Spontaneous Raman scattering is a powerful tool for chemical sensing and imaging but suffers from weak signal. In this Letter, we present an application of adaptive optics to enhance the signal detected through turbid, optically thick material. This technique utilizes recent advances in wavefront shaping techniques focusing light turbid media applies them detection achieve enhancement with little sacrifice overall simplicity experimental setup. With technique, demonstrate titanium dioxide...

A bipolar (BP) nanosecond electric pulse (nsEP) exposure generates reduced calcium influx compared to a unipolar (UP) nsEP. This attenuated physiological response from BP nsEP is termed "bipolar cancellation" (BPC). The predominant parameters that induce BPC consist of positive polarity (↑) front followed by the delivery negative (↓) back equal voltage and width; thereby duration twice UP exposure. We tested these parameters, discovered with symmetrical widths not required generate BPC. For...

Significance: Infrared neural stimulation (INS) utilizes pulsed infrared light to selectively elicit activity without exogenous compounds. Despite its versatility in a broad range of biomedical applications, no comprehensive comparison factors pertaining the efficacy and safety INS such as wavelength, radiant exposure, optical spot size exists literature. Aim: Here, we evaluate these parameters using three wavelengths commonly used for INS, 1450 nm, 1875 2120 nm. Approach: In an vivo rat...

Optical second harmonic generation is a fundamental nonlinear effect with large impact on laser technology and optical imaging/sensing. For most practical applications of generation, high conversion efficiency required. However, many techniques used to achieve are limited fabrication methods energy requirements. Here, we investigate demonstrate substantial enhancement in the crystal via application wavefront shaping. In one-dimensional understanding phase offset applied wave has no intensity...

Abstract The ability to characterize the combined structural, functional, and thermal properties of biophysically dynamic samples is needed address critical questions related tissue structure, physiological dynamics, disease progression. Towards this, we have developed an imaging platform that enables multiple nonlinear modalities be with on a common sample. Here demonstrate label-free multimodal live cells, excised tissues, rodent brain models. While potential applications this technology...

Abstract Iatrogenic nerve injuries contribute significantly to postoperative morbidity across various surgical disciplines and occur in approximately 500,000 cases annually the US alone. Currently, there are no clinically adopted means intraoperatively visualize nerves beyond surgeon’s visual assessment. Here, we report a label-free method for detection using diffuse reflectance spectroscopy (DRS). Starting with an vivo rat model, fiber- imaging-based DRS independently identified similar...

Peripheral nerve damage frequently occurs in challenging surgical cases resulting high costs and morbidity. Various optical techniques have proven effective detecting visually enhancing nerves, demonstrating their translational potential for assisting nerve-sparing medical procedures. However, there is limited data characterizing the properties of nerves comparison to surrounding tissues, thus limiting optimization detection systems. To address this gap, absorption scattering rat human...

Infrared neural stimulation (INS) uses pulsed infrared light to yield label-free with broad experimental and translational utility. Despite its robust demonstration, INS's mechanistic biophysical underpinnings have been the subject of debate for more than a decade. The role lipid membrane thermodynamics appears play an important in how fast IR-mediated heating nonspecifically drives action potential generation. Direct observation dynamics during INS remains be shown live model system. We...

Abstract The ability to characterize the combined structural, functional, and thermal properties of biophysically dynamic samples is needed address critical questions related tissue structure, physiological dynamics, disease progression. Towards this, we have developed an imaging platform that enables multiple nonlinear modalities be with on a common sample. Here demonstrate label-free multimodal live cells, excised tissues, rodent brain models. While potential applications this technology...

In surgical procedures where the risk of accidental nerve damage is prevalent, surgeons commonly use electrical stimulation (ES) during intraoperative monitoring (IONM) to assess a nerve's functional integrity. ES, however, subject off-target and artifacts disguising true functionality specific target complicating interpretation. Lacking artifact having higher degree spatial specificity, infrared neural (INS) has potential improve upon clinical ES for IONM. Here, we present direct comparison...

Infrared neural stimulation (INS) is a promising neuromodulation technique capable of exciting tissue without the need for exogeneous agents or genetic modification. Due to its high spatial specificity, INS could improve upon traditional methods selective in both laboratory and clinic. As yet, no study has compared efficacy safety using different parameters such as spot size wavelength. Moreover, differences determining energy deposition laser make it difficult compare used current...

