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Recording cell-specific neuronal activity while monitoring behaviors of freely moving subjects can provide some of the most significant insights into brain function. Current means for monitoring calcium dynamics in genetically targeted populations of neurons rely on delivery of light and recording of fluorescent signals through optical fibers that can reduce subject mobility, induce motion artifacts, and limit experimental paradigms to isolated subjects in open, two-dimensional (2D) spaces. Wireless alternatives eliminate constraints associated with optical fibers, but their use of head stages with batteries adds bulk and weight that can affect behaviors, with limited operational lifetimes. The systems introduced here avoid drawbacks of both types of technologies, by combining highly miniaturized electronics and energy harvesters with injectable photometric modules in a class of fully wireless, battery-free photometer that is fully implantable subdermally to allow for the interrogation of neural dynamics in freely behaving subjects, without limitations set by fiber optic tethers or operational lifetimes constrained by traditional power supplies. The unique capabilities of these systems, their compatibility with magnetic resonant imaging and computed tomography and the ability to manufacture them with techniques in widespread use for consumer electronics, suggest a potential for broad adoption in neuroscience research.
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Encéfalo/fisiologia , Fotometria/métodos , Animais , Encéfalo/diagnóstico por imagem , Encéfalo/cirurgia , Desenho de Equipamento , Imageamento por Ressonância Magnética , Camundongos , Camundongos Endogâmicos C57BL , Fotometria/instrumentação , Próteses e Implantes , Tecnologia sem Fio/instrumentaçãoRESUMO
This study offers a new perspective on the role of relative humidity in strategies to improve the health and wellbeing of office workers. A lack of studies of sufficient participant size and diversity relating relative humidity (RH) to measured health outcomes has been a driving factor in relaxing thermal comfort standards for RH and removing a lower limit for dry air. We examined the association between RH and objectively measured stress responses, physical activity (PA), and sleep quality. A diverse group of office workers (n = 134) from four well-functioning federal buildings wore chest-mounted heart rate variability monitors for three consecutive days, while at the same time, RH and temperature (T) were measured in their workplaces. Those who spent the majority of their time at the office in conditions of 30%-60% RH experienced 25% less stress at the office than those who spent the majority of their time in drier conditions. Further, a correlational study of our stress response suggests optimal values for RH may exist within an even narrower range around 45%. Finally, we found an indirect effect of objectively measured poorer sleep quality, mediated by stress responses, for those outside this range.
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Umidade , Saúde Ocupacional , Local de Trabalho , HumanosRESUMO
Acoustoelectric cardiac imaging (ACI) is a hybrid modality that exploits the interaction of an ultrasonic pressure wave and the resistivity of tissue to map current densities in the heart. This study demonstrates for the first time in vivo ACI in a swine model. ACI measured beat-to-beat variability (n=20) of the peak of the cardiac activation wave at one location of the left ventricle as 5.32±0.74µV, 3.26±0.54mm below the epicardial surface, and 2.67±0.56ms before the peak of the local electrogram. Cross-sectional ACI images exhibited propagation velocities of 0.192±0.061m/s along the epicardial-endocardial axis with an SNR of 24.9 dB. This study demonstrates beat-to-beat and multidimensional ACI, which might reveal important information to help guide electroanatomic mapping procedures during ablation therapy.
