ABSTRACT Lung function monitoring and prompt diagnosis of lung impairment are essential for optimal patient care. During surgery, anesthesia and ventilator assistance are standard, and mechanical ventilation is often required in severe cases, as highlighted during the recent COVID‐19 pandemic. There is a clear need for powerful, real‐time lung surveillance techniques that can provide feedback to ventilator settings. Gas in Scattering Media Absorption Spectroscopy (GASMAS) measures oxygen and water vapor in the gas‐filled cavities of the lungs, enabling assessment of lung aeration and oxygen concentration. Proof‐of‐concept studies in neonates have demonstrated the potential of GASMAS for continuous lung monitoring. This paper presents progress toward extending the method to older children and adults. By employing a semiconductor tapered amplifier, the diode‐laser output at the oxygen absorption wavelength (764 nm) was increased from ~30 mW to 900 mW. This enhanced power enabled model experiments on a polystyrene phantom and on ventilated porcine lungs, with added pork slabs simulating up to 9 cm total tissue thickness. Strong oxygen absorption signals were detected with both external illumination and internal delivery via the tracheal tube, demonstrating the potential of GASMAS for non‐invasive lung monitoring in large tissue phantoms simulating larger patient populations.

Wide‐fields swept‐source OCT angiography of a 43‐year‐old male with proliferative diabetic retinopathy consequent to poorly controlled diabetes. The patient was treated with pan‐retinal photocoagulation and later with serial anti‐VEGF injections. (With courtesy of Jonathan Russell, MD, PhD, Bascom Palmer Eye Institute, Florida, USA.) Further details can be found in the article by Matthew Everett, Stephanie Magazzeni, Tilman Schmoll, and Michael Kempe (e202000012). image

Abstract Breast conserving surgery (BCS) for breast cancer aims for optimal oncological results with minimal tissue excision. Positive margins due to insufficient resection results in significant numbers of patients requiring re‐excision, which could be resolved with intra‐operative margin analysis (IMA). High wavenumber (HWN) Raman Spectroscopy (RS) examines the difference in protein/lipid environment and water content in tissues. Fluorescence from haemoglobin and blue dye surgical pigments (commonly present in excised breast tissue) can confound HWN RS. We present a Raman system with 785 nm excitation laser and indium gallium arsenide camera capable of quantifying changes in water content in different environments (protein‐rich and lipid‐rich) by measuring the water/total area ratio (W/TAR) of the HWN spectrum. We demonstrate that haemoglobin and blue dye do not adversely affect water content analysis by the W/TAR calculation. Measurement of paired tumour/non‐tumour human breast tissue specimens showed the biochemical differences between tissues, and spectral analysis with W/TAR demonstrated large differences in water content and that our Raman system can accurately differentiate between tumour and non‐tumour tissue, even in the presence of surgical pigments. This provides proof of principle that this Raman system is suitable for further investigation with a view to providing IMA in the clinical environment.image

Abstract Real‐time fiber‐optic Raman spectroscopy has emerged as a compelling approach for biomedical diagnosis and characterization. This article reviews the following topics related to real‐time in vivo clinical Raman system development, such as (a) modern Raman instrumentation; (b) current developments in miniaturized fiber‐optic Raman probe designs and fabrications and (c) data processing techniques, artificial intelligence and machine learning for Raman classification and diagnosis. These synergistic advances over the past few decades play a central role in developing this unique label‐free biomolecular probe into a clinically relevant tool. The growing body of clinical literature at in vivo Raman endoscopy is an embodiment of an emerging powerful diagnostic technique that would revolutionize the future of healthcare in medicine. The past two decades of Raman endoscopic work are summarized with an emphasis on in vivo studies, illustrating the promising potential of real‐time fiber‐optic Raman spectroscopy to improve the early detection and diagnosis of precancer and cancer in vivo during clinical endoscopic examination. The challenges that exist in the widespread clinical implementation of this unique Raman diagnostic tool will be discussed, and the potential outlook in biomedical applications will also be outlined, particularly in endoscopy.

Abstract Dermatologists mainly entrust visual clinical examinations in conjunction with histopathology for an informed skin condition diagnosis, which is invasive and not adequate to assess skin conditions still present in subcutaneous skin layers. With emerging complementary imaging and spectroscopic technologies currently available, the assessment of skin conditions is more accessible than before. This review article will cover these technologies including: photoacoustic imaging, reflectance confocal microscopy, multiphoton microscopy, optical coherence tomography and confocal Raman spectroscopy. The basic concepts of these technologies and their configurations will be touched on, together with their limitations and future directions. The review article will discuss how these technologies are utilized for cutaneous applications, examining studies accomplished either in vivo on humans or on ex vivo human specimens.

A dual-frequency intravascular photoacoustic/ultrasound catheter is developed and validated for lipid-rich atherosclerotic plaque detection. By combining low-frequency transducer for highly sensitive lipid detection and high-frequency transducer for accurate localization in a single catheter with 1 mm diameter, this dual-frequency catheter design largely improves the performance of intravascular photoacoustic imaging. It takes a step forward for the translation of this imaging modality for identification of vulnerable plaque in the vascular wall and perivascular lipid. Further details can be found in the article by Yingchun Cao, Mouhamad Alloosh, Michael Sturek, and Ji-Xin Cheng (e202000004).

Abstract5‐Aminolevulinic acid‐photodynamic therapy (ALA‐PDT) is a relatively novel therapeutic technique that is used widely in dermatology. ALA can penetrate the stratum corneum into the skin and convert to the protoporphyrin IX (PpIX) to exert the photodynamic response. Due to its advantages of allowing repetitive application to multiple lesions, non‐trauma and excellent cosmetic results, ALA‐PDT is widely used for the treatment of actinic keratosis, moderate and severe acne, condyloma acuminate and other skin diseases showing a strong or promising effectiveness. However, pain is the main adverse reaction of ALA‐PDT. Daylight PDT (D‐PDT) and an optimized PDT may relieve the pain through the change of light source and therapeutic parameters. Both will be the tendency of the clinical application of ALA‐PDT.