Automated Monitoring of Platelet Aggregation in Multiple Samples of whole Blood

1975 ◽  
Author(s):  
N. Clarke ◽  
V. McCabe
Keyword(s):  
Whole Blood ◽  
Light Emitting Diode ◽  
Direct Reading ◽  
Light Emitting ◽  
Printed Circuit ◽  
Platelet Concentration ◽  
Light Effects ◽  
Multiple Samples ◽  
Free Plasma ◽  
Selection Of

Whole blood may be first agitated in a circular transparent rotor chamber, and then rotated continuously to produce plasma/red cell separation for monitoring. The rotor is driven by a low inertia, printed circuit d.c. motor (108 Watt) which is automatically controlled. The pattern of rotation is determined by a signal generator which provides various waveforms at adjustable frequencies and also at fixed speeds.By segmenting the rotor into multiple cuvettes (Vol = 0.4 ml) it is possible to monitor the platelet concentration, after agitation, as each cuvette spins through the stationary optical system. This consists of a light-emitting diode (peak: 900 nm), pulsed at 10 kHz in order to eliminate ambient light effects, and a photodetector with a built-in amplifier, fed to an amplifying circuit which eliminates other signals. An electronic circuit permits selection of the signal from each cuvette on a direct reading meter. Cuvette No. 1 is identified by a photocell-detector trigger.Platelet-free plasma is about zero O. D. in the infra red with respect to a water blank, and with attention to specific criteria such as optical geometry and light path, platelet concentration may be accurately determined.

Temperature and Humidity Dependent Reliability Analysis of RGB LED Chips

2006 ◽  
Author(s):  
Jun-Xian Fu ◽  
Shukri Souri ◽  
James S. Harris
Keyword(s):  
Reliability Analysis ◽  
Printed Circuit Board ◽  
Light Emitting Diode ◽  
Circuit Board ◽  
Light Emitting ◽  
Printed Circuit ◽  
Root Cause ◽  
Micro Cracks ◽  
Temperature And Humidity

Abstract Temperature and humidity dependent reliability analysis was performed based on a case study involving an indicator printed-circuit board with surface-mounted multiple-die red, green and blue light-emitting diode chips. Reported intermittent failures were investigated and the root cause was attributed to a non-optimized reflow process that resulted in micro-cracks and delaminations within the molding resin of the chips.

scholarly journals Effective photosensibilizator selection for e.n.t.-organ diseases treatment, based on their accumulation in pathologically changed tissues

2012 ◽  
Vol 58 (1) ◽  
pp. 112-120 ◽  
Author(s):  
Y.V. Alexeev ◽  
E.V. Likhacheva ◽  
D.V. Tereshkin ◽  
G.V. Ponomarev ◽  
E.M. Mazur
Keyword(s):  
Mucous Membrane ◽  
Light Emitting Diode ◽  
Clinical Results ◽  
Therapeutic Activity ◽  
Laser Device ◽  
Light Emitting ◽  
Selection For ◽  
Derivatives Of ◽  
Led Matrix ◽  
Selection Of

Accumulation of photosensibilisators - derivatives of E6 chlorines ("Radachlorine", "Photoditazine", "Zelevsky's balsam") in the mucous membrane and selection of most effective sources of emission have been investigated in 30 patients with rhinosinusitis and 10 with tonsillitis. As a source of emission we used light emitting diode (LED) matrix device "ACT" (wavelength approximately 405 nm (Sore band)) and a laser device LAHTA-"MILON"-ML500-SP (wavelength - 662 nm). Drug accumulation in the mucous membrane and changes of their concentrations after emission were evaluated by changes of fluorescence, measured with a LESA-01-BIOSPEC spectrometer. The percent of fluorescence decrease ranged from 50% to 92.7%. This suggests intensive disintegration of photosensibilisators, and consequently, high therapeutic activity of this method. Effectiveness of this method is also confirmed by clinical results.

