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1.
Genome Res ; 26(10): 1333-1341, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27646536

RESUMEN

We herein report the result of a large-scale, next generation sequencing (NGS)-based screen for embryonic lethal (EL) mutations in Belgian beef and New Zealand dairy cattle. We estimated by simulation that cattle might carry, on average, ∼0.5 recessive EL mutations. We mined exome sequence data from >600 animals, and identified 1377 stop-gain, 3139 frame-shift, 1341 splice-site, 22,939 disruptive missense, 62,399 benign missense, and 92,163 synonymous variants. We show that cattle have a comparable load of loss-of-function (LoF) variants (defined as stop-gain, frame-shift, or splice-site variants) as humans despite having a more variable exome. We genotyped >40,000 animals for up to 296 LoF and 3483 disruptive missense, breed-specific variants. We identified candidate EL mutations based on the observation of a significant depletion in homozygotes. We estimated the proportion of EL mutations at 15% of tested LoF and 6% of tested disruptive missense variants. We confirmed the EL nature of nine candidate variants by genotyping 200 carrier × carrier trios, and demonstrating the absence of homozygous offspring. The nine identified EL mutations segregate at frequencies ranging from 1.2% to 6.6% in the studied populations and collectively account for the mortality of ∼0.6% of conceptuses. We show that EL mutations preferentially affect gene products fulfilling basic cellular functions. The resulting information will be useful to avoid at-risk matings, thereby improving fertility.


Asunto(s)
Bovinos/genética , Fertilidad/genética , Genes Letales , Mutación , Animales , Bovinos/embriología , Bovinos/fisiología , Pruebas Genéticas/métodos , Heterocigoto , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Homocigoto , Genética Inversa/métodos , Análisis de Secuencia de ADN/métodos
2.
Inj Prev ; 25(4): 334-339, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-28385954

RESUMEN

BACKGROUND: Emergency department (ED) patients are among the many groups at risk for prescription drug overdose. There is limited research on how best to communicate with ED patients about options for pain management and the risks of opioids. The aim of this study is to pilot test a web-based, patient-centred educational programme that encourages the patient to have an informed discussion about pain medication options with their ED provider. METHODS: This multisite, randomised trial will evaluate an m-health programme designed to aid the patient in making an informed decision about their pain treatment. Patients reporting to the ED with an injury-related or pain- related chief complaint who agree to participate are randomised to receive the intervention programme, My Healthy Choices, or an attention-matched control. My Healthy Choices pairs tailored education with a patient decision aid to describe what opioid and non-opioid pain medications are, assess the patient's risk factors for opioid-related adverse effects, and produce a tailored report that patients are encouraged to share with their doctor. Data are collected through surveys at three time points during the ED encounter (baseline, immediately after the intervention and just before discharge), and at a 6-week follow-up survey. The primary outcomes are whether the patient prefers an opioid pain reliever (OPR) and whether the patient takes an OPR. DISCUSSION: We hope this programme will facilitate patient-provider communication, as well as reduce the number of prescriptions written for OPRs and thus the number of patients exposed to prescription opioids and the associated risks of addiction and overdose. TRIAL REGISTRATION NUMBER: NCT03012087; Pre-results.


Asunto(s)
Analgésicos Opioides/efectos adversos , Sobredosis de Droga/prevención & control , Servicio de Urgencia en Hospital/estadística & datos numéricos , Trastornos Relacionados con Opioides/prevención & control , Mal Uso de Medicamentos de Venta con Receta/prevención & control , Telemedicina , Adulto , Intervención Médica Temprana , Femenino , Humanos , Masculino , Alta del Paciente , Educación del Paciente como Asunto , Proyectos Piloto , Mal Uso de Medicamentos de Venta con Receta/estadística & datos numéricos
3.
W V Med J ; 110(3): 14-8, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24984400

