Objective: Abdominal aortic aneurysm (AAA) is associated with dilatation of central elastic arteries, while it is uncertain whether peripheral muscular arteries are affected. The aim of this study was to investigate radial artery diastolic lumen diameter (LD), wall thickness, and circumferential wall stress (CWS) in patients with AAA. Methods: We included 130 men with AAA (mean age, 70.4 ± 3.5 years) and 61 men without AAA (mean age, 70.5 ± 3.2 years) in the study. High-frequency ultrasound examination (50 MHz) was used to measure radial artery diameter, wall thickness, and CWS was calculated. Results: Men with AAA exhibited smaller radial artery LD (2.34 ± 0.42 mm vs 2.50 ± 0.38 mm; P <.01), thicker intima (0.094 ± 0.024 mm vs 0.081 ± 0.018 mm; P <.001), similar intima-media (0.28 ± 0.05 vs 0.26 ± 0.05 mm; P = NS), and lower CWS (42.9 ± 10.2 kPa vs 48.6 ± 11.4 kPa; P <.001), compared with controls. Subgroup analyses including all patients showed smaller LD and thicker intima in patients on statin therapy versus no statin therapy and current/ex-smoking versus never smoking. Individuals with hypertension versus no hypertension also presented with thicker intima, but with no difference in LD. Conclusions: AAAs demonstrated a smaller LD and thicker intima in the radial artery, in contrast with the theory of a general dilating diathesis of the arteries. Apart from AAA, other factors such as atherosclerosis, smoking habits, and hypertension might also be determinants of radial artery caliber and thickness. Clinical Relevance: The clinical relevance of this study is the added insight into the pathophysiology of abdominal aortic aneurysm (AAA). Today, the management of AAA is focused on reduction of general cardiovascular risk factors and treatment is based on surgical approaches when the AAA is already manifest. By shedding light on unknown pathophysiological aspects of AAA, it will eventually be possible to develop targeted pharmacological treatments to prevent the formation of AAA, to halt disease progression, and to find early cardiovascular markers of AAA. © 2022 Society for Vascular Surgery

It has been proposed that formation of abdominal aortic aneurysm (AAA) is part of a systemic arterial dilatative disease. However, arteries in the upper extremities are scarcely studied and it remains unclear whether both muscular and elastic arteries are affected by the proposed systemic arterial dilatation. The aim of this study was to investigate the diameter and stiffness of muscular and elastic arteries in arterial branches originating from the aortic arch. Twenty-six men with AAA (69 +/- 4 yr) and 57 men without AAA (70 +/- 5 yr) were included in the study. Ultrasound was used to examine the distal and proximal brachial artery, axillary artery, and common carotid artery (CCA), and measurement of diameter and diameter change was performed with wall-tracking software. Blood pressure measurements were used to calculate local arterial wall stiffness indices. The AAA cohort presented larger arterial diameters in the CCA and axillary artery after adjustment for body surface area (P = 0.002, respectively), whereas the brachial artery diameters were unchanged. Indices of increased stiffness in CCA (e.g., lower distensibility, P = 0.003) were seen in subjects with AAA after adjustments for body mass index and mean arterial blood pressure. This study supports the theory of a systemic arterial dilating diathesis in peripheral elastic, but not in muscular, arteries. Peripheral elastic arteries also exhibited increased stiffness, in analogy with findings in the aorta in AAA.

Objective: Abdominal aortic aneurysm (AAA) is associated with morphological and functional changes in both aneurysmal and non-aneurysmal arteries. However, it remains uncertain whether similar changes also exist in the venous vasculature. The aim of this study was to evaluate global venous function in patients with AAA and controls. Methods: This experimental study comprised 31 men with AAA (mean +/- standard deviation age 70.0 +/- 2.8 years) and 29 male controls (aged 70.6 +/- 3.4 years). Venous occlusion plethysmography (VOP) was used to evaluate arm venous compliance at venous pressures between 10 and 60 mmHg in steps of 5 mmHg. Compensatory mobilisation of venous capacitance blood (capacitance response) was measured with a volumetric technique during experimental hypovolaemia induced by lower body negative pressure (LBNP). Results: The VOP induced pressure-volume curve was significantly less steep in patients with AAA (interaction, p < .001), indicating lower venous compliance. Accordingly, the corresponding pressure-compliance curves displayed reduced venous compliance at lower venous pressures in patients with AAA vs. controls (interaction, p < .001; AAA vs. control, p = .018). After adjusting for arterial hypertension, diabetes mellitus, hyperlipidaemia, chronic obstructive pulmonary disease, and smoking, VOP detected differences in venous compliance remained significant at low venous pressures, that is, at 10 mmHg (p = .008), 15 mmHg (p = .013), and 20 mmHg (p = .026). Mean venous compliance was negatively correlated with aortic diameter (r = -.332, p = .010). Mobilisation of venous capacitance response during LBNP was reduced by approximately 25% in patients with AAA (p = .030), and the redistribution of venous blood during LBNP was negatively correlated with aortic diameter (r = -.417, p = .007). Conclusion: Men with AAA demonstrated reduced venous compliance and, as a result, a lesser capacity to mobilise peripheral venous blood to the central circulation during hypovolaemic stress. These findings imply that the AAA disease may be accompanied by functional changes in the venous vascular wall.

This paper introduces a low-complexity memoryless linearizer for suppression of distortion in analog-to-digital interfaces. It is inspired by neural networks, but has a substantially lower complexity than the neural network schemes that have appeared earlier in the literature in this context. The paper demonstrates that the proposed linearizer can outperform the conventional parallel memoryless Hammerstein linearizer even when the nonlinearities have been generated through a memoryless polynomial model. Further, a design procedure is proposed in which the linearizer parameters are obtained through matrix inversion. Thereby, the costly and time consuming it- erative nonconvex optimization that is traditionally used when training neural networks is eliminated. Moreover, the design and evaluation incorporate a large set of multi-tone signals covering the first Nyquist band. Simulations show signal-to-noise-and-distortion ratio (SNDR) improvements of some 25 dB for multi-tone signals that correspond to the quadrature parts of OFDM signals with QPSK modulation.

This paper introduces low-complexity frequency-dependent (memory) linearizers designed to suppress nonlinear distortion in analog-to-digital interfaces. Two different linearizers are considered, based on nonlinearity models which correspond to sampling before and after the nonlinearity operations, respectively. The proposed linearizers are inspired by convolutional neural networks but have an order-of-magnitude lower implementation complexity compared to existing neural-network-based linearizer schemes. The proposed linearizers can also outperform the traditional parallel Hammerstein linearizers even when the nonlinearities have been generated through a Hammerstein model. Further, a design procedure is proposed in which the linearizer parameters are obtained through matrix inversion. This eliminates the need for costly and time-consuming iterative nonconvex optimization that is traditionally associated with neural network training. The design effectively handles a wide range of wideband multi-tone signals and filtered white noise. Examples demonstrate significant signal-to-noise-and-distortion ratio (SNDR) improvements of about 20–30 dB, as well as a lower implementation complexity than the Hammerstein linearizers.

