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.

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.

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.

Tampere