RESUMEN

BACKGROUND: Patients with traumatic injuries transferred from rural hospitals to tertiary centers in West Virginia frequently undergo repeat computed axial tomography (CT) imaging upon arrival. The traditional method of sending images on a compact disc (CD) with EMS can be unreliable due to software incompatibility, CD malfunction, or misplacement of the CD. Given the known risks associated with ionizing radiation, physicians are increasingly aware of the need to avoid unnecessary CT imaging. Image storage applications such as ImageGrid provide a means to store images securely without the issues and inherent problems of a CD. These images can be uploaded at the referring hospital and may be viewed from any computer at the receiving facility, by multiple providers--even prior to patient arrival. The goal of this study was to determine if utilizing ImageGrid compared to traditional data transfer by CD resulted in a decrease in the amount and type of images obtained in the initial Emergency Department (ED) evaluation at the tertiary center. METHODS: We analyzed data from the Jon Michael Moore Trauma Registry for patients transferred to the Emergency Department at WVU Hospitals from an outside facility. Two study periods were reviewed; prior to ImageGrid implementation and after implementation of the system. Medical records of all patients admitted to the Trauma Surgery Service after a trauma system activation in the ED were reviewed during these time periods. Number and type of CT studies obtained in the Emergency Department were recorded for analysis. RESULTS: In the month of July 2010, 183 patients were admitted to the Trauma Surgery service after trauma team activation. Transfers from referring hospitals accounted for 77 of the 108 (42.1%). WVU Hospitals implemented ImageGrid during 2011. In July 2012, 243 patients were admitted to the Trauma Service, of which 105 (41.1%) were transfer patients. After implementation of ImageGridTM there was a significant decrease in the number of repeat CT Scans of the brain (19/27 [70.4%] vs. 18/40 [45.0%], p < .05), as well as CT scans of the chest, abdomen or chest/ abdomen/pelvis (9/18 [50.0%] vs. 2/23 [8.7%], p < .05). CT of the face showed a decreasing trend (5/9 [55.6%] vs. 1/9 [11%], p > .05 [p = 0.06]), but did not achieve statistical significance. After implementation of ImageGrid there was a marked decrease in total CT scans repeated (46/79 [58.2%] vs. 28/107 [26.2%], p < .05). CONCLUSION: In West Virginia, the use of image archival systems such as ImageGrid appears to result in less repeat CT imaging upon arrival at a tertiary trauma center. Given risks associated with ionizing radiation and costs of repeat imaging the benefits have important implications for patient safety and cost containment.


Asunto(s)
Transferencia de Pacientes , Telerradiología/normas , Tomografía Computarizada por Rayos X/efectos adversos , Heridas y Lesiones/diagnóstico por imagen , Hospitales Rurales , Humanos , Difusión de la Información/métodos , Dosis de Radiación , Radiación Ionizante , Sistema de Registros , Estudios Retrospectivos , Telerradiología/métodos , Tomografía Computarizada por Rayos X/estadística & datos numéricos , Centros Traumatológicos , West Virginia
4.
J Dairy Sci ; 96(12): 7684-91, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24140337

RESUMEN

Non-protein-bound oligosaccharides are important bioactive components of cow milk, with potential human-health benefits such as stimulation of the growth of beneficial gut bacteria and defense against pathogens. In bovine milk, the majority of oligosaccharides are sialylated; 3'-sialyllactose (3'-N-acetylneuraminyl-D-lactose; 3'-SL) is the predominant sialylated oligosaccharide, followed by 6'-sialyllactose (6'-N-acetylneuraminyl-D-lactose; 6'-SL). Both 3'-SL and 6'-SL have antimicrobial activity. As bovine milk products such as infant formula can be an important component of the human diet, and the concentrations of 3'-SL and 6'-SL are lower in bovine milk compared with human milk, we aimed to identify cows that naturally produce higher concentrations of sialyllactose in their milk. Milk from such cows could be used to produce foods with an increased sialyllactose content, potentially providing increased health benefits. We speculated that cows overexpressing 3'-SL and 6'-SL would exist at low frequency in the population and, to allow their efficient identification, we developed a novel assay for 3'-SL and 6'-SL utilizing flow-injection analysis-mass spectrometry, which could be used for high-throughput analysis of milk samples. We then determined 3'-SL and 6'-SL concentrations in milk samples from 15,507 cows from Friesian, Jersey, and Friesian-Jersey crossbred animals. We found 329 cows with concentrations of 3'-SL or 6'-SL >2-fold higher than the mean, 26 cows with concentrations of 3'-SL or 6'-SL >3-fold higher than the mean, and 1 cow with concentrations of 3'-SL >4-fold higher than the mean. Although these outliers were observed across the 3 groups of cows, breed had a strong effect on mean 3'-SL and 6'-SL concentrations.


