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1.
Sensors (Basel) ; 21(3)2021 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-33540774

RESUMO

In order to reduce Gaussian noise, this paper proposes a method via taking the average of the upper and lower envelopes generated by capturing the high and low peaks of the input signal. The designed fast response filter has no cut-off frequency, so the high order harmonics of the actual signal remain unchanged. Therefore, it can immediately respond to the changes of input signal and retain the integrity of the actual signal. In addition, it has only a small phase delay. The slew rate, phase delay and frequency response can be confirmed from the simulation results of Multisim 13.0. The filter outlined in this article can retain the high order harmonics of the original signal, achieving a slew rate of 6.34 V/µs and an almost zero phase difference. When using our filter to physically test the input signal with a noise level of 3 Vp-p Gaussian noise, a reduced noise signal of 120 mVp-p is obtained. The noise can be suppressed by up to 4% of the raw signal.

2.
Nature ; 496(7444): 210-4, 2013 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-23579680

RESUMO

Fossil dinosaur embryos are surprisingly rare, being almost entirely restricted to Upper Cretaceous strata that record the late stages of non-avian dinosaur evolution. Notable exceptions are the oldest known embryos from the Early Jurassic South African sauropodomorph Massospondylus and Late Jurassic embryos of a theropod from Portugal. The fact that dinosaur embryos are rare and typically enclosed in eggshells limits their availability for tissue and cellular level investigations of development. Consequently, little is known about growth patterns in dinosaur embryos, even though post-hatching ontogeny has been studied in several taxa. Here we report the discovery of an embryonic dinosaur bone bed from the Lower Jurassic of China, the oldest such occurrence in the fossil record. The embryos are similar in geological age to those of Massospondylus and are also assignable to a sauropodomorph dinosaur, probably Lufengosaurus. The preservation of numerous disarticulated skeletal elements and eggshells in this monotaxic bone bed, representing different stages of incubation and therefore derived from different nests, provides opportunities for new investigations of dinosaur embryology in a clade noted for gigantism. For example, comparisons among embryonic femora of different sizes and developmental stages reveal a consistently rapid rate of growth throughout development, possibly indicating that short incubation times were characteristic of sauropodomorphs. In addition, asymmetric radial growth of the femoral shaft and rapid expansion of the fourth trochanter suggest that embryonic muscle activation played an important role in the pre-hatching ontogeny of these dinosaurs. This discovery also provides the oldest evidence of in situ preservation of complex organic remains in a terrestrial vertebrate.


Assuntos
Dinossauros/anatomia & histologia , Dinossauros/embriologia , Fósseis , Animais , China , Fêmur/anatomia & histologia , Fêmur/embriologia , Espectroscopia de Infravermelho com Transformada de Fourier , Síncrotrons
3.
Opt Express ; 23(11): 14044-56, 2015 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-26072774

RESUMO

This paper presents a quick monitor method to measure micro height variations directly. Here we apply optical moiré technology with a program designed by ourselves to Traditional Chinese Medical Pulse diagnosis. We analyze the moiré pattern which records the information of pulse, and then examine the conditions of pulse, the conditions of pulse including the location of pulse (by image processing the moiré pattern), the rhythm of pulse (via the frequency), the shape of pulse (via moiré pattern) and the strength of pulse (via amplitude intensity). Therefore, we can quantify the conditions of pulse by the system.

4.
Sensors (Basel) ; 15(4): 8712-31, 2015 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-25875192

RESUMO

This study presents a new type of pulse auscultation system, which uses a condenser microphone to measure pulse sound waves on the wrist, captures the microphone signal for filtering, amplifies the useful signal and outputs it to an oscilloscope in analog form for waveform display and storage and delivers it to a computer to perform a Fast Fourier Transform (FFT) and convert the pulse sound waveform into a heartbeat frequency. Furthermore, it also uses an audio signal amplifier to deliver the pulse sound by speaker. The study observed the principles of Traditional Chinese Medicine's pulsing techniques, where pulse signals at places called "cun", "guan" and "chi" of the left hand were measured during lifting (100 g), searching (125 g) and pressing (150 g) actions. Because the system collects the vibration sound caused by the pulse, the sensor itself is not affected by the applied pressure, unlike current pulse piezoelectric sensing instruments, therefore, under any kind of pulsing pressure, it displays pulse changes and waveforms with the same accuracy. We provide an acquired pulse and waveform signal suitable for Chinese Medicine practitioners' objective pulse diagnosis, thus providing a scientific basis for this Traditional Chinese Medicine practice. This study also presents a novel circuit design using an active filtering method. An operational amplifier with its differential features eliminates the interference from external signals, including the instant high-frequency noise. In addition, the system has the advantages of simple circuitry, cheap cost and high precision.


