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1.
J Neuroeng Rehabil ; 20(1): 61, 2023 05 06.
Artículo en Inglés | MEDLINE | ID: mdl-37149621

RESUMEN

BACKGROUND: The aging of the population and the progressive increase of life expectancy in developed countries is leading to a high incidence of age-related cerebrovascular diseases, which affect people's motor and cognitive capabilities and might result in the loss of arm and hand functions. Such conditions have a detrimental impact on people's quality of life. Assistive robots have been developed to help people with motor or cognitive disabilities to perform activities of daily living (ADLs) independently. Most of the robotic systems for assisting on ADLs proposed in the state of the art are mainly external manipulators and exoskeletal devices. The main objective of this study is to compare the performance of an hybrid EEG/EOG interface to perform ADLs when the user is controlling an exoskeleton rather than using an external manipulator. METHODS: Ten impaired participants (5 males and 5 females, mean age 52 ± 16 years) were instructed to use both systems to perform a drinking task and a pouring task comprising multiple subtasks. For each device, two modes of operation were studied: synchronous mode (the user received a visual cue indicating the sub-tasks to be performed at each time) and asynchronous mode (the user started and finished each of the sub-tasks independently). Fluent control was assumed when the time for successful initializations ranged below 3 s and a reliable control in case it remained below 5 s. NASA-TLX questionnaire was used to evaluate the task workload. For the trials involving the use of the exoskeleton, a custom Likert-Scale questionnaire was used to evaluate the user's experience in terms of perceived comfort, safety, and reliability. RESULTS: All participants were able to control both systems fluently and reliably. However, results suggest better performances of the exoskeleton over the external manipulator (75% successful initializations remain below 3 s in case of the exoskeleton and bellow 5s in case of the external manipulator). CONCLUSIONS: Although the results of our study in terms of fluency and reliability of EEG control suggest better performances of the exoskeleton over the external manipulator, such results cannot be considered conclusive, due to the heterogeneity of the population under test and the relatively limited number of participants.


Asunto(s)
Actividades Cotidianas , Dispositivo Exoesqueleto , Masculino , Femenino , Humanos , Adulto , Persona de Mediana Edad , Anciano , Calidad de Vida , Reproducibilidad de los Resultados , Encéfalo
2.
J Neuroeng Rehabil ; 20(1): 41, 2023 04 11.
Artículo en Inglés | MEDLINE | ID: mdl-37041622

RESUMEN

BACKGROUND: The aging of the population and the progressive increase in life expectancy in developed countries is leading to a high incidence of cerebrovascular diseases. Several studies have demonstrated that robot-assisted rehabilitation therapies combined with serious games can improve rehabilitation outcomes. Social interaction in the form of multiplayer games has been highlighted as a potential element to increase patient's motivation and exercise intensity, which professionals have described as one of the determining factors in maximizing rehabilitation outcomes. Despite this, it has not been widely studied. Physiological measures have been proven as an objective tool to evaluate patients' experience in robot-assisted rehabilitation environments. However, they have not been used to evaluate patients' experience in multiplayer robot-assisted rehabilitation therapies. The main objective of this study is to analyze whether the interpersonal interaction inherent in a competitive game mode affects the patients' physiological responses in robot-assisted rehabilitation environments. METHODS: A total of 14 patients participated in this study. The results of a competitive game mode were compared with a single-player game mode with different difficulty levels. Exercise intensity and performance were measured through parameters extracted from the game and the information provided by the robotic rehabilitation platforms. The physiological response of patients in each game mode was measured by the heart rate (HR) and the galvanic skin response (GSR). Patients were asked to fill out the IMI and the overall experience questionnaire. RESULTS: The exercise intensity results show that high-difficulty single-player game mode is similar in terms of intensity level to a competitive game mode, based on velocity values, reaction time and questionnaire results. However, the results of the physiological responses of the patients measured by GSR and HR are lower in the case of the competitive mode compared to the high-difficulty single-player game mode, obtaining results similar to those obtained in the low-difficulty single-player game mode. CONCLUSIONS: Patients find the competitive game mode the most fun, which is also the mode they report experiencing the most effort and stress level. However, this subjective evaluation is not in line with the results of physiological responses. This study concludes that interpersonal interaction inherent to a competitive game mode influences patients' physiological responses. This could mean that social interaction is an important factor to consider when interpreting the results obtained from physiological measurements.


