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1.
Artigo em Inglês | MEDLINE | ID: mdl-38083646

RESUMO

The BioPoint is a new wireless and wearable device, targeting both the ambulatory and on-site monitoring of biosignals. It is described as being capable of streaming and recording the i) electromyography, ii) electrocardiography, iii) electrodermal activity, iv) photoplethysmography, v) skin temperature and vi) actigraphy simultaneously, while making the raw signals recorded by the sensors readily available. However, an in-depth assessment of the biophysical signals recorded by this device, as well as its ability to derive vital signs and other health metrics, remains to be carried out. Consequently, this work proposes a preliminary study to evaluate the quality of the signals that can be acquired by this wearable with a focus on the derivation of heart rate and peripheral blood oxygenation via photoplethysmography. The device is quantitatively compared to the medical-grade pulse oximeter NoninConnect 3245, by Nonin inc. This study was performed with participants wearing the BioPoint at different positions on the body (finger, wrist, forearm, biceps and plantar arch), while the NoninConnect was worn on the fingertip and used as the ground truth. The results show that the BioPoint can accurately determine both heart rate and oxygen saturation from various locations on the body. However, as the BioPoint's photoplethysmograph is not calibrated it cannot be used for medical purposes (non-medical-grade).


Assuntos
Fotopletismografia , Dispositivos Eletrônicos Vestíveis , Humanos , Fotopletismografia/métodos , Eletrocardiografia/métodos , Frequência Cardíaca/fisiologia , Oximetria
2.
Epidemiol Psychiatr Sci ; 32: e1, 2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36624694

RESUMO

AIMS: Childhood adversities (CAs) predict heightened risks of posttraumatic stress disorder (PTSD) and major depressive episode (MDE) among people exposed to adult traumatic events. Identifying which CAs put individuals at greatest risk for these adverse posttraumatic neuropsychiatric sequelae (APNS) is important for targeting prevention interventions. METHODS: Data came from n = 999 patients ages 18-75 presenting to 29 U.S. emergency departments after a motor vehicle collision (MVC) and followed for 3 months, the amount of time traditionally used to define chronic PTSD, in the Advancing Understanding of Recovery After Trauma (AURORA) study. Six CA types were self-reported at baseline: physical abuse, sexual abuse, emotional abuse, physical neglect, emotional neglect and bullying. Both dichotomous measures of ever experiencing each CA type and numeric measures of exposure frequency were included in the analysis. Risk ratios (RRs) of these CA measures as well as complex interactions among these measures were examined as predictors of APNS 3 months post-MVC. APNS was defined as meeting self-reported criteria for either PTSD based on the PTSD Checklist for DSM-5 and/or MDE based on the PROMIS Depression Short-Form 8b. We controlled for pre-MVC lifetime histories of PTSD and MDE. We also examined mediating effects through peritraumatic symptoms assessed in the emergency department and PTSD and MDE assessed in 2-week and 8-week follow-up surveys. Analyses were carried out with robust Poisson regression models. RESULTS: Most participants (90.9%) reported at least rarely having experienced some CA. Ever experiencing each CA other than emotional neglect was univariably associated with 3-month APNS (RRs = 1.31-1.60). Each CA frequency was also univariably associated with 3-month APNS (RRs = 1.65-2.45). In multivariable models, joint associations of CAs with 3-month APNS were additive, with frequency of emotional abuse (RR = 2.03; 95% CI = 1.43-2.87) and bullying (RR = 1.44; 95% CI = 0.99-2.10) being the strongest predictors. Control variable analyses found that these associations were largely explained by pre-MVC histories of PTSD and MDE. CONCLUSIONS: Although individuals who experience frequent emotional abuse and bullying in childhood have a heightened risk of experiencing APNS after an adult MVC, these associations are largely mediated by prior histories of PTSD and MDE.


