Non-invasive Technology Research Articles

Accurate retinal vessel segmentation in OCT-A images based on MsTCG-Net

Optical coherence tomography angiography (OCT-A) is a non-invasive visualization imaging technology with high-resolution that can more clearly image tiny blood vessels. Using OCT-A imaging technology, certain ophthalmic diseases can be better diagnosed by the morphological changes of retinal blood vessels. However, the task of segmenting retinal vessels is still very challenging due to the large variation in vessel size and shape and the presence of noise. In this paper, by introducing a transformer with a self-attention mechanism, we propose a novel multi-scale transformer-based channel and global attention network (MsTCG-Net) for segmentation of blood vessels in retinal OCT-A images. In MsTCG-Net, transformer-based channel joint attention (TC) block and transformer-based global joint attention (TG) block are proposed to capture multi-semantic features from spatial and channel dimension and fuse global contextual semantic features from different layers of encoder. Experimental results show that our proposed method achieves better segmentation performance than other state-of-the-art U-Net-based methods.

Accurate retinal vessel segmentation in OCT-A images based on MsTCG-Net

Optical coherence tomography angiography (OCT-A) is a non-invasive visualization imaging technology with high-resolution that can more clearly image tiny blood vessels. Using OCT-A imaging technology, certain ophthalmic diseases can be better diagnosed by the morphological changes of retinal blood vessels. However, the task of segmenting retinal vessels is still very challenging due to the large variation in vessel size and shape and the presence of noise. In this paper, by introducing a transformer with a self-attention mechanism, we propose a novel multi-scale transformer-based channel and global attention network (MsTCG-Net) for segmentation of blood vessels in retinal OCT-A images. In MsTCG-Net, transformer-based channel joint attention (TC) block and transformer-based global joint attention (TG) block are proposed to capture multi-semantic features from spatial and channel dimension and fuse global contextual semantic features from different layers of encoder. Experimental results show that our proposed method achieves better segmentation performance than other state-of-the-art U-Net-based methods.

Research on the Exoskeleton Enhancing Human Touch

The integration of brain-computer interfaces (BCIs) with exoskeleton systems offers a unique potential to enhance and restore human sensory and motor capabilities. This review delves into both invasive and non-invasive BCI technologies, with a special emphasis on the practical application of electroencephalography (EEG). It critically assess the effectiveness and limitations of EEG in controlling exoskeletons, while providing a detailed comparison of various control methods, including direct neuromuscular stimulation, neurofeedback, and machine learning-based intelligent strategies. Additionally, this review addresses the technical challenges faced by integrated systems, particularly in performing complex tasks and delivering real-time feedback, such as the intricacies of signal decoding, system stability, and user adaptability. The conclusion underscores the importance of future research in enhancing system reliability and accuracy, refining user interfaces, and developing novel algorithms to improve performance and user experience. This review aims to equip researchers in the field with a robust theoretical framework and practical insights, facilitating further advancements in the synergy between BCI and exoskeleton technologies.

Prospective comparative clinical trials of novel non-invasive intracranial pressure pulse wave monitoring technologies: preliminary clinical data.

Intracranial pressure (ICP) monitoring is crucial in the management of traumatic brain injury (TBI) and other neurological conditions. Elevated ICP or too low intracranial compliance (ICC) can compromise brain perfusion. Simultaneous monitoring of ICP and ICC is needed to optimize patient-specific brain perfusion in pathological conditions. Surrogate ICC changes can be extracted by analysis of ICP pulse wave morphology. Non-invasive, fully passive sensor and ICC changes monitoring are needed. This study introduces Archimedes, a novel, fully passive, non-invasive ICP wave monitor that utilizes mechanical pulsatile movement of the eyeball to assess ICP pulse waveforms. Preliminary findings indicate a high correlation r = [0.919; 0.96] between non-invasive and invasive ICP pulse wave morphologies, demonstrating the device's potential for accurate ICP pulse waveform monitoring. Additionally, the monitor can discern ICC changes, providing valuable insights for TBI and normal tension glaucoma patients according to the shape of non-invasive measured ICP pulse wave. The k-nearest neighbours algorithm used in preliminary glaucoma studies yielded promising diagnostic performance, with an accuracy of 0.89, sensitivity of 0.82, specificity of 1.0 and area under curve 0.91. Ethical approvals for ongoing studies have been secured. Initial results indicate that Archimedes real-time ICC non-invasive monitor is safe, cost-effective alternative to conventional monitoring techniques.