Inadvertent nerve injury is a common complication during many surgical procedures. Providing surgeons with means to visualize nerves within field could reduce the risk of and improve patient outcomes. Several wavelengths leveraging intrinsic optical properties have been identified enhance contrast in an animal model. Here, we demonstrate clinical feasibility this technique patients undergoing thyroidectomies. Spectral imaging successfully discriminated from surrounding tissues field. The...

Iatrogenic nerve injuries often occur during surgical procedures yielding high morbidity. Numerous optical techniques are being investigated to provide visualization and monitoring both avoid detect injury. However, there is insufficient VIS-IR properties data for surrounding tissues, facilitate needed advancements in the biophotonic approaches developed deployment. To fill this gap, we determined absorption reduced scattering coefficients of ex vivo nerve, muscle, tendon, adipose tissues...

Second-harmonic generation (SHG) has proven to be an effective method both image and detect structural variations in fibrillar collagen. The ability these differences is especially useful studying diseases like cancer fibrosis.¹ SHG techniques have historically been limited by their penetrate through strongly scattering tissues. Recently, optical wavefront shaping enabled light focused highly media such as biological tissue.^2-4 This technology also enables us examine...

The ability to non-invasively focus light through scattering media has significant applications in many fields ranging from nanotechnology deep tissue sensing. Until recently, the multiple events that occur complex such as biological have inhibited focusing and penetration depth of optical tools. Through use wavefront shaping, spatial distortions due these can be corrected, incident focused medium. Here, we demonstrate shaping used enhance Raman signal a material enhancement was achieved...

Parathyroid gland blood supply disruption causes post-surgical complications in nearly half of thyroid surgeries. Assessment parathyroid vascularity is thus critical to preserving function. The previous study used laser speckle contrast imaging (LSCI) for difference detection and showed reliability promises that the LSCI device can provide during surgery. current takes a step forward developed handheld had shown ability detect flow distinguish vascular parathyroids vivo.

Infrared neural stimulation (INS) has the potential to serve as a spatially precise tool for neuroscientists and clinicians. Because of difficulties comparing various INS techniques in current literature, we present study threshold transition rate 100% activation probability diode Ho:YAG lasers. The was lower than lasers across all examined spot sizes. also exhibited nearly binary that can be mimicked with by decreasing pulse width. These results will help maximize performance laser diodes INS.

Stimulated Raman scattering (SRS) offers a drastic speed advantage over conventional vibrational spectroscopic imaging techniques – making it ideal for studying fast biochemical dynamics. We developed an experimental paradigm that applies spectral stimulated to study the mechanisms of infrared (IR) photostimulation neuronal cells. Infrared neural stimulation (INS) is label-free optical neuromodulation technique with high spatial and temporal precision. Using SRS, changes in lipid water...

We have shown previously that astrocytes are independently sensitive to IR exposure in the context of infrared neural stimulation (INS). More recently, our advances identified some physiological basis astrocytic sensitivity INS. Single pulse INS evokes intracellular calcium signaling primarily mediated through inositol-triphosphate receptor (IP¬3R) activation, rather than thermally transient protein (TRP) pathways. Interestingly, different dosing strategies for appear evoke physiology. Our...

Currently, electrical stimulation (ES) is used during intraoperative nerve monitoring (IONM) to detect the onset of damage but suffers from current spread making results more uncertain. Infrared neural (INS) spatially precise than ES and has potential improve detection. Here, we compare INS for IONM in an vivo animal model. had comparable specificities, exhibited a higher sensitivity less severe forms damage. These provide foundation using procedures insight into future clinical translation.

Inadvertent nerve injury is a common complication during many surgical procedures. Intraoperative localization of nerves could reduce the risk and improve patients' quality life post-operation. To address this need, we combine diffuse reflectance polarization imaging techniques into single system for in vivo mapping. Both modalities successfully localize within field view an rat model together provide enhanced contrast relation to surrounding tissues. The results study valuable insight...

Schwann cells are the most abundant glial cell in peripheral nervous system. Apart from their important role on axonal myelination they exert a key regulation of excitability and metabolism, nerve repair, immunological response pain sensation. However, we still need to fully understand complete Infrared pulsed stimulation is label-free technique that proved useful stimulate neural cells. We present for first time use this method modulate physiology versatility induce different responses with...

Abstract Infrared neural stimulation, or INS, is a method of using pulsed infrared light to yield label-free stimulation with broad experimental and translational utility. Despite its robust demonstration, the mechanistic biophysical underpinnings INS have been subject debate for more than decade. The role lipid membrane thermodynamics appears play an important in how fast IR-mediated heating nonspecifically drives action potential generation. Direct observation dynamics during remains be...