This paper introduces a novel low-complexity memoryless linearizer for suppression of distortion in analog frontends. It is based on our recently introduced linearizer which is inspired by neural networks, but with orders-of-magnitude lower complexity than conventional neural-networks considered in this context, and it can also outperform the conventional parallel memoryless Hammerstein linearizer. Further, it can be designed through matrix inversion and thereby the costly and time consuming numerical optimization traditionally used when training neural networks is avoided. The linearizer proposed in this paper is different in that it uses 1-bit quantizations as nonlinear activation functions and different bias values. These features enable a look-up table implementation which eliminates all but one of the multiplications and additions required for the linearization. Extensive simulations and comparisons are included in the paper, for distorted multi-tone signals and bandpass filtered white noise, which demonstrate the efficacy of the proposed linearizer.

This letter considers the design and properties of linear-phase finite-length impulse response (FIR) filters for equalization of the frequency responses of digital-to-analog converters (DACs). The letter derives estimates for the filter orders required, as functions of the bandwidth and equalization accuracy, for four DAC pulses that are used in DACs in multiple Nyquist bands. The estimates are derived through a large set of minimax-optimal equalizers and the use of symbolic regression followed by minimax-optimal curve fitting for further enhancement. Design examples demonstrate the accuracy of the proposed estimates. In addition, the letter discusses the appropriateness of the four types of linear-phase FIR filters, for the different equalizer cases, as well as the corresponding properties of the equalized systems.

This paper introduces a sampling frequency offset (SFO) estimation method based on the Farrow structure, which is typically utilized for the SFO compensation and thereby enables a reduction of the implementation complexity of the SFO estimation. The proposed method is implemented in the time domain and works for arbitrary bandlimited signals, thus with no additional constraints on the waveform structure. Moreover, it can operate on only the real or imaginary part of a complex signal, which further reduces the estimation complexity. Furthermore, the proposed method can simultaneously estimate the SFO and additional sampling time offset (STO) and it is insensitive to other synchronization errors, like carrier frequency offset. Both the derivations of the proposed method and its implementation are presented, and through simulation examples, it is demonstrated that it can accurately estimate both SFO and STO for different types of bandlimited signals.

This letter presents a novel approach for \mbox{efficiently} computing time-index powered weighted sums of the form $\sum_{n=0}^{N-1} n^{K} v[n]$ using cascaded accumulators. Traditional direct computation requires $K{\times}N$ general multiplications, which become prohibitive for large $N$, while alternative strategies based on lookup tables or signal reversal require storing entire data blocks. By exploiting accumulator properties, the proposed method eliminates the need for such storage and reduces the multiplicative cost to only $K{+}1$ constant multiplications, enabling efficient real-time implementation. The approach is particularly useful when such sums need to be efficiently computed in sample-by-sample processing systems.

The purpose of this study was to compare the correlation and agreement between AS derived from either an energy-integrating detector CT (EID-CT) or a photon-counting detector CT (PCD-CT). Reproducibility was also compared. In total, 26 calcified coronary lesions (from five cadaveric hearts) were identified for inclusion. The hearts were positioned in a chest phantom and scanned in both an EID-CT and a prototype PCD-CT. The EID-CT and PCD-CT acquisition and reconstruction parameters were matched. To evaluate the reproducibility, the phantom was manually repositioned, and an additional scan was performed using both methods. The EID-CT reconstructions were performed using the dedicated calcium score kernel Sa36. The PCD-CT reconstructions were performed with a vendor-recommended kernel (Qr36). Several monoenergetic energy levels (50-150 keV) were evaluated to find the closest match with the EID-CT scans. A semi-automatic evaluation of calcium score was performed on a post-processing multimodality workplace. The best match with Sa36 was PCD-CT Qr36 images, at a monoenergetic level of 72 keV. Statistical analyses showed excellent correlation and agreement. The correlation and agreement with regards to the Agatston score (AS) between the two methods, for each position as well as between the two positions for each method, were assessed with the Spearman s rank correlation. The correlation coefficient, rho, was 0.98 and 0.97 respectively 0.99 and 0.98. The corresponding agreements were investigated by means of Bland-Altman plots. High correlation and agreement was observed between the AS derived from the EID-CT and a PCD-CT. Both methods also demonstrated excellent reproducibility.

Background: As guidelines endorse the use of computed tomography (CT) for examining coronary artery disease (CAD), it is important to compare the advantages and disadvantages of the novel photon counting detector CT (PCD-CT) technology with the established energy integrating detector CT (EID-CT). Purpose: To compare the image quality of coronary computed tomography angiography (CCTA) and the Agatston scores (AS) derived from EID-CT and PCD-CT. Material and Methods: In this prospective observational study, 28 patients underwent clinical calcium score and CCTA scans on an EID-CTand a PCD-CT scanner. CCTA images were qualitatively analyzed by five observers using visual grading characteristics. The correlation and agreement of the AS were assessed using Spearmans rank correlation and Bland-Altman plots. Results: This qualitative analyses demonstrated a high fraction of " good" or "excellent" ratings for the image criteria in both CT systems. The sharpness of the distal lumen and image quality regarding motion artifacts were rated significantly higher for EID-CT (P < 0.05). However, the sharpness of coronary calcification was rated significantly higher for PCD-CT (P < 0.05). Spearmans rank correlation and Bland-Altman plots showed good correlation (P = 0.95) and agreement regarding the AS between EID-CT and PCD-CT. Conclusion: Both CT systems exhibited high CCTA image quality. The sharpness of calcifications was rated significantly higher for PCD-CT. A good correlation was observed between the AS derived from the two systems.

Objectives 

Coronary computed tomography angiography is the primary modality for noninvasive assessment of coronary artery disease. Photon-counting computed tomography (PCCT) offers superior spatial resolution and spectral imaging for detailed characterization of atherosclerotic plaques. This study aimed to evaluate the impact of virtual monoenergetic imaging (VMI) energy levels and reconstruction kernels on segmentation-based measurement of plaque volume in individuals with coronary atherosclerosis using PCCT.

Materials and Methods 

Fifty study participants underwent coronary computed tomography angiography with ultra-high-resolution PCCT. Both polyenergetic, 120 kVp (T3D) images and spectral images at varying VMI energy levels were reconstructed using different kernels. Plaque volumes were measured using semiautomated attenuation-based segmentation, adjusting segmentation thresholds for each VMI energy level. In addition, absolute plaque volume measurements were conducted using a coronary phantom simulating different plaque types.

Results 

Using a sharper kernel (Bv64 vs Bv48) significantly increased noncalcified plaque volume measurements (P < 0.005) in study participants, whereas a 0.2-mm slice thickness reduced calcified plaque volumes compared with 0.4 mm (P < 0.005). VMI energy level had no impact on measured volumes. Phantom measurements confirmed significant variability in measured volumes of calcified and noncalcified plaques depending on reconstruction method, as well as a minor effect of VMI level.

Conclusions 

In PCCT, the reconstruction kernel predominantly affects noncalcified coronary plaque quantification, whereas slice thickness mainly impacts calcified plaque volumes. In study participants, measured plaque volumes were not affected by VMI energy level when energy-specific segmentation thresholds were used, although a minor effect of VMI was observed in the phantom model.

Background: Coronary CT angiography (CCTA) is a key non-invasive tool for evaluating coronary artery disease (CAD). While energy-integrating detector CT (EID-CT) offers high negative predictive value (NPV), its positive predictive value (PPV) is limited in heavily calcified vessels. Photon-counting detector CT (PCD-CT), with higher spatial resolution and reduced blooming, may enhance diagnostic performance. Current PCD-CT systems provide both standard-resolution (SR) and ultra-high-resolution (UHR) modes, but the clinical impact of these modes remains under investigation.