Transcranial magneto-acoustic stimulation enhances motor function and modulates cortical excitability of motor cortex in a Parkinson's disease mouse model

Parkinson's disease (PD) is a neurodegenerative disorder characterized primarily by motor dysfunction. Transcranial magneto-acoustic stimulation (TMAS), an emerging non-invasive brain neuromodulation technology, is increasingly being applied in the treatment of brain diseases. However, the effects of TMAS on PD are unknown, which is not well studied. Here, we utilized TMAS on PD model mice induced by MPTP to investigate the underlying mechanism of therapy. Our study found that TMAS improved the behavioral performance of PD model mice, enhancing the motor function and motivation for movement. Besides, it inhibited the increased beta oscillations in the motor cortex, while also reducing gamma oscillations. Moreover, the abnormally exaggerated beta-broad gamma phase amplitude coupling (PAC) was decreased after TMAS, and there was a significant negative correlation between PAC and both distance traveled and mean speed during the open filed test. Additionally, the ongoing stimulation could provide neuroprotection, implying that TMAS could ameliorate the loss of dopaminergic neurons, with no damage observed in the brain tissue of mice. Our findings suggest that TMAS could provide a non-invasive tool for the treatment of Parkinson's disease and beta-broad gamma phase amplitude coupling could be employed as a biomarker for PD.

Development of Non-Invasive Continuous Blood Pressure Measurement System Based on Multiple Feature Parameters

To address the issue of the difficulty in implementing non-invasive continuous blood pressure measurement technology in China, this study developed a high-performance synchronous electrocardiogram (ECG) and photoplethysmography (PPG) signal acquisition system. A PC-based human-computer interaction software platform was constructed, and continuous blood pressure measurement-related algorithms were integrated. Multiple feature parameters such as pulse wave transit time based on synchronous ECG and PPG signals were extracted, enabling non-invasive continuous blood pressure measurement. To verify the measurement accuracy of the system, tests and comparative verifications were carried out. The results demonstrated that the system could meet the requirements of relevant standards and have good application value.

Research Progress on Medical Imaging and New Ultrasound Techniques for Assessing the Degree of Carotid Artery Stenosis

The paper summarizes the imaging evaluation methods for assessing the degree of carotid artery stenosis and analyzes the unique advantages and limitations of various imaging techniques in vascular imaging based on existing guidelines and consensus. The paper focuses on reviewing the clinical applications of several novel ultrasound technologies, including the use of advanced hemodynamic parameters such as blood flow dispersion (Tur index) and wall shear stress (WSS). Carotid artery stenosis is closely associated with cardiovascular disease. Although non-invasive and radiation-free ultrasound technology has certain limitations in diagnostic accuracy to a certain extent, with the continuous emergence of advanced functions such as ultrasound hemodynamics and vascular elasticity, the combination of multi-modality and multi-parameter ultrasound is expected to become an important method for efficient diagnosis of arterial stenosis in the future.

Innovations in transdermal delivery: Exploring nicotine patches, microneedles and glucose monitoring technologies

Transdermal devices for delivering drugs have been invented in response to obstacles caused by oral administration of medications. An adhesive patch comprising medication that is applied topically for transferring a preset proportion of treatment through the skin and into the bloodstream is called a transdermal patch. The method of manufacturing for various transdermal application types, including matrix patches, is described in this review article. Addiction to cigarettes affects millions different people throughout. One example of a nicotine replacement treatment that is currently widely accessible and utilized is transdermal nicotine patches. Nicotine substitution therapy is an assortment of products that provide nicotine and are authorized for use as a smoking cessation aid for the treatment of withdrawal. An increasing number of participants have been impacted by the global rise in diabetes in the past few years are experiencing discomfort and infections because of the intrusive design of most commercial glucose meters. Non-invasive blood glucose monitoring technology is now a hot issue for research worldwide and a novel approach that has the potential to help a lot of patients.

