scholarly journals Light-Emitting Diode Based Photoacoustic Imaging System

2020 ◽  
Author(s):  
Ebrahim Najafzadeh ◽  
Parastoo Farnia ◽  
Alireza Ahmadian ◽  
Hossein Ghadiri
Keyword(s):  
Imaging System ◽  
Photoacoustic Imaging ◽  
Light Emitting Diode ◽  
Imaging Modality ◽  
Optical Excitation ◽  
Poly Vinyl Alcohol ◽  
Ultrasound Images ◽  
Light Emitting ◽  
Non Invasive ◽  
Wide Range

Purpose: A Photoacoustic Imaging (PAI) as a non-invasive hybrid imaging modality has the potential to be used in a wide range of pre-clinical and clinical applications. There are different optical excitation sources that affect the performance of PAI systems. Our goal is proving the capability of the Light-Emitting Diode (LED) based PAI system for imaging of objects in different depths. Materials and Methods: In this study the Full Width of Half Maximum (FWHM) and Contrast to Noise Ratio (CNR) of LED-based PAI system is evaluated using agar, and Poly-Vinyl Alcohol Cryogel (PVA-C) phantoms. Results: The results show that axial and lateral FWHM of the photoacoustic image in agar phantom 1%, are 0.59 and 1.16 mm, respectively. It is capable of distinguishing objects about 250 µm. Furthermore, one of the main improvements of photoacoustic images is achieved by proposed LED-based system that is a 26% higher CNR versus the ultrasound images. Conclusion: Therefore, the provided technical characteristics in this study have made designed LED-based PAI system as a suitable tool for preclinical and clinical imaging.

scholarly journals Low-cost photoacoustic imaging systems based on laser diode and light-emitting diode excitation

2017 ◽  
Vol 10 (04) ◽  
pp. 1730003 ◽  
Author(s):  
Qingkai Yao ◽  
Yu Ding ◽  
Guodong Liu ◽  
Lvming Zeng
Keyword(s):  
Laser Diode ◽  
Near Infrared ◽  
Photoacoustic Imaging ◽  
Light Emitting Diode ◽  
Imaging Modality ◽  
Low Cost ◽  
Laser System ◽  
Great Promise ◽  
Light Emitting ◽  
Wide Range

Photoacoustic imaging, an emerging biomedical imaging modality, holds great promise for preclinical and clinical researches. It combines the high optical contrast and high ultrasound resolution by converting laser excitation into ultrasonic emission. In order to generate photoacoustic signal efficiently, bulky Q-switched solid-state laser systems are most commonly used as excitation sources and hence limit its commercialization. As an alternative, the miniaturized semiconductor laser system has the advantages of being inexpensive, compact, and robust, which makes a significant effect on production-forming design. It is also desirable to obtain a wavelength in a wide range from visible to near-infrared spectrum for multispectral applications. Focussing on practical aspect, this paper reviews the state-of-the-art developments of low-cost photoacoustic system with laser diode and light-emitting diode excitation source and highlights a few representative installations in the past decade.

Abstract 131: Quantification of in vivo Placental Oxygenation Using Ultrasound-guided Spectral Photoacoustic Imaging

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Carolyn Bayer ◽  
Geoffrey P Luke ◽  
Jason R Cook ◽  
Stanislav Y Emelianov
Keyword(s):  
Imaging System ◽  
Photoacoustic Imaging ◽  
Imaging Modality ◽  
Imaging Method ◽  
Ultrasound Images ◽  
Calibration Standard ◽  
Ultrasound Guided ◽  
Placental Development ◽  
Placental Function

Preeclampsia, linked to abnormal placental development and ischemia, is a major cause of fetal and maternal death. Currently, the only cure is high-risk preterm delivery. Although clinical therapies to regulate the symptoms of preeclampsia—mean arterial pressure and proteinuria—it is unknown whether these therapeutics restore placental blood flow and reduce ischemia. We are developing ultrasound-guided spectral photoacoustic imaging to quantify placental ischemia and characterize therapeutic response. Ultrasound imaging is the preferred imaging modality to monitor pregnancy due to its safety, low cost, and mobility. Similar to ultrasound, photoacoustic imaging can provide co-registered images of tissue function. In these studies, pregnant SWV mice were imaged longitudinally from E12.5 to 18.5 using a Vevo LAZR small animal imaging system. Algorithms were developed to correlate the spectral photoacoustic data to a hemoglobin oxygenation (%sO 2 ) calibration standard—a phantom containing blood at varying partial pressures of oxygen. The phantom calibration standard deviation was 7.9% (n=3). The resulting ultrasound images were used to segment the placenta (Figure 1). An overlay of the %sO 2 on the ultrasound image maps placental variation in %sO 2 during longitudinal development. We demonstrate that our imaging method is capable of quantifying %sO2 and monitoring placental function in vivo . Future work will use our preclinical %sO2 quantification methods to characterize placental function during treatment for preeclampsia.

scholarly journals LED Rail Signals: Full Hardware Realization of Apparatus with Independent Intensity by Temperature Changes

Electronics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1291
Author(s):  
Giuseppe Schirripa Schirripa Spagnolo ◽  
Fabio Leccese
Keyword(s):  
Temperature Sensor ◽  
Energy Efficient ◽  
Light Emitting Diode ◽  
Junction Temperature ◽  
Light Emitting ◽  
Temperature Changes ◽  
Wide Range ◽  
International Regulations ◽  
Long Lifetime ◽  
Set Up