Objectives: To compare the diagnostic accuracy and image quality of SR-PCD-CT versus EID-CT in quantifying coronary stenosis, using quantitative coronary angiography (QCA) as reference. Materials and methods: In this prospective, single-centre study, 21 patients (5 women, mean age 71.5 years) with suspected CAD underwent CCTA with both EID-CT and SR-PCD-CT prior to QCA. A total of 301 coronary segments were assessed for stenosis severity, with ≥50 % stenosis deemed significant. Image quality was graded using a 5-point scale. 

Results: No significant differences in percentage diameter stenosis (%DS) were found between imaging techniques (p = 0.20). Both EID-CT and SR-PCD-CT showed good agreement with QCA (AUC: PCD-CT 0.89, EID-CT 0.86). Specificity and NPV were high for both; sensitivity and PPV were moderate. SR-PCD-CT yielded higher image quality compared to EID-CT (p < 0.001).

Conclusions: In standard resolution mode, PCD-CT offers excellent image quality for quantifying coronary stenosis at comparable diagnostic accuracy compared to EID-CT

Conducting polymers (CP) have shown great features in building textile actuators. To date, most of the yarn-based or CP-yarn actuators have been operated in liquid electrolytes in a three-electrode-cell configuration, comprising an external counter and a reference electrode. For integration in textiles, a two-electrode system is needed, where both electrodes are in a yarn format. This can be achieved by having two CP-yarns, where one acts as the anode and the other as the cathode. For these two CP-yarns to operate synchronically, they both need to expand (or contract) during opposite reactions. This can be achieved by doping one CP-yarn with mobile anions that will expand during oxidation, while the other CP-yarn should be doped with immobile anions expanding during reduction. As a result, the same movement is created upon opposite redox reactions, both collaborating with the actuation in the same direction without the need for an external passive electrode to close the electrical circuit, which could oppose or hinder the movement. Most of the studies on textile actuators are based on cation-driven CP-yarn actuators, while little is known about anion-driven systems in CP-yarn actuators. Here, we first present a study of the effect of the dopants, solvents, and polymer layer combinations on the mechanism and strain of CP-yarns. The CP-yarns are coated with two layers: an inner poly(3,4-ethylenedioxythiophene) (PEDOT) layer and the outer and active polypyrrole (PPy) layer. According to our results, the dopant of the inner PEDOT layer seems to affect the actuation mechanism of the outer PPy layer and, thereby, of the whole CP-yarn actuator, influencing the direction of the movement and enhancing or hindering the total strain of the actuator. We show that a CP-yarn coated with PEDOT(Tos)/PPy(ClO4) and actuated in LiClO4 aqueous solution showed a pure anion-driven actuation. Next, based on the latter results, we demonstrate for the first time the dual actuation of two CP-yarns, doped with two different dopants, ClO4- and DBS-, actuating simultaneously driven by opposite redox reactions and exhibiting an average of 0.5% of strain, an important step toward in-air actuating yarns.

Cellular mechanotransduction signals play a crucial role in physiological and pathological conditions, including skeletal disorders. Although various systems exist to mechanically stimulate cultured cells, most are constrained by incubator incompatibility, limited physiological relevance, nonuniform stimulation, or complexity. The objective of this article is to develop and validate a compact, incubator-compatible tool capable of delivering localized and physiologically relevant mechanical stimulation to small cell populations. Here, we introduce a polypyrrole-based wire-shaped microactuator designed to induce localized mechanical stress to adjacent cells. These wire-shaped microactuators are biocompatible, easy-to-use, and compact for use within standard in vitro cell culture systems. Using a noncontact optical method, we characterize the actuation of polypyrrole-coated wires in an aqueous NaDBS electrolyte, showing radial expansion of 1.5–8 µm depending on the deposited polypyrrole film thickness, comparable to cellular dimensions. Next, the actuation is confirmed to be robust and stable to use in cell culture media at physiological temperature. To evaluate biological relevance, osteoblastic KUSA-A1 cells are mechanically stimulated inside the incubator and transcriptomic changes are assessed. Mechanical stimulation resulted in upregulation of genes previously associated with mechanotransduction, including Fos and Fosb. Additionally, several uncharacterized long noncoding RNAs are differentially expressed, suggesting potential novel players in the mechanotransduction pathway.

This paper investigates an urban Emergency Evacuation Network Design (EEND) problem on a large scale when geographical risk in different areas varies. The decisions to make are (i) determining active shelters, (ii) selecting evacuation routes, and (iii) managing the supply of relief commodities from distribution centers to shelters. A region prone to floods and hurricanes is divided into zones, each with a specific vulnerability risk. For each zone, a risk measure is calculated by combining the risk factors -transporting people and relief commodities and the placement of temporary shelters. The objective is to minimize the maximum risk across the network, ensuring a balanced distribution of risk. A combinatorial scenario planning approach is developed to manage the uncertainty in disaster severity and the evacuee numbers. To incorporate varied geographical risks, a smart hybrid optimization approach as a new solution technique is developed, tuned, and validated to solve the EEND problem. The proposed approach uses directed local search structures designed for the EEND problem and an AI-based self-parameter tuning module, enhancing performance. To extract insights, Rennes, France, is considered a case study. The results indicate a reduction in casualties using a min-max formulation compared to traditional sum-risk objectives. Further, a detailed evacuation plan that increases the number of city regions enhances EEND performance. Practical insights suggest minimizing the number of shelters to the essential capacity needed to host all evacuees, as additional shelters may lead to increased evacuation and supply routes, potentially in areas with higher risk.

Background: The Swedish naval specialized boarding element participated in Operation Atalanta in 2013 to mitigate piracy by escorting and protecting ships included in the United Nations World Food Program in the Indian Ocean. We describe the experiences of the Swedish naval specialized boarding-element members during 4 months of international naval hostile duty. Some studies have reported experiences of naval duty for the Coast Guard or the merchant fleet; however, we did not find any studies that identified or described experiences of long-time duty onboard ship for the naval armed forces.

Materials and Methods: The respondents wrote individual notes of daily events while onboard. Conventional content analysis was used on the collected data, using an inductive approach.

Results: The findings revealed three broad themes: military preparedness, coping with the naval context, and handling physical and mental strain. Different categories emerged indicating that the participants need the ability to adapt to the naval environment and to real situations.

Conclusion: The Swedish naval forces should train their specialized element members in coping strategies.

Background: Sweden has been part of Operation Atalanta four times since 2009. Being part of an international naval deployment means acting in a substantially different context and environment. The Swedish Armed Forces leadership training includes the use of Wheelan’s IMGD model, whereby trust is a significant part of group dynamics.

Materials and Methods: Interviews took place after deployment when the respondents had been back in Sweden for 8 months. The constant comparative analysis method according to Glaser was used to answer the aim of the study.

Results: Trust was seen as the core of the interviews and was based on three categories: leadership, preparedness and endurance.

Discussion: The core category trust, and the lack of trust, may be a result of poor preparedness. The respondents expressed that they felt safe and secure within their own group. The “us and them” mentality was an important finding, and the cause should be examined more closely to increase trust and team spirit.

