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Background: It is challenging to visually identify tiny and concealed foreign objects within the body due to their small size and subcutaneous location while they can cause infections. Methods: A non‐contact photoacoustic system based on Rosencwaig‐Gersho photoacoustic theory and dual modulator method is developed for detecting foreign objects in meat. Result: The experiments conducted validate the successful development of this measurement technique with 10 μm spatial resolution and its corresponding mathematical model, demonstrating an 11% Mean Absolute Percentage Error (MAPE) in comparison to the experimental results. Dual modulator successfully regulates laser energy at MPE limit. Conclusion: The utilization of non‐contact photoacoustic signal intensity measurements enables the identification of foreign objects within the body. Further, the application of mathematical modelling can validate the measurement outcomes. These findings serve as a foundation for creating an affordable and straightforward foreign body detector. [ABSTRACT FROM AUTHOR]

Linear assumption on the level of stiffness in a tissue shows a significant correlation with disease. Photoacoustic imaging techniques that are non-contact by design have been developed in this study to detect differences in phantom (soft tissue mimicking materials) stiffness. This study aims to detect differences in phantom stiffness based on the results of image reconstruction at the resonance frequency. Four phantom agars with differing concentrations were made to achieve different stiffnesses. The position of each phantom agar's highest photoacoustic signal amplitude is identified by a frequency modulation sweep. The characterization results show an increase in resonance frequency along with an increase in phantom stiffness. The image difference can be detected because the intensity of the photoacoustic image in samples that have a resonance frequency with laser modulation is comparatively higher than in other samples. [ABSTRACT FROM AUTHOR]

Background: Hidden caries is a type of tooth decay that is difficult to identify through visual diagnosis because teeth with hidden caries appear normal on the tooth surface but are damaged underneath. Methods: A photoacoustic imaging system based on visible light using a diode laser with a wavelength of 532 nm was developed to detect hidden caries in teeth. Results: The results indicate that the average of acoustic intensity level for healthy teeth is −74.2 ± 0.1 dB, and the average of acoustic intensity range for teeth with hidden caries is −81.2 ± 0.5 dB. The intensity level for the caries area varies depending on the severity of caries. Conclusion: Based on the acoustic intensity level measured by the interaction of teeth with laser light, the photoacoustic imaging system in the study can accurately detect the presence of hidden caries and recognize the difference between caries teeth and healthy teeth. This research can be developed into a prototype of a simple device that makes it easy to operate in dental practice. [ABSTRACT FROM AUTHOR]

Introduction: Indonesia ranked seventh in the prevalence of diabetes mellitus in the world. Improved glycemic control has been proven to prevent the diabetes and its complications. Adherence to treatment, weight regulation with benchmarks for Body Mass Index (BMI) indicators, activity or exercise habits, diet, and smoking history play an important role in glycemic control. Objective: The aim of this study was to identify factors affecting glycemic control in outpatient with diabetes mellitus. Methods: A cross sectional study among 32 diabetes mellitus patients. This study was conducted from April 2019 to September 2019 at Rumah Sakit Nasional Diponegoro (RSND), Semarang. The glycemic control status were assesed by HbA1c. Factors such medication adherence, diet adherence, smoking status, and physical activity were assesed with a structured questionnaire. Anthropometric measurement done to get the BMI status. Data were analyzed with bivariat analysis with chi square test (p<0.05). Result: The factors that were significantly have relationship with glycemic control status are diet adherence (p=0.046), and medication adherence (p=0.040). Physical activity, smoking status and BMI doesn't have significant relationship with glycemic control status. Conclusion: Factors affecting glycemic control of diabetes mellitus patients in this study were diet adherence and medication adherence. History of smoking, BMI, and physical activity were not factors that influenced the control status in diabetes mellitus patients in this study. [ABSTRACT FROM AUTHOR]

Subsurface imaging is challenging; it is difficult to detect objects visually. In this research, a novel non-contact photoacoustic (PA) imaging system was developed to detect subsurface objects. The Rosencwaig-Gersho (RG) model was successfully employed to capture microobject images covered by rough paint. The experiments were conducted using a copper ring with a 1-mm diameter fully coated by rough paint with an average thickness of 2.3 μm. The resulting PA images exhibited up to 72% consistency despite the rough paint; the shapes of the objects were clearly recognized before and after coating. To conduct the experiment, simulations and image acquisitions were arranged. Then, the system capability to produce tomographic images was improved by adjusting the thermal diffusion lengths, and subsurface object images were successfully acquired at depths of 2.0, 2.6, 9.8, and 52 μm. The detailed composition of image slices displayed the structure profile of subsurface objects appropriately. [ABSTRACT FROM AUTHOR]

Photoacoustic measurement in an imaging system is a unique method as it uses optical disturbance but observes its effect acoustically. Acoustical observation increases the quality of a measurement by reducing the scattering effect that often occurs in optical research. However, a few problems, such as cost and complexity, hinder development of a photoacoustic system. This report presents a design of a photoacoustic system using a laser diode and a commercial microphone as the acoustic emission source and sensor, respectively. Analysis of the photoacoustic signal received by the microphone was performed with software-based Fourier transformation, which makes the photoacoustic system simpler and lower in cost. By measuring the amplitude of the signal, the system accurately detects surface micrometer cracks. The report shows that the system is capable of producing a photoacoustic image of an object with microcracks on its surface. The results indicate that the photoacoustic imaging system developed in the experiment is a more promising way to generate images of cracks than optical imaging. [ABSTRACT FROM AUTHOR]

Photoacoustic imaging is a hybrid modality that combines high-contrast and spectroscopy-based optical imaging specificity with the high spatial resolution of ultrasonography. This review highlights the development and progress of photoacoustic imaging technology over the past decade. This imaging technology has evolved to be more user-friendly, cost-effective, and portable, demonstrating its potential for diverse clinical applications. A potential clinical application lies in the use of photoacoustic imaging as a guiding tool for photothermal therapy. This review was conducted by initially filtering through three databases, namely, Google Scholar, PubMed, and Scopus, resulting in 460 articles published between 2019 and May 2023. Of these, 54 articles were deemed suitable for review after identification. The selected articles were research papers focusing on the development of therapeutic agents that enhance contrast in photoacoustic imaging. All reviewed articles tested these agents both in vitro and in vivo . This review focuses on wavelength absorption and radiation sources for photothermal therapy. The developed agents predominantly used NIR-I wavelengths, whereas the NIR-II region has been less explored, indicating significant potential for future research. This review provides comprehensive insights into the advancement of compounds serving as therapeutic agents and contrast agents in photoacoustic imaging-guided photothermal therapy., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Linear assumption on the level of stiffness in a tissue shows a significant correlation with disease. Photoacoustic imaging techniques that are non-contact by design have been developed in this study to detect differences in phantom (soft tissue mimicking materials) stiffness. This study aims to detect differences in phantom stiffness based on the results of image reconstruction at the resonance frequency. Four phantom agars with differing concentrations were made to achieve different stiffnesses. The position of each phantom agar's highest photoacoustic signal amplitude is identified by a frequency modulation sweep. The characterization results show an increase in resonance frequency along with an increase in phantom stiffness. The image difference can be detected because the intensity of the photoacoustic image in samples that have a resonance frequency with laser modulation is comparatively higher than in other samples., Competing Interests: Authors have no conflict of interest to declare., (2024 THE BIOPHYSICAL SOCIETY OF JAPAN.)