Publications by authors named "Koivisto T"

Supercontinuum generation in optical fiber involves complex nonlinear dynamics, making optimization challenging, and typically relying on trial-and-error or extensive numerical simulations. Machine learning and metaheuristic algorithms offer more efficient optimization approaches. We report here an experimental study of supercontinuum spectral shaping by tuning the phase of the input pulses, different optimization approaches including a genetic algorithm, particle swarm optimizer, and simulated annealing.

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Objective: Dolichoectatic vertebrobasilar aneurysms (DVBAs) are expansions of arterial tissue leading to aneurysmal formations without an obvious neck. Their natural history is poorly understood; usually patients are admitted with thromboembolic complications and/or neurological symptoms from the mass effect. There have not been international collective data, and correct timing for highly risky treatments has been under discussion.

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Background: The Finnish public healthcare system aims to ensure equal access to health services for all but faces challenges in meeting the demand for specialized care, such as neurosurgery, due to resource constraints. This study investigates interventions to increase resources at a neurosurgery outpatient clinic to improve patient care without compromising waiting times for diagnoses and treatments, leveraging Finland's unique healthcare landscape.

Methods: The study was conducted at Kuopio University Hospital's Department of Neurosurgery, the sole provider of neurosurgical care in Eastern Finland.

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Article Synopsis
  • Prior studies reported cavernomas' incidence at 0.2-1.9/100,000; this study found a higher rate of 2.01/100,000 from 2004-2020.
  • The research, conducted at two Finnish hospitals, identified 669 cavernoma cases and analyzed trends by sex, age group, and time using Poisson regression.
  • Findings show that incidence peaked in individuals aged 40-59 and notably increased, particularly for asymptomatic cases, indicating a growing healthcare burden.
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Purpose: An "open communication culture" in the workplace is considered a key contributor to high-quality interaction and providing means to address problems at work. We study how the ideals of "open communication" operate in healthcare.

Design/methodology/approach: We use discourse analysis to investigate the audio-recorded data from 14 workshop team discussions in older people services.

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Background: Chronic subdural haematoma is a common surgically treated intracranial emergency. Burr-hole drainage surgery, to evacuate chronic subdural haematoma, involves three elements: creation of a burr hole for access, irrigation of the subdural space, and insertion of a subdural drain. Although the subdural drain has been established as beneficial, the therapeutic effect of subdural irrigation has not been addressed.

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Results from two independent clinical validation studies for measuring hemodynamics at the patient's bedside using a compact finger probe are reported. Technology comprises a barometric pressure sensor, and in one implementation, additionally, an optical sensor for photoplethysmography (PPG) is developed, which can be used to measure blood pressure and analyze rhythm, including the continuous detection of atrial fibrillation. The capabilities of the technology are shown in several form factors, including a miniaturized version resembling a common pulse oximeter to which the technology could be integrated in.

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The intrinsic presence of ghosts in the symmetric teleparallel framework is elucidated. We illustrate our general arguments in f(Q) theories by studying perturbations in the three inequivalent spatially flat cosmologies. Two of these branches exhibit reduced linear spectra, signalling they are infinitely strongly coupled.

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Article Synopsis
  • Heart failure (HF) is a major health issue for those over 65, and seismocardiography, which measures heart vibrations through the chest, is being explored as a noninvasive detection method.
  • A multicenter study involving both inpatient and outpatient participants in Finland and the U.S. found that smartphone-based seismocardiography can effectively distinguish HF patients from healthy controls using advanced algorithms.
  • The study involved 217 HF patients and 786 control subjects, achieving high accuracy rates (89%) for HF detection, regardless of factors like age and sex.
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Eldercare workers experience higher levels of moral distress than other health and social care service workers. Moral distress is a psychological response to a morally challenging event. Very little is known about moral distress in the context of eldercare and about the mechanisms of preventing or mitigating moral distress.

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Article Synopsis
  • The study focused on aneurysmal intracerebral hemorrhage (aICH), highlighting the absence of personalized patient timelines and detailed brain imaging throughout treatment and recovery.
  • Researchers analyzed 54 patients who underwent surgical clipping for a specific type of aneurysm, compiling data from emergency calls to clinical outcomes using timeline and imaging panels.
  • Findings indicate that larger aICH volumes at the time of admission were linked to higher rates of rebleeds and mortality, emphasizing the need for timely intervention and enhanced imaging during surgery to monitor recovery.
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The right internal jugular vein is connected to the right atrium of the heart via the superior vena cava, and consequently its pressure, known as the jugular venous pressure or the jugular venous pulse (JVP), is an important indicator of cardiac function. The JVP can be estimated visually from the neck but it is rather difficult and imprecise. In this article we propose a method to measure the JVP using a motion sensor patch attached to the neck.