Assuntos
Transtorno Depressivo Maior , Transtornos de Estresse Pós-Traumáticos , Adulto , Humanos , Adolescente , Adulto Jovem , Pessoa de Meia-Idade , Idoso , Transtornos de Estresse Pós-Traumáticos/epidemiologia , Transtornos de Estresse Pós-Traumáticos/etiologia , Transtornos de Estresse Pós-Traumáticos/diagnóstico , Transtorno Depressivo Maior/psicologia , Depressão/psicologia , Inquéritos e Questionários , Veículos Automotores
3.
Annu Int Conf IEEE Eng Med Biol Soc ; 2021: 1226-1229, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34891508

RESUMO

This study optimally designed and implemented highly sensitive microscale interdigitated electrodes (IDEs) to monitor microorganisms' growth in diverse environments. Gold interdigitated electrodes (AuIDE) with 4 mm×4 mm effective sensing area and varying microscale interdigitate gaps were designed and fabricated. The electrodes were electrically characterized voltametrically. Electrochemical impedance spectroscopy (EIS) measurements were conducted to determine the optimal geometry by observing the impedance spectra of microelectrodes through varying pH and temperature. Furthermore, the sensors sensitivity was evaluated by measuring the impedance properties of a microscale volume of microorganism concentrations in growth media solution.


Assuntos
Espectroscopia Dielétrica , Ouro , Impedância Elétrica , Microeletrodos
4.
Annu Int Conf IEEE Eng Med Biol Soc ; 2021: 7489-7492, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34892825

RESUMO

Surface electromyography (sEMG) can be used to detect motor epileptic seizures non-invasively. For clinical use, a compact-size, user-friendly, safe and accurate sEMG measurement system can be worn by epileptic patients to detect and characterize a seizure. Such devices must be small, wireless, power-efficient minimally invasive and robust to avoid movement artefacts, friction, and slipping of the electrode, which can compromise data integrity and/or generate false positives or false negatives. This paper presents a highly versatile device that can be worn in different locations on the body to capture sEMG signals in a freely moving user without movement artefact. The system can be safely worn on the body for several hours to capture sEMG from wet Ag/AgCl electrodes, while sEMG data is wirelessly transmitted to a host computer within a range of 20 m. We demonstrate the versatility of our sensor by recording sEMG from five different body locations in a freely moving volunteer. Then, simulated seizure data was captured while the device was placed on the extensor carpi ulnaris. We show that sEMG bursts were successfully recorded to characterize the seizure afterward. The presented sensor prototype is small (5 cm x 3.5 cm x 1 cm), lightweight (46 g), and has an autonomy of 12 hrs from a small 110-mAh battery.


Assuntos
Convulsões , Dispositivos Eletrônicos Vestíveis , Eletromiografia , Humanos , Monitorização Fisiológica , Movimento , Convulsões/diagnóstico
5.
J Exp Med ; 182(6): 1897-904, 1995 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-7500035

RESUMO

T lymphocytes and eosinophils are important components of the inflammatory cell infiltrate in bronchial mucosa in asthma. Because activated lymphocytes migrate through the thoracic duct and the general circulation to remote glandular and mucosal sites, we initiated this study to evaluate pathological abnormalities and immunoreactivity for interleukin (IL) 3, IL-5, and granulocyte/macrophage colony-stimulating factor (GM-CSF) of intestinal mucosa in bronchial asthma. 15 asthmatic patients, 8 nonasthmatic patients with chronic obstructive pulmonary disease, 6 atopic nonasthmatic healthy controls, and 6 nonatopic healthy controls were studied. Duodenal biopsies were performed by endoscopy. A significantly increased number of intraepithelial lymphocytes and eosinophils and a significant accumulation of mononuclear cells (lymphocytes and mast cells) and eosinophils in the lamina propria were detected in asthmatics and atopic controls. Immunostaining with antibodies directed against IL-3, IL-5, and GM-CSF was positive in asthmatics and atopic controls, whereas no staining was observed in nonatopic controls and chronic obstructive pulmonary disease. Combined ultrastructural study and immunogold labeling demonstrated that IL-3, IL-5, and GM-CSF were localized in eosinophils and mast cells. Although devoid of gastrointestinal symptoms, asthmatics and asymptomatic atopics had duodenal pathological abnormalities mimicking those observed in the bronchial mucosa in asthma, suggesting that the whole mucosal immune system is involved in bronchial asthma.