Assuntos
Auscultação/métodos , Algoritmos , Análise de Fourier , Frequência Cardíaca , Humanos , Medicina Tradicional Chinesa , Pulso Arterial
5.
Sensors (Basel) ; 15(5): 9899-914, 2015 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-25923936

RESUMO

This study is to construct a non-contact pulse automatic positioning measurement system for Traditional Chinese Medicine (TCM) using optical triangulation measurements. The system consists of a linear laser, a CMOS image sensor and image analysis software. The linear laser is projected on the pulse beat location on the wrists; the CMOS image sensor records the process and the software analyzes the images. The program mainly uses the optical centroid and fast Fourier transform (FFT) principles to calculate centroid changes (pulse amplitude changes) from the images taken by the CMOS image sensor. It returns the positions of cun, guan and chi pulses automatically in terms of the amplitudes and the signals are then transformed from the time domain (time-amplitude) into the frequency domain (frequency-amplitude) via FFT to obtain the waveforms and frequencies of the cun, guan and chi pulses. It successfully extracts the data from the TCM pulse reading and can be a medical aid system for TCM. Combining the advantages of optical measurement and computer automation, this system provides a non-contact, easy to operate, fast in detection and low-cost equipment design.


Assuntos
Medicina Tradicional Chinesa/instrumentação , Desenho de Equipamento , Análise de Fourier
6.
Brain Behav Immun ; 25(7): 1452-9, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21669281

RESUMO

The aim of this study was to investigate the role of retained acupuncture (RA) in neurotoxin-induced Parkinson's disease (PD) mice. Male C57BL/6 mice were injected with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to induce the PD model. The mice were divided into four groups, namely, (1) normal; (2) MPTP+retained acupuncture (RA); (3) MPTP+electroacupuncture (EA); (4) MPTP+sham acupuncture (SA). After mice being manipulated with/without acupuncture at acupoints (Daling, PC 7), groups 2-4 were injected with MPTP (15 mg/kg/d). The mice were evaluated for behavioral changes, in terms of time of landing, after acupuncture treatment. The animals were sacrificed and their brains assayed for dopamine and its metabolites and tyrosine hydroxylase (TH) expression by using HPLC and immunohistochemistry/Western blotting, respectively. [(123)I] IBZM-SPECT imaging between SA and RA groups were compared. The results showed that the time of landing of the three groups with treatment was significant longer than group 1 (normal) (4.33±0.15 s). Nonetheless, group 2 (RA) (7.13±0.20 s) had a shorter time of landing than group 4 (SA) (7.89±0.46 s). The number of TH (+) neurons and the expression of TH proteins were significantly higher in the RA group than in the SA/EA groups. RA also increased the uptake of [(123)I] IBZM into the triatum compared to the SA group. We conclude that RA possibly attenuates neuronal damage in MPTP-induced PD mice, which suggests RA may be useful as a complementary strategy when treating human PD.


Assuntos
Terapia por Acupuntura/métodos , Comportamento Animal/fisiologia , Intoxicação por MPTP/metabolismo , Intoxicação por MPTP/terapia , Neurônios/metabolismo , Substância Negra/metabolismo , Animais , Contagem de Células , Modelos Animais de Doenças , Dopamina/metabolismo , Intoxicação por MPTP/induzido quimicamente , Intoxicação por MPTP/fisiopatologia , Masculino , Camundongos , Tirosina 3-Mono-Oxigenase/metabolismo
7.
Sensors (Basel) ; 11(8): 7851-64, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22164049

RESUMO

This paper describes a method for producing a novel type of ferromagnetic coded micro-carrier. The ferromagnetic coded micro-carriers are about 200 µm in length, 200 µm in width and 50 µm in thickness, and contain eight code elements with two distinguishable codes (hollow and solid), allowing for 2(8) unique codes. The code shapes include rectangle, circle, etc. Differently shaped coded micro-carriers could carry different antigens for detection of its complementary antibody. These many shapes of coded micro-carriers would be used simultaneously allowing us to make multiple detections for different antibodies at the same time. A molding process is applied for fabrication of the ferromagnetically coded micro-carriers where Fe material (Fe powder mixed with binder) is shaped in many tiny molds to produce the coded shapes used for identification of the bio-molecules. Magnetic force is used to control the movement and location of the ferromagnetic coded micro-carriers to prevent the loss during the hybridization process. The results of image process and analysis system testing are satisfactory. The results of our micro-carrier detection system for two sets of R and B color analysis are proportional to those obtained from ELISA antibody detection.


