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1.
Sensors (Basel) ; 24(14)2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-39065827

RESUMO

Congestive heart failure (CHF) is a fatal disease with progressive severity and no cure; the heart's inability to adequately pump blood leads to fluid accumulation and frequent hospital readmissions after initial treatments. Therefore, it is imperative to continuously monitor CHF patients during its early stages to slow its progression and enable timely medical interventions for optimal treatment. An increase in interstitial fluid pressure (IFP) is indicative of acute CHF exacerbation, making IFP a viable biomarker for predicting upcoming CHF if continuously monitored. In this paper, we present an inductor-capacitor (LC) sensor for subcutaneous wireless and continuous IFP monitoring. The sensor is composed of inexpensive planar copper coils defined by a simple craft cutter, which serves as both the inductor and capacitor. Because of its sensing mechanism, the sensor does not require batteries and can wirelessly transmit pressure information. The sensor has a low-profile form factor for subcutaneous implantation and can communicate with a readout device through 4 layers of skin (12.7 mm thick in total). With a soft silicone rubber as the dielectric material between the copper coils, the sensor demonstrates an average sensitivity as high as -8.03 MHz/mmHg during in vitro simulations.


Assuntos
Líquido Extracelular , Tecnologia sem Fio , Tecnologia sem Fio/instrumentação , Líquido Extracelular/química , Líquido Extracelular/fisiologia , Humanos , Monitorização Fisiológica/instrumentação , Monitorização Fisiológica/métodos , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/fisiopatologia , Pressão , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos
2.
Comput Biol Med ; 179: 108679, 2024 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-39033682

RESUMO

Sleep staging is a crucial tool for diagnosing and monitoring sleep disorders, but the standard clinical approach using polysomnography (PSG) in a sleep lab is time-consuming, expensive, uncomfortable, and limited to a single night. Advancements in sensor technology have enabled home sleep monitoring, but existing devices still lack sufficient accuracy to inform clinical decisions. To address this challenge, we propose a deep learning architecture that combines a convolutional neural network and bidirectional long short-term memory to accurately classify sleep stages. By supplementing photoplethysmography (PPG) signals with respiratory sensor inputs, we demonstrated significant improvements in prediction accuracy and Cohen's kappa (k) for 2- (92.7 %; k = 0.768), 3- (80.2 %; k = 0.714), 4- (76.8 %, k = 0.550), and 5-stage (76.7 %, k = 0.616) sleep classification using raw data. This relatively translatable approach, with a less intensive AI model and leveraging only a few, inexpensive sensors, shows promise in accurately staging sleep. This has potential for diagnosing and managing sleep disorders in a more accessible and practical manner, possibly even at home.

3.
Laryngoscope Investig Otolaryngol ; 9(3): e1272, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38803458

RESUMO

Objective: Currently, diagnosis of cerebrospinal fluid (CSF) rhinorrhea relies on a multimodal approach, increasing costs and ultimately delaying diagnosis. In the United States and internationally, the crux of such a diagnosis relies on confirmation testing (via biomarkers) and localization (e.g., imaging). Biomarker testing may require analysis at an outside facility, resulting in delays diagnosis and treatment. In addition, specialized imaging may be nonspecific and often requires an active leak for diagnosis. There remains a clear need for innovative new technology. Methods: A comprehensive review was conducted on both foundational and innovative scholarly articles regarding current and emerging diagnosis modalities for CSF. Results: Current modalities in CSF rhinorrhea diagnosis and localization include laboratory tests (namely, B2T immunofixation), imaging (CT and/or MRI) with or without intrathecal administration, and surgical exploration. Each of these modalities carry flaws, risks, and benefits, ultimately contributing to delays in diagnosis and morbidity. Promising emerging technologies include lateral flow immunoassays (LFI) and biologically functionalized field-effect transistors (BioFET). Nevertheless, these carry some drawbacks of their own, and require further validation. Conclusion: CSF rhinorrhea remains a challenging diagnosis, requiring a multimodal approach to differentiate from nonpathologic causes of rhinorrhea. Current methods in diagnosis are imperfect, as the ideal test would be a readily accessible, inexpensive, rapid, highly accurate point-of-care test without the need for excess fluid or specialized processing. Critical work is being done to develop promising, new, improved tests, though a clear successor has not yet emerged. Level of Evidence: N/A.