Assuntos
Asma/imunologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/imunologia , Hipersensibilidade Imediata/imunologia , Interleucina-3/imunologia , Interleucina-5/imunologia , Mucosa Intestinal/imunologia , Pneumopatias Obstrutivas/imunologia , Adolescente , Adulto , Asma/tratamento farmacológico , Asma/patologia , Feminino , Humanos , Mucosa Intestinal/patologia , Pneumopatias Obstrutivas/patologia , Masculino , Mastócitos/ultraestrutura , Pessoa de Meia-Idade , Estudos Prospectivos , Esteroides/uso terapêutico
6.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 722-727, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018089

RESUMO

Electromyography offers a way to interface an amputee's resilient muscles to control a bionic prosthesis. While myoelectric prostheses are promising, user acceptance of these devices remain low due to a lack of intuitiveness and ease-of-use. Using a low-cost wearable flexible electrodes array, the proposed system leverages high-density surface electromyography (HD-EMG) and deep learning techniques to classify forearm muscle contractions. These techniques allow for increased intuitiveness and ease-of-use of a myoelectric control scheme with a single easy-to-install electrodes apparatus. This paper proposes a flexible electrodes array construction using standard printed circuit board manufacturing processes for low-cost and quick design-to-production cycles. HD-EMG dataset visualization with t-distributed Stochastic Neighbor Embedding (t-SNE) is introduced, and offline classification results of the wearable gesture recognition system for hand prosthesis control are validated on a group of 8 able-bodied subjects. Using a majority vote on 5 successive inferences, a median recognition accuracy of 98.61 % was obtained across the group for an 8 gestures set. For a 6 gestures set containing commonly used prosthesis positions, the median accuracy reached 99.57 % with the majority vote.


Assuntos
Visualização de Dados , Antebraço , Eletromiografia , Mãos , Humanos , Aprendizado de Máquina
7.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 4101-4104, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018900

RESUMO

This paper presents the EcoChip 2, an autonomous multimodal bio-environmental sensor platform for the monitoring of microorganisms in the northern habitat. The EcoChip 2 prototype includes an array of 96-wells for the continuous monitoring of microbiological growth through a multichannel electrochemical impedance analyzer circuit. In addition, the platform includes luminosity, humidity, temperature sensors and monitoring. The developed electronic board uses an ultra-low-power microcontroller unit, a custom power management unit, a low-power wireless ISM-2.45 GHz transceiver, and a flash memory to accumulate and store the sensor data over extended monitoring periods. When a wireless base station is placed within the transmission range of the EcoChip 2, an embedded low-power wireless transceiver transmits the 96-wells impedance data and the other sensor data stored in the flash memory to the user interface. We present the measured performance of the prototype, along with laboratory test results of bacterial growth measurements inside the 96 wells in parallel. We show that the EcoChip 2 can successfully measure the impedances associated with bacterial growth over several hours using an excitation frequency of 2 kHz with power consumption of 114.6 mW under operating mode.


Assuntos
Ecossistema , Eletrônica , Impedância Elétrica , Monitoramento Ambiental , Desenho de Equipamento
8.
Annu Int Conf IEEE Eng Med Biol Soc ; 2019: 6040-6044, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31947223