Investigating the Possibilities of Applying the TENS as a Neurostimulation Method

Transcranial electrical stimulation (TES) is a non-invasive technology used to change the functions of the nervous system as one of the methods of neuromodulation. This method modulates brain activity by applying low-intensity electrical current to different regions of the brain. The use of transcranial electrical stimulation has shown promising results in the treatment of depression, chronic pain, neurodegenerative diseases and other neurological problems. Research shows that the application of transcranial electrical stimulation can be effective in areas such as improving memory, developing motor skills and increasing cognitive functions. However, safety, efficacy, and individual differences should be considered when using this method in clinical practice. The article examines the clinical and scientific basis, applications, and potential benefits of transcranial electrical stimulation. It is very important to study the parameters such as the shape, amplitude and frequency of the influencing signal used for the optimal solution of the treatment process. In the article, the types of the effective signal in transcranial electrical stimulation were investigated. The role of different forms of affective signals on the effectiveness of neurostimulation was investigated. In addition, it was concluded that electroacupuncture stimulation belongs to neurostimulation in terms of its essence and parameters.

Transcutaneous Non-Invasive Vagus Nerve Stimulation: Changing the Paradigm for Stroke and Atrial Fibrillation Therapies?

A new therapeutic approach, known as neuromodulation therapy—which encompasses a variety of interventional techniques meant to alter the nervous system in order to achieve therapeutic effects—has emerged in recent years as a result of advancements in neuroscience. Currently used methods for neuromodulation include direct and indirect approaches, as well as invasive and non-invasive interventions. For instance, the two primary methods of stimulating the vagus nerve (VN) are invasive VN stimulation (iVNS) and transcutaneous VN stimulation (tVNS). Since the latter is non-invasive, basic, clinical, and translational studies have focused on transcutaneous auricular VN stimulation (taVNS), the primary tVNS therapy, because of its advantages over iVNS, including ease of use, greater accessibility, and a lower side effect profile. taVNS is currently used as a novel neuromodulatory application to treat cardiovascular, mental, and autoimmune diseases. Future applications of this non-invasive neuromodulation technology to conditions like atrial fibrillation (AF) or ischemic stroke are highly likely due to its advancement.

Intradermal delivery of a liposomal formulation encapsulating amphiphilic ascorbic acid by iontophoresis for promotion of collagen synthesis

Collagen is a structural protein in skin that is an important component for maintaining skin functions, such as elasticity. As the amount and functional capacity of collagen in the skin decreases with age, wrinkles and skin sagging are induced. Treatment of the skin with vitamin C (ascorbic acid, AsA) is attracting attention as a means of inducing collagen production. However, penetration of AsA into the skin is difficult due to its hydrophilicity. To overcome this limitation, we focused on a combination of iontophoresis (ItP), which is a non-invasive intradermal drug delivery technology, and use of a liposome formulation, to improve skin penetration of AsA. In this study, palmitoylated AsA was used to increase the encapsulation efficiency into liposomes. We prepared liposomes encapsulating palmitoylated AsA (AsA-lipo) and performed ItP of fluorescently-labeled AsA-lipo on the shaved dorsal skin of rats. Fluorescence of the liposomes was observed in skin sections following ItP, indicating that AsA-lipo was delivered into the skin. The amount of collagen in the skin after ItP of AsA-lipo increased with the number of doses, and the amount of collagen mRNA also showed an increasing trend. Furthermore, the amount of hydroxyproline, which is a major component of collagen, was significantly increased in skin treated with AsA-lipo via ItP. In conclusion, results of this study demonstrate the successful promotion of skin collagen synthesis by non-invasive iontophoretic intradermal delivery of AsA-lipo.

Blood pressure monitoring using telemedicine technologies in patients with chronic heart failure

Continuous monitoring of cardiovascular patients is one of the most important tasks in modern cardiology. Monitoring chronic heart failure (CHF) patients is critical because of instability, high prevalence and life-threatening nature of this disease. Currently, active search and development of optimal devices and programs for medical telemonitoring continues. This review presents the results of Russian and foreign studies on the use of invasive and non-invasive technologies for monitoring blood pressure (BP) levels and demonstrates their clinical significance. Innovative cuffed and cuffless BP monitoring devices are evaluated. The effectiveness of hypertension and CHF management using remote monitoring is compared with standard practice. The relationship between the risk of hospitalization for CHF and the monitoring is demonstrated. The paper presents data on the cost-effectiveness of using telemedicine technologies such as BP monitoring for CHF management.