4.
Sci Rep ; 13(1): 19245, 2023 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-37935766

RESUMO

Associations between cerebrovascular disease and impaired autonomic function and cerebrovascular reactivity have led to increased interest in variability of heart rate (HRV) and blood pressure (BPV) following stroke. In this study, beat-to-beat pulse rate variability (PRV) and BPV were measured in clinically stable stroke patients (6 ischemic, 2 hemorrhagic) at least one year after their last cerebrovascular event. Beat-to-beat blood pressure (BP) measurements were collected from subjects while resting in the sitting position for one hour. Compared with healthy controls, stroke patients exhibited significantly greater time-domain (standard deviation, coefficient of variation, average real variability) and normalized high-frequency BPV (all p < 0.05). Stroke patients also exhibited lower LF:HF ratios than control subjects (p = 0.003). No significant differences were observed in PRV between the two groups, suggesting that BPV may be a more sensitive biomarker of cerebrovascular function in long-term post-stroke patients. Given a paucity of existing literature investigating beat-to-beat BPV in clinically stable post-stroke patients long (> 1 year) after their cerebrovascular events, this pilot study can help inform future studies investigating the mechanisms and effects of BPV in stroke. Elucidating this physiology may facilitate long-term patient monitoring and pharmacological management to mitigate the risk for recurrent stroke.


Assuntos
Acidente Vascular Cerebral , Humanos , Pressão Sanguínea/fisiologia , Frequência Cardíaca/fisiologia , Projetos Piloto , Monitorização Fisiológica
5.
Nat Commun ; 14(1): 7522, 2023 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-37980425

RESUMO

The human body exhibits complex, spatially distributed chemo-electro-mechanical processes that must be properly captured for emerging applications in virtual/augmented reality, precision health, activity monitoring, bionics, and more. A key factor in enabling such applications involves the seamless integration of multipurpose wearable sensors across the human body in different environments, spanning from indoor settings to outdoor landscapes. Here, we report a versatile epidermal body area network ecosystem that enables wireless power and data transmission to and from battery-free wearable sensors with continuous functionality from dry to underwater settings. This is achieved through an artificial near field propagation across the chain of biocompatible, magneto-inductive metamaterials in the form of stretchable waterborne skin patches-these are fully compatible with pre-existing consumer electronics. Our approach offers uninterrupted, self-powered communication for human status monitoring in harsh environments where traditional wireless solutions (such as Bluetooth, Wi-Fi or cellular) are unable to communicate reliably.


Assuntos
Ecossistema , Realidade Virtual , Humanos , Tecnologia sem Fio , Epiderme , Monitorização Fisiológica
6.
Sci Rep ; 12(1): 16772, 2022 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-36202815

RESUMO

Accurate continuous non-invasive blood pressure (CNIBP) monitoring is the holy grail of digital medicine but remains elusive largely due to significant drifts in signal and motion artifacts that necessitate frequent device recalibration. To address these challenges, we developed a unique approach by creating a novel intra-beat biomarker (Diastolic Transit Time, DTT) to achieve highly accurate blood pressure (BP) estimations. We demonstrated our approach's superior performance, compared to other common signal processing techniques, in eliminating stochastic baseline wander, while maintaining signal integrity and measurement accuracy, even during significant hemodynamic changes. We applied this new algorithm to BP data collected using non-invasive sensors from a diverse cohort of high acuity patients and demonstrated that we could achieve close agreement with the gold standard invasive arterial line BP measurements, for up to 20 min without recalibration. We established our approach's generalizability by successfully applying it to pulse waveforms obtained from various sensors, including photoplethysmography and capacitive-based pressure sensors. Our algorithm also maintained signal integrity, enabling reliable assessments of BP variability. Moreover, our algorithm demonstrated tolerance to both low- and high-frequency motion artifacts during abrupt hand movements and prolonged periods of walking. Thus, our approach shows promise in constituting a necessary advance and can be applied to a wide range of wearable sensors for CNIBP monitoring in the ambulatory and inpatient settings.