RESUMO

This paper presents a portable and modular wireless multichannel sensor system for high-density surface electromyography (HD-sEMG) signals acquisition. Featuring low-power and high-quality off-the-shelf components such as the Intan Technologies RHD2132 digital electrophysiology interface chip, the current iteration of the proposed sensor system allows the recording of 32 surface electromyography (sEMG) channels, each at a sampling rate of 1 kHz, and a sample resolution of 16 bits. It features the RHD2132's typical input-referred noise of 2.4 µVrms, with <; 15% variation with amplifier bandwidth as specified by the manufacturer, and a total power consumption of 49.5 mW. Data is sent in real-time to a base station using a 2.4-GHz industrial, scientific and medical (ISM) wireless link. Along with the recording platform, the integrated sensor system includes a dry surface electrodes array prototype directly built on a printed circuit board. Intended for complex muscles activity patterns detection on the forearm, the flexible 32 surface electrodes array is designed to be placed flat or to fit a curved area like the forearm in a hand gestures recognition prosthetic system. In such applications, this device will offer improved prosthesis control scheme intuitiveness and ease-of-use. Among other core features of the system are its compact, light-weight and easy to install physical design. The complete system fits on a 2 by 6.5 cm2 printed circuit board mounted on a 7.6 by 11.8 cm2 electrodes array. HD-sEMG user forearm output data collected with the system is presented with a proposed frequency-time-space cross-domain preprocessing method for visualization of HD-EMG data and building training datasets.


Assuntos
Dispositivos Eletrônicos Vestíveis , Tecnologia sem Fio , Amplificadores Eletrônicos , Membros Artificiais , Eletromiografia , Gestos
9.
Annu Int Conf IEEE Eng Med Biol Soc ; 2018: 1608-1611, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30440700

RESUMO

We present a new head mountable wireless fiber biophotometry microsystem conceived to detect fluorescent signal fluctuations correlated with neuronal activity. The proposed system incorporates all aspects of a conventional tethered fiber-based biophotometry system encompassed into a wireless microsystem. The interface includes an LED as excitation light source, a custom designed CMOS biosensor, a multimode fiber, a microcontroller (MCU), and a wireless data transceiver enclosed within a 3D-printed, small and light weight, plastic housing. Precisely, the system incorporates a new optoelectronic biosensor merging two individual building blocks, namely a low-noise sensing front-end and $\mathrm {a}2 ^{nd}$ order continuous-time $\Sigma \Delta $ modulator (CTSDM), into a single module for enabling high-sensitivity and high energy-efficiency photo-sensing. The proposed CMOS biosensor is implemented in $\mathrm {a}0 .18- \mu m$ CMOS technology, consuming $41 \mu W$ from $\mathrm {a}1 .8- V$ supply voltage, while achieving a peak dynamic range of $86 dB$ over a $50- Hz$ input bandwidth at a 20-kS/s sampling rate. This new interface opens new avenues for conducting in-vivo experiments with live animals.


Assuntos
Técnicas Biossensoriais , Sistema Nervoso/metabolismo , Tecnologia sem Fio , Animais , Fluorescência , Roedores
10.
J Laryngol Otol ; 131(8): 740-744, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28592347

RESUMO

OBJECTIVES: This study aimed to: describe the incidence of thyroid gland involvement in advanced laryngeal cancer, analyse patterns of spread to the thyroid and elucidate predictors of thyroid involvement. METHODS: A retrospective review was performed on patients who underwent laryngectomy from 1991 to 2015 as a primary or salvage treatment for squamous cell carcinoma of the larynx, hypopharynx or base of tongue. The incidence of thyroidectomy during total laryngectomy, type of thyroidectomy, incidence of gland involvement, route of spread, and positive predictors of spread were analysed and reported. RESULTS: A total of 188 patients fit the inclusion criteria. Of these, 125 (66 per cent) underwent thyroidectomy. The thyroid was involved in 10 of the 125 patients (8 per cent), 9 by direct extension and 1 by metastasis. Cartilage invasion was a predictor of thyroid gland involvement, with a positive predictive value of 26 per cent. CONCLUSION: There is a low incidence of thyroid gland involvement in laryngeal carcinoma. Most cases of gland involvement occurred by direct extension. Thyroidectomy during laryngectomy should be considered for advanced stage tumours with cartilage invasion.