Asunto(s)
Procedimientos Quirúrgicos Robotizados , Robótica , Rehabilitación de Accidente Cerebrovascular , Humanos , Rehabilitación de Accidente Cerebrovascular/métodos , Terapia por Ejercicio/métodos , Relaciones Interpersonales , Robótica/métodos
3.
Health Expect ; 25(6): 3114-3123, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36181714

RESUMEN

INTRODUCTION: A person-centred model of care, developed in the early days of the HIV epidemic when there were no effective treatments for HIV, led to relatively close relationships between carers and people living with HIV (PLWH). Our study examines the experiences of carers using a relational framework, exploring the traumas and challenges involved, coping practices instigated by carers and the emergence of 'relational traumatic growth' opportunities. METHODS: Twenty-two UK healthcare workers and charity volunteers working with PLWH from the early years of the epidemic were recruited. Semistructured interviews were used to elicit participants' own stories of working with PLWH, from their initial involvement to the present time, and their reflections on the personal impact of working in the field of HIV. Data were analysed using a thematic approach employing relational categories. RESULTS: The impact of care was related to the formation of close relationships, identification with PLWH, high numbers of deaths and the difficulties and challenges encountered relationally. Participants described attempts to cope through informal and formal support, as well as endeavours to manage professional boundaries. Various ways of making sense of experiences were described, ranging from denial to abandoning the HIV field, to intense commitment. For some, traumatic experiences lead to validation, a search for personal meaning and managing the sense of loss with an exploration of further ventures, contributing to the achievement of relational traumatic growth. CONCLUSION: The intensity of relationships in HIV work, developed through the emotional and practical work of caring for PLWH, led healthcare workers and volunteers to experience a range of psychological consequences, both negative (including distress and emotional exhaustion) and also positive (such as acquiring a sense of purpose). PATIENT OR PUBLIC CONTRIBUTION: People living with HIV and those working with them were involved in the initial study conceptualization and design. The second and fourth authors of this paper were professionals working in HIV throughout the pandemic and have led on all aspects of the study. People living with HIV and those working with them additionally guided participant selection by suggesting participants and supporting recruitment. Narrative transcripts were checked and amended (if necessary) by participants. Initial findings were presented at the AIDS impact conference, where PLWH and those working with them attended and feedback on important ideas that helped to prioritize and shape the study findings.


Asunto(s)
Cuidadores , Infecciones por VIH , Humanos , Cuidadores/psicología , Adaptación Psicológica , Infecciones por VIH/terapia , Infecciones por VIH/psicología , Emociones , Narración
4.
BMC Public Health ; 21(1): 1022, 2021 05 30.
Artículo en Inglés | MEDLINE | ID: mdl-34053441

RESUMEN

BACKGROUND: The introduction of effective antiretroviral treatment in the late 1990s led to the perception that HIV was a chronic but manageable condition. Nevertheless, stigma remains one of the major hurdles for people living with HIV (PLWH) to accessing healthcare and biomedical preventions. Thus, Fast Track Cities has set a target of zero HIV discrimination by 2030 as part of its strategy to end HIV transmission. METHODS: Fifty-three participants from the United Kingdom, including PLWH (n = 21, 40%), health and social care workers (n = 24, 45%), and charity workers and activists (n = 13, 25%), were recruited. Semi-structured interviews investigated stigma and discrimination, focusing on both before and after the widespread use of effective antiretroviral treatment in the late 1990s. Data were analysed using a thematic approach. RESULTS: Before effective antiretroviral treatment narratives were shaped by two main themes: 1) the media's role in influencing public opinion and contributing to misunderstandings of HIV transmission; and 2) personal experiences of HIV-related stigma, which for PLWH included incidents of physical violence and aggression, as well as fears of their HIV status being publicised. Contemporary narratives on stigma experiences were organised around four themes: 1) discrimination in healthcare settings; 2) stigma amongst men who have sex with men (MSM); 3) stigma towards African and Afro-Caribbean PLWH; and 4) the limits of change in public HIV-related knowledge and attitudes. Contemporary narratives indicated a reduction in enacted stigma, but continued anticipation of discrimination and self-reported shame, particularly in MSM and African and Afro-Caribbean PLWH. CONCLUSION: The nature of stigma against those with HIV has evolved. The intersection of PLWH and minority groups (e.g. MSM and African and Afro-Caribbean persons) may enhance anticipatory and internalised stigma, with some suggestion that this may contribute to reduced engagement in HIV care and prevention services. Our findings indicate the need for further research in this area, as well as proactive interventions with community groups to enhance knowledge of HIV.