Assuntos
Determinação da Pressão Arterial , Fotopletismografia , Biomarcadores , Pressão Sanguínea/fisiologia , Determinação da Pressão Arterial/métodos , Frequência Cardíaca/fisiologia , Humanos , Fotopletismografia/métodos
7.
Sci Rep ; 12(1): 14873, 2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-36050339

RESUMO

A rising number of authors are drawing evidence on the diagnostic capacity of specific volatile organic compounds (VOCs) resulting from some body fluids. While cancer incidence in society is on the rise, it becomes clear that the analysis of these VOCs can yield new strategies to mitigate advanced cancer incidence rates. This paper presents the methodology implemented to test whether a device consisting of an electronic nose inspired by a dog's olfactory system and olfactory neurons is significantly informative to detect breast cancer (BC). To test this device, 90 human urine samples were collected from control subjects and BC patients at a hospital. To test this system, an artificial intelligence-based classification algorithm was developed. The algorithm was firstly trained and tested with data resulting from gas chromatography-mass spectrometry (GC-MS) urine readings, leading to a classification rate of 92.31%, sensitivity of 100.00%, and specificity of 85.71% (N = 90). Secondly, the same algorithm was trained and tested with data obtained with our eNose prototype hardware, and class prediction was achieved with a classification rate of 75%, sensitivity of 100%, and specificity of 50%.


Assuntos
Neoplasias da Mama , Compostos Orgânicos Voláteis , Animais , Inteligência Artificial , Neoplasias da Mama/diagnóstico , Cães , Nariz Eletrônico , Feminino , Cromatografia Gasosa-Espectrometria de Massas/métodos , Humanos , Compostos Orgânicos Voláteis/análise
9.
Front Digit Health ; 3: 696606, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34713172

RESUMO

We test a new wireless soft capacitance sensor (CAP) based on applanation tonometry at the radial and dorsalis pedis arteries against the gold standard, invasive arterial line (A-Line), for continuous beat to beat blood pressure (BP) measurements in the Operating Room during surgical procedures under anesthesia in 17 subjects with the mean age and body mass index (BMI) of 57. 35 ± 18.72 years and 27.36 ± 4.20 kg/m2, respectively. We have identified several parameters to monitor in order to compare how well the CAP sensor tracks the entire hemodynamic waveform as compared to the A-Line. This includes waveform similarity, heart rate (HR), absolute systolic BP (SBP), diastolic BP (DBP), and temporal response to a vasopressor. Overall, the CAP sensor shows good correlations with A-Line with respect to hemodynamic shape (r > 0.89), HR (mean bias = 0.0006; SD = 0.17), absolute SBP, and DBP in a line of best fit (slope = 0.98 in SBP; 1.08 in DBP) and the mean bias derived from Bland-Altman method to be 1.92 (SD = 12.55) in SBP and 2.38 (SD = 12.19) in DBP across body habitus and age in OR patients under general anesthesia. While we do observe drifts in the system, we still obtain decent correlations with respect to the A-Line as evidenced by excellent linear fit and low mean bias across patients. When we post-process using a different calibration method to account for the drift, the mean bias and SD improve dramatically to -1.85 and 7.19 DBP as well as 1.43 and 7.43 SBP, respectively, indicating a promising potential for improvement when we integrate strategies to account for movement identified by our integrated accelerometer data.