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Técnicas de Imagem Cardíaca/métodos , Técnicas Eletrofisiológicas Cardíacas/métodos , Coração/diagnóstico por imagem , Contração Miocárdica/fisiologia , Animais , Mapeamento Potencial de Superfície Corporal , Estudos Transversais , Condutividade Elétrica , Coração/fisiologia , Sistema de Condução Cardíaco/fisiologia , Masculino , Modelos Cardiovasculares , SuínosRESUMO
PURPOSE: To build an evidence-informed theoretical model describing how to support people with dementia to live well or for longer at home. METHODS: We searched electronic databases to August 2018 for papers meeting predetermined inclusion criteria in two reviews that informed our model. We scoped literature for theoretical models of how to enable people with dementia to live at home independently, with good life quality or for longer. We systematically reviewed Randomised Controlled Trials (RCTs) reporting psychosocial intervention effects on time lived with dementia at home. Two researchers independently rated risk of bias. We developed our theoretical model through discussions with experts by personal, clinical and academic experiences, informed by this evidence base. RESULTS: Our scoping review included 52 studies. We divided models identified into: values and approaches (relational and recovery models; optimising environment and activities; family carer skills and support); care strategies (family carer-focused; needs and goal-based; self-management); and service models (case management; integrated; consumer-directed). The 11 RCTs included in our systematic review, all judged at low risk of bias, described only two interventions that increased time people with dementia lived in their own homes. These collectively encompassed all these components except for consumer-directed and integrated care. We developed and revised our model, using review evidence and expert consultation to define the final model. CONCLUSIONS: Our theoretical model describes values, care strategies and service models that can be used in the design of interventions to enable people with dementia to live well and for longer at home. TRIAL REGISTRATION: PROSPERO 2018 registration number: CRD42018099693 (scoping review). PROSPERO 2018 registration number: CRD42018099200 (RCT systematic review).
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Administração de Caso , Demência/psicologia , Vida Independente/psicologia , Cuidadores/psicologia , Demência/terapia , Assistência Domiciliar , Humanos , Modelos Teóricos , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
Peripheral lung lesions treated with a single fraction of stereotactic ablative body radiotherapy (SABR) utilizing volumetric modulated arc therapy (VMAT) delivery and flattening filter-free (FFF) beams represent a potentially high-risk scenario for clinically significant dose blurring effects due to interplay between the respiratory motion of the lesion and dynamic multi-leaf collimators (MLCs). The aim of this study was to determine an efficient means of developing low-modulation VMAT plans in the Eclipse treatment planning system (v15.5, Varian Medical Systems, Palo Alto, USA) in order to minimize this risk, while maintaining dosimetric quality. The study involved 19 patients where an internal target volume (ITV) was contoured to encompass the entire range of tumor motion, and a planning target volume (PTV) created using a 5-mm isotropic expansion of this contour. Each patient had seven plan variations created, with each rescaled to achieve the clinical planning goal for PTV coverage. All plan variations used the same field arrangement, and consisted of one dynamic conformal arc therapy (DCAT) plan, and six VMAT plans with varying degrees of modulation restriction, achieved through utilizing different combinations of the aperture shape controller (ASC) in the calculation parameters, and monitor unit (MU) objective during optimization. The dosimetric quality was assessed based on RTOG conformity indices (CI100/CI50), as well as adherence to dose-volume metrics used clinically at our institution. Plan complexity was assessed based on the modulation factor (MU/cGy) and the field edge metric. While VMAT plans with the least modulation restriction achieved the best dosimetry, it was found that there was no clinically significant trade-off in terms of dose to organs at risk and conformity by reducing complexity. Furthermore, it was found that utilizing the ASC and MU objective could reduce plan complexity to near-DCAT levels with improved dosimetry, which may be sufficiently robust to overcome the interplay effect.
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Neoplasias Pulmonares , Radiocirurgia , Radioterapia de Intensidade Modulada , Humanos , Pulmão , Neoplasias Pulmonares/radioterapia , Neoplasias Pulmonares/cirurgia , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por ComputadorRESUMO
OBJECTIVE: Slowing functional decline could enable people living with dementia to live for longer and more independently in their own homes. We aimed to update previous syntheses examining the effectiveness of nonpharmacological interventions in reducing functional decline (activities of daily living, activity-specific physical functioning, or function-specific goal attainment) in people living in their own homes with dementia. METHODS: We systematically searched electronic databases from January 2012 to May 2018; two researchers independently rated risk of bias of randomised controlled trials (RCTs) fitting predetermined inclusion criteria using a checklist; we narratively synthesised findings, prioritising studies judged to have a lower risk of bias. RESULTS: Twenty-nine papers (describing 26 RCTs) met eligibility criteria, of which we judged 13 RCTs to have a lower risk of bias. Study interventions were evaluated in four groups: physical exercise, occupational, multicomponent, and cognition-oriented interventions. Four out of 13 RCTs reported functional ability as a primary outcome. In studies judged to have a lower risk of bias, in-home tailored exercise, individualised cognitive rehabilitation, and in-home activities-focussed occupational therapy significantly reduced functional decline relative to control groups in individual studies. There was consistent evidence from studies at low risk of bias that group-based exercise and reminiscence therapies were ineffective at reducing functional decline. CONCLUSION: We found no replicated evidence of intervention effectiveness in decreasing functional decline. Interventions associated with slower functional decline in individual trials have been individually delivered and tailored to the needs of the person with dementia. This is consistent with previous findings. Future intervention trials should prioritise these approaches.