Conclusion: The Swedish Navy could benefit from improvement in education, team building and pre-deployment training to increase trust and the level of readiness and to reduce stress.

Introduction: Stress week was included during training of Special Forces (SF) Operators in Sweden to test their ability and limits for handling stress in different unknown situations and environments at a military training facility in Sweden. The aim of the study was to examine the effects of stress and workload experienced in various tasks during firefighting and military medicine simulation training.

Methods: This pilot study was performed during the second day of stress week. The National Aeronautics and Space Administration Task Load Index (NASA-TLX) is a validated, subjective, and multidimensional assessment tool for rating perceived workload with six subscales: mental demand, physical demand, temporal demand, performance, effort, and frustration. These subscales were used as an indicator of stress experienced. The different tasks were assessed by the SF Operators by rating the NASA-TLX subscales for each task, which were then analyzed and compared using ANOVA.

Results: There was a significant difference between the two simulation exercises assessed by the participants and instructors, and both groups considered firefighting to be more demanding than medical. The participants perceived the mental and physical demands as more demanding in the firefighting exercises, as well as for the level of frustration and effort. However, no differences regarding performance or temporal demands between the simulation exercises were found.

Conclusion: The principle "train as you fight" implies difficult and demanding situations. When exposing Swedish SF Operators to challenging situations, assessment of perceived stress and performance are possible.

The study compared two simulation environments for training of Swedish naval Command and Control teams by using indirect measures, including workload, combat readiness, and situation awareness. The literature explains simulation-based training as providing a safe avenue to practice relevant scenarios. Fidelity, the degree of realism in the simulation, and workload, the equilibrium between demands and assigned tasks, are crucial factors examined in this study of low- and high-fidelity naval simulations. This study was conducted to better understand the effects of various training methods. An experimental design with repeated measures was used with three consecutive escalating parts. The subjective, multidimensional assessment tool, NASA-Task Load Index was used to rate perceived workload. Combat readiness of the ship and mental demand yielded significant results. For combat readiness of the ship, there was a difference between the low and the high-fidelity setting, for the initial part of the scenario p = 0.037 and for the second part p = 0.028. Mental demand was experienced as higher in the low-fidelity setting, p = 0.036. Notably, the simulated internal battle training for onboard command teams in a low-fidelity setting was found to induce a level of stress comparable with that experienced in a high-fidelity setting. The results indicate that low-fidelity training results in a workload not distinguishable from high-fidelity training and has practical implications for increased use of low-fidelity training as part of (naval) command team training programmes.

Simulation-based training (SBT) has a positive effect on learning. The aim of this study was to examine perceived learning of a command and control (C2) team in a Swedish naval exercise conducted in two settings (low and high fidelity). The participants were part of the permanent C2 team onboard a vessel in the Navy and could maintain their ordinary roles during the SBT. A within-group design was used whereby the C2 team first took part in the low-fidelity setting followed by the high-fidelity setting. The questionnaires used in this study were developed based on the learning objectives for the exercise, and questions were asked as statements. The results indicate that SBT may constitute a learning opportunity. The conclusion of the research highlights the same learning effects in a low-fidelity setting.

Electrical signals in plants are mediators of long-distance signaling and correlate with plant movements and responses to stress. These signals are studied with single surface electrodes that cannot resolve signal propagation and integration, thus impeding their decoding and link to function. Here, we developed a conformable multielectrode array based on organic electronics for large-scale and high-resolution plant electrophysiology. We performed precise spatiotemporal mapping of the action potential (AP) in Venus flytrap and found that the AP actively propagates through the tissue with constant speed and without strong directionality. We also found that spontaneously generated APs can originate from unstimulated hairs and that they correlate with trap movement. Last, we demonstrate that the Venus flytrap circuitry can be activated by cells other than the sensory hairs. Our work reveals key properties of the AP and establishes the capacity of organic bioelectronics for resolving electrical signaling in plants contributing to the mechanistic understanding of long-distance responses in plants.

Plants are able to sense and respond to a myriad of external stimuli, using different signal transduction pathways, including electrical signaling. The ability to monitor plant responses is essential not only for fundamental plant science, but also to gain knowledge on how to interface plants with technology. Still, the field of plant electrophysiology remains rather unexplored when compared to its animal counterpart. Indeed, most studies continue to rely on invasive techniques or on bulky inorganic electrodes that oftentimes are not ideal for stable integration with plant tissues. On the other hand, few studies have proposed novel approaches to monitor plant signals, based on non-invasive conformable electrodes or even organic transistors. Organic electrochemical transistors (OECTs) are particularly promising for electrophysiology as they are inherently amplification devices, they operate at low voltages, can be miniaturized, and be fabricated in flexible and conformable substrates. Thus, in this study, we characterize OECTs as viable tools to measure plant electrical signals, comparing them to the performance of the current standard, Ag/AgCl electrodes. For that, we focused on two widely studied plant signals: the Venus flytrap (VFT) action potentials elicited by mechanical stimulation of its sensitive trigger hairs, and the wound response of Arabidopsis thaliana. We found that OECTs are able to record these signals without distortion and with the same resolution as Ag/AgCl electrodes and that they offer a major advantage in terms of signal noise, which allow them to be used in field conditions. This work establishes these organic bioelectronic devices as non-invasive tools to monitor plant signaling that can provide insight into plant processes in their natural environment.

Background Benign peripheral nerve tumours consist of different types, most commonly Schwannomas. Preoperative Magnetic Resonance Imaging (MRI) is commonly performed before surgery and Pathoanatomical Diagnosis (PAD) confirms the diagnosis. Our aims were to study the utility of MRI and the relation between tumour size and symptoms.Methods Retrospectively, patients, surgically treated for benign nerve tumours between 2008 and 2019, were identified and preoperative MRI, with measurement of tumour size, PAD, symptoms, peroperative details, and symptomatic outcomes of surgery, were analysed.Results The sensitivity and specificity to correctly identify Schwannomas with preoperative MRI were 85% and 50%, respectively, based on 30 Schwannomas and nine neurofibromas that were identified. Tumour size did not affect the presence of preoperative symptoms, but patients with sensory dysfunction at last follow-up had larger Schwannomas (p &lt; 0.05). Symptoms as a palpable tumour, paraesthesia and pain improved by surgical excision (p &lt; 0.001, p &lt; 0.001 and p &lt; 0.012, respectively), but sensory and motor dysfunction were common postoperatively. No malignant peripheral nerve sheath tumours (MPNST) were found. Using a surgical microscope, instead of only loop magnification, lowered the risk of perioperative nerve injuries (p &lt; 0.05), but did not further diminish postoperative symptoms.Conclusions Early and accurate diagnosis of Schwannomas is valuable for adequate presurgical preparation and prompt surgical intervention. Preoperative examination with MRI has a high sensitivity, but low specificity; although recent advancement in MRI technology indicates improvement in diagnostic precision. Surgical excision is preferably performed early in conjunction with symptomatic debut to improve outcome.

