The project focuses on the possibility of detecting blood loss using electrical impedance tomography. Based on previous animal experiments, it was found that the bolus of saline significantly affects the signal of chest bioimpedance. It is assumed that blood loss of a similar volume will cause a similar signal change with the opposite trend. The aim of this project is to determine whether there is a significant change in the thoracic electrical impedance tomography signal when blood loss is caused by voluntary blood donation.

Electrical impedance tomography is a bedside method of ventilation monitoring. The bioimpedance of the tissue depends, among other things, on its blood content. The area of the chest and especially the lungs is a heavily perfused tissue, which also serves as one of the reservoirs of blood in case of blood loss. It is therefore possible that blood loss will be visible on chest bioimpedance relatively soon.

The study will be performed on voluntary blood donors. Blood loss of 450 mL will be caused by the collection of donated blood. During blood collection at the transfusion department, thoracic bioimpedance will be measured using electrical impedance tomography. The resulting signal change will then be analyzed to determine the possibility of detecting and measuring blood loss using electrical impedance tomography.

Inclusion Criteria:

• voluntary blood donation

Exclusion Criteria:

• standard exclusion criteria for voluntary blood donation based on the transfusion station protocol
• standard exclusion criteria for electrical impedance tomography according to the manufacturer