Gravity in Flow: Automating Diuresis

March 17, 2026 updated by: R.E. Knops, Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA)

Gravity of Flow: Automating Diuresis

The goal of this randomized clinical trial is to evaluate the accuracy of automated urine output monitoring using the FlowSure system compared to standard manual urine monitoring in hospitalized patients with an indwelling urinary catheter.

The main questions it aims to answer are:

How accurate is the automated FlowSure monitoring compared with manual urine monitoring over defined time intervals (8-hour nursing shifts and 24-hour periods)?

Does the automated system improve completeness of hourly urine output registration compared with manual documentation?

Researchers will compare patients monitored with the automated FlowSure device to those monitored using the manual method to determine whether automation provides more accurate and complete diuresis data.

Participants will:

Be adult patients admitted to the hospital with a urinary catheter inserted for routine medical reasons (not related to this study).

In Part B, be randomized to either manual urine monitoring or automated FlowSure monitoring for defined time intervals.

There is no direct benefit to participants. The potential societal benefit lies in improving the accuracy, efficiency, and safety of diuresis monitoring through automation. The risks are minimal and limited to use of the FlowSure device in addition to, or instead of, standard monitoring; no additional procedures are performed.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Accurate monitoring of urine output is essential in the management of hospitalized patients, particularly those with hemodynamic instability or fluid balance disorders. Currently, diuresis monitoring is performed manually by nursing staff, which is labor intensive and prone to transcription or timing errors. The FlowSure system is an automated urine output monitoring device designed to continuously measure and record urine production and transfer these data directly to the electronic medical record (EMR). Automation may improve data quality, reduce nursing workload, and enhance patient safety.

This study consists of two parts. Part A is a technical feasibility study in which patients are simultaneously monitored using both manual and automated FlowSure systems to evaluate concordance between the two methods under real-world conditions. Part B is a two-arm randomized, non-blinded intervention study comparing automated versus manual urine output monitoring. Patients will be randomized in a 1:1 ratio to either standard manual monitoring or automated FlowSure monitoring. Randomization occurs after insertion of a urinary catheter, which is placed for medical reasons unrelated to the study.

The primary objective of Part B is to assess the accuracy of urine production measurement by the automated FlowSure monitor compared with manual monitoring over two time frames: (1) an 8-hour nursing shift and (2) a full 24-hour period. The primary endpoint is the completeness and accuracy of hourly diuresis registration between the two monitoring methods. Secondary analyses will include evaluation of data recording efficiency and the rate of missing or incorrect entries in the EMR.

There is no direct therapeutic benefit to participants. The anticipated scientific and societal benefit lies in improving the reliability and efficiency of diuresis monitoring, potentially enhancing patient care and reducing nursing workload. The risks associated with participation are minimal. In Part A, the automated monitor operates in addition to the manual system; in Part B, patients are monitored using only one method. In case of device malfunction or data loss, urine output can be estimated from total collected volume over time. Given the low risk profile and the potential to improve clinical monitoring practices, the overall risk-benefit balance of the study is considered favorable.

Study Type

Interventional

Enrollment (Actual)

75

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Netherlands
    • North Holland
      • Amsterdam, North Holland, Netherlands, 1105 AZ
        • Amsterdam UMC, locatie AMC

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age 18 years or older.
  • Currently hospitalized.
  • Indwelling urinary catheter inserted for medical reasons unrelated to the study.
  • Able and willing to provide written informed consent.
  • No specific urological problems.

Exclusion Criteria:

  • No urinary catheter in place.
  • Diuresis < 30 mL per hour at screening.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Health Services Research
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Manual Urine Monitoring
Participants in this arm will be monitored using the standard manual urine measurement system consisting of a measuring chamber and urine collection bag. Nursing staff will manually record hourly urine output in the electronic medical record according to routine hospital procedures.
Device: Manual Urine Monitoring System
The current standard-of-care manual urine monitoring system consisting of a measuring chamber and urine collection bag. Nursing staff manually record hourly urine output in the electronic medical record according to routine hospital procedures.
Experimental: Automated Monitoring
Participants in this arm will be monitored using the investigational automated urine output monitoring device. The device continuously weighs the urine collection bag to calculate urine volume in milliliters per hour and automatically transfers data to the electronic medical record.
Device: FlowSure Automated Urine Output Monitor
A digital hanging scale that continuously weighs the urine collection bag to determine urine output in milliliters per hour. The device provides real-time diuresis data and automatically transfers measurements to the electronic medical record. FlowSure does not come into contact with the patient or urine and can be reused after surface disinfection.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Accuracy of urine output measurement using the FlowSure automated monitoring device compared with manual monitoring
Time Frame: Over a single 8-hour nursing shift and a full 24-hour monitoring period
Accuracy will be defined as the agreement between urine output measured by the FlowSure device and manual measurement (reference standard) over predefined time intervals of 8 hours and 24 hours.
Over a single 8-hour nursing shift and a full 24-hour monitoring period

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Completeness of hourly urine output registration in the electronic medical record
Time Frame: Over a single 8-hour nursing shift and a full 24-hour monitoring period
Percentage of expected hourly urine output entries successfully recorded in the electronic medical record during the 8-hour and 24-hour measurement periods.
Over a single 8-hour nursing shift and a full 24-hour monitoring period

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA)

Investigators

  • Principal Investigator: Tom Brouwer, MD, PhD, Amsterdam UMC

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 2, 2025

Primary Completion (Actual)

January 15, 2026

Study Completion (Actual)

March 10, 2026

Study Registration Dates

First Submitted

January 6, 2026

First Submitted That Met QC Criteria

January 29, 2026

First Posted (Actual)

February 3, 2026

Study Record Updates

Last Update Posted (Actual)

March 18, 2026

Last Update Submitted That Met QC Criteria

March 17, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • NL84838.018.23
  • NL-005919 (Registry Identifier: ToetsingOnline (CCMO, Netherlands))

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

There is no plan to share individual participant data because this is a single-center device validation study with limited sample size. Aggregated results will be published in peer-reviewed journals.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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