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Atividades Cotidianas , Demência/terapia , Demência/fisiopatologia , Terapia por Exercício/métodos , Humanos , Terapia Ocupacional/métodos , Psicoterapia/métodos , Psicoterapia de Grupo/métodos , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
IMPORTANCE: Excessive ocular sun exposure is linked to various eye pathologies. Conjunctival ultraviolet autofluorescence (CUVAF) is a method of detecting sun-related conjunctival damage; however, the custom-built camera system required is not readily available. BACKGROUND: We investigated whether blue laser autofluorescence (BAF) on a commonly used confocal scanning laser ophthalmoscope (cSLO) can be utilized to measure CUVAF area. DESIGN: Cross-sectional evaluation of a diagnostic technology at a medical research institute. PARTICIPANTS: Sixty-four participants recruited from three on-going observational eye studies in Western Australia. METHODS: All participants had four images, two of each eye, captured using the CUVAF camera and BAF on the same day. Participants with pterygium or poor quality images were excluded from the analysis. Two graders measured CUVAF area in each image twice. CUVAF area measured by BAF was then compared to measurements determined with the conventional camera system. MAIN OUTCOME MEASURES: CUVAF area. RESULTS: After exclusions, 50 participants' images were analysed. Intra- and inter-observer repeatability were similar between the two systems. When comparing CUVAF area measured by BAF to the camera measurement, grader 1 had a mean difference of +1.00 mm2 , with 95% limits of agreement -5.75 to 7.77 mm2 . Grader 2 had a mean difference of +0.21mm2 , with 95% limits of agreement -7.22 to 7.64 mm2 . CONCLUSIONS AND RELEVANCE: BAF on a commercially available cSLO is a valid method for measuring CUVAF area. This finding provides broader opportunity for identifying, monitoring and educating patients with sun-exposure-related ocular conditions and for researching the ocular impacts of sun exposure.
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Túnica Conjuntiva/efeitos da radiação , Doenças da Túnica Conjuntiva/diagnóstico por imagem , Imagem Óptica/métodos , Lesões por Radiação/diagnóstico por imagem , Luz Solar/efeitos adversos , Adulto , Doenças da Túnica Conjuntiva/etiologia , Estudos Transversais , Exposição Ambiental , Feminino , Humanos , Masculino , Microscopia Confocal/instrumentação , Variações Dependentes do Observador , Lesões por Radiação/etiologia , Reprodutibilidade dos Testes , Raios Ultravioleta/efeitos adversos , Austrália OcidentalRESUMO
Dosimetry audits for passive motion management require dynamically-acquired measurements in a moving phantom to be compared to statically calculated planned doses. This study aimed to characterise the relationship between planning and delivery errors, and the measured dose in the Imaging and Radiation Oncology Core (IROC) thorax phantom, to assess different audit scoring approaches. Treatment plans were created using a 4DCT scan of the IROC phantom, equipped with film and thermoluminescent dosimeters (TLDs). Plans were created on the average intensity projection from all bins. Three levels of aperture complexity were explored: dynamic conformal arcs (DCAT), low-, and high-complexity volumetric modulated arcs (VMATLo, VMATHi). Simulated-measured doses were generated by modelling motion using isocenter shifts. Various errors were introduced including incorrect setup position and target delineation. Simulated-measured film doses were scored using gamma analysis and compared within specific regions of interest (ROIs) as well as the entire film plane. Positional offsets were estimated based on isodoses on the film planes, and point doses within TLD contours were compared. Motion-induced differences between planned and simulated-measured doses were evident even without introduced errors Gamma passing rates within target-centred ROIs correlated well with error-induced dose differences, while whole film passing rates did not. Isodose-based setup position measurements demonstrated high sensitivity to errors. Simulated point doses at TLD locations yielded erratic responses to introduced errors. ROI gamma analysis demonstrated enhanced sensitivity to simulated errors compared to whole film analysis. Gamma results may be further contextualized by other metrics such as setup position or maximum gamma.
