Deep Vein Thrombosis (DVT)NCT07665320
Impedance Plethysmography Based Deep Vein Thrombosis Monitoring During Catheter-directed Thrombolysis
An observational study of Deep Vein Thrombosis (DVT), run by Tampere University at 2 sites in Finland.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Deep Vein Thrombosis (DVT)
- What is being tested?
- Impedance plethysmography IPG, Venous Occlusion Plethysmography VOP and Breathing and leg movement exercise
- Type of treatment
- Medical device
- How many people
- 40 participants
- Where
- 2 sitesFinland
- Study dates
- 17 Jul 2025to Dec 2027
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Tampere
Who may be able to join
- Age: 18 or older;
- DVT detected on other lower limb;
- Suitable for CDT treatment;
- Ability to give informed consent;
- Volunteering for the study.
- Age: 18 or older;
- Ability to give informed consent;
- Volunteering for the study
Who cannot join
- Age under 18 years;
- Inability to give informed consent;
- Denial;
- Too injured skin in the measurement area
- Diagnosed DVT in lower limbs;
- Age under 18 years;
Show all 9Show fewer
- Inability to give informed consent;
- Denial;
- Too injured skin in the measurement area.
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Finland2 sites, 1 recruiting
- Recruiting
Tampere University Hospital
Tampere
Oksala, +3583311611, niku.oksala@tuni.fi
- Completed
Tampere University
Tampere
About this study
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.
Read the 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
- Collect IPG data for developing signal processing, data analysis and ML algorithms for DVT detection and assessment.
- Evaluate the performance of the developed methods to gold standard references including angiography, ultrasound imaging and venous occlusion plethysmography.
- Investigate whether multi-frequency IPG measurement improves the performance of DVT detection compared to single frequency measurement and determine the optimal measurement frequency.
- 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
- To investigate methods for simulating DVT and to compare the performance of these methods for DVT simulation.
- Conditions
- Deep Vein Thrombosis (DVT)
- Being tested
- Impedance plethysmography IPG, Venous Occlusion Plethysmography VOP, Breathing and leg movement exercise
- Keywords
- deep vein thrombosis, DVT
- Medical subject headings
- Venous Thrombosis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Impedance plethysmography IPGDevice
Also called IPG
IPG signal is measured with ThrombUS+ prototype device
Venous Occlusion Plethysmography VOPDevice
Also called 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).
Breathing and leg movement exerciseOther
Also called Valsalva
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.
| Study group | Role | What they receive |
|---|---|---|
| Patients | DVT detected on other lower limb, undergoing catheter-directed thrombolysis Receives: Device: Impedance plethysmography IPG; Device: Venous Occlusion Plethysmography VOP; Other: Breathing and leg movement exercise | |
| Healthy volunteers | Healthy volunteers Receives: Device: Impedance plethysmography IPG; Device: Venous Occlusion Plethysmography VOP; Other: Breathing and leg movement exercise |
What is being measured
The primary outcome is the main question the study is designed to answer.
Impedance plethysmography (IPG) data during CDT treatment
Measured: From enrollment to the end of the CDT treatment (up to 2 days)
Impedance plethysmography (IPG) data from healthy volunteers
Measured: From enrollment to the end of measurements (up to 2 hours)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Jun 2026
- Study start17 Jul 2025
- Primary completionDec 2027 (estimated)
- Study completionDec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Deep Vein Thrombosis (DVT)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 40 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Tampere University
- Sponsor type
- University, hospital or other
- Collaborators
- Tampere University Hospital
- Responsible party
- Principal investigator, Antti Vehkaoja, Tampere University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07665320
- Sponsor's protocol ID
- ThrombUS+B4
- Status last verified
- Jun 2026
- First submitted
- 15 May 2026
- Last updated
- 29 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 29 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Impedance Plethysmography Based Deep Vein Thrombosis Monitoring During Catheter-directed Thrombolysis
- ClinicalTrials.gov ID
- NCT07665320
- Acronym / sponsor ID
- ThrombUS+B4
- Conditions
- Deep Vein Thrombosis (DVT)
- Keywords
- deep vein thrombosis, DVT
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 40 participants (estimated)
- Lead sponsor
- Tampere UniversityUniversity, hospital or other
- Collaborators
- Tampere University Hospital
- Study start
- 17 Jul 2025 (actual)
- Primary completion
- Dec 2027 (estimated)
- Study completion
- Dec 2027 (estimated)
- First posted
- 24 Jun 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
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
- Collect IPG data for developing signal processing, data analysis and ML algorithms for DVT detection and assessment.
- Evaluate the performance of the developed methods to gold standard references including angiography, ultrasound imaging and venous occlusion plethysmography.
- Investigate whether multi-frequency IPG measurement improves the performance of DVT detection compared to single frequency measurement and determine the optimal measurement frequency.
- 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
- To investigate methods for simulating DVT and to compare the performance of these methods for DVT simulation.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Patients | – | Device: Impedance plethysmography IPG, Device: Venous Occlusion Plethysmography VOP, Other: Breathing and leg movement exerciseDVT detected on other lower limb, undergoing catheter-directed thrombolysis |
| Healthy volunteers | – | Device: Impedance plethysmography IPG, Device: Venous Occlusion Plethysmography VOP, Other: Breathing and leg movement exerciseHealthy volunteers |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Tampere
Key inclusion criteria (8 listed)
- Age: 18 or older;
- DVT detected on other lower limb;
- Suitable for CDT treatment;
- Ability to give informed consent;
- Volunteering for the study.
Key exclusion criteria (9 listed)
- Age under 18 years;
- Inability to give informed consent;
- Denial;
- Too injured skin in the measurement area
- Diagnosed DVT in lower limbs;
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Impedance plethysmography IPGAlso: IPGIPG signal is measured with ThrombUS+ prototype device | Device | Healthy volunteers, Patients |
| Venous Occlusion Plethysmography VOPAlso: VOPIn 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). | Device | Healthy volunteers, Patients |
| Breathing and leg movement exerciseAlso: ValsalvaThe 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 | Healthy volunteers, Patients |
Primary outcome
Impedance plethysmography (IPG) data during CDT treatment
Time frame: 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)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 Jun 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Deep Vein Thrombosis (DVT), run by Tampere University at 2 sites in Finland.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 29 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Finland. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Vehkaoja (+358407393181, antti.vehkaoja@tuni.fi), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Impedance plethysmography (IPG) data during CDT treatment (time frame: From enrollment to the end of the CDT treatment (up to 2 days)). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 Jun 2026.