Assuntos
Neoplasias Laríngeas/cirurgia , Laringectomia/métodos , Glândula Tireoide/cirurgia , Neoplasias da Glândula Tireoide/cirurgia , Tireoidectomia/estatística & dados numéricos , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/cirurgia , Cartilagem/patologia , Cartilagem/cirurgia , Feminino , Neoplasias de Cabeça e Pescoço/patologia , Neoplasias de Cabeça e Pescoço/cirurgia , Humanos , Neoplasias Hipofaríngeas/patologia , Neoplasias Hipofaríngeas/cirurgia , Incidência , Neoplasias Laríngeas/patologia , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Valor Preditivo dos Testes , Estudos Retrospectivos , Carcinoma de Células Escamosas de Cabeça e Pescoço , Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/epidemiologia , Neoplasias da Glândula Tireoide/secundário , Tireoidectomia/métodos , Resultado do Tratamento
11.
Annu Int Conf IEEE Eng Med Biol Soc ; 2016: 5741-5744, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28269558

RESUMO

Advancement in wireless and microsystems technology have ushered in new devices that can directly interface with the central nervous system for stimulating and/or monitoring neural circuitry. In this paper, we present an ultra low-power sigma-delta analog-to-digital converter (ADC) intended for utilization into large-scale multi-channel neural recording implants. This proposed design, which provides a resolution of 9 bits using a one-bit oversampled ADC, presents several desirable features that allow for an in-channel ADC scheme, where one sigma-delta converter is provided for each channel, enabling development of scalable systems that can interface with different types of high-density neural microprobes. The proposed circuit, which have been fabricated in a TSMC 180-nm CMOS process, employs a first order noise shaping topology with a passive integrator and a low-supply voltage of 0.6 V to achieve ultra low-power consumption and small size. The proposed ADC clearly outperforms other designs with a power consumption as low as 110 nW for a precision of 9 bits (11-fJ per conversion), a silicon area of only 82 µm × 84 µm and one of the best reported figure of merit among recently published data converters utilized in similar applications.


Assuntos
Conversão Análogo-Digital , Interfaces Cérebro-Computador , Eletrodos Implantados , Tecnologia sem Fio
12.
Annu Int Conf IEEE Eng Med Biol Soc ; 2016: 6315-6318, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28269693

RESUMO

In this paper, a short-impulse ultra-wide band (UWB) transmitter is introduced to enable large-scale neural recordings within miniature brain implants including thousands of channels. The proposed impulse radio UWB transmitter uses a BPSK modulation scheme, the carrier signal of which uses only two delayed impulses to encode the transmitted signal. The proposed UWB transmitter has been implemented into a CMOS 180 nm technology. It occupies 300 µm × 230 µm, and consumes only 6.7 pJ/bit from a 1.8-V supply. Experimental results show that the transmitter has a bandwidth of 2.6 GHz to 5.6 GHz and achieves a maximum data rate of 800 Mbps, which outperforms existing low-power UWB transmitters for similar applications.


Assuntos
Interfaces Cérebro-Computador , Encéfalo/fisiologia , Próteses e Implantes , Desenho de Equipamento , Tecnologia sem Fio
13.
J Clin Oncol ; 13(4): 812-20, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7707106

