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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
191

A P300-Based Brain-Computer Interface for People With Amyotrophic Lateral Sclerosis

Nijboer, F., Sellers, Eric W., Mellinger, J., Jordan, M. A., Matuz, T., Furdea, A., Halder, S., Mochty, U., Krusienski, D. J., Vaughan, T. M., Wolpaw, J. R., Birbaumer, N., Kübler, A. 01 August 2008 (has links)
Objective: The current study evaluates the efficacy of a P300-based brain-computer interface (BCI) communication device for individuals with advanced ALS. Methods: Participants attended to one cell of a N x N matrix while the N rows and N columns flashed randomly. Each cell of the matrix contained one character. Every flash of an attended character served as a rare event in an oddball sequence and elicited a P300 response. Classification coefficients derived using a stepwise linear discriminant function were applied to the data after each set of flashes. The character receiving the highest discriminant score was presented as feedback. Results: In Phase I, six participants used a 6 x 6 matrix on 12 separate days with a mean rate of 1.2 selections/min and mean online and offline accuracies of 62% and 82%, respectively. In Phase II, four participants used either a 6 x 6 or a 7 x 7 matrix to produce novel and spontaneous statements with a mean online rate of 2.1 selections/min and online accuracy of 79%. The amplitude and latency of the P300 remained stable over 40 weeks. Conclusions: Participants could communicate with the P300-based BCI and performance was stable over many months. Significance: BCIs could provide an alternative communication and control technology in the daily lives of people severely disabled by ALS.
192

Suppressing Surrounding Characters During Calibration may Improve P300-Based BCI Performance

Frye, G. E., Townsend, G., Hauser, C. K., Sellers, Eric W. 01 November 2010 (has links)
Since the introduction of the P300 BCI speller by Farwell and Donchin1 speed and accuracy of the system has been significantly improved. Larger electrode montages and various signal processing techniques are responsible for most of the improvement in performance. The present study takes advantage of a new presentation paradigm to improve performance, the “checkerboard?(CB) paradigm2. The CB presents quasi-random groups of six items instead of using the typical row/column presentation. To determine if reducing distraction from neighbouring items could improve subsequent performance on a copy-spelling task, the CB paradigm was used and compared to a condition that suppressed (i.e., did not flash) items during the calibration phase of the experiment.
193

Towards Clinically Acceptable BCI Spellers: Preliminary Results for Different Stimulus-Selection Patterns and Pattern- Recognition Techniques

Throckmorton, Chandra S., Ryan, David B., Hanmer, B., Caves, C., Colwell, Kenneth, Sellers, Eric W., Collins, Leslie M. 01 June 2010 (has links)
Individuals affected by severe physical limitations, such as those caused by amyotrophic lateral sclerosis (ALS) or brainstem stroke, may not have the physical ability required to use clinically available augmentative and assistive communication systems. The P300 speller relies on the detection of responses elicited in EEG signals and has been used as a method of technology access for individuals with significant disability 1, 2. Our research focuses on improving P300 spellers in two areas: improved pattern recognition techniques and channel selection techniques for detecting P300 event-related potentials (ERPs) in the measured multi-channel EEG data, and optimal stimulus selection for improved efficiency and performance.
194

Do People with ALS Perform Better with the Checkerboard Paradigm than with the Standard Row/Column P300-BCI?

Feldman, Sara, Petaccio, Vincent, Sellers, Eric W., Townsend, George, Vaughan, Theresa M., Hauser, Christopher, Harriman-Patterson, Terry, Wolpaw, Jonathan R. 01 June 2010 (has links)
Brain-computer interfaces (BCIs) provide communication that does not depend on neuromuscular activity. Several studies have demonstrated that those with advanced ALS can use noninvasive BCIs (e.g.,1,2,3). In able-bodied users, Townsend et al2 showed that a pseudorandom -or checkerboard paradigm (CBP) significantly improves P300-BCI performance compared to the standard or row/column paradigm (RCP). The CBP flashes stimuli in quasi-random groups that do not contain adjacent items, and it ensures at least six flashes between flashes of a given item. The combination of these two factors improves accuracy and bitrate. Townsend et al [2] also reported anecdotal improvements with the CBP in people with ALS who had extensive experience with the RCP. The present study seeks to verify these results in a larger group of people with ALS.
195

Attentional Manipulations Can Enhance P300-Based BCI Performance

Berry, Daniel R., Lakey, Chad E., Sellers, Eric W. 01 June 2010 (has links)
Severe motor disabilities such as amyotrophic lateral sclerosis (ALS) reduce or eliminate neuromuscular control and deprive affected patients of vital communication and control. Recent advances in noninvasive EEG-based BCIs have given patients new hope for communication and environmental control not provided by other assistive devices[1]. General lapses of attention, mind wandering, and lack of focus may all undermine BCI performance[2]. In a P300-BCI, non-target flashes are exogenous cues that could attract attention away from the endogenous task of attending to target item flashes. Thus, inducing a heightened state of attentional awareness and reducing distractibility may improve BCI performance. Mindfulness meditation and induction (MMI) offers such a possibility[3,4]. We expect MMI to have several important consequences for P300-based BCI use: one, it will focus attention to the target item; two, it will reduce distraction from non-target flashes; three, it will reduce P300 target latencies; four it will produce higher amplitude ERPs
196