Asunto(s)
Infecciones por VIH , Minorías Sexuales y de Género , Infecciones por VIH/tratamiento farmacológico , Homosexualidad Masculina , Humanos , Masculino , Estigma Social , Reino Unido
5.
Sensors (Basel) ; 21(11)2021 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-34070583

RESUMEN

Interpersonal rehabilitation games, compared to single-player games, enhance motivation and intensity level. Usually, it is complicated to restrict the use of the system to pairs of impaired patients who have a similar skill level. Thus, such games must be dynamically adapted. Difficulty-adaptation algorithms are usually based only on performance parameters. In this way, the patient's condition cannot be considered when adapting the game. Introducing physiological reactions could help to improve decision-making. However, it is difficult to control how social interaction influences physiological reactions, making it difficult to interpret physiological responses. This article aimed to explore the changes in physiological responses due to the social interaction of a competitive game modality. This pilot study involved ten unimpaired participants (five pairs). We defined different therapy sessions: (i) a session without a competitor; (ii) two sessions with a virtual competitor with different difficulty levels; (iii) a competitive game. Results showed a difference in the physiological response in the competitive mode concerning single-player mode only due to the interpersonal game modality. In addition, feedback from participants suggested that it was necessary to keep a certain difficulty level to make the activity more challenging, and therefore be more engaging and rewarding.


Asunto(s)
Rehabilitación de Accidente Cerebrovascular , Juegos de Video , Terapia por Ejercicio , Humanos , Motivación , Proyectos Piloto
6.
Heart Surg Forum ; 23(6): E763-E769, 2020 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-33234222

RESUMEN

BACKGROUND: Isolated tricuspid valve surgery is a rarely performed procedure and traditionally is associated with a bad prognosis, although its clinical outcomes still are little known. The aim of this study was to assess the short- and long-term clinical outcomes obtained at our center after isolated tricuspid valve surgery as treatment for severe tricuspid regurgitation. METHODS: This retrospective study included 71 consecutive patients with severe tricuspid regurgitation who underwent isolated tricuspid valve surgery between December 1996 and December 2017. Perioperative and long-term mortality, tricuspid valve reoperation, and functional class were analyzed after follow up. RESULTS: Regarding surgery, 7% of patients received a De Vega annuloplasty, 14.1% an annuloplasty ring, 11.3% a mechanical prosthesis, and 67.6% a biological prosthesis. Perioperative mortality was 12.7% and no variable was shown to be predictive of this event. After a median follow up of 45.5 months, long-term mortality was 36.6%, and the multivariate analysis identified atrial fibrillation as the only predictor (Hazard Ratio 3.014, 95% confidence interval 1.06-8.566; P = 0.038). At the end of follow up, 63.6% of survivors had functional class I. CONCLUSIONS: Isolated tricuspid valve surgery was infrequent in our center. Perioperative mortality was high, as was long-term mortality. However, a high percentage of survivors were barely symptomatic after follow up.


Asunto(s)
Anuloplastia de la Válvula Cardíaca/métodos , Prótesis Valvulares Cardíacas , Insuficiencia de la Válvula Tricúspide/cirugía , Válvula Tricúspide/cirugía , Anciano , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Reoperación , Estudios Retrospectivos , Factores de Riesgo , España/epidemiología , Tasa de Supervivencia/tendencias , Resultado del Tratamiento , Válvula Tricúspide/diagnóstico por imagen , Insuficiencia de la Válvula Tricúspide/diagnóstico , Insuficiencia de la Válvula Tricúspide/mortalidad
7.
Sensors (Basel) ; 21(1)2020 Dec 23.
Artículo en Inglés | MEDLINE | ID: mdl-33374744

RESUMEN

Hand exoskeleton potential applications reach further than grasping or assistance during manipulation. In this paper, we present a preliminary study of how this technology can be applied in order to improve performance during standing to help the user to keep balance under perturbations. Non-impaired users wearing a hand exoskeleton gripping a hand rail were pushed by a cable-driven robot, so that their standing equilibrium was perturbed. The center of pressure, surface electromyography, and interaction force data were recorded in order to assess the performance of users and their postural strategy. The results showed that users could keep their balance with the same outcomes using their bare hands and the hand exoskeleton. However, when wearing the exoskeleton, a higher muscular activity was registered in hand flexor muscles. This is also supported by the grasping force, which shows that users stretched their hand more than expected when wearing the hand exoskeleton. This paper concludes that it is possible that the lack of tactile feedback could lead to over compensation in the grasping. Therefore, the next studies will aim to check whether this effect can be reversed by training users to wear the exoskeleton.