Asunto(s)
Leche Humana , Leche , Animales , Cruzamiento , Dieta , Humanos , Fórmulas Infantiles/química , Espectrometría de Masas , Leche/química , Leche Humana/química
5.
Nat Rev Earth Environ ; 4(4): 205-206, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37065615

RESUMEN

Global CO2 emissions for 2022 increased by 1.5% relative to 2021 (+7.9% and +2.0% relative to 2020 and 2019, respectively), reaching 36.1 GtCO2. These 2022 emissions consumed 13%-36% of the remaining carbon budget to limit warming to 1.5 °C, suggesting permissible emissions could be depleted within 2-7 years (67% likelihood).

6.
Diagnostics (Basel) ; 13(22)2023 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-37998567

RESUMEN

This paper presents a technique for high sensitivity measurement of singlet oxygen luminescence generated during photodynamic therapy (PDT) and ultraviolet (UV) irradiation on skin. The high measurement sensitivity is achieved by using a computational spectroscopy (CS) approach that provides improved photon detection efficiency compared to spectral filtering methodology. A solid-state InGaAs photodiode is used as the CS detector, which significantly reduces system cost and improves robustness compared to photomultiplier tubes. The spectral resolution enables high-accuracy determination and subtraction of photosensitizer fluorescence baseline without the need for time-gating. This allows for high sensitivity detection of singlet oxygen luminescence emission generated by continuous wave light sources, such as solar simulator sources and those commonly used in PDT clinics. The value of the technology is demonstrated during in vivo and ex vivo experiments that show the correlation of measured singlet oxygen with PDT treatment efficacy and the illumination intensity on the skin. These results demonstrate the potential use of the technology as a dosimeter to guide PDT treatment and as an analytical tool supporting the development of improved sunscreen products for skin cancer prevention.

7.
J Eval Clin Pract ; 29(3): 495-512, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36648226

RESUMEN

RATIONALE: Mobile stroke units (MSUs) are increasingly being implemented to provide acute stroke care in the prehospital environment, but a comprehensive implementation evaluation has not been undertaken. AIM: To identify successes and challenges in the pre- and initial operations of the first Australian MSU service from an interdisciplinary perspective. METHODS: Process evaluation of the Melbourne MSU with a mixed-methods design. Purposive sampling targeted key stakeholder groups. Online surveys (administered June-September 2019) and semistructured interviews (October-November 2019) explored experiences. Directed content analysis (raters' agreement 85%) and thematic analysis results are presented using the Interactive Sociotechnical Analysis framework. RESULTS: Participants representing executive/program operations, MSU clinicians and hospital-based clinicians completed 135 surveys and 38 interviews. Results converged, with major themes addressing successes and challenges: stakeholders, vehicle, knowledge, training/education, communication, work processes and working relationships. CONCLUSIONS: Successes and challenges of establishing a new MSU service extend beyond technical, to include operational and social aspects across prehospital and hospital environments.


Asunto(s)
Accidente Cerebrovascular , Humanos , Australia , Hospitales , Unidades Móviles de Salud
9.
Anim Genet ; 43(6): 781-4, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22497350

RESUMEN

Animal growth relative to food energy input is of key importance to agricultural production. Several recent studies highlighted genetic markers associated with food conversion efficiency in beef cattle, and there is now a requirement to validate these associations in additional populations and to assess their potential utility for selecting animals with enhanced food-use efficiency. The current analysis tested a population of dairy cattle using 138 DNA markers previously associated with food intake and growth in a whole-genome association analysis of beef animals. Although seven markers showed point-wise significance at P < 0.05, none of the single-nucleotide polymorphisms tested were significantly associated with food conversion efficiency after correction for multiple testing. These data do not support the involvement of this subset of previously implicated markers in the food conversion efficiency of the physiologically distinct New Zealand Holstein-Friesian dairy breed.