Abstract B075: Detection of early gastric carcinoma by micronuclei DNA from erythrocytes

Abstract Background: Advancements in non-invasive diagnostic technologies for gastric carcinoma (GC), including serum microRNA and cell-free DNA assays, have shown promise but still face challenges in achieving consistent early detection. Micronuclei (MN), extranuclear bodies harboring fragmented chromosomal segments, are indicative of genomic instability and have been employed in genotoxicity assessments and cancer diagnostics. We have developed a novel technique (WO2021/228246 A1) for the purification and characterization of micronuclei DNA (MN-DNA) extracted from erythrocytes in peripheral blood. Here, we evaluated the potential of micronuclei DNA (MN-DNA) from 2ml peripheral blood for early gastric carcinoma detection and explored its application for early cancer diagnosis. Methods: We assembled a clinical cohort consisting of 425 healthy donors (HDs) and 282 gastric cancer patients, from whom 1-2 mL peripheral blood samples were collected. Participants were randomly allocated into training, validation, and independent test cohorts in a 7:2:1 ratio, ensuring similar distributions of cancer stages and gender. MN-DNA was isolated from erythrocytes and subjected to comprehensive whole-genome sequencing. Predictive machine learning models were constructed utilizing distinct tumor-associated MN-DNA features identified through genome-wide analysis to distinguish between HDs and GC. Results: Comprehensive genome-wide analysis of MN-DNA demonstrated pronounced disparities in distribution patterns between HDs and GC patients. The predictive model built on MN-DNA features achieved an AUC of 97.69% (95%CI: 95.57- 99.81%), with an 96.47% specificity and 91.07% sensitivity in the independent test cohort. The model identified early GC (stage 0-I) and advanced GC (stage II-IV) with sensitivities of 95.24% or 78.57%, respectively. Conclusions: Our results demonstrate that MN-DNA from 1-2mL peripheral blood enable accurate detection of GC, especially in early GC. As a type of cytoplasmic DNA, MN-DNA can provide a valuable tool for early cancer detection, offering different underlying mechanisms compared to current methods. Research sponsor: Timing Biotech. Citation Format: Yuehua Han, Xingyun Yao, Haobo Sun, Cheng Fang, Peiwei Li, Honghao Liang, Jie Jin, Xiaofei Gao. Detection of early gastric carcinoma by micronuclei DNA from erythrocytes [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr B075.

Application of functional magnetic resonance imaging to evaluate renal structure and function in type 2 cardiorenal syndrome

BackgroundThere is a lack of diagnostic non-invasive imaging technology for assessing the early structural and functional changes of the kidney in type 2 cardiorenal (CRS) patients. This study aims to explore the value of intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) for clinical application in type 2 CRS patients, to provide imaging markers for the assessment of kidney damage.MethodsThis is a retrospective observational clinical study conducted in Nanjing, China. The clinical characteristics, including age, gender, medical history, laboratory results, and ultrasound and magnetic resonance imaging results were collected from the electronic medical record. Thirty-one patients with type 2 CRS, 20 patients with chronic heart failure (HF) and 20 healthy controls were enrolled and divided into type 2 CRS, HF and control groups. All the participants underwent magnetic resonance imaging (MRI) scanning. The apparent diffusion coefficient (ADC) value and IVIM-DWI parameters including true diffusion coefficient (D), pseudodiffusion coefficient (D*), and perfusion fraction (f) were obtained. The correlation between estimated glomerular filtration rate (eGFR), renal size and imaging parameters was evaluated by Spearman correlation analysis.ResultsADC and D of the renal cortex in patients with type 2 CRS were lower than those in the healthy control group. ADC and f in the HF group were lower than those in the control group. D was positively correlated with the length (r = 0.3752, P = 0.0013) and transverse diameter (r = 0.3258, P = 0.0056) of the kidney. ADC (r = 0.2964, P = 0.0121) and D (r = 0.3051, P = 0.0097) were positively correlated with eGFR. Renal cortical ADC and D values could distinguish type 2 CRS patients from the healthy controls with area under the curve (AUC) of 0.723 and 0.706, respectively.ConclusionThe ADC and D values were not only correlated with renal function, but also had lower levels in type 2 CRS. The IVIM-DWI parameter D was also related to kidney size, but further research is needed to determine whether it can be used as a novel imaging marker for type 2 CRS.

Non-invasive vagus nerve stimulation in anti-inflammatory therapy: mechanistic insights and future perspectives.