Simple, Accurate Solid-State Diode Photometer for Use in Measuring Oxygen Saturation of Whole Blood

1974 ◽  
Vol 20 (9) ◽  
pp. 1135-1137 ◽  
Author(s):  
R Fesler ◽  
Th Clerbaux
Keyword(s):  
Solid State ◽  
Oxygen Saturation ◽  
Light Source ◽  
Whole Blood ◽  
Continuous Measurement ◽  
Light Emitting Diode ◽  
Detector Response ◽  
Typical Application ◽  
Light Emitting ◽  
Absorption Characteristics

Abstract A small, easily-built photometer is described, in which a solid-state light-emitting diode is used as the light source and a phototransistor as the detector. The detector response is kept constant by modulating the diode intensity in proportion to the absorption characteristics of the sample being analyzed. Linearity and stability are good, even with turbid solutions (drift is <0.001 absorbance unit per hour). A typical application of this photometer is the continuous measurement of the percentage of oxyhemoglobin (0 to 100 %) in blood. For hemoglobin concentrations from 3 to 18 g/dl, the relation between oxyhemoglobin as estimated with this diode photometer and by a galvanic method (LEX-O2-CON) was: SO2LED = 0.993 SO2 % LEX + 0.69;r = 0.9975; n = 129; Syx = 1.59.

Damage-free plasma etching to enhance performance of AlGaInP-based micro-light emitting diode

2020 ◽  
pp. 1-1
Author(s):  
Sang-Youl Lee ◽  
Eunduk Lee ◽  
Ji-Hyung Moon ◽  
Byoungjun Choi ◽  
Jeong-Tak Oh ◽  
...  
Keyword(s):  
Plasma Etching ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
Free Plasma

PENGARUH DIMENSI GEOMETRIK LAMPU LED TERHADAP PERSEPSI KECERAHAN

2013 ◽  
Vol 3 (2) ◽  
pp. 41
Author(s):  
Andrea Marisi ◽  
Revantino Revantino
Keyword(s):  
Solid State ◽  
Printed Circuit Board ◽  
Light Emitting Diode ◽  
Circuit Board ◽  
Solid State Lighting ◽  
Light Emitting ◽  
Printed Circuit ◽  
Surface Mounting

Perkembangan teknologi di bidang Solid State Lighting selama dekade terakhir membuat diversifikasi penggunaan Light Emitting Diode untuk pelayanan pencahayaan umum. Balai Besar Bahan dan Barang Teknik sejak tahun 2011 telah melakukan penelitian dan pengembangan lampu LED berbasis Surface Mounting Device (SMD) 5050. Pada perancangan Printed Circuit Board (PCB) untuk memasangkan LED-smd tersebut, dilakukan analisis dimensi geometrik yang optimal sehingga dapat memancarkan cahaya ke segala arah dan memberikan persepsi kecerahan yang lebih baik. Untuk perancangan PCB tersebut, dipilih 2 (dua) model berbentuk silinder dengan memperhatikan rasio antara tinggi dan diameter alas. Dari pendekatan sumber titik dan perhitungan eksitansi luminus, diperoleh bahwa model dengan rasio ≈ 1 menghasilkan persepsi lebih cerah terhadap visual manusia.Kata kunci : dimensi geometrik, pendekatan sumber titik, eksitansi luminus, persepsi kecerahan

scholarly journals Machine vision based in-process light-emitting diode chip mounting system

2018 ◽  
Vol 51 (7-8) ◽  
pp. 293-303 ◽  
Author(s):  
Chao-Ching Ho ◽  
You-Min Chen ◽  
Po-Chieh Li
Keyword(s):  
Machine Vision ◽  
Printed Circuit Board ◽  
Vision System ◽  
Light Emitting Diode ◽  
Circuit Board ◽  
Robot Arm ◽  
Light Emitting ◽  
Printed Circuit ◽  
Delta Robot ◽  
A Charge

