Asgeir Alexandersson

Össur · Research and Development

Transfemoral amputation is a debilitating condition that leads to long-term mobility restriction and secondary disorders that negatively affect the quality of life of millions of individuals worldwide. Currently available prostheses are not able to restore energetically efficient and functional gait, thus, recently, the alternative strategy to inje...

This study was designed to investigate the feasibility and the potential effects on walking performance of a short gait training with a novel impairment-specific hip assistance (iHA) through a bilateral active pelvis orthosis (APO) in patients with acquired brain injury (ABI). Fourteen subjects capable of independent gait and exhibiting mild-to-mod...

Introduction Neuroprostheses that can relay signals to and from the nervous system and work with lower-limb prostheses are currently being developed to provide users with sensory feedback and/or intent control over their prostheses. Such systems incorporate functions not available to persons with lower-limb amputation before, and many of their pote...

Introduction Neuroprosthetic systems that can work with prosthetic legs are currently being developed to provide individuals with lower-limb amputation with intent control over their device and sensory feedback. No such system is commercially available, and the effects of providing functions that have previously not been available to lower-limb pro...

Lower limb amputation (LLA) destroys the sensory communication between the brain and the external world during standing and walking. Current prostheses do not restore sensory feedback to amputees, who, relying on very limited haptic information from the stump-socket interaction, are forced to deal with serious issues: the risk of falls, decreased m...

Conventional leg prostheses do not convey sensory information about motion or interaction with the ground to above-knee amputees, thereby reducing confidence and walking speed in the users that is associated with high mental and physical fatigue1–4. The lack of physiological feedback from the remaining extremity to the brain also contributes to the...

External recordings of the electrohysterogram (EHG) can provide new knowledge on uterine electrical activity associated with contractions. Better understanding of the mechanisms underlying labor can contribute to preventing preterm birth which is the main cause of mortality and morbidity in newborns. Promising results using the EHG for labor predic...

The electrohysterogram (EHG) is a promising means of monitoring pregnancy and of detecting a risk of preterm labor. To improve our understanding of the EHG as well as its relationship with the physiologic phenomena involved in uterine contractility, we plan to model these phenomena in terms of generation and propagation of uterine electrical activi...

The Objective of this paper is to evaluate novel method for analyzing the nonlinear correlation of the uterine electromyography (EMG). The application of this method may improve monitoring in pregnancy, labor detection and preterm labor detection. Uterine EMG signals recorded from a 4x4 matrix of electrodes on the subjects' abdomen are used here. T...

The proportion of patients with non-small-cell lung cancer (NSCLC) who undergo surgery with curative intent is one measure of effectiveness in treating lung cancer. To the best of our knowledge, surgical resection rate (SRR) for a whole nation has never been reported before. We studied the SRR and surgical outcome of NSCLC patients in Iceland durin...

Following resection for non-small cell lung cancer (NSCLC), patients are usually admitted to the post-anesthesia care unit (PACU)for a few hours before admission to a general ward (GW). However, some patients need ICU-admission, either immediately post-surgery or from the PACU or GW. The aim of this study was to investigate the indications and risk...

A sublobar resection is performed on patients with non-small cell lung cancer (NSCLC) who are not candidates for a lobectomy due to reduced pulmonary function or comorbid disease. The aim of this study was to investigate the outcomes of these operations in Iceland. A retrospective study of all patients with NSCLC who underwent wedge resection or se...

The analysis of the electrical activity of the uterus recorded externally, the electrohysterogram (EHG), may find an application in the prediction of labor. In the literature parameters that are supposed to be related to the excitability of the uterine cells have almost exclusively been used for this purpose. In the present paper we evaluate the po...

Most of the studies on the synchronization between EHG signals, recorded during the same contractions at different locations, are limited to the use of only two channels. Multichannel techniques have however been widely applied to EEG signals but rarely to EHG. In this paper, we investigate the use of multichannel uterine EMG signals for classifyin...

Labor prediction using the electrohysterogram has immediate clinical applications and has been the aim of several studies in recent years. Studies using various linear methods such as classic spectral analysis do not give clinically useful results. In this paper we present the use of two methods that investigate nonlinearity to predict normal labor...

This study investigates phase synchronization in the time-frequency domain between uterine signals recorded at different sites during the same contraction from women during pregnancy and women in labor. We used the complex Morlet wavelet transform to estimate the phase synchronization between the uterine signals. The method was applied on a set of...