AVF-MONITOR POC Proof-of-concept Study (AVFMONITOR POC)

January 12, 2026 updated by: Mario Negri Institute for Pharmacological Research

AVF-MONITOR: a New Wearable Device for Vascular Access Monitoring in Hemodialysis Patients - Proof-of-concept Study

This is a proof-of-concept single-centre prospective longitudinal interventional study performed in AVF patients under HD treatment at the Nephrology and Dialysis Department of the ASST-Papa Giovanni XXIII (Bergamo, Italy), involving the recording of AVF sounds by the AVF-MONITOR wearable prototype device.

Participants will undergo a screening and enrollment visit, then follow-up visits for AVF sounds registration will be conducted once a week for all participants, prior to dialysis session, over a period of 8 weeks.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

End-stage renal disease (ESRD) is an increasingly prevalent global health issue, closely linked to the aging population. The majority of individuals with ESRD requiring renal replacement therapy undergo hemodialysis (HD) treatment . A successful HD procedure requires a well-functioning vascular access (VA) to ensure a safe and durable connection between the patient's circulation and the artificial kidney. To date, VA dysfunction remains the leading cause of morbidity and hospitalization among HD patients, representing a major limitation of this treatment modality. The current recommended VA for hemodialysis is the native arteriovenous fistula (AVF), which is surgically created in the forearm by connecting a vein and an artery through an anastomosis. Although the AVF is considered the first-choice access, it is still associated with high rates of non-maturation and early failure, with up to 40% failing within the first year post-intervention, mainly due to vascular stenosis. Identifying patients at risk of AVF failure is crucial, yet current surveillance strategies remain inadequate. In practice, AVF function is rarely monitored using the gold standard Doppler ultrasound (US) after surgical creation and initiation of HD, unless nurses report significant cannulation difficulties. By that time, however, the AVF is often already occluded, requiring the urgent placement of a central venous catheter to continue HD, followed by surgical intervention to create a new AVF. Moreover, Doppler US is time-consuming and requires a dedicated nephrologist with specific imaging expertise. Furthermore, in smaller dialysis centres, the lack of access to a Doppler US machine further restricts effective surveillance.

Continuous monitoring of AVF function could enable early identification of reduced blood flow or stenosis development, allowing timely salvage intervention by interventional radiologists before the complete closure of the AVF.

Over the years, nurses and nephrologists got used to assess AVF by palpation and auscultation, qualitatively evaluating its vibration (thrill) and the sounds it emits using a stethoscope. A non-stenotic AVF typically produces a soft, continuous murmur: a strong sound during systole and a weaker one during diastole, both associated with laminar blood flow. In contrast, a malfunctioning AVF often lacks a palpable thrill and emits a systolic-only high-pitched, hissing sound caused by turbulent and disturbed blood flow. In more severe cases of stenosis, a distinct 'whistling' sound may be heard, indicating critical dysfunction or complete failure of the AVF.

Based on these clinical evidences, recent studies have revealed significant differences in the acoustic characteristics of AVF sounds, recorded with electronic stethoscopes, between functioning and non-functioning AVFs. The frequency spectra of these sounds show that patent AVFs are characterized by low-frequency sounds, whereas stenotic AVFs exhibit higher frequencies, reaching up to 700-800 Hz. Furthermore, it has been demonstrated that AVF sounds acquired with an electronic stethoscope can be used to extract key information about hemodynamic conditions, providing indications of complex flow dynamics and adequate blood volume for effective HD. These results suggest that sound analysis has significant potential to improve clinical AVF surveillance and enhance patient outcomes.

However, the monitoring technique involving the use of an electronic stethoscope requires expert personnel, as it demands numerous precautions during both sound recording (e.g., avoiding friction and excessive pressure) and analysis, which requires technical expertise. These factors limit the use of this technological solution to only a small subset of HD patients.

To overcome these limitations, a prototype wearable device called AVF-MONITOR has been designed which allows to record AVF sound, possibly enabling simple and continuous AVF surveillance. In the future, after adequate testing, AVF-MONITOR could be potentially used in a home setting, allowing patients to independently monitor their AVF function on a daily basis.

Study Type

Interventional

Enrollment (Estimated)

6

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 Contact

Study Locations

  • Italy
    • BG
      • Bergamo, BG, Italy
        • ASST HPG23 - Unità di Nefrologia
        • Contact:
        • Principal Investigator:
          • Simona Zerbi, M.D.

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:

  • Provision of informed consent prior to any study specific procedures.
  • Female and/or male aged ≥ 18.
  • Patients undergoing HD with a mature and functioning native AVF.

Exclusion Criteria:

  • Patients with a history of complications related to the AVF in use.
  • Patients who use a graft or catheter to perform HD.
  • Patients with reduced life expectancy (less than 1 year).

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: Device Feasibility
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Patients
Patients undergoing HD with a functioning native AVF
Device: AVF MONITOR
Wearable non-invasive device consisting in an electronic platform that can acquire acoustic data by means of an analog microphone.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
High-low peak ratio
Time Frame: Once weekly for 8 weeks after the initial screening and enrollment visit
Correlation between the high-low peak ratio (HLPR) calculated from acoustic recordings obtained using the AVF-MONITOR device (in Hz) and the gold standard electronic stethoscope (in Hz).
Once weekly for 8 weeks after the initial screening and enrollment visit

Collaborators and Investigators

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

Sponsor

Mario Negri Institute for Pharmacological Research

Investigators

  • Study Director: Giuseppe Remuzzi, M.D., Istituto Di Ricerche Farmacologiche Mario Negri

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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 (Estimated)

March 1, 2026

Primary Completion (Estimated)

September 1, 2026

Study Completion (Estimated)

September 1, 2026

Study Registration Dates

First Submitted

December 19, 2025

First Submitted That Met QC Criteria

December 19, 2025

First Posted (Estimated)

January 5, 2026

Study Record Updates

Last Update Posted (Actual)

January 14, 2026

Last Update Submitted That Met QC Criteria

January 12, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • AVF-MONITOR POC

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

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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