Surgery for benign nerve tumours is performed for pathoanatomical diagnosis and symptomatic relief, but might cause residual problems. We aimed to assess patient-reported symptoms and disability before and after surgery at a national level. In total, 206 cases surgically treated for a benign peripheral nerve tumour 2010-2019 registered in the Swedish Quality Registry for Hand Surgery (HAKIR; response rates 22-34%) were analysed. Surgery reduced overall disability in the affected limb (QuickDASH 18/100 [IQR 5-36] preoperatively and 5/100 [IQR 0-22] 12 months postoperatively), improved ability to perform daily activities (HQ-8; 11/100 [IQR 0-50] preoperatively and 0/100 [IQR 0-20] 12 months postoperatively) and decreased three evaluated pain modalities: pain at rest (HQ-8; 20/100 [IQR 0-40] preoperatively and 0/100 [IQR 0-10] 12 months postoperatively), pain on motion without load (HQ-8; 20/100 [IQR 0-40] preoperatively and 0/100 [IQR 0-10] 12 months postoperatively), and pain on load (HQ-8; 24/100 [IQR 1-69] preoperatively and 1/100 [IQR 0-30] 12 months postoperatively). Cold sensitivity was a minor problem both before and after surgery (HQ-8; 0/100 [IQR 0-30] preoperatively and 1/100 [IQR 0-40] 12 months postoperatively). We conclude that surgery for benign peripheral nerve tumours provides good symptomatic relief with low risk for residual problems.

Peripheral nerve tumours, most commonly schwannomas and neurofibromas, might present significant challenges by eliciting physical symptoms and emotional distress. We aimed to explore patients' expectations, perceptions, and experiences regarding their diagnosis and the surgical treatment of a nerve tumour in the upper limb. Fourteen adults (10 women, 4 men; age range 35-85) from two Swedish hand surgery clinics participated in semi-structured interviews. Data saturation was reached. The interviews were transcribed verbatim and analysed following a conventional content analysis approach. Three main categories emerged. Causal Reasoning and Anticipations included explanatory thoughts of tumour aetiology, expectations of surgery, and concerns for the future. Anxiety and Adaptation comprised psychological strain, but also how to overcome challenges in daily life. Course of Care encompassed uncertainty and waiting time, interaction with health care and decision making on whether or not to have surgery. Recognising the interplay between physical symptoms and psychological responses underscores the need for personalised communication and patient-centred strategies, such as clear and empathetic information and shared decision-making, to reduce uncertainty and support individuals facing peripheral nerve tumours in the upper limb.

Logistics networks need to conform to arising market trends and public requirements for greening freight transport through a series of Green Logistics Practices (GLPs). This study sets out to explore the use of fossil-free fuels as a GLP and possible influence on business strategy and system design. A literature review was conducted which concluded that literature about the use of fossil-free fuels is limited. An explorative interview study was conducted to further explore the use of biomethane among actors in logistics networks. Customers increasingly request green freight transport typically accepting moderately higher prices for green transport. Development of green logistics services is predominately driven by corporate stakeholders and internal initiatives, while public regulation appeared to have a weak influence. The study revealed new insights into how GLPs can relate to each other.

Purpose: The need to decarbonize logistics is pressing. In implementing fossil-free fuels, like biomethane, involved actors perceive drivers and barriers have been described at a surface level in green logistics literature. However, actors act in the context of each other, and there lacks research to understand the effects these drivers and barriers may have on actor relationships. Therefore, the purpose of this study is to increase understanding of how actors are influenced and influence other actors when using biomethane in logistics. Design/Methodology/Approach: This study is an embedded case study of a Swedish regional logistics network that has implemented biomethane. The embedded case study is built upon three rounds of interviews: explorative and semi-structured. The analysis is guided by theory on stakeholder engagement to understand the relationship aspects. Findings: The actors included in the case study perceived drivers and barriers identified in literature to various degrees. These perceptions later affected how they engaged with each other to implement biomethane. Stakeholder engagement in this case study occurred as collaboration, disseminate, and assessing as result of the actor's perceptions. One example is how organizational culture influences how actors engage in transition to fossil-free fuels. Originality: This research sheds light on a fossil-free fuel not commonly researched. It also expands the existing research on drivers and barriers by exploring their effect on actor relationships. Use of stakeholder engagement theoretical lens provides depth in understanding of this phenomenon while also proposing further stakeholder engagement.

Purpose: Road freight is one of the largest emitters of greenhouse gases in the European Union, yet decarbonization is slow. Transition to fossil-free fuels in the logistics sphere is emerging from an innovation phase to where early adopters have begun to undertake decarbonization into their operation. To decarbonize road freight, logistics actors, such as hauliers and freight forwarders, need to feel supported. However, it is uncertain how support may be defined or impact logistics actors. Thus, leading to the purpose of this study: To define and explore support for logistics actors using fossil-free fuels. Methods: This is a mixed-method paper utilizing both document analysis (69 documents) and an interview study (12 interviews). Selection of these documents and interview respondents follow a purposive sampling state. Findings: Findings of the document analysis show that support for biomethane-fueled road freight in a regional context may originate from four actor types: government, business, logistics or societal. The resulting support types may be defined as managerial, financial, social or layered. From the interview study, layered support in using biomethane in road freight proved to be the most influential for logistics actors. Original/Value: Within green logistics literature, the use of document analysis as a method is not common. This research utilizes documents that have otherwise gone unrecognized to shed light on a topical issue.

Children and young people seeking asylum on their own face violence in many forms. Little is known about how they seek protection from criminalised violence. This article is based on ethnographic research, interviews and a survey of young migrants living precariously, mostly from Afghanistan, who fled to Sweden alone when they were children, but who did not have their protection needs recognised. Through lived experiences of not reporting criminalised violence to police, the article examines how protection is further denied in the context of recent changes to the Swedish migratory and welfare regime. This article finds that young migrants often perceive non-reporting as a zero-sum strategy of survival over safety. Insecure legal status prevents young migrants from engaging the law for protection from criminalised violence. Experiences of discriminatory and violent police treatment and institutional violence forming part of trajectories of displacement reinforce the lack of protection. Strategies of silence and solidarity are used to ensure the preservation of the self, the migratory project, to protect friends, and, occasionally, perpetrators. By examining young migrants experiences of non-protection from criminalised violence, intersecting structural forms of violence become visible. These failures of protection constitute part of a continuum of violence experienced by young people seeking asylum.

Young people seeking asylum face many different forms of violence, including violent crime, yet their illegalization, as well as their experiences of police contact and border violence, often lead to reporting of crime not being perceived as a safe or viable option. But what are the experiences of those who, in spite of their fears, do attempt to engage with law by reporting crime? Drawing on in-depth interviews with Omid, Hussein, and Akram - three young men who have sought refuge in Sweden - this article examines their attempts to mobilize law as victims of crime at the intersection of restrictive migration controls and welfare exclusions. I argue that the legal consciousness of young people in this situation is shaped by the same legal structures that create the underlying conditions for their victimization as well as by other people's perceptions of how law operates in relation to their legal status. Relationships of trust, friendship, and support can aid engagement with the criminal justice system, yet such engagement often results in re-victimization instead of protection and a lack of meaningful remedies, reinforcing feelings of disenchantment with law.

In this article we investigate the harmful effects of the 2018 Upper Secondary School Act (the ‘Study Law’) upon young people in Sweden who have sought to regularise their stay with the help of this law. We analyse these harmful impacts as ‘legal violence’: structural and symbolic violence embedded in or intensified by law (Menjívar and Abrego, 2012), in the context of Swedish welfare regulation.