Suppressing Surrounding Characters During Calibration May Improve P300-Based BCI Performance

Frye, Gerald E., Hauser, Christopher K., Townsend, Geroge, Sellers, Eric W. 01 June 2010 (has links)
Since the introduction of the P300 BCI speller by Farwell and Donchin1 speed and accuracy of the system has been significantly improved. Larger electrode montages and various signal processing techniques are responsible for most of the improvement in performance. The present study takes advantage of a new presentation paradigm to improve performance, the “checkerboard?(CB) paradigm2. The CB presents quasi-random groups of six items instead of using the typical row/column presentation. To determine if reducing distraction from neighbouring items could improve subsequent performance on a copy-spelling task, the CB paradigm was used and compared to a condition that suppressed (i.e., did not flash) items during the calibration phase of the experiment.
197

P300-BCI: Disassociating Flash Groups from Physical Organizations Provides Improved Performance

Townsend, George, Shanahan, Jessica, Frye, Gerald E., Sellers, Eric W. 01 June 2010 (has links)
Since its inception, the P300-based BCI has typically flashed in rows and columns [1]. Recently, the “checkerboard?(CB) paradigm was introduced in which targets are grouped in rows and columns on two “virtual matrices?taken from the white and black squares of a checkerboard overlaid on the physical matrix [2]. Disassociating the physical rows and columns of the matrix from how they are grouped to flash brings advantages by: 1) avoiding the problematic effects of double target flashes [3], and 2) not allowing adjacent targets to flash together. In this study, this disassociation of the “flash groups?from the physical matrix is taken further. The flash groups become purely “abstract?bearing no relationship to rows or columns either physical or virtual. This study compares performance of this new paradigm named ?-Flash?(5F) to the CB.
198

Att vara närstående till en person som drabbats av ”den värsta tänkbara sjukdomen”, ALS / Being close to a person affected by ”the worst disease imaginable”, ALS

Hermansson, Maja, Lindström, Daniel January 2023 (has links)
Bakgrund: Amyotrofisk lateralskleros (ALS) är en obotlig sjukdom som bryter ned de perifera och centrala motoriska nervcellerna i nervsystemet och har ett dödligt utfall. Närstående får ofta ta rollen som primärvårdgivare och sjukdomen innebär en stor livsomställning för såväl den sjuke som närstående. Som sjuksköterska är det viktigt att ha kunskap om närståendes upplevelser för att kunna bidra med rätt stöttning samt att ge god omvårdnad. Syfte: Syftet med litteraturstudien var att beskriva upplevelser av att vara närstående till en person med amyotrofisk lateralskleros. Metod: En litteraturstudie baserad på nio kvalitativa studier. Fribergs femstegsmodell användes för att analysera, hitta likheter och skillnader i artiklarna för att kunna framställa ett resultat. Resultat: Ur analysen framkom tre huvudkategorier: Känslor som följer med sjukdomen, Tankar under sjukdomsprogressionen och Förändrad situation för de närstående, med medföljande underkategorier. Konklusion: Närstående till personer med ALS upplever en rad känslor, begränsningar och förändringar i relationer och vardagen under sjukdomsförloppet. Vårdpersonal och sjuksköterska kan arbeta hälsofrämjande genom hälsostödjande familjesamtal, då ges möjlighet till närstående och drabbad att lyfta känslor och tankar. / Background: Amyotrophic lateral sclerosis is a disease that breaks down the peripheral and central motor neurons of the nervous system and has a fatal outcome. Relatives often have to take on the role of primary care provider, and the disease means a major life adjustment for both the sick person and the relatives. As a nurse, it is important to have knowledge of the experiences of relatives in order to be able to give the right support and to provide good care. Aim: The aim of the study was to describe experiences of being a relative to a person with amyotrophic lateral sclerosis. Methods: A literature study based on nine qualitative studies. Friberg's five-step model was used to analyze, find similarities and differences in the articles. Results: Three main categories emerged from the analysis: Feelings that accompany the illness, Thoughts during the progression of the illness and Changed situation for the relatives, with accompanying subcategories. Conclusion: Relatives experience a range of emotions, limitations and changes in relationships and everyday life during the course of the disease. Nurses can work to promote health through health-supporting family conversations, then relatives and those affected are given the opportunity to raise feelings and thoughts.
199

Anhörigas upplevelse av att leva med en närstående som drabbats av ALS : En litteraturstudie / Relatives’ experience of living with a next of kin affected by ALS : A literature study