Asunto(s)
Bovinos/genética , Bovinos/metabolismo , Estudio de Asociación del Genoma Completo/veterinaria , Leche/metabolismo , Animales , Industria Lechera , Dieta/veterinaria , Alimentos , Marcadores Genéticos , Polimorfismo de Nucleótido Simple
10.
J Ethn Subst Abuse ; 11(1): 1-21, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22381120

RESUMEN

This study examined variations by race and ethnicity in initiation and engagement, two performance measures of treatment for substance use disorders that focus on the timely receipt of services during the early stage of substance abuse treatment. Administrative data from the Oklahoma Department of Mental Health and Substance Abuse Services were linked with facility-level information from the National Survey of Substance Abuse Treatment Services. We found that Black clients were least likely to initiate treatment, but no race or ethnic differences in treatment engagement were found when compared by race or ethnicity. Most client and facility characteristics' association with initiation or engagement did not differ across racial or ethnic groups. Increased attention is needed to understand what may contribute to the differences and how to address them. This study also offers an approach that state agencies may implement for monitoring treatment quality and examining racial and ethnic disparities in substance abuse treatment services.


Asunto(s)
Aceptación de la Atención de Salud/etnología , Grupos Raciales/estadística & datos numéricos , Centros de Tratamiento de Abuso de Sustancias/estadística & datos numéricos , Trastornos Relacionados con Sustancias/rehabilitación , Adolescente , Adulto , Población Negra/estadística & datos numéricos , Etnicidad/estadística & datos numéricos , Femenino , Encuestas Epidemiológicas , Humanos , Masculino , Persona de Mediana Edad , Oklahoma , Trastornos Relacionados con Sustancias/etnología , Factores de Tiempo , Estados Unidos , Adulto Joven
11.
J Appalach Health ; 3(2): 32-42, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-35769171

RESUMEN

Introduction: Medication-assisted treatment (MAT) is an evidence-based therapy for opioid use disorder (OUD) that has not been fully implemented in rural areas due to patient, provider, and logistical barriers. Limited information is available on provider perceptions of barriers to MAT in rural Central Appalachia which has very high rates of OUD compared to the rest the United States. Purpose: Determine perceived barriers for potential prescribers to using MAT, including buprenorphine, as part of treatment for OUD in West Virginia. Methods: A 30-question, anonymous survey was sent to physicians, physician assistants and advanced practice registered nurses using an online link. Link was distributed through the WV Medicaid provider list, professional association and institutional contact lists, and social media. Comparisons were made by provider waivered or non-waivered status. Results: Overall, 84% of waivered providers (n = 77) and only 8% of non-waivered providers (n = 341) indicated ever prescribing a form of MAT for OUD; 73% percent of waivered providers were currently prescribing MAT and accepting new patients with OUD. Only 4% of non-waivered providers were currently prescribing MAT and 21% were currently accepting new patients with OUD. Lack of available mental health and psychosocial support services and concerns about diversion or misuse of medication were the top perceived barriers to implementing MAT programs. Implications: Implementing strategies to improve access to behavioral health care including telehealth and apps, provider training and addressing stigma around OUD treatment were identified as priorities that would help increase providers' willingness to prescribe medications for OUD treatment.

12.
Pragmat Obs Res ; 12: 93-104, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34408531

RESUMEN

INTRODUCTION: Symptoms may persist after the initial phases of COVID-19 infection, a phenomenon termed long COVID. Current knowledge on long COVID has been mostly derived from test-confirmed and hospitalized COVID-19 patients. Data are required on the burden and predictors of long COVID in a broader patient group, which includes both tested and untested COVID-19 patients in primary care. METHODS: This is an observational study using data from Platform C19, a quality improvement program-derived research database linking primary care electronic health record data (EHR) with patient-reported questionnaire information. Participating general practices invited consenting patients aged 18-85 to complete an online questionnaire since 7th August 2020. COVID-19 self-diagnosis, clinician-diagnosis, testing, and the presence and duration of symptoms were assessed via the questionnaire. Patients were considered present with long COVID if they reported symptoms lasting ≥4 weeks. EHR and questionnaire data up till 22nd January 2021 were extracted for analysis. Multivariable regression analyses were conducted comparing demographics, clinical characteristics, and presence of symptoms between patients with long COVID and patients with shorter symptom duration. RESULTS: Long COVID was present in 310/3151 (9.8%) patients with self-diagnosed, clinician-diagnosed, or test-confirmed COVID-19. Only 106/310 (34.2%) long COVID patients had test-confirmed COVID-19. Risk predictors of long COVID were age ≥40 years (adjusted Odds Ratio [AdjOR]=1.49 [1.05-2.17]), female sex (adjOR=1.37 [1.02-1.85]), frailty (adjOR=2.39 [1.29-4.27]), visit to A&E (adjOR=4.28 [2.31-7.78]), and hospital admission for COVID-19 symptoms (adjOR=3.22 [1.77-5.79]). Aches and pain (adjOR=1.70 [1.21-2.39]), appetite loss (adjOR=3.15 [1.78-5.92]), confusion and disorientation (adjOR=2.17 [1.57-2.99]), diarrhea (adjOR=1.4 [1.03-1.89]), and persistent dry cough (adjOR=2.77 [1.94-3.98]) were symptom features statistically more common in long COVID. CONCLUSION: This study reports the factors and symptom features predicting long COVID in a broad primary care population, including both test-confirmed and the previously missed group of COVID-19 patients.