The Study Law was ostensibly enacted to provide a new opportunity for some 7,000 young people, the majority of whom had fled Afghanistan. These young people had sought asylum in Sweden in 2015, but had not had their needs for protection recognised, instead being subjected to exclusionary laws, policies and growing racism. The Study Law substituted the possibility of protection with strict requirements of study, work and conduct, while the social and material support needed to fulfil these requirements largely was withheld.

In our analysis, we draw upon interviews with young people collected as part of a doctoral research project, legal materials, and our own, earlier joint experiences as legal practitioners working with those affected by this law. The legal violence of the Study Law, we argue, has produced individual and social harms, particularly impacting the lives of young people seeking asylum. The law has created a complex and hard-to-navigate, legally-violent regime that, directly and indirectly, has exacerbated hardships and facilitated suffering and even death.

Introduction Cerebrovascular reactivity imaging (CVR) is a diagnostic method for assessment of alterations in cerebral blood flow in response to a controlled vascular stimulus. The principal utility is the capacity to evaluate the cerebrovascular reserve, thereby elucidating autoregulatory functioning. In CVR, CO2 gas challenge is the most prevalent method, which elicits a vascular response by alterations in inspired CO2 concentrations. While several systems have been proposed in the literature, only a limited number have been devised to operate in tandem with mechanical ventilation, thus constraining the majority CVR investigations to spontaneously breathing individuals. Methods We have developed a new method, denoted Additional CO2, designed to enable CO2 challenge in ventilators. The central idea is the introduction of an additional flow of highly concentrated CO2 into the respiratory circuit, as opposed to administration of the entire gas mixture from a reservoir. By monitoring the main respiratory gas flow emanating from the ventilator, the CO2 concentration in the inspired gas can be manipulated by adjusting the proportion of additional CO2. We evaluated the efficacy of this approach in (1) a ventilator coupled with a test lung and (2) in spontaneously breathing healthy subjects. The method was evaluated by assessment of the precision in attaining target inspired CO2 levels and examination of its performance within a magnetic resonance imaging environment. Results and discussion Our investigations revealed that the Additional CO2 method consistently achieved a high degree of accuracy in reaching target inspired CO2 levels in both mechanical ventilation and spontaneous breathing. We anticipate that these findings will lay the groundwork for a broader implementation of CVR assessments in mechanically ventilated patients.

Background Older patients living with frailty have an increased risk for adverse events. The Clinical Frailty Scale (CFS) is a 9-point frailty assessment instrument that has shown promise to identify frail emergency department (ED) patients at increased risk of adverse outcomes. The aim of this study was to investigate the association between CFS scores and 30-day mortality in an ED setting when assessments are made by regular ED staff.Method This was a prospective multicentre observational study carried out between May and November 2021 at three EDs in Sweden, where frailty via CFS is routinely assessed by ED staff. All patients &gt;= 65 years of age were eligible for inclusion. Mortality at 7, 30 and 90 days, admission rate, ED and hospital length of stay (LOS) were compared between patients living with frailty (CFS &gt;= 5) and robust patients. Logistic regression was used to adjust for confounders.Results A total of 1840 ED visits of patients aged &gt;= 65 years with CFS assessments done during the study period were analysed, of which 606 (32.9%) were patients living with frailty. Mortality after the index visit was higher in patients living with frailty at 7 days (2.6% vs 0.2%), 30 days (7.9% vs 0.9%) and 90 days (15.5% vs 2.4%). Adjusted ORs for mortality for those with frailty compared with more robust patients were 9.9 (95% CI 2.1 to 46.5) for 7-day, 6.0 (95% CI 3.0 to 12.2) for 30-day and 5.7 (95% CI 3.6 to 9.1) 90-day mortality. Patients living with frailty had higher admission rates, 58% versus 36%, a difference of 22% (95% CI 17% to 26%), longer ED LOS, 5 hours:08 min versus 4 hours:36 min, a difference of 31 min (95% CI 14 to 50), and longer in-hospital LOS, 4.8 days versus 2.7 days, a difference of 2.2 days (95% CI 1.2 to 3.0).Conclusion Patients living with frailty, had significantly higher mortality and admission rates as well as longer ED and in-hospital LOS compared with robust patients. The results confirm the capability of the CFS to risk stratify short-term mortality in older ED patients.Trial registration number NCT04877028.

Objectives: Frailty, assessed with clinical frailty scale (CFS), alone or in combination with aggregated vital signs, has been proposed as a measure to better predict mortality of older patients in the emergency department (ED), but the added predictive value to conventional triage is unclear. Methods: This was a secondary analysis of a prospective observational study in three EDs in Sweden that evaluated the prognostic performance of the CFS alone or in combination with the national early warning score (NEWS), triage early warning score (TEWS) or the rapid emergency triage and treatment system (RETTS) triage tool using logistic regression. The primary outcome was 30-day mortality with 7- and 90-day mortality and admission as secondary outcomes reported as area under the receiver operating curve (AuROC) scores with 95% confidence intervals (CIs). The sensitivity, specificity, accuracy, predictive values, and likelihood ratios are reported for all models. Results: A total of 1832 patients were included with 17 (0.9%), 57 (3.1%), and 121 (6.6%) patients dying within 7, 30, and 90 days, respectively. The admission rate was 43% (795/1832). Frailty (CFS &gt; 4) was significantly associated with 30-day mortality (odds ratio 6, 95% CI 3-12, p &lt; 0.01). Prognostication of 30-day mortality was similar for all CFS-based models and better compared with models without CFS. The AuROC (95% CI) improved for RETTS from 0.67 (0.61-0.74) to 0.83 (0.79-0.88) (p = 0.008), for NEWS from 0.53 (0.45-0.61) to 0.82 (0.77-0.87) (p &lt; 0.001), and for TEWS from 0.63 (0.55-0.71) to 0.82 (0.77-0.87) (p = 0.002). Conclusion: Frailty measured with the CFS in combination with RETTS or structured vital sign assessment using NEWS or TEWS was better at prognosticating 30-day mortality compared to RETTS or early warnings score alone. Improved prognostication provides more realistic expectations and allows for informed discussions with patients and initiation of individualized treatment plans early in the ED process.

Background: The Clinical Frailty Scale (CFS) is a frailty assessment tool used to identify frailty in older patients visitingthe emergency department (ED). However, the current understanding of how it is used and accepted in ED clinicalpractice is limited. This study aimed to assess the feasibility of CFS in an ED setting.

Methods :This was a prospective, mixed methods study conducted in three Swedish EDs where CFS had recentlybeen introduced. We examined the completion rate of CFS assessments in relation to patient- and organisationalfactors. A survey on staff experience of using CFS was also conducted. All quantitative data were analyseddescriptively, while free text comments underwent a qualitative content analysis.

Results: A total of 4235 visits were analysed, and CFS assessments were performed in 47%. The completion rate exceeded 50% for patients over the age of 80. Patients with low triage priority were assessed to a low degree (24%). There was a diurnal variation with the highest completion rates seen for arrivals between 6 and 12 a.m. (58%). The survey response rate was 48%. The respondents rated the perceived relevance and the ease of use of the CFS with a median of 5 (IQR 2) on a scale with 7 being the highest. High workload, forgetfulness and critical illness were rankedas the top three barriers to assessment. The qualitative analysis showed that CFS assessments benefit from a clearroutine and a sense of apparent relevance to emergency care.