RESUMO

PURPOSE: To correlate the presence of p53 mutations and initial characteristics, response to chemotherapy, and survival in newly diagnosed Burkitt's lymphoma (BL) and Burkitt's acute lymphoblastic leukemia (L3 ALL). PATIENTS AND METHODS: Forty-eight patients with newly diagnosed BL or L3 ALL, most of whom were treated with very intensive regimens, including early CNS disease treatment, were studied. Detection of p53 mutations was made by single-strand conformation polymorphism (SSCP) analysis of exons 5 to 8 of the gene, and mutations were determined by direct sequencing of exons with abnormal SSCP findings. Comparison of outcome between mutated and nonmutated cases was made in all patients and also after excluding five patients who received therapeutic regimens considered as suboptimal and one patient who died of AIDS while in complete remission (CR), as those six patients had no p53 mutations. RESULTS: A point mutation was found in nine patients (19%), and consisted of a missense mutation in seven and a chain-terminating mutation in two. SSCP, sequence, and cytogenetic analysis strongly suggested that eight of nine patients with mutations had retained the normal p53 allele, which had been lost in the remaining patient. These findings were confirmed by fluorescence-in-situ hybridization (FISH) with a p53-specific probe in two patients, including the one who had lost the normal p53 allele. Unexpectedly, mutations were significantly less frequent in patients with disseminated disease, ie, L3 ALL or stage IV BL (four of 35, 11%), than in more localized forms, ie, BL stage I, II, or III (five of 13, 38%) (P = .03). CR rates were similar in mutated (78%) and nonmutated cases (78%). The actuarial disease-free interval (DFI) after 12 months and actuarial survival rates after 24 months were 49% and 66%, respectively, in patients with mutations, and 73% and 48%, respectively, those without mutations. The differences were not significant. CONCLUSION: Our findings suggest that, contrary to what is seen in most other neoplasias, p53 mutations in newly diagnosed BL and L3 ALL are not associated with extensive tumor mass or poor response to intensive therapeutic regimens. It is hypothesized that this difference with most tumors could be due to the fact that p53 mutations in BL and L3 ALL are generally associated with persistence of a normal residual p53 allele, contrary to what is observed in the majority of tumors.


Assuntos
Linfoma de Burkitt/genética , Genes p53/genética , Mutação Puntual , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Análise Atuarial , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Sequência de Bases , Linfoma de Burkitt/tratamento farmacológico , Linfoma de Burkitt/mortalidade , Criança , Pré-Escolar , Intervalo Livre de Doença , Feminino , Humanos , Hibridização in Situ Fluorescente , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Polimorfismo Conformacional de Fita Simples , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidade , Taxa de Sobrevida
14.
J Clin Oncol ; 10(7): 1078-85, 1992 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-1607914

RESUMO

PURPOSE: We analyzed prognostic factors in 80 adult patients with lymphoblastic lymphoma (LBL). PATIENTS AND METHODS: Twenty-one patients received six monthly courses of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) and maintenance chemotherapy for 12 months. The LNH-84 protocol (30 patients) consisted of four courses of high-dose CHOP followed by consolidation for 4 months. Both FRALLE (22 patients) and LALA (seven patients) protocols were two intensive chemotherapy regimens for acute lymphoblastic leukemia (ALL) that included an induction with daunorubicin, vincristine, cyclophosphamide, prednisolone (and asparaginase for the FRALLE regimen), consolidation, and maintenance chemotherapy that lasted for 2 years. RESULTS: Sixty-six patients (82%) achieved a complete remission (CR). The CR duration rate and overall survival rate at 30 months were estimated to be 46% and 51%, respectively, with a median follow-up of 55 months. Only two of 37 relapses occurred after 26 months. Chemotherapy protocol did not influence CR rate, CR duration, and survival. A higher CR rate was associated with an age of less than 40 years, lactic dehydrogenase (LDH) level of less than two times the upper limits of normal, and no or one extranodal site of disease. Short survival was associated with a failure to achieve CR, age older than 40 years, B symptoms, LDH level more than two times the upper limits of normal, and hemoglobin level of less than 100 g/L. Bone marrow involvement had no prognostic value. We could not evaluate precisely the prognostic value of Ann Arbor stage because inclusion criteria differed among treatment groups. CONCLUSION: Our findings suggest that age and LDH are two important pretreatment prognostic factors for adult LBL, and that the optimal prognostic staging system remains a controversial issue.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Adolescente , Adulto , Fatores Etários , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Transplante de Medula Óssea , Terapia Combinada , Esquema de Medicação , Feminino , Humanos , L-Lactato Desidrogenase/sangue , Masculino , Pessoa de Meia-Idade , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/cirurgia , Prognóstico , Análise de Regressão
15.
Artigo em Inglês | MEDLINE | ID: mdl-26737934

