Bioimpedance-based measurement method for simultaneous acquisition of respiratory and cardiac gating signals

Abstract

Respiratory and cardiac motion artefacts impair the quality and reliability of medical imaging, particularly in nuclear medicine. At worst, the interpretation of distorted images may lead to inadequate or unnecessary treatment. Image artefacts can be minimized by gating the image acquisition according to respiratory phase and cardiac contractions. However, currently there are no clinically established dual-gating methods in nuclear medicine imaging. The aim of this study is to validate a previously determined optimized bioimpedance measurement configuration against traditional respiratory and cardiac measurement systems in 12 volunteers. High agreement and excellent correlations (r = 0.944-0.999) were found between respiratory peak-to-peak amplitudes as well as temporal respiratory and cardiac intervals. Above all, good quality respiratory and cardiac gating signals were obtained from all test subjects with a fairly regular sinus rhythm. Importantly, both signals were acquired simultaneously with a single device. Due to the simplicity of this inexpensive method, the technique has high potential to be adopted for dual-gating in clinical practice in the future.

Galvanically Decoupled Current Source Modules for Multi-Channel Bioimpedance Measurement Systems

“…One exemplary application for single measurements is body composition scales [2][3][4]. Transient measurements can, for example, be executed for respiration monitoring or detection of muscle contractions [5,6]. Additionally, in some applications, such as the electrical impedance tomography (EIT) imaging technique [7,8], multi-channel measurement devices are required.…”

A Miniaturized MEMS Motion Processing System for Nuclear Medicine Imaging Applications

“…In cardiac and oncologic Positron emission tomography (PET)/computed tomography (CT) imaging, cardiac, respiratory, and patient body motions may impair the image quality and the quantitative accuracy of heart imaging [1][2][3]. To reduce motion-related inaccuracies, cardiac and respiratory gating methods are the most common approaches applied in clinical PET imaging [4].…”

“…Cardiac gating is accomplished by an electrocardiography (ECG) measurement system, while respiratory gating can be performed by external devices such as spirometry, elastic belts (consisting of pressure or load cell sensors) monitors or using optical techniques including a camera and laser sensor that track chest wall or abdomen displacement [3,6,7]. However, respiratory gating devices have been considered for only research purposes due to the need for complex logistics and long data processing which may increase patient discomfort and be laborious for the clinicians [2,3]. Additionally, ECG is able to show only electrical activity of the heart and still fails to trace the instantaneous mechanical state of the heart due to the stirring movements of the myocardium [8].…”

“…Thus, these challenges complicate PET imaging protocols and create a serious demand for simultaneous recording of cardiac and respiratory signals in dual gating. Recently, new techniques based on bioimpedance [2,9] and accelerometers [10] have been suggested for concurrent acquisition of both respiratory and cardiac signals in oncologic and cardiac PET imaging. However, there is still space to optimize these methods, especially in terms of technology, accuracy, and patient comfort.…”

Derivation of a respiration trigger signal in small animal list-mode PET based on respiration-induced variations of the ECG signal

“…To this end, the most common and best established technique entails recording chest wall motion using a pressure sensor integrated in an elastic belt placed around the patient's thorax. 4,13,14 Other respiratory gating techniques employ a pneumotachographic recording device, which measures airway flow, 15 list-mode driven techniques using PET raw data, 6,16 bioimpedance-based measurement methods responsive to changes in thoracic impedance during breath-taking, 17,18 or assessment of respiration through a video monitoring device. 19 Despite the availability of these several techniques, respiratory gating has achieved a significant clinical foothold only in oncological studies aiming to identify and localize small lesions in the lung or the liver.…”