Assuntos
Anticorpos/química , Antígenos/química , Técnicas Biossensoriais , Biotecnologia/métodos , Ensaio de Imunoadsorção Enzimática/métodos , Imãs/química , Análise em Microsséries/métodos , Animais , Materiais Biocompatíveis , Cristalização , Drosophila melanogaster , Processamento Eletrônico de Dados , Desenho de Equipamento , Humanos , Magnetismo , Nanotecnologia/métodos
8.
Sensors (Basel) ; 11(2): 1461-75, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22319363

RESUMO

This paper presents a non-invasive, non-contact system for the measurement of the arterial dorsum manus vibration waveforms of Parkinson disease patients. The laser line method is applied to detect the dorsum manus vibration in rest and postural situations. The proposed measurement system mainly consists of a laser diode and a low cost complementary metal-oxide semiconductor (CMOS) image sensor. Laser line and centroid methods are combined with the Fast Fourier Transform (FFT) in this study. The shape and frequency and relative frequency of the dorsum manus vibration waveforms can be detected rapidly using our Parkinson's disease measurement system. A laser line near the wrist joint is used as the testing line. The experimental results show an obvious increase in the amplitude and frequency of dorsum manus variation in the measured region in patients suffering from Parkinson's disease, indicating the obvious effects of the disease. Both in postural and rest state measurements, as the patient disease age increases the vibration frequency increases. The measurement system is well suited for evaluating and pre-diagnosing early stage Parkinson's disease.


Assuntos
Eletrônica Médica/instrumentação , Eletrônica Médica/métodos , Lasers , Metais/química , Óxidos/química , Doença de Parkinson/diagnóstico , Semicondutores , Braço , Calibragem , Humanos , Doença de Parkinson/complicações , Doença de Parkinson/fisiopatologia , Postura/fisiologia , Reprodutibilidade dos Testes , Descanso , Tremor/complicações , Tremor/fisiopatologia , Vibração
9.
Appl Opt ; 48(13): 2566-73, 2009 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-19412217

RESUMO

A small-displacement sensing system based on multiple total internal reflections in heterodyne interferometry is proposed. In this paper, a small displacement can be obtained only by measuring the variation in phase difference between s- and p-polarization states for the total internal reflection effect. In order to improve the sensitivity, we increase the number of total internal reflections by using a parallelogram prism. The theoretical resolution of the method is better than 0.417 nm. The method has some merits, e.g., high resolution, high sensitivity, and real-time measurement. Also, its feasibility is demonstrated.

10.
Sensors (Basel) ; 7(12): 3366-3385, 2007 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-28903299

RESUMO

This paper presents a novel, non-invasive, non-contact system to measure pulsewaveforms of artery via applying laser triangulation method to detect skin surfacevibration. The proposed arterial pulsation measurement (APM) system chiefly consists of alaser diode and a low cost complementary metal-oxide semiconductor (CMOS) imagesensor. Laser triangulation and centroid method are combined with the Fast FourierTransform (FFT) in this study. The shape and frequency of the arterial pulsation can bedetected rapidly by using our APM system. The relative variation of the pulse at differentmeasurement points near wrist joint is used as a prognostic guide in traditional Chinesemedicine (TCM). An extensive series of experiments was conducted to evaluate theperformance of the designed APM system. From experimental results, the pulse amplitudeand frequency at the Chun point (related to the small intestine) of left hand showed anobvious increase after having food. In these cases, the peak to peak amplitudes and thefrequencies of arterial pulsations range from 38 to 48 µm and from 1.27 to 1.35 Hz,respectively. The height of arterial pulsations on the area near wrist joint can be estimatedwith a resolution of better than 4 µm. This research demonstrates that applying a CMOSimage sensor in designing a non-contact, portable, easy-to-use, low cost pulse measurementsystem is feasible. Also, the designed APM system is well suited for evaluating and pre-diagnosing the health of a human being in TCM clinical practice.