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Movimento , Imagens de Fantasmas , Planejamento da Radioterapia Assistida por Computador , Tórax , Tórax/diagnóstico por imagem , Planejamento da Radioterapia Assistida por Computador/métodos , Humanos , Radiometria/instrumentação , Dosagem Radioterapêutica , Radioterapia de Intensidade Modulada , Tomografia Computadorizada Quadridimensional , Movimento (Física)RESUMO
Electrical stimulation of the neuromuscular system holds promise for both scientific and therapeutic biomedical applications. Supplying and maintaining the power necessary to drive stimulation chronically is a fundamental challenge in these applications, especially when high voltages or currents are required. Wireless systems, in which energy is supplied through near field power transfer, could eliminate complications caused by battery packs or external connections, but currently do not provide the harvested power and voltages required for applications such as muscle stimulation. Here, we introduce a passive resonator optimized power transfer design that overcomes these limitations, enabling voltage compliances of ± 20 V and power over 300 mW at device volumes of 0.2 cm2, thereby improving power transfer 500% over previous systems. We show that this improved performance enables multichannel, biphasic, current-controlled operation at clinically relevant voltage and current ranges with digital control and telemetry in freely behaving animals. Preliminary chronic results indicate that implanted devices remain operational over 6 weeks in both intact and spinal cord injured rats and are capable of producing fine control of spinal and muscle stimulation.
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Fontes de Energia Elétrica , Próteses e Implantes , Ratos , Animais , Medula Espinal , Estimulação Elétrica/métodos , Telemetria/métodos , Tecnologia sem Fio , Eletrodos ImplantadosRESUMO
Neurotransmitters and neuromodulators mediate communication between neurons and other cell types; knowledge of release dynamics is critical to understanding their physiological role in normal and pathological brain function. Investigation into transient neurotransmitter dynamics has largely been hindered due to electrical and material requirements for electrochemical stimulation and recording. Current systems require complex electronics for biasing and amplification and rely on materials that offer limited sensor selectivity and sensitivity. These restrictions result in bulky, tethered, or battery-powered systems impacting behavior and that require constant care of subjects. To overcome these challenges, we demonstrate a fully implantable, wireless, and battery-free platform that enables optogenetic stimulation and electrochemical recording of catecholamine dynamics in real time. The device is nearly 1/10th the size of previously reported examples and includes a probe that relies on a multilayer electrode architecture featuring a microscale light emitting diode (µ-LED) and a carbon nanotube (CNT)-based sensor with sensitivities among the highest recorded in the literature (1264.1 nA µM-1 cm-2). High sensitivity of the probe combined with a center tapped antenna design enables the realization of miniaturized, low power circuits suitable for subdermal implantation even in small animal models such as mice. A series of in vitro and in vivo experiments highlight the sensitivity and selectivity of the platform and demonstrate its capabilities in freely moving, untethered subjects. Specifically, a demonstration of changes in dopamine concentration after optogenetic stimulation of the nucleus accumbens and real-time readout of dopamine levels after opioid and naloxone exposure in freely behaving subjects highlight the experimental paradigms enabled by the platform.