RESUMO

In this paper, we present a digital spike detector using an adaptive threshold which is suitable for real time processing of 32 electrophysiological channels in parallel. Such a new scheme is based on a Sigma-delta control loop that precisely estimates the standard deviation of the amplitude of the noise of the input signal to optimize the detection rate. Additionally, it is not dependent on the amplitude of the input signal thanks to a robust algorithm. The spike detector is implemented inside a Spartan-6 FPGA using low resources, only FPGA basic logic blocks, and is using a low clock frequency under 6 MHz for minimal power consumption. We present a comparison showing that the proposed system can compete with a dedicated off-line spike detection software. The whole system achieves up to 100% of true positive detection rate for SNRs down to 5 dB while achieving 62.3% of true positive detection rate for an SNR as low as -2 dB at a 150 AP/s firing rate.


Assuntos
Algoritmos , Eletrofisiologia , Processamento de Sinais Assistido por Computador
16.
Annu Int Conf IEEE Eng Med Biol Soc ; 2015: 2167-70, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26736719

RESUMO

This paper presents a resources-optimized digital action potential (AP) detector featuring an adaptive threshold based on a new Sigma-delta control loop. The proposed AP detector is optimized for utilizing low hardware resources, which makes it suitable for implementation on most popular low-power microcontrollers units (MCU). The adaptive threshold is calculated using a digital control loop based on a Sigma-delta modulator that precisely estimates the standard deviation of the amplitude of the neuronal signal. The detector was implemented on a popular low-power MCU and fully characterized experimentally using previously recorded neural signals with different signal-to-noise ratios. A comparison of the obtained results with other thresholding approaches shows that the proposed method can compete with high performance and highly resources demanding spike detection approaches while achieving up to 100% of true positive detection rate at high SNR, and up to 63% for an SNR as low as 0 dB, while necessitating an execution time as low as 11 µs with the MCU operating at 8 MHz.


Assuntos
Potenciais de Ação/fisiologia , Optogenética/instrumentação , Processamento de Sinais Assistido por Computador , Animais , Desenho de Equipamento , Camundongos Transgênicos , Optogenética/métodos , Razão Sinal-Ruído
17.
Annu Int Conf IEEE Eng Med Biol Soc ; 2015: 4399-402, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26737270

RESUMO

Assistive Technologies (ATs) also called extrinsic enablers are useful tools for people living with various disabilities. The key points when designing such useful devices not only concern their intended goal, but also the most suitable human-machine interface (HMI) that should be provided to users. This paper describes the design of a highly intuitive wireless controller for people living with upper body disabilities with a residual or complete control of their neck and their shoulders. Tested with JACO, a six-degree-of-freedom (6-DOF) assistive robotic arm with 3 flexible fingers on its end-effector, the system described in this article is made of low-cost commercial off-the-shelf components and allows a full emulation of JACO's standard controller, a 3 axis joystick with 7 user buttons. To do so, three nine-degree-of-freedom (9-DOF) inertial measurement units (IMUs) are connected to a microcontroller and help measuring the user's head and shoulders position, using a complementary filter approach. The results are then transmitted to a base-station via a 2.4-GHz low-power wireless transceiver and interpreted by the control algorithm running on a PC host. A dedicated software interface allows the user to quickly calibrate the controller, and translates the information into suitable commands for JACO. The proposed controller is thoroughly described, from the electronic design to implemented algorithms and user interfaces. Its performance and future improvements are discussed as well.