Asunto(s)
Dispositivo Exoesqueleto , Adulto , Electromiografía , Mano , Fuerza de la Mano , Humanos , Músculo Esquelético
8.
Qual Health Res ; 30(10): 1561-1571, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32507074

RESUMEN

Death and infection were closely linked from the start of the HIV epidemic, until successful treatments became available. The initial impact of mostly young, gay men dying from HIV was powerful in shaping UK responses. Neoliberal discourses developed at the same time, particularly focusing on how citizens (rather than the state) should take responsibility to improve health. Subsequently "successful ageing" became an allied discourse, further marginalising death discussions. Our study reflected on a broad range of meanings around death within the historical UK epidemic, to examine how dying narratives shape contemporary HIV experiences. Fifty-one participants including people living with HIV, professionals, and activists were recruited for semistructured interviews. Assuming a symbolic interactionist framework, analysis highlighted how HIV deaths were initially experienced as not only traumatic but also energizing, leading to creativity. With effective antiretrovirals, dying changed shape (e.g., loss of death literacy), and better integration of palliative care was recommended.


Asunto(s)
Infecciones por VIH , Cuidados Paliativos , Envejecimiento , Infecciones por VIH/epidemiología , Humanos , Masculino , Narración , Reino Unido/epidemiología
10.
Ann Vasc Surg ; 55: 308.e1-308.e4, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30217704

RESUMEN

Angiosarcoma (AS) is a type of malignancy within sarcomas affecting soft tissue and bone. It presents a very heterogeneous distribution in the human body, and it can appear in multiple locations, from breast to liver or skin. The incidence of this type of tumor is low; however, it is aggressive and requires an early diagnosis to initiate the treatment as soon as possible. In the present article, we report the case of a male patient who was diagnosed with epithelioid AS of popliteal artery after an aneurysm popliteal surgery, as well as its treatment and evolution. This kind of tumors has controversial treatment and poor survival rates in the early years.


Asunto(s)
Aneurisma/cirugía , Hemangiosarcoma/etiología , Arteria Poplítea/cirugía , Vena Safena/trasplante , Injerto Vascular/efectos adversos , Neoplasias Vasculares/etiología , Anciano , Aneurisma/diagnóstico por imagen , Aneurisma/fisiopatología , Angiografía por Tomografía Computarizada , Resultado Fatal , Hemangiosarcoma/diagnóstico por imagen , Hemangiosarcoma/patología , Hemangiosarcoma/terapia , Humanos , Imagen por Resonancia Magnética , Masculino , Cuidados Paliativos , Arteria Poplítea/diagnóstico por imagen , Arteria Poplítea/patología , Arteria Poplítea/fisiopatología , Factores de Riesgo , Trasplante Autólogo , Resultado del Tratamiento , Neoplasias Vasculares/diagnóstico por imagen , Neoplasias Vasculares/patología , Neoplasias Vasculares/terapia
11.
Sensors (Basel) ; 19(15)2019 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-31382363

RESUMEN

In this paper, the analysis of the intensity of muscle activations in different subjects when they perform an industrial task in a repetitive way assisted by a robotic upper-limb exoskeleton is presented. To do that, surface electromyography (EMG) signals were monitored with and without a robotic upper-limb exoskeleton for 10 subjects during a drilling task, a typical tedious maintenance or industrial task. Our results show that wearing the upper-limb exoskeleton substantially reduces muscle activity during a drilling task above head height. Specifically, there is statistically significant differences in the pectoralis major and rhomboids muscles between the groups wearing or not wearing the robotic upper-limb exoskeleton.


Asunto(s)
Brazo/fisiología , Electromiografía/métodos , Adulto , Fenómenos Biomecánicos , Electromiografía/instrumentación , Diseño de Equipo , Dispositivo Exoesqueleto , Femenino , Humanos , Masculino , Músculo Esquelético/fisiología , Impresión Tridimensional , Adulto Joven
12.
Sensors (Basel) ; 19(22)2019 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-31726745

