also be performed. The combined results from these assessments will serve as reference measures to determine whether the patient's hydration status has changed over time.

At hospital discharge, the assessments are repeated, the sensors are removed, and participants complete a short questionnaire regarding their experience with the device. In addition, fluid balance data (fluid intake and output) will be collected retrospectively from medical records to allow comparison between the sensor measurements and routine clinical monitoring methods. Relevant clinical information obtained as part of standard patient care will also be recorded if considered important for the assessment of hydration status.

• Study Type: Observational
• Enrollment (Estimated): 60

Contacts and Locations

• Study Contact: Name: Sigve N Aas, PhD; Phone Number: 004741499074; Email: sigve.aas@modesensors.com
• Study Contact Backup: Name: Frida Bremnes, MSc; Email: frida.bremnes@modesensors.com

Study Locations

• Norway
  • Trøndelag
    • Trondheim, Trøndelag, Norway, 7030
      • St. Olavs hospital
      • Contact: Lars P Bjørnsen, PhD; Phone Number: 004793212617; Email: lars.petter.bache-wiig.bjornsen@stolav.no
      • Principal Investigator: Lars P Bjørnsen, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

The study population consists of hospitalized patients aged 65 years or older who are admitted with suspected dehydration and are planned to receive fluid therapy. Participants may have varying underlying medical conditions and comorbidities that could influence hydration status during their hospital stay.

Description

Inclusion Criteria:

• Age ≥ 65 years
• Planned fluid management due to presumed dehydration
• Expected duration of hospital stay ≥ 3 days

Exclusion Criteria:

• Known allergies or skin sensitivities to electrode hydrogel and/or acrylic adhesives
• Implantable pulse generators such as pacemakers and defibrillators, and/or use of other electrical medical equipment for which an interaction effect with the investigational device cannot be ruled out.
• Scheduled MRI
• Scheduled diathermy
• Breached skin at device application areas (upper back, anterior thigh and upper arm)
• Unconsciousness
• Critically ill (presence of acute organ dysfunction requiring intensive monitoring and management)
• Any medical or psychiatric condition, which in the opinion of the investigator precludes participation
• Incapable of giving informed consent

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Dehydrated patients; The cohort includes individuals 65 years or older admitted to the hospital with dehydration	Device: Bioimpedance sensor; Subjects will wear three bioimpedance sensors throughout their stay at the hospital

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Relative change in device output from admission to discharge	Relative change in device output from admission to discharge in patients with a confirmed increase in fluid volume, compared with subjects whose hydration status remain stable	Day 1 and day of discharge (up to 1 week)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Sensitivity/specificity of the device for the detection of significant fluid volume changes	Proportion of true positives (changed hydration) and true negatives (unchanged hydration) correctly identified by the device	Once daily during hospital stay, assessed up to 7 days
Sensitivity/specificity at the three placements	Proportion of true positives (changed hydration) and true negatives (unchanged hydration) correctly identified by the device	Once daily during hospital stay, assessed up to 7 days
Sensitivity/specificity of different device outputs	Proportion of true positives (changed hydration) and true negatives (unchanged hydration) correctly identified by the device	Once daily during hospital stay, assessed up to 7 days
Correlation between device output and reference measurements	Correlation between changes in device output and reference measurements during the hospital stay	Day 1 and day of discharge (up to 1 week)
User satisfaction among patients	Subjects will respond to a questionnaire related to user comfort. The questionnaire uses a 5-point Likert scale ranging from 1 to 5, where lower scores indicate better outcomes and higher scores indicate worse outcomes. The questionnaire will be filled out on day 3 of the hospital stay.	Day 3

Collaborators and Investigators

• Sponsor: Mode Sensors AS
• Collaborators: St. Olavs Hospital
• Investigators: Study Director: Sigve N Aas, PhD, Mode Sensors AS

Study record dates

Study Major Dates

• Study Start (Estimated): August 1, 2026
• Primary Completion (Estimated): March 15, 2027
• Study Completion (Estimated): March 31, 2027

Study Registration Dates

• First Submitted: May 21, 2026
• First Submitted That Met QC Criteria: June 15, 2026
• First Posted (Actual): June 17, 2026

Study Record Updates

• Last Update Posted (Actual): June 17, 2026
• Last Update Submitted That Met QC Criteria: June 15, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Metabolic Diseases; Water-Electrolyte Imbalance; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Dehydration; Hypovolemia
• Other Study ID Numbers: CTR0062A VAMOS

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No