14.
Front Robot AI ; 7: 115, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33501281

RESUMEN

This article proposed a novel controller structure to track the non-linear behavior of the pneumatic muscle actuator (PMA), such as the elongation for the extensor actuator and bending for the bending PMA. The proposed controller consists of a neural network (NN) controller laid in parallel with the proportional controller (P). The parallel neural network proportional (PNNP) controllers provide a high level of precision and fast-tracking control system. The PNNP has been applied to control the length of the single extensor PMA and the bending angle of the single self-bending contraction actuator (SBCA) at different load values. For further validation, the PNNP has been applied to control a human-robot shared control system. The results show the efficiency of the proposed controller structure.

15.
Brain ; 131(Pt 1): 50-9, 2008 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17928317

RESUMEN

Though stuttering is manifest in its motor characteristics, the cause of stuttering may not relate purely to impairments in the motor system as stuttering frequency is increased by linguistic factors, such as syntactic complexity and length of utterance, and decreased by changes in perception, such as masking or altering auditory feedback. Using functional and diffusion imaging, we examined brain structure and function in the motor and language areas in a group of young people who stutter. During speech production, irrespective of fluency or auditory feedback, the people who stuttered showed overactivity relative to controls in the anterior insula, cerebellum and midbrain bilaterally and underactivity in the ventral premotor, Rolandic opercular and sensorimotor cortex bilaterally and Heschl's gyrus on the left. These results are consistent with a recent meta-analysis of functional imaging studies in developmental stuttering. Two additional findings emerged from our study. First, we found overactivity in the midbrain, which was at the level of the substantia nigra and extended to the pedunculopontine nucleus, red nucleus and subthalamic nucleus. This overactivity is consistent with suggestions in previous studies of abnormal function of the basal ganglia or excessive dopamine in people who stutter. Second, we found underactivity of the cortical motor and premotor areas associated with articulation and speech production. Analysis of the diffusion data revealed that the integrity of the white matter underlying the underactive areas in ventral premotor cortex was reduced in people who stutter. The white matter tracts in this area via connections with posterior superior temporal and inferior parietal cortex provide a substrate for the integration of articulatory planning and sensory feedback, and via connections with primary motor cortex, a substrate for execution of articulatory movements. Our data support the conclusion that stuttering is a disorder related primarily to disruption in the cortical and subcortical neural systems supporting the selection, initiation and execution of motor sequences necessary for fluent speech production.


Asunto(s)
Encéfalo/fisiopatología , Tartamudeo/fisiopatología , Adolescente , Adulto , Encéfalo/patología , Mapeo Encefálico/métodos , Imagen de Difusión por Resonancia Magnética/métodos , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Corteza Motora/patología , Corteza Motora/fisiopatología , Lectura , Tartamudeo/patología
17.
Appl Neuropsychol Child ; 8(4): 355-365, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30265574

RESUMEN

The purpose of this study was to determine whether children who stutter (CWS) and children who do not stutter (CWNS) differ in terms of attentional ability. Participants were 40 age- and gender-matched CWS and CWNS (aged between 72 and 120 months). Attentional ability was assessed using the Test of Everyday Attention for Children (TEA-Ch), a clinical assessment battery comprising 13 attentional measures, assessing three areas of attention: selective attention, sustained attention, and attentional switching. A low score on the assessment indicates attentional difficulty. There was an overall tendency for CWS to score lower than CWNS on all 13 TEA-Ch measures and all three attentional abilities. This difference reached statistical significance for the sustained attentional component. The present study provides support for the hypothesis that there are some differences between CWS and CWNS in terms of attentional ability. The findings are interpreted within existing models of attention with regard to previous studies of attention in CWS.