Background: In this study, a machine vision–based method was developed for automated in-process light-emitting diode chip mounting lines with position uncertainty. In order to place the tiny light-emitting diode chips on the pattern of a printed circuit board, a highly accurate mounting process is achieved with online feedback of the visual assistance. Methods: The system consists of a charge-coupled device camera, a six-axis robot arm, and a delta robot. The lighting system is a critical point for the in-process machine vision problem. Hence, designing the optimal lighting solution is one of the most difficult parts of a machine vision system, and several lighting techniques and experiments are examined in this study. In order to commence the mounting process, the light-emitting diode chip targets inside the camera field were identified and used to guide the delta robot to the grabbing zone based on the calibrated homography transformation. Efforts have been focused on the field of machine vision–based feature extraction of the chip pins and the holes on the printed circuit board. The correspondence of each other is determined by the position of the chip pins and the printed circuit board circuit pattern. The image acquisition is achieved directly online in real time. The image analysis algorithm must be sufficiently fast to follow the production rate. In order to compensate for the uncertainty of the light-emitting diode chip mounting process, a visual feedback strategy in conjunction with an uncertainty compensation strategy is employed. Results: Finally, the light-emitting diode chip was automatically grabbed and accurately placed at the desired positions. Conclusion: On-line and off-line experiments were conducted to investigate the performance of the vision system with respect to detecting and mounting light-emitting diode chips.

Maker Chemistry: Exploring Redox Reactions in Introductory Laboratory through Light-Emitting Diode Printed Circuit Board Fabrication

2019 ◽  
Vol 97 (2) ◽  
pp. 490-496
Author(s):  
Scott L. Wallen ◽  
Jaspreet Dhau ◽  
Robert Green ◽  
Laura B. Wemple ◽  
Troy Kelly ◽  
...  
Keyword(s):  
Redox Reactions ◽  
Printed Circuit Board ◽  
Light Emitting Diode ◽  
Circuit Board ◽  
Light Emitting ◽  
Printed Circuit

Circadian tuning with metameric white light: Visual and non-visual aspects

2020 ◽  
pp. 147715352097693
Author(s):  
T Aderneuer ◽  
O Stefani ◽  
O Fernández ◽  
C Cajochen ◽  
R Ferrini
Keyword(s):  
White Light ◽  
Light Emitting Diodes ◽  
Light Stimulus ◽  
Light Emitting Diode ◽  
Biological Effects ◽  
Theoretical Models ◽  
Light Emitting ◽  
Single Colour ◽  
Light Effects ◽  
New Research

The growing awareness of the biological effects of electric light on humans has stimulated ample research. New research has been devoted to lighting solutions that dynamically change their colour to mimic spectral changes of daylight. However, in some situations, the visual properties of light must be preserved, such as when working under standardised lighting conditions to do colour correction in post-production. We have investigated the possibility to tune circadian effects using white lights that are spectrally different but nonetheless appear as a similar white tone. Our simulation results, for example, sets of light-emitting diodes, indicate that it is possible to modulate circadian light effects from 0.20 to 0.41 circadian stimulus by combining light-emitting diodes to create neutral white (4000 K) light. However, the results also show that the solutions combining single-colour light-emitting diodes leading to similar range between maximum and minimum circadian stimulus (ΔCS > 0.20) have a CRI below 80. Combining narrowband light-emitting diodes with a broadband white light-emitting diode improves the colour-rendering quality, and we show how far circadian light effects can be tuned according to common theoretical models. The aim is to maintain the natural cycle of melatonin levels as much as possible with high light stimulus in the morning and low light stimulus in the evening. Therefore, we show what maximum and minimum circadian effects are possible with a given set of light-emitting diodes.

The Effect of Light Curing Source on the Residual Yellowing of Resin Composites

2007 ◽  
Vol 32 (5) ◽  
pp. 443-450 ◽  
Author(s):  
M. G. Brackett ◽  
W. W. Brackett ◽  
W. D. Browning ◽  
F. A. Rueggeberg
Keyword(s):  
Blue Light ◽  
Clinical Relevance ◽  
Light Emitting Diode ◽  
Color Difference ◽  
Resin Composites ◽  
Light Emitting ◽  
Quartz Tungsten Halogen ◽  
Light Curing ◽  
Selection Of ◽  
Effect Of Light

Clinical Relevance The selection of light curing unit (quartz-tungsten-halogen or blue light-emitting diode), composite classification and shade have an influence on the amount of residual yellow after photocuring and, in some combinations, the color difference may be visually detectable.

Sign in / Sign up

Export Citation Format

Share Document