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Catecolaminas , Optogenética , Camundongos , Animais , Dopamina , Tecnologia sem Fio , Próteses e ImplantesRESUMO
Hardware removal is among the most common orthopedic procedures performed in the United States. The goal of this study was to report the outcomes of deep hardware removal for children. This study received institutional review board approval. Patients younger than 18 years who underwent deep hardware removal between 2007 and 2017 were studied. We reviewed 227 procedures involving 132 boys and 95 girls. Mean follow-up was 25 months (range, 14-36 months). Mean age at the time of surgery was 12.8 years (range, 2-17 years). Mean time from initial surgery to hardware removal was 8.4 months (range, 1-72 months). Of the 227 cases, 75 used a tourniquet. Mean tourniquet time was 30.1 minutes (range, 1-118 minutes). Mean length of surgery was 44.0 minutes (range, 4-173 minutes). Mean resident level performing the surgery was postgraduate year 3 (range, postgraduate year 2 to fellow). There were 3 complications. Locations of the implanted hardware included: femur, 85; humerus, 49; tibia, 46; hip/pelvis, 17; ulna, 11; miscellaneous foot, 10; radius, 6; and fibula, 3. Indications for surgery included surgeon recommendations in 122 cases; symptomatic hardware in 68 cases, and parent wishes in 37 cases. Hardware removal for children was safe, and the outcomes were excellent. Complications of hardware removal at a teaching hospital can be minimized when a more senior resident is the primary surgeon. Despite the challenging and historically troublesome nature of deep hardware removal, the current study shows that hardware removal for children is safe and effective. [Orthopedics. 2022;45(2):e91-e95.].
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Fíbula , Procedimentos de Cirurgia Plástica , Adolescente , Criança , Pré-Escolar , Remoção de Dispositivo , Feminino , Fêmur/cirurgia , Fíbula/cirurgia , Humanos , Masculino , Próteses e Implantes , Procedimentos de Cirurgia Plástica/métodos , Estudos Retrospectivos , Resultado do TratamentoRESUMO
Background and Purpose: A survey on the patterns of practice of respiratory motion management (MM) was distributed to 111 radiation therapy facilities to inform the development of an end-to-end dosimetry audit including respiratory motion. Materials and methods: The survey (distributed via REDCap) asked facilities to provide information specific to the combinations of MM techniques (breath-hold gating - BHG, internal target volume - ITV, free-breathing gating - FBG, mid-ventilation - MidV, tumour tracking - TT), sites treated (thorax, upper abdomen, lower abdomen), and fractionation regimes (conventional, stereotactic ablative body radiation therapy - SABR) used in their clinic. Results: The survey was completed by 78% of facilities, with 98% of respondents indicating that they used at least one form of MM. The ITV approach was common to all MM-users, used for thoracic treatments by 89% of respondents, and upper and lower abdominal treatments by 38%. BHG was the next most prevalent (41% of MM users), with applications in upper abdominal and thoracic treatment sites (28% vs 25% respectively), but minimal use in the lower abdomen (9%). FBG and TT were utilised sparingly (17%, 7% respectively), and MidV was not selected at all. Conclusions: Two distinct treatment workflows (including use of motion limitation, imaging used for motion assessment, dose calculation, and image guidance procedures) were identified for the ITV and BHG MM techniques, to form the basis of the initial audit. Thoracic SABR with the ITV approach was common to nearly all respondents, while upper abdominal SABR using BHG stood out as more technically challenging. Other MM techniques were sparsely used, but may be considered for future audit development.