Conclusion: Most emergency staff perceived CFS as relevant and easy to use, yet far from all older ED patientswere assessed. The most common barrier to assessment was high workload. Measures to facilitate use may includeclarifying the purpose of the assessment with explicit follow-up actions, as well as formulating a clear routine for the assessment.

Registration: The study was registered on ClinicalTrials.gov 2021-06-18 (identifier: NCT04931472).

Background

Prolonged emergency department waiting times are associated with increased mortality among older patients. In January 2025, the ED of Linkoping University Hospital, Sweden, implemented a low-resource routine to expedite the workup of older patients living with frailty by prioritized physician assessment and subsequent workup.

Aim

To investigate if a frailty alert using the Clinical Frailty Scale followed by prioritized clinical assessment influences ED operating metrics.

Design

This was an observational before and after study of a pre-implementation group (control) and a post-implementation group (intervention) between October 2024 and February 2025.

Setting/Participants

Consecutive patients aged >64 years, with a documented CFS assessment during the ED visit at the Linkoping University Hospital, Sweden, who consented to participation, were included.

Method

Standard ED operating metrics, Time to physician, ED length of stay (LOS), and admission rates were compared between a pre-implementation group and a post-implementation group.

Results

A total of 542 ED visits were analyzed (248 pre-implementation, 294 post-implementation). Time to physician was shorter in the post-implementation group at 31 min (IQR 15, 65) versus 44 min (IQR 20, 94) (p < 0.001). ED LOS was reduced from 352 (IQR 266, 515) to 319 (IQR 240, 458) minutes (p = 0.014). The admission rate was unchanged at 59% and 60% (p = 0.4).

Conclusion

Frailty alerts based on the CFS with prioritized workup reduced ED LOS and time to physician in older patients living with frailty in this single center study and may be a low-resource intervention to reduce the risks of adverse events in the ED.

Trial Registration

ClinicalTrials.gov identifier: NCT06869148

Cerebral blood flow is monitored in the neurointensive care unit (NICU) to avoid further brain damage caused by secondary insults following subarachnoid hemorrhage and brain trauma. Current techniques are mainly snap-shot based and focus on larger vessels. However, continuous monitoring of the smaller vessels may help detect the onset of secondary insults at an earlier stage. In this study, long-term measurements of brain microcirculation with laser Doppler flowmetry (LDF) were performed and evaluated. The aim was to identify and describe physiological signal variations and separate these from movement artifacts. Fiberoptic probes for subcortical LDF recordings of perfusion and total light intensity (TLI) were implanted in three patients with subarachnoid hemorrhage. Data were successfully collected and visualized in real-time over 4 days, resulting in 34, 12, and 8.5 h per patient. Visual observation, wavelet transforms, moving medians, and peak envelopes were used to identify and describe movement artifacts and physiological changes. Artifacts occurred in &lt;5% of the total recording time and could be identified through signal processing. Identified physiological signal patterns included a slowly increasing perfusion trend over hours, vasomotion mainly at 2 cycles/min both in the perfusion and the TLI, and rapid, synchronized changes in the TLI and the perfusion on 38 occasions. Continuous LDF recordings indicating changes in the microvascular blood flow can increase the understanding of the microcirculation in the injured brain. In the long run, this may become a complement for the detection of secondary insults at an earlier stage than possible with todays techniques.

Purpose: Multimodal monitoring is used in the neurointensive care unit (NICU) to avoid further brain injury in patients with subarachnoid haemorrhage (SAH). The aims were to investigate cerebral microcirculation in patients with SAH using laser Doppler flowmetry (LDF), and to compare LDF data with intracranial pressure (ICP) and mean arterial pressure (MAP). Methods: An LDF system with an in-house developed two-channel fibre optical probe and software was used for bedside monitoring of microvascular CBF (Perf) in seven patients. Analyses of mean, peak-to-peak amplitude and frequency variations were performed on selected data based on protocol information. Analysis of frequency variations focused on vasomotion. Data comparisons were evaluated on longer timescales using Pearson correlation and on shorter timescales using a moving correlation index. Results: Microvascular data were successfully recorded for up to 10 days, resulting in 274 h of artefact-free data. The average perfusion ranged from 91 +/- 29 a.u. to 424 +/- 242 a.u. across patients and channels. Vasomotion was observed in 7-37 % and 4-44 % in the Perf and ICP data, respectively, with spatial, temporal, and interpersonal variations. Occasional positive and negative correlations between Perf and clinically monitored data were found on shorter timescales. Conclusion: Correlations varied daily among all individuals, confirming the need for moving indices to track correlation over time. Combining vasomotion analysis and correlations with clinical data can increase the knowledge about the underlying mechanisms of blood flow regulation in the injured brain in SAH patients.

BackgroundSubarachnoid haemorrhage (SAH) is one of the most severe forms of stroke in which delayed cerebral ischemia is one of the major complications. Neurointensive care aims at preventing and treating such complications and identification of biomarkers of early signs of ischemia might therefore be helpful.MethodsWe aimed at describing proteome profile in cerebral microdialysate in four patients with aneurysmal SAH using two dimensional gel electrophoresis in combination with mass spectrometry in search for new biomarkers for delayed cerebral ischemia and to investigate if there were temporal fluctuations in those biomarkers over time after aneurysmal bleed.ResultsThe results showed transthyretin in nine different proteoforms (1001, 1102, 2101, 3101, 4101, 4102, 5001, 5101, 6101) in cerebral microdialysate samples from four patients having sustained SAH. Several proteoforms show highly differing levels and pooled analysis of all samples showed varying optical density related to time from aneurysmal bleed, indicating a temporal evolution.ConclusionsTransthyretin proteoforms have not earlier been shown in cerebral microdialysate after SAH and we describe differing levels based on proteoform as well as time from subarachnoid bleed. Transthyretin is well known to be synthetized in choroid plexus, whilst intraparenchymal synthesis remains controversial. The results need to be confirmed in larger studies in order to further describe transthyretin.

Introduction: In orthognathic surgery, understanding the patients motives for treatment is a key factor for postoperative patient satisfaction and treatment success. In countries/systems where orthognathic surgery is funded by public means, patients are referred mainly due to functional problems, although studies of quality of life related changes after treatment indicate that psychosocial and aesthetic reasons might be equal or more important for the patient. There is no available validated condition specific instruments in the Swedish language for quality of life evaluation of patients with dentofacial deformities. Aims/objectives: Cross cultural translation and adaptation of the English-language instrument Orthognathic Quality of Life Questionnaire (OQLQ) into Swedish. Methods: OQLQ was translated into Swedish. A total of 121 patients in four groups were recruited and the Swedish version of the OQLQ (OQLQ-S) was tested by psychometric methods. Reliability was assessed by internal consistency and test-retest reliability. Validity was evaluated by face, convergent and discriminant validity. Results/findings and conclusions: OQLQ-S is reliable and showed good construct validity and internal consistency and can be used in a Swedish speaking population as a complement to clinical variables to evaluate patients with dentofacial deformity.