10.
Sensors (Basel) ; 21(18)2021 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-34577492

RESUMO

The relationship between the robustness of HRV derived by linear and nonlinear methods to the required minimum data lengths has yet to be well understood. The normal electrocardiography (ECG) data of 14 healthy volunteers were applied to 34 HRV measures using various data lengths, and compared with the most prolonged (2000 R peaks or 750 s) by using the Mann-Whitney U test, to determine the 0.05 level of significance. We found that SDNN, RMSSD, pNN50, normalized LF, the ratio of LF and HF, and SD1 of the Poincaré plot could be adequately computed by small data size (60-100 R peaks). In addition, parameters of RQA did not show any significant differences among 60 and 750 s. However, longer data length (1000 R peaks) is recommended to calculate most other measures. The DFA and Lyapunov exponent might require an even longer data length to show robust results. Conclusions: Our work suggests the optimal minimum data sizes for different HRV measures which can potentially improve the efficiency and save the time and effort for both patients and medical care providers.


Assuntos
Eletrocardiografia , Adulto , Voluntários Saudáveis , Frequência Cardíaca , Humanos , Estatísticas não Paramétricas
11.
Anal Methods ; 13(7): 874-883, 2021 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-33576354

RESUMO

Using the children's toy, Shrinky-Dink©, we present an aptamer-based electrochemical (E-AB) assay that recognizes the spike protein of SARS-CoV-2 in saliva for viral infection detection. The low-cost electrodes are implementable at population scale and demonstrate detection down to 1 ag mL-1 of the S1 subunit of the spike protein.


Assuntos
Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Poliestirenos/química , SARS-CoV-2/química , Saliva/química , Glicoproteína da Espícula de Coronavírus/análise , Aptâmeros de Nucleotídeos/química , Técnicas Eletroquímicas/instrumentação , Eletrodos , Ouro/química , Humanos , Limite de Detecção , Domínios Proteicos , Glicoproteína da Espícula de Coronavírus/química
12.
Materials (Basel) ; 14(2)2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33450998

RESUMO

Practical wearable applications of soft strain sensors require sensors capable of not only detecting subtle physiological signals, but also of withstanding large scale deformation from body movement. Encapsulation is one technique to protect sensors from both environmental and mechanical stressors. We introduced an encapsulation layer to crack-based wrinkled metallic thin film soft strain sensors as an avenue to improve sensor stretchability, linear response, and robustness. We demonstrate that encapsulated sensors have increased mechanical robustness and stability, displaying a significantly larger linear dynamic range (~50%) and increased stretchability (260% elongation). Furthermore, we discovered that these sensors have post-fracture signal recovery. They maintained conductivity to the 50% strain with stable signal and demonstrated increased sensitivity. We studied the crack formation behind this phenomenon and found encapsulation to lead to higher crack density as the source for greater stretchability. As crack formation plays an important role in subsequent electrical resistance, understanding the crack evolution in our sensors will help us better address the trade-off between high stretchability and high sensitivity.

13.
Lab Chip ; 21(1): 83-92, 2021 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-33300516

RESUMO

Microfluidic devices are traditionally monitored by bulky and expensive off-chip sensors. We have developed a soft piezoresistive sensor capable of measuring micron-level strains that can be easily integrated into devices via soft lithography. We apply this sensor to achieve fast and localized monitoring of pressure, flow, and valve actuation.


Assuntos
Dispositivos Lab-On-A-Chip , Microfluídica
14.
medRxiv ; 2020 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-33236028

RESUMO

Using the children's toy, Shrinky-Dink ©, we present an aptamer-based electrochemical (E-AB) assay that recognizes the spike protein of SARS-CoV-2 in saliva for viral infection detection. The low-cost electrodes are implementable at population scale and demonstrate detection down to 0.1 fg mL -1 of the S1 subunit of the spike protein.