11.
Nat Commun ; 8: 14220, 2017 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-28140389

RESUMO

Fossilized organic remains are important sources of information because they provide a unique form of biological and evolutionary information, and have the long-term potential for genomic explorations. Here we report evidence of protein preservation in a terrestrial vertebrate found inside the vascular canals of a rib of a 195-million-year-old sauropodomorph dinosaur, where blood vessels and nerves would normally have been present in the living organism. The in situ synchrotron radiation-based Fourier transform infrared (SR-FTIR) spectra exhibit the characteristic infrared absorption bands for amide A and B, amide I, II and III of collagen. Aggregated haematite particles (α-Fe2O3) about 6∼8 µm in diameter are also identified inside the vascular canals using confocal Raman microscopy, where the organic remains were preserved. We propose that these particles likely had a crucial role in the preservation of the proteins, and may be remnants partially contributed from haemoglobin and other iron-rich proteins from the original blood.


Assuntos
Colágeno/análise , Fósseis/diagnóstico por imagem , Costelas/química , Amidas/análise , Amidas/história , Animais , Colágeno/história , Dinossauros/anatomia & histologia , Dinossauros/fisiologia , Compostos Férricos/análise , Compostos Férricos/história , Fósseis/anatomia & histologia , Fósseis/história , História Antiga , Costelas/anatomia & histologia , Costelas/irrigação sanguínea , Costelas/diagnóstico por imagem , Espectroscopia de Infravermelho com Transformada de Fourier , Síncrotrons
12.
Appl Opt ; 45(26): 6702-7, 2006 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-16926900

RESUMO

A high-sensitivity small-angle sensor based on surface plasmon resonance technology and heterodyne interferometry is proposed that uses a new technique with two right-angle prisms. Interestingly, the technique provides a novel method for designing small-angle sensors with high sensitivity and high resolution. Its theoretical resolution can reach 1.2x10(-7) rad over the measurement range of -0.15 degrees < or =theta< or =0.15 degrees . The method has some merits, e.g., a simple optical setup, easy operation, high resolution, high sensitivity, and rapid measurement. Its feasibility is demonstrated.

13.
Opt Lett ; 30(3): 233-5, 2005 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-15751869

RESUMO

A D-type fiber biosensor based on surface-plasmon resonance (SPR) technology and heterodyne interferometry is presented. The sensing device is a single-mode optical fiber in which half the core is polished away and a thin-film layer of gold is deposited. We measure the phase-difference variations instead of the light intensity as in traditional SPR techniques. Therefore the accuracy and resolution of our method are very high. Its sensitivity can reach 2 x 10(-6) refractive-index units. The sensor has some merits, e.g., tunable high sensitivity, small size, lower cost, smaller sample volume, and suitability for in vivo testing. This novel method of a D-type fiber biosensor based on SPR technology and heterodyne interferometry is valuable for chemical, biological, and biochemical sensing, and the novel method of D-type fiber biosensing is a feasible means of study.


Assuntos
Álcoois/análise , Álcoois/química , Técnicas Biossensoriais/instrumentação , Tecnologia de Fibra Óptica/instrumentação , Interferometria/instrumentação , Ressonância de Plasmônio de Superfície/instrumentação , Técnicas Biossensoriais/métodos , Desenho de Equipamento , Análise de Falha de Equipamento , Estudos de Viabilidade , Tecnologia de Fibra Óptica/métodos , Interferometria/métodos , Fibras Ópticas , Ressonância de Plasmônio de Superfície/métodos
14.
Appl Opt ; 41(13): 2408-13, 2002 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-12009149

RESUMO

Seidel aberration coefficients can be expressed by Zernike coefficients. The least-squares matrix-inversion method of determining Zernike coefficients from a sampled wave front with measurement noise has been found to be numerically unstable. We present a method of estimating the Seidel aberration coefficients by using a two-dimensional discrete wavelet transform. This method is applied to analyze the wave front of an optical system, and we obtain not only more-accurate Seidel aberration coefficients, but we also speed the computation. Three simulated wave fronts are fitted, and simulation results are shown for spherical aberration, coma, astigmatism, and defocus.

15.
Appl Opt ; 43(29): 5438-42, 2004 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-15508599

RESUMO

A new instrument for measuring small angles by use of multiple total internal reflections in heterodyne interferometry is presented. With this instrument we can achieve a small rotation angle only by measuring the variation in phase difference between s- and p-polarization states. To improve its sensitivity we increase the number of total internal reflections by using two parallelogram prisms instead of two right-angle prisms. The angular resolution of the new instrument is better than 2.2 x 10(-6) rad over the measurement range -2.12 degrees < or = theta < or = 2.12 degrees for 20 total-internal reflections. The experimental results and the theoretical curve are in good agreement.

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