Assuntos
Pessoas com Deficiência , Algoritmos , Braço , Humanos , Procedimentos Cirúrgicos Robóticos , Tecnologia Assistiva , Interface Usuário-Computador , Tecnologia sem Fio
18.
Front Biosci ; 6: D1264-75, 2001 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-11578957

RESUMO

Mucins are glycoproteins synthesized by epithelial cells and thought to promote tumor-cell invasion. Eight human mucin genes have been well characterized: MUC2, MUC5AC, MUC5B, MUC6 map to 11p15.5 and encode secretory gel forming mucins while MUC1, MUC3, MUC4, MUC7 are scattered on different chromosomes and encode membrane-bound or secreted mucins. The expression pattern of the mucin genes is complex in normal airways involving six genes, mainly MUC5AC and MUC5B in mucus-producing cells and MUC4 in a wide array of epithelial cells. MUC5AC overexpression in metaplasia, dysplasia and normal epithelium adjacent to squamous cell carcinoma provides additional arguments for a mucous cell origin of preneoplastic squamous lesions. MUC5AC and MUC5B expression is related to mucus formation in adenocarcinomas. Mucinous bronchioloalveolar carcinoma (BAC) has a particular pattern of mucin gene expression indicating that it has sustained a well-differentiated phenotype similar to the goblet cell, correlated with distinctive features i.e. a noninvasive pattern and a better prognosis than nonBACs. MUC4 is the earlier mucin gene expressed in the foregut, before epithelial differentiation and is expressed independently of mucus secretion both in normal adult airways and carcinomas. These findings are in favor the histogenetic theory of non-small-cell carcinoma originating from a pluripotent mucous cell.


Assuntos
Neoplasias Pulmonares/genética , Mucinas/genética , Lesões Pré-Cancerosas/genética , Mucosa Respiratória/metabolismo , Regulação da Expressão Gênica , Humanos , Isoformas de Proteínas/genética
19.
Transplantation ; 70(1): 227-9, 2000 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-10919610

RESUMO

BACKGROUND: The infiltration of epithelium by CD8+ T lymphocytes in human renal or liver allografts is a critical feature of acute rejection. CD103 expression can be acquired in vitro by CD8+ cytotoxic T lymphocytes in response to allogeneic renal epithelial cells and promotes their adhesion to epithelium and subsequent lysis of epithelial cells. We investigated the expression of CD103 in T-cell infiltrates during acute renal or liver rejection (grade < III). METHODS: Immunohistochemical detection of CD103 in 11 liver and 10 kidney transplant biopsies with histopathological diagnosis of acute rejection. RESULTS: None of the infiltrates expressed detectable CD103, although positive controls were stained under our conditions. CONCLUSIONS: Failure to detect CD103 in renal biopsies can be related to the early posttransplantation interval (<6 months) corresponding to a first rejection episode. In our hands, immunohistological detection of CD103 was not possible in the infiltrates of acute rejection in liver or kidney transplantation.


Assuntos
Antígenos CD/análise , Rejeição de Enxerto , Cadeias alfa de Integrinas , Transplante de Rim/efeitos adversos , Transplante de Fígado/efeitos adversos , Doença Aguda , Complexo CD3/análise , Antígenos CD8/análise , Humanos , Imuno-Histoquímica
20.
J Histochem Cytochem ; 43(6): 645-8, 1995 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7769236

RESUMO

Human mucous proteinase inhibitor (MPI) is present in bronchial secretions, where it participates in the protection of lung structures against degradation by leukocyte elastase. The protein has been localized by immunohistochemical studies and immunogold labeling essentially in the serous cells of the submucosal glands and also in the surface epithelial cells of central and peripheral airways. However, until now no gene expression study has been performed at the tissue level. In this study, in situ hybridization was used to precisely study MPI mRNA expression in bronchial tissue sections with a specific radiolabeled oligonucleotide probe. By light microscopy, MPI gene expression was localized exclusively in the serous and seromucinous acini of the submucosal glands of large airways. The MPI gene was expressed in submucosal glands of normal and carcinomatous tissue sections, whereas it was not expressed in bronchial and bronchiolar surface epithelia.


Assuntos
Biossíntese de Proteínas , Proteínas , Sistema Respiratório/metabolismo , Inibidores de Serina Proteinase/biossíntese , Sequência de Bases , Primers do DNA , Humanos , Hibridização In Situ , Dados de Sequência Molecular , Proteínas Secretadas Inibidoras de Proteinases , RNA Mensageiro/análise
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