RESUMEN

When combined with assistive robotic devices, such as wearable robotics, brain/neural-computer interfaces (BNCI) have the potential to restore the capabilities of handicapped people to carry out activities of daily living. To improve applicability of such systems, workload and stress should be reduced to a minimal level. Here, we investigated the user's physiological reactions during the exhaustive use of the interfaces of a hybrid control interface. Eleven BNCI-naive healthy volunteers participated in the experiments. All participants sat in a comfortable chair in front of a desk and wore a whole-arm exoskeleton as well as wearable devices for monitoring physiological, electroencephalographic (EEG) and electrooculographic (EoG) signals. The experimental protocol consisted of three phases: (i) Set-up, calibration and BNCI training; (ii) Familiarization phase; and (iii) Experimental phase during which each subject had to perform EEG and EoG tasks. After completing each task, the NASA-TLX questionnaire and self-assessment manikin (SAM) were completed by the user. We found significant differences (p-value < 0.05) in heart rate variability (HRV) and skin conductance level (SCL) between participants during the use of the two different biosignal modalities (EEG, EoG) of the BNCI. This indicates that EEG control is associated with a higher level of stress (associated with a decrease in HRV) and mental work load (associated with a higher level of SCL) when compared to EoG control. In addition, HRV and SCL modulations correlated with the subject's workload perception and emotional responses assessed through NASA-TLX questionnaires and SAM.

13.
AIDS Care ; 30(sup2): 102-107, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29848063

RESUMEN

Recent research into "successful ageing" and "resilience" in the context of ageing with HIV highlights older people living with HIV's (OPLWH) adaptations and coping strategies hitherto neglected by early research's emphasis on difficulties and challenges. Yet "resilience" and "successful ageing" are limited by their inconsistent definition, conflation of personal traits and coping strategies, normative dimension, and inattention to cultural variation and the distinctive nature of older age. This article thus adopts an interpretivist approach to how OPLWH manage the challenges to their mental health and wellbeing of ageing with HIV. Drawing on interviews with 76 OPLWH (aged 50+) living in the United Kingdom, we document both the strategies these participants use (for example, "accentuating the positive" and accessing external support) and the challenges to these strategies' success posed by the need to manage their HIV's social and clinical dimensions and prevent their HIV from dominating their lives. This points to (a) the complex overlaps between challenges to and strategies for improving or maintaining mental health and wellbeing in the context of ageing with HIV, and (b) the limitations of the "resilience" and "successful ageing" approaches to ageing with HIV.


Asunto(s)
Adaptación Psicológica , Envejecimiento/psicología , Infecciones por VIH/psicología , Salud Mental , Adulto , Anciano , Anciano de 80 o más Años , Fármacos Anti-VIH/uso terapéutico , Femenino , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/epidemiología , Humanos , Entrevistas como Asunto , Masculino , Persona de Mediana Edad , Investigación Cualitativa , Apoyo Social , Factores Socioeconómicos , Reino Unido/epidemiología
14.
Sensors (Basel) ; 18(8)2018 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-30042372

RESUMEN

Assistive technologies help all persons with disabilities to improve their accessibility in all aspects of their life. The AIDE European project contributes to the improvement of current assistive technologies by developing and testing a modular and adaptive multimodal interface customizable to the individual needs of people with disabilities. This paper describes the computer vision algorithms part of the multimodal interface developed inside the AIDE European project. The main contribution of this computer vision part is the integration with the robotic system and with the other sensory systems (electrooculography (EOG) and electroencephalography (EEG)). The technical achievements solved herein are the algorithm for the selection of objects using the gaze, and especially the state-of-the-art algorithm for the efficient detection and pose estimation of textureless objects. These algorithms were tested in real conditions, and were thoroughly evaluated both qualitatively and quantitatively. The experimental results of the object selection algorithm were excellent (object selection over 90%) in less than 12 s. The detection and pose estimation algorithms evaluated using the LINEMOD database were similar to the state-of-the-art method, and were the most computationally efficient.


Asunto(s)
Algoritmos , Robótica/métodos , Visión Ocular , Interfaces Cerebro-Computador , Electroencefalografía , Electrooculografía , Humanos
15.
Sensors (Basel) ; 18(2)2018 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-29414861

RESUMEN

This paper presents the development of an optical force sensor architecture directed to prototyping and cost-effective applications, where the actual force requirements are still not well defined or the most suitable commercial technologies would highly increase the cost of the device. The working principle of this sensor consists of determining the displacement of a lens by measuring the distortion of a refracted light beam. This lens is attached to an elastic interface whose elastic constant is known, allowing the estimation of the force that disturbs the optical system. In order to satisfy the requirements of the design process in an inexpensive way, this sensor can be built by fast prototyping technologies and using non-optical grade elements. To deal with the imperfections of this kind of manufacturing procedures and materials, four fitting models are proposed to calibrate the implemented sensor. In order to validate the system, two different sensor implementations with measurement ranges of ±45 N and ±10 N are tested with the proposed models, comparing the resulting force estimation with respect to an industrial-grade load cell. Results show that all models can estimate the loads with an error of about 6% of the measurement range.