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BACKGROUND: Hallux valgus deformity is the lateral deviation of the metatarsophalangeal (MTP) joint and is the most common pathology of the great toe, affecting 2%-4% of the population. It is commonly believed that the condition progresses over time both in the magnitude of deformity and development of arthritic changes. To our knowledge, there are rare studies describing the rate of deformity progression and the development of arthritic changes. Our aim is to quantify the progression of hallux valgus and associated arthritic changes in an adult population using radiographs. METHODS: Patients who are 18 years of age and older (mean age: 61.7 years and range: 18.6-94.2) who presented to our institutions between January 1, 2004, and December 1, 2019, were included. Patients were included in the study if they had hallux valgus on weight-bearing radiographs and two such radiographs at least six months apart. Hallux valgus angle (HVA), intermetatarsal angle (IMA), metatarsophalangeal (MTP) arthritis, tarsometatarsal (TMT) osteoarthritis, Hardy-Clapham sesamoid position, and round sign were collected per patient in the initial and final radiographs. Included cases were first studied together in a whole group. Then, cases were separated into three groups based on the time between initial and final radiographs. RESULTS: A total of 52 radiographic records for 43 patients were included. HVA and IMA progress with time; however, progression does not follow a direct relationship with the time elapsed between initial and final radiographs (p = 0.92 and p = 0.35, respectively). The progression of TMT osteoarthritis, sesamoid position, and round sign do not show a dependence on the time elapsed (p = 0.20, p = 0.11, and p = 0.42, respectively). An increase of one sesamoid unit position over baseline is associated with a 0.85-degree increase in IMA. A one-unit progression of sesamoid position at baseline raises the odds of MTP osteoarthritis progression at the follow-up visit by 2.14 (OR = 2.14, p = 0.0007, CI = [1.35, 3.83]). A HVA increase of one degree increases the odds of TMT osteoarthritis progression at follow-up by a factor of 1.17 (OR = 1.17, p = 0.0005, CI = [1.07, 1.34]). Patients with MTP arthritis at the initial visit have 3.77 times higher odds of round sign progression on their follow-up visit (OR = 3.77, p = 0.027, CI = [1.16, 13.13]). DISCUSSION: Hallux valgus progression can be quantified. Upon their first visit, a patient's hallux valgus parameters can be utilized to demonstrate expected progression. Progression of the deformity and arthritic changes is slow. Nonetheless, the results should be considered by surgeons and patients when developing a treatment plan with patients.
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Nicotine, an addictive substance in tobacco products and electronic cigarettes (e-cigs), is recognized for increasing the risk of cardiovascular and respiratory disorders. Careful real-time monitoring of nicotine exposure is critical in alleviating the potential health impacts of not just smokers but also those exposed to second-hand and third-hand smoke. Monitoring of nicotine requires suitable sensing material to detect nicotine selectively and testing under free-living conditions in the standard environment. Here, we experimentally demonstrate a vanadium dioxide (VO2)-based nicotine sensor and explain its conductometric mechanisms with compositional analysis and density functional theory (DFT) calculations. For real-time monitoring of nicotine vapor from e-cigarettes in the air, the sensor is integrated with an epidermal near-field communication (NFC) interface that enables battery-free operation and data transmission to smart electronic devices to record and store sensor data. Collectively, the technique of sensor development and integration expands the use of wearable electronics for real-time monitoring of hazardous elements in the environment and biosignals wirelessly.
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Sistemas Eletrônicos de Liberação de Nicotina , Produtos do Tabaco , Vaping , Dispositivos Eletrônicos Vestíveis , NicotinaRESUMO
BACKGROUND: Foot and ankle surgeries in the United States (US) are currently performed by orthopaedic surgeons or podiatrists with specialty surgical training. With the trend in healthcare now placing increased emphasis on quality and standardizing patient care, this study aimed to characterize the distribution, volume, and trends of certain foot and ankle surgeries performed in the US by both orthopaedic surgeons and podiatrists. MATERIALS AND METHODS: A retrospective analysis was performed using the Marketscan Claims Database (Truven Health Analytics, Ann Arbor, Michigan) which covers most privately insured patients under the age of 65 in the USA from 2005 to 2014. We searched current procedural terminology (CPT) codes for total ankle replacement (TAR), triple arthrodesis, hallux valgus correction, pilon fracture open reduction and internal fixation (ORIF), calcaneus fracture ORIF, and ankle fracture ORIF. We recorded the timing and nature of procedures along with various features associated with the surgeon and the geographic location of the treatment facility. RESULTS: We found that the number of foot and ankle procedures performed annually is steadily increasing. Orthopaedic surgeons are the main treating surgeon for common foot and ankle traumatic conditions or complex hind foot cases like TAR. On the other hand, our study showed that podiatrists perform almost 9 out of 10 hallux valgus correction surgeries. DISCUSSION: Our study showed the trends in surgical volumes and differences between surgical podiatrists and orthopaedic surgeons and the evolution of these volumes over a ten year period and differences in surgical repertoire between orthopaedists and podiatrists.Levels of Evidence: Level IV: Case series, Clinical research.