Asunto(s)
Atención/fisiología , Función Ejecutiva/fisiología , Tartamudeo/fisiopatología , Niño , Estudios de Cohortes , Femenino , Humanos , Masculino , Pruebas Neuropsicológicas
18.
J Clin Exp Neuropsychol ; 40(6): 544-558, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29064318

RESUMEN

INTRODUCTION: Compelling findings into the relationship between stuttering and attentional ability have started to emerge, with some child and adult studies indicating poorer attentional ability among people who stutter (PWS). The purpose of the present research was to provide a more complete picture of the attentional abilities of PWS, as well as to gather insights into their individual attentional performance. METHOD: We compared the attentional ability of PWS to that of people who do not stutter (PWNS) by using the Test of Everyday Attention (TEA). TEA is a clinical assessment battery with a very good validity and reliability comprising 8 subtests that pose differential demands on sustained attention, selective attention, attentional switching, and divided attention. Fifty age- and gender-matched PWS and PWNS (aged 19-77 years) took part in the study. Importantly, we also examined stuttering severity in the PWS group. RESULTS: PWS performed significantly worse on tasks tapping into visual selective and divided attentional resources. Furthermore despite failing to reach statistical significance, the results also revealed an interesting trend for stuttering to be associated with poorer performance on two subtests measuring attentional switching and one tapping into auditory selective attention. Moreover, as hypothesized, there was also a negative association between stuttering severity and performance on two TEA subtests measuring visual selective attention. Finally, the type of TEA test variant produced no significant effect on performance. CONCLUSIONS: We interpret these results as indicative of stuttering being associated with poorer performance on tasks measuring certain attentional abilities. These tie in well with theoretical models identifying speech production as particularly attention-demanding in stuttering or approaches placing attentional dysfunction at the heart of the condition. The present research also has practical implications for the use of attentional training to improve fluency.


Asunto(s)
Atención , Desempeño Psicomotor , Tartamudeo/psicología , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Tartamudeo/diagnóstico , Percepción Visual , Adulto Joven
19.
Soft Robot ; 5(5): 576-591, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30040059

RESUMEN

This article presents the design of a novel extensor-contractor pneumatic artificial muscle (ECPAM). This new actuator has numerous advantages over traditional pneumatic artificial muscles. These include the abilities to both contract and extend relative to a nominal initial length, to generate both contraction and extension forces, and to vary stiffness at any actuator length. A kinematic analysis of the ECPAM is presented in this article. A new output force mathematical model has been developed for the ECPAM based on its kinematic analysis and the theory of energy conservation. The correlation between experimental results and the new mathematical model has been investigated and show good correlation. Numerous stiffness experiments have been conducted to validate the variable stiffness ability of the actuator at a series of specific fixed lengths. This has proven that actuator stiffness can be adjusted independently of actuator length. Finally, a stiffness-position controller has been developed to validate the effectiveness of the novel actuator.


Asunto(s)
Diseño de Equipo , Contracción Muscular , Robótica/métodos , Animales , Biomimética , Modelos Teóricos
20.
Soft Robot ; 5(1): 54-70, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29412080

RESUMEN

Soft robot arms possess unique capabilities when it comes to adaptability, flexibility, and dexterity. In addition, soft systems that are pneumatically actuated can claim high power-to-weight ratio. One of the main drawbacks of pneumatically actuated soft arms is that their stiffness cannot be varied independently from their end-effector position in space. The novel robot arm physical design presented in this article successfully decouples its end-effector positioning from its stiffness. An experimental characterization of this ability is coupled with a mathematical analysis. The arm combines the light weight, high payload to weight ratio and robustness of pneumatic actuation with the adaptability and versatility of variable stiffness. Light weight is a vital component of the inherent safety approach to physical human-robot interaction. To characterize the arm, a neural network analysis of the curvature of the arm for different input pressures is performed. The curvature-pressure relationship is also characterized experimentally.

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