Nowadays, signal lights are made using light-emitting diode arrays (LEDs). These devices are extremely energy efficient and have a very long lifetime. Unfortunately, especially for yellow/amber LEDs, the intensity of the light is closely related to the junction temperature. This makes it difficult to design signal lights to be used in naval, road, railway, and aeronautical sectors, capable of fully respecting national and international regulations. Furthermore, the limitations prescribed by the standards must be respected in a wide range of temperature variations. In other words, in the signaling apparatuses, a system that varies the light intensity emitted according to the operating temperature is useful/necessary. In this paper, we propose a simple and effective solution. In order to adjust the intensity of the light emitted by the LEDs, we use an LED identical to those used to emit light as a temperature sensor. The proposed system was created and tested in the laboratory. As the same device as the ones to be controlled is used as the temperature sensor, the system is very stable and easy to set up.

scholarly journals Pinhole microLED Array as Point Source Illumination for Miniaturized Lensless Cell Monitoring Systems

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 866 ◽  
Author(s):  
Shinta Mariana ◽  
Gregor Scholz ◽  
Feng Yu ◽  
Agus Budi Dharmawan ◽  
Iqbal Syamsu ◽  
...  
Keyword(s):  
Image Quality ◽  
Light Emitting Diode ◽  
Free Cell ◽  
Monitoring Systems ◽  
Label Free ◽  
Light Emitting ◽  
Non Invasive ◽  
Cell Monitoring ◽  
Blue Spectral Region ◽  
Led Arrays

Pinhole‐shaped light‐emitting diode (LED) arrays with dimension ranging from 100 μm down to 5 μm have been developed as point illumination sources. The proposed microLED arrays, which are based on gallium nitride (GaN) technology and emitting in the blue spectral region (λ = 465 nm), are integrated into a compact lensless holographic microscope for a non‐invasive, label‐free cell sensing and imaging. From the experimental results using single pinhole LEDs having a diameter of 90 μm, the reconstructed images display better resolution and enhanced image quality compared to those captured using a commercial surface‐mount device (SMD)‐based LED.

scholarly journals Non-invasive Autonomic Neuromodulation Is Opening New Landscapes for Cardiovascular Diseases

2020 ◽  
Vol 11 ◽  
Author(s):  
Mingxian Chen ◽  
Songyun Wang ◽  
Xuping Li ◽  
Lilei Yu ◽  
Hui Yang ◽  
...  
Keyword(s):  
Cardiovascular Diseases ◽  
Vagus Nerve ◽  
Nerve Stimulation ◽  
Vagus Nerve Stimulation ◽  
Light Emitting Diode ◽  
Heart Diseases ◽  
Bipolar Electrode ◽  
Light Emitting ◽  
Non Invasive ◽  
Emerging Therapies

Autonomic imbalance plays a crucial role in the genesis and maintenance of cardiac disorders. Approaches to maintain sympatho-vagal balance in heart diseases have gained great interest in recent years. Emerging therapies However, certain types of emerging therapies including direct electrical stimulation and nerve denervation require invasive implantation of a generator and a bipolar electrode subcutaneously or result in autonomic nervous system (ANS) damage, inevitably increasing the risk of complications. More recently, non-invasive neuromodulation approaches have received great interest in ANS modulation. Non-invasive approaches have opened new fields in the treatment of cardiovascular diseases. Herein, we will review the protective roles of non-invasive neuromodulation techniques in heart diseases, including transcutaneous auricular vagus nerve stimulation, electromagnetic field stimulation, ultrasound stimulation, autonomic modulation in optogenetics, and light-emitting diode and transcutaneous cervical vagus nerve stimulation (gammaCore).

Near-Infrared Light Emitting Diode Based Non-Invasive Glucose Detection System

2019 ◽  
Vol 19 (10) ◽  
pp. 6187-6191 ◽  
Author(s):  
Seung Ho Lee ◽  
Min Seok Kim ◽  
Ok-Kyun Kim ◽  
Hyung-Hwan Baik ◽  
Ji-Hye Kim
Keyword(s):  
Near Infrared ◽  
Detection System ◽  
Light Emitting Diode ◽  
Infrared Light ◽  
Glucose Detection ◽  
Near Infrared Light ◽  
Light Emitting ◽  
Non Invasive

scholarly journals Photoacoustic Imaging of Tattoo Inks: Phantom and Clinical Evaluation

2020 ◽  
Vol 10 (3) ◽  
pp. 1024 ◽  
Author(s):  
Eftekhar Rajab Bolookat ◽  
Laurie J. Rich ◽  
Gyorgy Paragh ◽  
Oscar R. Colegio ◽  
Anurag K. Singh ◽  
...  
Keyword(s):  
Photoacoustic Imaging ◽  
Imaging Modality ◽  
Preoperative Evaluation ◽  
Healthy Human ◽  
Non Invasive ◽  
Diagnostic Applications ◽  
Yellow Pigments ◽  
Tattoo Inks

Photoacoustic imaging (PAI) is a novel hybrid imaging modality that provides excellent optical contrast with the spatial resolution of ultrasound in vivo. The method is widely being investigated in the clinical setting for diagnostic applications in dermatology. In this report, we illustrate the utility of PAI as a non-invasive tool for imaging tattoos. Ten different samples of commercially available tattoo inks were examined for their optoacoustic properties in vitro. In vivo PAI of an intradermal tattoo on the wrist was performed in a healthy human volunteer. Black/gray, green, violet, and blue colored pigments provided higher levels of PA signal compared to white, orange, red, and yellow pigments in vitro. PAI provided excellent contrast and enabled accurate delineation of the extent of the tattoo in the dermis. Our results reveal the photoacoustic properties of tattoo inks and demonstrate the potential clinical utility of PAI for intradermal imaging of tattoos. PAI may be useful as a clinical adjunct for objective preoperative evaluation of tattoos and potentially to guide/monitor laser-based tattoo removal procedures.

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