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Traumatismos do Tornozelo/cirurgia , Tornozelo/cirurgia , Bases de Dados Factuais , Traumatismos do Pé/cirurgia , Pé/cirurgia , Procedimentos Ortopédicos/estatística & dados numéricos , Cirurgiões Ortopédicos/estatística & dados numéricos , Podiatria/estatística & dados numéricos , Feminino , Hallux Valgus/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Tempo , Estados Unidos/epidemiologiaRESUMO
Recent progress in biosensors have quantitively expanded current capabilities in exploratory research tools, diagnostics and therapeutics. This rapid pace in sensor development has been accentuated by vast improvements in data analysis methods in the form of machine learning and artificial intelligence that, together, promise fantastic opportunities in chronic sensing of biosignals to enable preventative screening, automated diagnosis, and tools for personalized treatment strategies. At the same time, the importance of widely accessible personal monitoring has become evident by recent events such as the COVID-19 pandemic. Progress in fully integrated and chronic sensing solutions is therefore increasingly important. Chronic operation, however, is not truly possible with tethered approaches or bulky, battery-powered systems that require frequent user interaction. A solution for this integration challenge is offered by wireless and battery-free platforms that enable continuous collection of biosignals. This review summarizes current approaches to realize such device architectures and discusses their building blocks. Specifically, power supplies, wireless communication methods and compatible sensing modalities in the context of most prevalent implementations in target organ systems. Additionally, we highlight examples of current embodiments that quantitively expand sensing capabilities because of their use of wireless and battery-free architectures.
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Técnicas Biossensoriais/instrumentação , Tecnologia sem Fio/instrumentação , Inteligência Artificial , Fontes de Energia Bioelétrica , Técnicas Biossensoriais/tendências , COVID-19/fisiopatologia , Fontes de Energia Elétrica , Fenômenos Eletrofisiológicos , Desenho de Equipamento , Humanos , Pandemias , Tecnologia de Sensoriamento Remoto/instrumentação , SARS-CoV-2 , Telemetria/instrumentação , Dispositivos Eletrônicos Vestíveis , Tecnologia sem Fio/tendênciasRESUMO
Wireless battery free and fully implantable tools for the interrogation of the central and peripheral nervous system have quantitatively expanded the capabilities to study mechanistic and circuit level behavior in freely moving rodents. The light weight and small footprint of such devices enables full subdermal implantation that results in the capability to perform studies with minimal impact on subject behavior and yields broad application in a range of experimental paradigms. While these advantages have been successfully proven in rodents that move predominantly in 2D, the full potential of a wireless and battery free device can be harnessed with flying species, where interrogation with tethered devices is very difficult or impossible. Here we report on a wireless, battery free and multimodal platform that enables optogenetic stimulation and physiological temperature recording in a highly miniaturized form factor for use in songbirds. The systems are enabled by behavior guided primary antenna design and advanced energy management to ensure stable optogenetic stimulation and thermography throughout 3D experimental arenas. Collectively, these design approaches quantitatively expand the use of wireless subdermally implantable neuromodulation and sensing tools to species previously excluded from in vivo real time experiments.
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Neuroestimuladores Implantáveis , Fenômenos Fisiológicos do Sistema Nervoso , Optogenética/instrumentação , Aves Canoras/fisiologia , Telemetria/instrumentação , Tecnologia sem Fio/instrumentação , Animais , Encéfalo/fisiologia , Optogenética/métodos , Nervos Periféricos/fisiologia , Reprodutibilidade dos Testes , Telemetria/métodosRESUMO
Bioelectronic interfaces have been extensively investigated in recent years and advances in technology derived from these tools, such as soft and ultrathin sensors, now offer the opportunity to interface with parts of the body that were largely unexplored due to the lack of suitable tools. The musculoskeletal system is an understudied area where these new technologies can result in advanced capabilities. Bones as a sensor and stimulation location offer tremendous advantages for chronic biointerfaces because devices can be permanently bonded and provide stable optical, electromagnetic, and mechanical impedance over the course of years. Here we introduce a new class of wireless battery-free devices, named osseosurface electronics, which feature soft mechanics, ultra-thin form factor and miniaturized multimodal biointerfaces comprised of sensors and optoelectronics directly adhered to the surface of the bone. Potential of this fully implanted device class is demonstrated via real-time recording of bone strain, millikelvin resolution thermography and delivery of optical stimulation in freely-moving small animal models. Battery-free device architecture, direct growth to the bone via surface engineered calcium phosphate ceramic particles, demonstration of operation in deep tissue in large animal models and readout with a smartphone highlight suitable characteristics for exploratory research and utility as a diagnostic and therapeutic platform.