Non-invasive vagus nerve stimulation (VNS) represents a transformative approach for managing a broad spectrum of inflammatory and autoimmune conditions, including rheumatoid arthritis and inflammatory bowel disease. This comprehensive review delineates the mechanisms underlying VNS, emphasizing the cholinergic anti-inflammatory pathway, and explores interactions within the neuro-immune and vagus-gut axes based on both clinical outcomes and pre-clinical models. Clinical applications have confirmed the efficacy of VNS in managing specific autoimmune diseases, such as rheumatoid arthritis, and chronic inflammatory conditions like inflammatory bowel disease, showcasing the variability in stimulation parameters and patient responses. Concurrently, pre-clinical studies have provided insights into the potential of VNS in modulating cardiovascular and broader inflammatory responses, paving the way for its translational application in clinical settings. Innovations in non-invasive VNS technology and precision neuromodulation are enhancing its therapeutic potential, making it a viable option for patients who are unresponsive to conventional treatments. Nonetheless, the widespread adoption of this promising therapy is impeded by regulatory challenges, patient compliance issues, and the need for extensive studies on long-term efficacy and safety. Future research directions will focus on refining VNS technology, optimizing treatment parameters, and exploring synergistic effects with other therapeutic modalities, which could revolutionize the management of chronic inflammatory and autoimmune disorders.

Systematic Review and Meta-Analysis of Thermal Stress Assessment in Poultry Using Infrared Thermography in Specific Body Areas.

Thermal stress is a health and welfare concern in the poultry industry. Poultry have specific thermoregulation strategies for heat stress (i.e., vasodilatation) or cold stress (i.e., vasoconstriction). Infrared thermal (IRT) analysis is a non-invasive temperature assessment technology with significant benefits compared to conventional temperature measurements, which are invasive and time-consuming. However, a wide range of IRT methodologies and equipment are used for temperature assessment in poultry. The aim of this study was to perform a systematic review and meta-analysis of IRT applications in poultry undergoing thermal stress. The bibliographic search yielded 17 records for qualitative synthesis and 10 for quantitative analysis. The results showed IRT is more commonly studied during heat stress than cold stress, and more research is being conducted on laying hens than other poultry species. Also, four body areas (parts of the head, body, face, and leg) were identified as common areas of interest for body surface temperature measurement. There is a clear thermoregulation response to thermal stress in poultry, with marked differences between featherless and feather-covered areas. IRT in poultry undergoing thermal stress has a good diagnostic value and represents an important welfare assessment tool for future research, particularly when combined with other welfare assessment methods.

Quercetin Alleviates Scleral Remodeling Through Inhibiting the PERK-EIF2α Axis in Experiment Myopia.

This study aims to investigate the effect of quercetin (QUE) on scleral remodeling by inhibiting the PERK-EIF2α signaling pathway and to evaluate its potential role in slowing myopia. Lens-induced myopia (LIM) guinea pigs were obtained and treated with QUE. After 4 and 6 weeks of treatments, ocular biological measurements were conducted. Hematoxylin and eosin (H&E) staining was used to observe the changes in scleral morphology and thickness, and Masson staining was used to examine scleral collagen fiber arrangement. Quantitative PCR (qPCR) and Western bolt were utilized to detect the mRNA and protein expression of PERK, EIF2α, MMP-2, TIMP-2, and collagen I in the scleral tissues. Calcium ion flow in each group was measured using noninvasive micro-test technology, and reactive oxygen species levels were detected by flow cytometry. Compared with the LIM group, the ocular measurements showed that the refractive errors and axial length of the eyes were significantly reduced in the LIM+QUE group (P < 0.01). H&E and Masson staining showed that sclera in the LIM+QUE group was thickened, collagen was dense, and the fiber gap was reduced. In the LIM+QUE group, the expression levels of PERK, EIF2α, and MMP-2 were decreased, whereas the expression levels of TIMP-2 and collagen I were increased. Calcium release and reactive oxygen species (ROS) in the LIM+QUE group were decreased. Quercetin ameliorates scleral remodeling in myopic guinea pigs by inhibiting the PERK-EIF2α signaling pathway, thereby alleviating the progression of myopia. These findings provide new experimental evidence for the potential application of quercetin in myopia prevention and treatment.