15.
Polymers (Basel) ; 12(7)2020 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-32610500

RESUMO

Soft stretchable sensors rely on polymers that not only withstand large deformations while retaining functionality but also allow for ease of application to couple with the body to capture subtle physiological signals. They have been applied towards motion detection and healthcare monitoring and can be integrated into multifunctional sensing platforms for enhanced human machine interface. Most advances in sensor development, however, have been aimed towards active materials where nearly all approaches rely on a silicone-based substrate for mechanical stability and stretchability. While silicone use has been advantageous in academic settings, conventional silicones cannot offer self-healing capability and can suffer from manufacturing limitations. This review aims to cover recent advances made in polymer materials for soft stretchable conductors. New developments in substrate materials that are compliant and stretchable but also contain self-healing properties and self-adhesive capabilities are desirable for the mechanical improvement of stretchable electronics. We focus on materials for stretchable conductors and explore how mechanical deformation impacts their performance, summarizing active and substrate materials, sensor performance criteria, and applications.

16.
Front Physiol ; 11: 165, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32226389

RESUMO

Although biomimetic stimuli, such as microgroove-induced alignment (µ), triiodothyronine (T3) induction, and electrical conditioning (EC), have been reported to promote maturation of human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs), a systematic examination of their combinatorial effects on engineered cardiac tissue constructs and the underlying molecular pathways has not been reported. Herein, human embryonic stem cell-derived ventricular cardiomyocytes (hESC-VCMs) were used to generate a micro-patterned human ventricular cardiac anisotropic sheets (hvCAS) for studying the physiological effects of combinatorial treatments by a range of functional, calcium (Ca2+)-handling, and molecular analyses. High-resolution optical mapping showed that combined µ-T3-EC treatment of hvCAS increased the conduction velocity, anisotropic ratio, and proportion of mature quiescent-yet-excitable preparations by 2. 3-, 1. 8-, and 5-fold (>70%), respectively. Such electrophysiological changes could be attributed to an increase in inward sodium current density and a decrease in funny current densities, which is consistent with the observed up- and downregulated SCN1B and HCN2/4 transcripts, respectively. Furthermore, Ca2+-handling transcripts encoding for phospholamban (PLN) and sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) were upregulated, and this led to faster upstroke and decay kinetics of Ca2+-transients. RNA-sequencing and pathway mapping of T3-EC-treated hvCAS revealed that the TGF-ß signaling was downregulated; the TGF-ß receptor agonist and antagonist TGF-ß1 and SB431542 partially reversed T3-EC induced quiescence and reduced spontaneous contractions, respectively. Taken together, we concluded that topographical cues alone primed cardiac tissue constructs for augmented electrophysiological and calcium handling by T3-EC. Not only do these studies improve our understanding of hPSC-CM biology, but the orchestration of these pro-maturational factors also improves the use of engineered cardiac tissues for in vitro drug screening and disease modeling.

17.
RSC Adv ; 11(2): 671-677, 2020 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-35423693

RESUMO

Electrochemical aptamer-based (E-AB) sensors provide a great opportunity towards the goal of point-of-care and wearable sensing technologies due to their good sensitivity and selectivity. Nevertheless, the output signals from this sensor class remain low when sensors are interrogated via square-wave voltammetry. This low signaling limits the sensor's precision for its capability to detect small changes in target concentrations. To circumvent this, we proposed here the use of a readily shrink-induced, wrinkled Au-coating polyolefin film to immobilize a greater number of DNA probes and thus improve the signaling. Specifically, wrinkled gold film exhibits a 5.5-fold increase of surface area in comparison to the unwrinkled ones. Using these substrates we fabricated a set of E-AB sensors of three biological molecules, including kanamycin, doxorubicin and ATP. We achieved up to 10-fold increase in its current and also good accuracies within ±20% error in the target concentration range across 2 orders of magnitude.

