Impedance Plethysmography Based Deep Vein Thrombosis Monitoring During Catheter-directed Thrombolysis

June 24, 2026 updated by: Antti Vehkaoja, Tampere University

The purpose of this study is to collect data on blood circulation using a multi-frequency impedance plethysmography device developed in the ThrombUS+ project. Impedance plethysmography (IPG) is a non-invasive method that measures changes in blood volume using electrodes placed on the skin. The collected data will be used for device development, the improvement of diagnostic data analysis methods, and AI training.

A total of 40 participants will be recruited for this study, with 20 healthy volunteers in Tampere University and 20 patients undergoing thrombolytic therapy for DVT at Tampere University Hospital.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

This study aims to collect IPG data set from healthy volunteers and DVT patients using ThrombUS+ prototype device developed during the project and commercial IPG device as a reference. The data will be used to develop ThrombUS+ IPG device, its signal processing and analysis algorithms and to train ML models.

Objectives of the study are to

  1. Collect IPG data for developing signal processing, data analysis and ML algorithms for DVT detection and assessment.
  2. Evaluate the performance of the developed methods to gold standard references including angiography, ultrasound imaging and venous occlusion plethysmography.
  3. Investigate whether multi-frequency IPG measurement improves the performance of DVT detection compared to single frequency measurement and determine the optimal measurement frequency.
  4. Investigate and compare different interventions to cause changes in venous blood volume for DVT detection, such as venous occlusion by thigh cuff, active respiration and muscle activation.

Secondary objectives are

1) To investigate methods for simulating DVT and to compare the performance of these methods for DVT simulation.

Study Type

Observational

Enrollment (Estimated)

40

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

  • Finland
      • Tampere, Finland
        • Recruiting
        • Tampere University Hospital
        • Contact:
      • Tampere, Finland
        • Completed
        • Tampere University

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

Yes

Sampling Method

Non-Probability Sample

Study Population

Tampere

Description

Inclusion Criteria for Patients group:

  • Age: 18 or older;
  • DVT detected on other lower limb;
  • Suitable for CDT treatment;
  • Ability to give informed consent;
  • Volunteering for the study.

Exclusion Criteria for Patients group:

  • Age under 18 years;
  • Inability to give informed consent;
  • Denial;
  • Too injured skin in the measurement area

Inclusion Criteria for Healthy volunteers group:

  • Age: 18 or older;
  • Ability to give informed consent;
  • Volunteering for the study

Exclusion Criteria for Healthy volunteers group:

  • Diagnosed DVT in lower limbs;
  • Age under 18 years;
  • Inability to give informed consent;
  • Denial;
  • Too injured skin in the measurement area.

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

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Healthy volunteers
Device: Impedance plethysmography IPG
IPG signal is measured with ThrombUS+ prototype device
Other Names:
  • IPG
Device: Venous Occlusion Plethysmography VOP
In VOP measurement, a temporal blood restriction is caused by an occlusive cuff blocking venous outflow but allowing arterial inflow. The cuff intervention causes a change in venous blood volume, and it can be measured by electrical impedance plethysmography (IPG).
Other Names:
  • VOP
Other: Breathing and leg movement exercise
The first exercise is the Valsalva maneuver, where the subject first inhales and then pushes out the breath while the larynx is closed. In the second exercise, the subject inhales for approximately 10 seconds, holds the breath for approximately 5 seconds, and then breathes out. Finally, the subject moves the ankles to contract calf muscles, and further to cause changes in venous blood volume. The IPG signal is measured on both calves by ThrombUS+ prototype device during these exercises.
Other Names:
  • Valsalva
Patients
DVT detected on other lower limb, undergoing catheter-directed thrombolysis
Device: Impedance plethysmography IPG
IPG signal is measured with ThrombUS+ prototype device
Other Names:
  • IPG
Device: Venous Occlusion Plethysmography VOP
In VOP measurement, a temporal blood restriction is caused by an occlusive cuff blocking venous outflow but allowing arterial inflow. The cuff intervention causes a change in venous blood volume, and it can be measured by electrical impedance plethysmography (IPG).
Other Names:
  • VOP
Other: Breathing and leg movement exercise
The first exercise is the Valsalva maneuver, where the subject first inhales and then pushes out the breath while the larynx is closed. In the second exercise, the subject inhales for approximately 10 seconds, holds the breath for approximately 5 seconds, and then breathes out. Finally, the subject moves the ankles to contract calf muscles, and further to cause changes in venous blood volume. The IPG signal is measured on both calves by ThrombUS+ prototype device during these exercises.
Other Names:
  • Valsalva

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Impedance plethysmography (IPG) data during CDT treatment
Time Frame: From enrollment to the end of the CDT treatment (up to 2 days)
From enrollment to the end of the CDT treatment (up to 2 days)
Impedance plethysmography (IPG) data from healthy volunteers
Time Frame: From enrollment to the end of measurements (up to 2 hours)
From enrollment to the end of measurements (up to 2 hours)

Collaborators and Investigators

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

Sponsor

Tampere University

Collaborators

Tampere University Hospital

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)

July 17, 2025

Primary Completion (Estimated)

December 1, 2027

Study Completion (Estimated)

December 1, 2027

Study Registration Dates

First Submitted

May 15, 2026

First Submitted That Met QC Criteria

June 23, 2026

First Posted (Actual)

June 24, 2026

Study Record Updates

Last Update Posted (Actual)

June 29, 2026

Last Update Submitted That Met QC Criteria

June 24, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • ThrombUS+B4

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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