Kasper Sørensen

Aalborg University · Department of Health Science and Technology

Background Low cardiorespiratory fitness (ie, peak oxygen consumption [V.O2peak]) is associated with cardiovascular disease and all-cause mortality and is recognized as an important clinical tool in the assessment of patients. Cardiopulmonary exercise test (CPET) is the gold standard procedure for determination of V.O2peak but has methodological ch...

Cardiorespiratory fitness measured as V̇O2max is considered an important variable in the risk prediction of cardiovascular disease and all-cause mortality. Non-exercise V̇O2max prediction models are applicable, but lack accuracy. Here a model for the prediction of V̇O2max using seismocardiography (SCG) was investigated. 97 healthy participants (18-...

Objective Conduction-induced heart failure in patients with left bundle branch block (LBBB) can benefit from cardiac resynchronization therapy (CRT). However, some patients are non-responders to the therapy with one contributing factor being poor optimization of the atrioventricular (AV) pacing delay. In this study, we have investigated the pacing-...

Introduction Echocardiography is a key diagnostic tool for assessment of myocardial performance and hemodynamics. Seismocardiography can potentially provide fast and reliable assessments of key components related to myocardial performance. Aims The aims of this study were to investigate the correlation between SCG and echocardiographic measures an...

Objective: Seismocardiography is the measurement of vibration waves caused by the beating heart with accelerometer(s) placed on the chest. Investigating the nature and the behavior of these vibration waves, by comparing measurements from multiple sites, would help to understand the heart's mechanical contraction activity. Approach: Using newly d...

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

The purpose of this study was to investigate the correlation between the seismocardiogram and cardiorespiratory fitness. Cardiorespiratory fitness can be estimated as VO2max using non-exercise algorithms, but the results can be inaccurate. Healthy subjects were recruited for this study. Seismocardiogram and electrocardiogram were recorded at rest....

Cardiac time intervals are important hemodynamic indices and provide information about left ventricular performance. Phonocardiography (PCG), impedance cardiography (ICG), and recently, seismocardiography (SCG) have been unobtrusive methods of choice for detection of cardiac time intervals and have potentials to be integrated into wearable devices....

The purpose of this work is to define fiducial points in the seismocardiogram (SCG) and to correlate them with physiological events identified in ultrasound images. For 45 healthy subjects the SCG and the electrocardiogram (ECG) were recorded simultaneously at rest. Immediately following the SCG and ECG recordings ultrasound images of the heart wer...

Introduction: Robot assisted laparoscopic surgeries are becoming the standard procedure for radical prostatectomies (RALRP). General anesthesia, Trendelenburg positioning and capnoperitoneum during RALRP affect patient’ gas exchange, leading to possible complications in the postoperative phase, such as hypoxemia. The aim of this paper is to examine...

Temporal alignment of signals obtained using different acquisition systems is often complicated by asynchronous sampling. In the current study we aligned 3-lead ECGs recorded in a phonocardiogram setup with 12-lead Holter ECGs. Two signals with common morphology (lead II from both devices, recorded synchronously with closely placed electrodes) were...

Introduction: Doppler Tissue M-Mode ultrasound facilitates a method for measuring both mitral and aortic valve opening and closing. These measures can be used when assessing global information about the cardiac cycle. The method depends on an operator to manually setting points in the ultrasound image to obtain the timing intervals. We developed an...

Signal-averaged ECG (saECG) has been used to show delayed ventricular activation and myocardial infarction, but alignment jitter acts as a low-pass filter. Jitter arises due to sampling of the signal, and due to imperfect alignment algorithms. In this study we investigated the influence of the sample rate on the saECG spectrum, i.e. if the jitter c...

The present work investigates the use of a Laser Doppler Vibrometer (LDV) to record valve sounds and characterizes those recordings. An LDV (Polytec PDV-100) was used to measure the normal component of the velocity of the chest wall at 30 points (grid of 6 × 5 points) in each of seven subjects. The recorded signals were analyzed in the frequency do...

A 2015 consensus paper proposed a unified definition of the early repolarization (ER) pattern based upon quantification of end-QRS notches and slurs in the ECG. In this study we investigated the relationship between end-QRS concave “bite” segments in the vectorcardiogram (VCG) and the consensus ER pattern. We reviewed digital 12-lead ECG recordings...

Introduction: Studies of the movement of the chest wall show their potential in the diagnosis of heart diseases. Few studies have focused on mapping these movements especially in the lower inaudible frequency band. Aims: This study evaluates Body Surface Mapping (BSM) as a method for describing mechanical cardiac activity. Methods: The chest wall's...