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Fontes de Energia Elétrica , Fenômenos Eletromagnéticos , Eletrônica/instrumentação , Fenômenos Fisiológicos Musculoesqueléticos , Termografia/instrumentação , Tecnologia sem Fio/instrumentação , Animais , Eletrônica/métodos , Masculino , Microscopia Eletrônica de Varredura , Sistema Musculoesquelético/anatomia & histologia , Sistema Musculoesquelético/ultraestrutura , Redes Neurais de Computação , Ratos Sprague-Dawley , Estresse Mecânico , Termografia/métodos , Microtomografia por Raio-X/métodosRESUMO
Implantable deep brain stimulation (DBS) systems are utilized for clinical treatment of diseases such as Parkinson's disease and chronic pain. However, long-term efficacy of DBS is limited, and chronic neuroplastic changes and associated therapeutic mechanisms are not well understood. Fundamental and mechanistic investigation, typically accomplished in small animal models, is difficult because of the need for chronic stimulators that currently require either frequent handling of test subjects to charge battery-powered systems or specialized setups to manage tethers that restrict experimental paradigms and compromise insight. To overcome these challenges, we demonstrate a fully implantable, wireless, battery-free platform that allows for chronic DBS in rodents with the capability to control stimulation parameters digitally in real time. The devices are able to provide stimulation over a wide range of frequencies with biphasic pulses and constant voltage control via low-impedance, surface-engineered platinum electrodes. The devices utilize off-the-shelf components and feature the ability to customize electrodes to enable broad utility and rapid dissemination. Efficacy of the system is demonstrated with a readout of stimulation-evoked neural activity in vivo and chronic stimulation of the medial forebrain bundle in freely moving rats to evoke characteristic head motion for over 36 days.
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BACKGROUND: The Slip! Slop! Slap! Sunsmart safety campaign was an Australian initiative implemented in the 1980s. To assess this campaign's effect on pterygium, we examined the rate of pterygium surgery across Australia and described the prevalence and associations of pterygium in Perth, Australia's sunniest capital city. METHODS: The rate of pterygium surgery was examined using Australian Medicare data. A cross-sectional analysis of the Generation 1 (Gen1) cohort of the Raine Study was performed to investigate the prevalence of pterygium in Perth. We investigated the association between pterygium and conjunctival ultraviolet autofluorescence (CUVAF) area, an objective biomarker of sun exposure, and demographics and health variables derived from a detailed questionnaire. RESULTS: Between 1994 and 2017, the rate of Medicare funded pterygium surgery in Western Australia fell 11%, well below the national average decline of 47%. Of the 1049 Gen1 Raine Study participants, 994 (571 females; mean age 56.7 years, range = 40.9-81.7) were included in the analysis. The lifetime prevalence of pterygium was 8.4% (n = 83). A higher prevalence of pterygium was associated with outdoor occupation (p-trend = 0.007), male sex (p-trend 0.01) and increasing CUVAF area (p-value <0.001). CONCLUSIONS: The effect of Australia's Slip! Slop! Slap! Sunsmart safety campaign on pterygium been mixed. Since 1994, the rate of private pterygium surgery has declined significantly in all Australian states except Western Australia. Perth, Western Australia, has the highest pterygium prevalence of any mainland-Australian cohort. Higher CUVAF area, male sex, and outdoor occupation were associated with an increased risk of pterygium.