When treating patients with orthognathic surgery, there might be a risk of obstructive sleep apnoea (OSA) due to soft tissue changes in the upper airways, especially in patients treated with isolated mandibular setback or mandibular setback in combination with maxillary advancement. In the present study, we assessed respiratory function during sleep with home cardiorespiratory polygraphy in 62 patients who had not been previously been diagnosed with OSA at three times: prior to orthognathic surgery for aesthetic and functional indications, and then 3 months and 1 year after surgery. We evaluated surgical displacement based on measurements in three dimensions using pre- and post-operative computed tomography. There were only minor changes in the respiratory parameters such as the apnoea-hypopnoea index (AHI), the apnoea-hypopnoea index in the supine position (AHIsup), the oxygen saturation index (ODI) and the snore index. There was no significant correlation between surgical displacement and the AHI, AHIsup and ODI. There was a weak but significant correlation between vertical displacement of the anterior mandible and the snore index. Within the limitations of the present study, the risk for iatrogenic obstruction of the upper airways seems to be low in patients without OSA treated with orthognathic surgery.

This paper introduces realizations of a reconfigurable finite -impulse -response (FIR) filter for simultaneous equalization and lowpass filtering. The main advantage of the proposed solutions is computational complexity reduction compared to existing solutions for a given performance, which leads to reduced hardware complexity. The proposed structures employ properties of both a variable bandwidth (VBW) filter and a variable equalizer (VE) with variable coefficients. The overall transfer function of the proposed reconfigurable lowpass equalizer (RLPE) is a weighted linear combination of fixed subfilters where the weights are directly determined by the bandwidth and one or several parameters of the channel needed to be equalized. The paper provides design procedures based on minimax optimization and introduces a fast design method for the filter with several variable parameters that can substantially decrease the design time. Filter order estimation expressions as well as complexity expressions are presented for all proposed realizations. Design examples include comparison of the RLPE structures and a common approach of using a regular FIR equalization filter requiring online redesign when the bandwidth or channel characteristics are changed. It is shown that the number of general multiplications can be reduced up to 91% using the proposed RLPE.

Implementation techniques and results for a recently proposed real-time reconfigurable low-pass equalizer (RLPE) consisting of a variable bandwidth (VBW) filter and a variable equalizer (VE) are presented. Both components utilize fixed finite-length impulse response (FIR) filters combined with a few general multipliers, resulting in lower area and power consumption compared to a general FIR filter, despite requiring more multiplications. This is because the constant multipliers in the fixed FIR filters of the RLPE can be optimized for implementation. An additional advantage is that the proposed RLPE does not require online design. Various implementation alternatives for fixed FIR filters, including ways to increase the frequency, are evaluated to optimize the implementation of the RLPE. Several versions of the proposed RLPE and a general FIR filter for comparison are implemented using a 28-nm fully depleted silicon on insulator (FD-SOI) standard cell library. The results demonstrate that the RLPE baseline design requires less power and area than the general equalizer, and although the frequency of the baseline implementation is lower, the design can reach the same frequency while still having significantly less power and area. Furthermore, an approach is introduced to break the chain in the polynomial section of the VBW filter by using fewer additional registers compared to standard pipelining. Instead, this method reformulates the constant multiplication problem to produce correct results. For the considered case, the power consumption is reduced between 49% and 70% for different frequencies, with an area decrease in the range of 64%-67%, by using the proposed RLPE compared to a general FIR filter.

The paper introduces frequency-domain implementations of variable digital filters using the overlap-save method. Expressions for implementation and design complexities are derived for real-valued impulse responses. Design examples include implementations of a variable bandwidth (VBW) filter alone as well as a cascade of a VBW filter and a variable fractional delay(VFD) filter. Compared to a time-domain implementation and a filter bank approach, the proposed structures can reduce the implementation complexity significantly and achieve savings up to 95% in the multiplication rate and up to 89% in the addition rate.

This paper introduces an efficient design approach for a fast-convolution-based variable-bandwidth (VBW) filter. The proposed approach is based on a hybrid of frequency sampling and optimization (HFSO), that offers significant computational complexity reduction compared to existing solutions for a given performance. The paper provides a design procedure based on minimax optimization to obtain the minimum complexity of the overall filter. A design example includes a comparison of the proposed design-based VBW filter and time-domain designed VBW filters implemented in the time domain and in the frequency domain. It is shown that not only the implementation complexity can be reduced but also the design complexity by excluding any computations when the bandwidth of the filter is adjusted. Moreover, memory requirements are also decreased compared to the existing frequency-domain implementations. Index Terms—Variable bandwidth filter, fast convolution, frequency-domain design, time-varying systems, overlap-save, multirate filter banks.

This paper introduces a closed-form least-squares (LS) design approach for fast-convolution (FC) based variable-bandwidth (VBW) finite-impulse-response (FIR) filters. The proposed LS design utilizes frequency sampling and the VBW filter frequency-domain implementation using the overlap-save (OLS) method, that together offer significant savings in implementation and online bandwidth reconfiguration complexities. Since combining frequency-domain design and OLS implementation leads to a linear periodic time-varying (LPTV) behavior of the VBW filter, a set of the corresponding time-invariant impulse responses is considered in the proposed design. Through numerical examples, it is demonstrated that the proposed approach enables not only closed-form design of FC-based VBW filters with substantial complexity reductions compared to existing solutions for a given performance, but also allows the variable bandwidth range to be extended without any increase in complexity. Moreover, a way of reducing the maximum approximation error energy over the whole set of the time-invariant filters of the LPTV system is shown by introducing appropriate weighting functions in the design.

This paper introduces a sampling frequency offset (SFO) estimation method based on the Farrow structure, which is typically utilized for the SFO compensation and thereby enables a reduction of the implementation complexity of the SFO estimation. The proposed method is implemented in the time domain and works for arbitrary bandlimited signals, thus with no additional constraints on the waveform structure. Moreover, it can operate on only the real or imaginary part of a complex signal, which further reduces the estimation complexity. Furthermore, the proposed method can simultaneously estimate the SFO and additional sampling time offset (STO) and it is insensitive to other synchronization errors, like carrier frequency offset. Both the derivations of the proposed method and its implementation are presented, and through simulation examples, it is demonstrated that it can accurately estimate both SFO and STO for different types of bandlimited signals.

This letter presents a novel approach for \mbox{efficiently} computing time-index powered weighted sums of the form $\sum_{n=0}^{N-1} n^{K} v[n]$ using cascaded accumulators. Traditional direct computation requires $K{\times}N$ general multiplications, which become prohibitive for large $N$, while alternative strategies based on lookup tables or signal reversal require storing entire data blocks. By exploiting accumulator properties, the proposed method eliminates the need for such storage and reduces the multiplicative cost to only $K{+}1$ constant multiplications, enabling efficient real-time implementation. The approach is particularly useful when such sums need to be efficiently computed in sample-by-sample processing systems.

This paper deals with modeling, analysis, and optimization of power amplifiers (PAs) placed in a cascaded structure, particularly the effect of cascaded nonlinearities is studied by showing potential ways to minimize the total nonlinearities. The nonlinear least-squares algorithm is proposed to optimize the PA parameters along with the input power level, and thereby minimize the total nonlinearities in the cascaded structure. The simulation results demonstrate that the performance of the optimized configurations for up to five PAs using the proposed framework can improve the linearity properties of the overall cascade.