18.
NPJ Digit Med ; 2: 8, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31304358

RESUMO

Current methods for continuous respiration monitoring such as respiratory inductive or optoelectronic plethysmography are limited to clinical or research settings; most wearable systems reported only measures respiration rate. Here we introduce a wearable sensor capable of simultaneously measuring both respiration rate and volume with high fidelity. Our disposable respiration sensor with a Band-Aid© like formfactor can measure both respiration rate and volume by simply measuring the local strain of the ribcage and abdomen during breathing. We demonstrate that both metrics are highly correlated to measurements from a medical grade continuous spirometer on participants at rest. Additionally, we also show that the system is capable of detecting respiration under various ambulatory conditions. Because these low-powered piezo-resistive sensors can be integrated with wireless Bluetooth units, they can be useful in monitoring patients with chronic respiratory diseases in everyday settings.

19.
Adv Healthc Mater ; 8(13): e1900109, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31033256

RESUMO

Wrinkled gold thin films on elastomeric substrates are used as robust parallel plate electrodes for soft capacitive pressure sensors. The wrinkled structures create a robust integration with the polymer, allowing repeated normal force to deform the thin film without failure. By incorporating microridged structures that support the counter electrodes to create air cavities within the elastomeric dielectric layer, pressure sensitivity is further increased to 0.148 kPa-1 over a wide dynamic range of up to 10 kPa. The wide dynamic range and pressure sensitivity of the pressure sensor allow for consistent measurements of the pressure exerted by the radial artery located on the wrist. The soft capacitive pressure sensor displays comparable results when tested against an FDA approved device (Clearsight, Edwards Lifesciences, Irvine, CA) measuring beat-to-beat blood pressure. These soft pressure sensors using wrinkled thin films, therefore, illustrate considerable potential to continuously monitor beat-to-beat blood pressure.


Assuntos
Pressão Sanguínea/fisiologia , Monitorização Fisiológica/métodos , Dispositivos Eletrônicos Vestíveis , Eletrodos , Ouro/química , Humanos , Monitorização Fisiológica/instrumentação
20.
Protein Pept Lett ; 26(1): 61-69, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30543161

RESUMO

BACKGROUND: For almost four decades, hydroxyl radical chemically generated by Fenton chemistry has been a mainstay for the oxidative 'footprinting' of macromolecules. OBJECTIVE: In this article, we start by reviewing the application of chemical generation of hydroxyl radical to the development of oxidative footprinting of DNA and RNA and the subsequent application of the method to oxidative footprinting of proteins. We next discuss a novel strategy for generating hydroxyl radicals by Fenton chemistry that immobilizes catalytic iron on a solid surface (Pyrite Shrink Wrap laminate) for the application of nucleic acid and protein footprinting. METHOD: Pyrite Shrink-Wrap Laminate is fabricated by depositing pyrite (Fe-S2, aka 'fool's gold') nanocrystals onto thermolabile plastic (Shrinky Dink). The laminate can be thermoformed into a microtiter plate format into which samples are deposited for oxidation. RESULTS: We demonstrate the utility of the Pyrite Shrink-Wrap Laminate for the chemical generation of hydroxyl radicals by mapping the surface of the T-cell co-stimulatory protein Programmed Death - 1 (PD-1) and the interface of the complex with its ligand PD-L1. CONCLUSION: We have developed and validated an affordable and reliable benchtop method of hydroxyl radical generation that will broaden the application of protein oxidative footprinting. Due to the minimal equipment required to implement this method, it should be easily adaptable by many laboratories with access to mass spectrometry.


Assuntos
Radical Hidroxila , Espectrometria de Massas/métodos , Pegadas de Proteínas/métodos , DNA/análise , DNA/química , Radical Hidroxila/análise , Radical Hidroxila/química , Ferro/química , Oxirredução , Proteínas/análise , Proteínas/química , RNA/análise , RNA/química , Sulfetos/química
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