16.
AIDS Res Ther ; 14: 22, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28400851

RESUMEN

BACKGROUND: People with HIV with access to treatment are growing older and living healthier lives than in the past, and while health improvements and increased survival rates are welcome, the psychological and social consequences and quality of life of ageing are complex for this group. Understanding how ageing, HIV and quality of life intersect is key to developing effective interventions to improve QoL. METHODS: One hundred people with HIV over the age of 50 (range 50-87, mean 58), were recruited through HIV community organizations, and clinics, and included men who have sex with men (MSM), and Black African and White heterosexual men and women. The WHOQOL-HIV BREF was used, as well as the Every Day Memory Questionnaire, and additional questions on anxiety and depression to supplement the WHOQOL. RESULTS: While most rated their quality of life (QoL) positively, bivariate analysis showed that better QoL (total score and most domains) was strongly associated with being a man; in a relationship; in paid employment; having higher level of income; not on benefits, and to a lesser degree with being MSM, having higher level of education, and diagnosed after the age of 40. Multivariate analysis showed that not being on benefits was the variable most consistently associated with better quality of life, as was being partnered. Concerns about everyday memory difficulties, and anxiety and depression scores were strong predictors of poorer quality of life. CONCLUSION: While the cross-sectional nature of the investigation could not establish that the associations were causal, the findings indicate that concerns about memory difficulties, anxiety and depression, as well as gender, ethnicity, financial factors, and relationship status, are important contributors to QoL in this group. These findings point towards the need for further research to clarify the mechanisms through which the factors identified here affect QoL, and to identify possible interventions to improve the QoL of older people living with HIV.


Asunto(s)
Envejecimiento/psicología , VIH/fisiología , Calidad de Vida , Anciano , Anciano de 80 o más Años , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Encuestas y Cuestionarios
18.
Sensors (Basel) ; 15(12): 30571-83, 2015 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-26690160

RESUMEN

This paper presents a novel kinematic reconstruction of the human arm chain with five degrees of freedom and the estimation of the shoulder location during rehabilitation therapy assisted by end-effector robotic devices. This algorithm is based on the pseudoinverse of the Jacobian through the acceleration of the upper arm, measured using an accelerometer, and the orientation of the shoulder, estimated with a magnetic angular rate and gravity (MARG) device. The results show a high accuracy in terms of arm joints and shoulder movement with respect to the real arm measured through an optoelectronic system. Furthermore, the range of motion (ROM) of 50 healthy subjects is studied from two different trials, one trying to avoid shoulder movements and the second one forcing them. Moreover, the shoulder movement in the second trial is also estimated accurately. Besides the fact that the posture of the patient can be corrected during the exercise, the therapist could use the presented algorithm as an objective assessment tool. In conclusion, the joints' estimation enables a better adjustment of the therapy, taking into account the needs of the patient, and consequently, the arm motion improves faster.


Asunto(s)
Articulaciones/fisiología , Rehabilitación/instrumentación , Robótica/instrumentación , Extremidad Superior/fisiología , Tecnología Inalámbrica/instrumentación , Acelerometría , Algoritmos , Fenómenos Biomecánicos , Humanos , Sistemas Hombre-Máquina , Rehabilitación/métodos , Robótica/métodos
20.
Front Bioeng Biotechnol ; 11: 1199459, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37840666

RESUMEN

One of the most important forces generated during gait is the vertical ground reaction force (vGRF). This force can be measured using force plates, but these can limit the scope of gait analysis. This paper presents a method to estimate the vGRF using inertial measurement units (IMU) and machine learning techniques. Four wearable IMUs were used to obtain flexion/extension angles of the hip, knee, and ankle joints, and an IMU placed over the C7 vertebra to measure vertical acceleration. We trained and compared the performance of two machine learning algorithms: feedforward neural networks (FNN) and random forest (RF). We investigated the importance of the inputs introduced into the models and analyzed in detail the contribution of lower limb kinematics and vertical acceleration to model performance. The results suggest that the inclusion of vertical acceleration increases the root mean square error in the FNN, while the RF appears to decrease it. We also analyzed the ability of the models to construct the force signal, with particular emphasis on the magnitude and timing of the vGRF peaks. Using the proposed method, we concluded that FNN and RF models can estimate the vGRF with high accuracy.

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