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Cardiac resynchronization therapy (CRT) is commonly used to manage heart failure with dyssynchronous ventricular contraction. CRT pacing resynchronizes the ventricular contraction, while AAI (single-chamber atrial) pacing does not affect the dyssynchronous function. This study compared waveform characteristics during CRT and AAI pacing at similar pacing rates using seismocardiogram (SCG) and gyrocardiogram (GCG), collectively known as mechanocardiogram (MCG).

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Our aim is to develop a blood pressure (BP) measurement technology that could be integrated into a finger-worn pulse oximeter, eliminating the need for a brachial cuff. We present a miniature cuffless tonometric finger probe system that uses the oscillometric method to measure BP. Our approach uses a motorized press that is used to apply pressure to the fingertip to measure BP.

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  • The study explores the relationship between pre-eclampsia and saccular intracranial aneurysms (sIAs), focusing on female patients, their relatives, and matched controls, to assess the prevalence of pre-eclampsia in these groups.
  • It analyzed data from 265 female sIA patients, their female relatives, and a control group, revealing a higher prevalence of pre-eclampsia in sIA patients (11%) compared to matched controls (6%).
  • The findings indicate that pre-eclampsia is more common among sIA patients, with familial occurrences observed in seven families, suggesting a need for further research into how pre-eclampsia may increase the risk of sIA rupture.
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Article Synopsis
  • - The study investigates the connection between having a family history of epilepsy in first-degree relatives and the likelihood of developing epilepsy after experiencing an aneurysmal subarachnoid hemorrhage (aSAH), which is a severe type of stroke often leading to significant complications.
  • - Researchers analyzed data from 760 aSAH survivors and compared it with a control group of 2,240 individuals, finding that 15% of aSAH patients developed epilepsy within about 7 months post-stroke, significantly higher than the rates in the general population and their relatives.
  • - The findings indicate that having at least one first-degree relative with epilepsy increases the risk of developing epilepsy after aSAH, with nearly 28% of patients
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Background: Aneurysmal subarachnoid hemorrhage (aSAH) is a neurological emergency, affecting a younger population than individuals experiencing an ischemic stroke; aSAH is associated with a high risk of mortality and permanent disability. The noble gas xenon has been shown to possess neuroprotective properties as demonstrated in numerous preclinical animal studies. In addition, a recent study demonstrated that xenon could attenuate a white matter injury after out-of-hospital cardiac arrest.

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Treatment for arteriovenous malformations of the brain (bAVMs) aims to achieve complete removal or occlusion of the lesion in order to eradicate the risk of rupture and subsequent morbidity associated with these lesions. Despite initially successful treatment, bAVMs may carry a risk of recurrence especially in younger patients. We studied the rate of recurrence of surgically treated bAVMs at Kuopio University Hospital (KUH) in 1981-2021.

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Background: Hyperspectral imaging (HSI) has the potential to enhance surgical tissue detection and diagnostics. Definite utilization of intraoperative HSI guidance demands validated machine learning and public datasets that currently do not exist. Moreover, current imaging conventions are dispersed, and evidence-based paradigms for neurosurgical HSI have not been declared.

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Introduction: During the transcatheter aortic valve replacement (TAVR) procedure, hemodynamic measurements can be used to evaluate transcatheter heart valve (THV) performance. We hypothesized that the occurrence of a significant decrease in invasive aortic pressure immediately after annular contact by a self-expanding THV indicates effective annular sealing. This phenomenon could thus be used as a marker for the occurrence of paravalvular leak (PVL).

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Sport facilities represent extreme indoor environments due to intense cleaning and disinfection. The aim of this study was to describe the composition of the cultivated microbiota in dust samples collected in sport facilities during the COVID-19 pandemic. A dust sample is defined as the airborne dust sedimented on 0.

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Elderly care practitioners are at specific risk of experiencing prolonged moral distress, which is associated with occupational health-related problems, low job satisfaction, and staff turnover. So far, little attention has been paid to the moral concerns specific to elderly care, a field whose importance is constantly growing as the populations in Western countries age. By drawing on seven workshop conversations as data and interaction-oriented focus group research, conversation analysis and discursive psychology as methods, we aim to study the ways in which elderly care practitioners discuss moral distress in their work.

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Purpose: Our review of acute brain insult articles indicated that the patients' individual (i) timeline panels with the defined time points since the emergency call and (ii) serial brain CT/MRI slice panels through the neurointensive care until death or final brain tissue outcome at 12 months or later are not presented.

Methods: We retrospectively constructed such panels for the 45 aneurysmal subarachnoid hemorrhage (aSAH) patients with a secondary decompressive craniectomy (DC) after the acute admission to neurointensive care at Kuopio University Hospital (KUH) from a defined population from 2005 to 2018. The patients were indicated by numbers (1.

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Heart failure (HF) is a disease related to impaired performance of the heart and is a significant cause of mortality and treatment costs in the world. During its progression, HF causes worsening (decompensation) periods which generally require hospital care. In order to reduce the suffering of the patients and the treatment cost, avoiding unnecessary hospital visits is essential, as hospitalization can be prevented by medication.

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