Environmental challenge trials induce a biofluorescent response in the green sea urchin Strongylocentrotus droebachiensis

Stress in sea urchins leads to high mortality and economic losses in both the environment and aquaculture. The green sea urchin Strongylocentrotus droebachiensis has been documented emitting complex biofluorescence, yet how this responds to external stressors is unknown. Adult sea urchins (n = 210) were divided between control (n = 30) and experimental groups (n = 180), using three transport variables: out of water, in water at elevated temperatures, (warm-water) and in water at seawater temperature (cold-water). Hyperspectral imaging of external fluorescence and fluorospectrometric analysis on coelomic fluid was measured at five intervals (hour 0,3,6,9,12). External green emissions (∼580 nm) responded to all treatments, peaking at h9. External red emissions (∼680–730 nm) in the cold-water remained low until an h9 peak. The warm water increased emissions at each interval, peaking at h9. The out of water gradually increased, with the highest at h12. The coelomic fluid fluorescence (∼680 nm) was low to nonexistent except in warm-water, whose elevated levels suggest that fluorescent emissions are a measurable byproduct of internal adaptation(s) to stress. Early detection of fluorescent emissions (broken spines, lesions) may prevent economic losses. The observed link between fluorescence and the applied stressors provides a baseline for developing non-invasive technology for improving echinoderm welfare.

Could point-of-care bioimpedance analysis be another tool in the prevention of osteoporotic fractures?

A treatment gap exists in osteoporosis, with people at risk of fracture often not identified. Dual X-Ray Absorptiometry is the gold standard technique for the identification of low bone mass, but it is not always easily accessible. Bioimpedance analysis (BIA) is a non-invasive, safe and portable technology, which can provide a calculated estimate of bone mass. However, the validity of using BIA in the assessment of bone health is largely unknown. The objective of this study was to examine BIA-derived bone mass (BBM) data from a local population, with the aim of exploring its potential for use as a preliminary osteoporosis screening tool.A convenience sample of 124 participants (40 males, 84 females) was recruited from the local population. BIA was performed on participants according to standard procedures. BBM data was analysed in relation to weight, height, sex, age and BMI. Data was analysed using ANOVA, hierarchial regression, and bivariate correlation as appropriate.Weight was strongly associated with BBM (R2 = 0.637, p < 0.001), providing the greatest contribution to variance, of the factors examined. BBM was also positively associated with height, in a model that included weight (ΔR2 = 0.218, p < 0.001). Females had a significantly lower bone mass than males, independent of weight and height (ΔR2 = 0.055, p < 0.001). There was a small negative association of BBM with age, in a model that included weight and sex (ΔR2 = 0.011; p = 0.002). A positive correlation between BMI and BBM was found in both males (rs(38) = 0.482, p = 0.002), and females (rs(82) = 0.565, p < 0.001). The finding that BBM values are associated with factors known to be relevant to fracture risk, provides a rationale to perform further studies to investigate if BBM values could have validity for point-of-care assessment of bone health.

Counterillumination reduces bites by Great White sharks.

In the open ocean, achieving camouflage is complicated by the fact that the downwelling light is generally much brighter than the upwelling light, which means that any object, even if its ventral surface is white due to countershading, will appear as a dark silhouette when viewed from below.1,2,3 To overcome this, many marine species employ counterillumination, whereby light is emitted from photophores on their ventral surface to replace the downwelling light blocked by their body.4,5,6 However, only a single behavioral study has tested the efficacy of counterillumination as an anti-predation strategy.7 Counterillumination is predicted to be particularly useful against predators that have poor visual acuity and lack color vision,8 like the Great White shark (Carcharodon carcharias), the species responsible for most human shark-bite fatalities globally.9 Here, we take inspiration from nature to show that counterillumination can prevent Great White sharks from attacking artificial seal decoys. Using seal decoys fitted with LED lights and towed behind a boat, we explored the efficiency of different light configurations on the deterrence effect, showing that visual shape and motion cues are critical for prey recognition by Great White sharks. Counterillumination that is brighter than the background is most effective in deterring sharks, implying that, in this context, counterillumination works through disruptive camouflage rather than background matching. Our results reveal the importance of a dark silhouette against a lighter background in predatory behavior in Great White sharks and that altering the silhouette may form the basis of new non-invasive shark deterrent technology to protect human life. VIDEO ABSTRACT.