Börjesson, Linnea, Wallentin, Maja January 2023 (has links)
Bakgrund: ALS är en fortskridande neurodegenerativ sjukdom som leder till förlust av frivillig muskelfunktion vilket slutligen leder till döden. Det finns ännu inget botemedel för sjukdomen, behandlingsåtgärderna inriktas istället på att lindra symtomen. Det är inte bara individen som drabbas av ALS som påverkas utan även de anhöriga. Att sjuksköterskan är lyhörd och bemöter hela familjens behov är därför viktigt. Syfte: Syftet med studien var att beskriva anhörigas upplevelse av att leva med en närstående som drabbats av ALS. Metod: Allmän litteraturstudie som baserades på åtta vetenskapliga resultatartiklar. Resultat: Anhörigas välbefinnande påverkades i samband med sjukdomen. Egentiden åsidosattes i samband med den ökade belastningen vilket genererade i emotionell påverkan. Anhöriga upplevde behov av stöd från vårdpersonalen. Sjukvårdspersonalen i hemdistriktet upplevdes dock inte vara tillräckligt kompetenta vilket resulterade i att anhöriga tog över ansvaret som omsorgsgivare. Bristande utbildning i omvårdnadsåtgärder beskrevs även bidra till ökad osäkerhet och rädsla. Konklusion: Anhörigas livssituation påverkades negativt och de önskade ett större stöd från vårdpersonalen än vad som erbjöds. Vården bör samordnas bättre så att vårdpersonalen kan möta hela familjens behov och erbjuda det stöd som familjen behöver i omvårdnadsprocessen. / Background: ALS is a progressive neurodegenerative disease leading to deterioration and loss of voluntary muscle function, ultimately leading to fatality. There is yet no medical interventions for the disease, the focus lays on mitigating the symptoms. It´s not only the individual that are suffering, but also their relatives. Therefore, it´s important that the nurses are attentive and responsive to the needs of the family as whole. Aim: The aim was to describe the relatives’ experiences of living with a next of kin with ALS. Method: A general litterature study, which generated in eight research articles. Result: Relatives' well-being was affected in correlation with the illness. The heightened stressors affected the individual’s time spent on themselves, which in turn had a negative emotional effect. The relatives expressed increased needs from health professionals. The local health-care workers were reportedly not meeting their needs in terms of competence, resulting in relatives taking over the responsibility as caregiver. Lack of education regarding nursing measures were described as a factor of the heightened uncertainty and fear. Conclusion: Relatives’ life situation was negatively affected and they wished for more support from the caregivers than what they were offered. The care should be better coordinated so the caregivers can meet the needs of the entire family and offer the support that the family needs in the nursing process.
200

Support and encounter of patients with ALS and those who are close to them - A litterature review

Starck, Camilla, Wahlgren, Carolina January 2005 (has links)
Amyotrofisk lateralskleros (ALS) är i nuläget en obotlig sjukdom och sjukdomsförloppet går ofta väldigt fort. Omvårdnaden måste därför vara specifik för dessa patienter. Syfte: Huvudsyftet med denna litteraturstudie var att belysa vårdpersonalens stöd och bemötande av patienter med en obotlig sjukdom som ALS och deras närstående. Syftet var även att belysa hur de närstående påverkas av att vara vårdgivande åt sin närstående med ALS. Metod: För att besvara våra frågeställningar har vi valt att göra en litteraturstudie som bygger på tio vetenskapliga artiklar. Artiklarna kvalitetsbedömdes utifrån Carlsson och Eimans bedömningsmall för kvalitativa och kvantitativa studier. Som teoretisk referensram har vi använt oss av en modell av Carnevali. Resultat: Att vara närstående till patienter med ALS påverkar de flesta negativt på något sätt i deras dagliga liv. Alla patienter och dess närstående måste bemötas utifrån sina behov och individuell information är en viktig del i omvårdnadsarbetet. Slutsats: De slutsatser vi drar utifrån vårt resultat är att alla patienter och deras närstående är individer och bör därför bemötas på ett individuellt sätt utifrån deras individuella behov. / In the present time amyotrophic lateral sclerosis (ALS) is an untreatable disease and the course of the disease is often very fast. Nursing of the patients has to be specific. Purpose: The purpose of this literature study was to elucidate caregivers encounter of patients with an untreatable disease like ALS and those who are close to the patients. Method: To answer our research questions we have chosen to do a literature study witch is based on ten scientific articles. The articles were quality rated using Carlsson and Eimans ratingscale for qualitative and quantitative studies. As a frame of reference we used a model by Carnevali. Result: To be one of those who are close to the patients with ALS can affect them in a negative way in their daily life. All patients and those who are close to them have to be encountered by their own needs and individual information is an important part of nursing. Conclusion: From our result we made the conclusions that all patients and those who are close to them are individuals and should be encountered by their personal needs.

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