Blood Oxygen Research Articles

A broadband hyperspectral image sensor with high spatio-temporal resolution.

Hyperspectral imaging provides high-dimensional spatial-temporal-spectral information showing intrinsic matter characteristics1-5. Here we report an on-chip computational hyperspectral imaging framework with high spatial and temporal resolution. By integrating different broadband modulation materials on the image sensor chip, the target spectral information is non-uniformly and intrinsically coupled to each pixel with high light throughput. Using intelligent reconstruction algorithms, multi-channel images can be recovered from each frame, realizing real-time hyperspectral imaging. Following this framework, we fabricated a broadband visible-near-infrared (400-1,700 nm) hyperspectral image sensor using photolithography, with an average light throughput of 74.8% and 96 wavelength channels. The demonstrated resolution is 1,024 × 1,024 pixels at 124 fps. We demonstrated its wide applications, including chlorophyll and sugar quantification for intelligent agriculture, blood oxygen and water quality monitoring for human health, textile classification and apple bruise detection for industrial automation, and remote lunar detection for astronomy. The integrated hyperspectral image sensor weighs only tens of grams and can be assembled on various resource-limited platforms or equipped with off-the-shelf optical systems. The technique transforms the challenge of high-dimensional imaging from a high-cost manufacturing and cumbersome system to one that is solvable through on-chip compression and agile computation.

THE ROLE OF BRONCHOSCOPY IN INTENSIVE CARE MEDICINE, CASE REPORT

Purpose. Airway maintenance, adequate ventilation, and pulmonary gas exchange are crucial for critically ill patients. The challenges of performing in intensive care patients often differ significantly from routine surgical procedures in the operating room. The aim of our study was to assess the effectiveness of bronchoscopic aspiration in improving respiratory function in a patient on prolonged artificial ventilation. Material/Methods. A 69-year-old male was admitted to the ICU six days after an open cystoprostatectomy, presenting with respiratory failure. Initial treatment included blind airway suctioning, nebulization, chest physiotherapy, and empirical antibiotics. Due to persistent atelectasis and respiratory failure, bronchoscopic aspiration was performed. A total of nine bronchoscopies with bronchoalveolar lavage (BAL) were conducted for aspiration and microbiological testing, guiding adjustments in antibiotic therapy. After 61 days in the ICU, the patient was transferred to the Department of Urology and later discharged. Results. Bronchoscopic aspiration significantly improved the patient's condition, with noticeable improvements after the first bronchoalveolar lavage (BAL). Pulmonary imaging on X-ray and blood oxygenation showed clear progress, with better lung function and enhanced ventilation parameters. These changes allowed for a reduction in oxygen concentration and improved gas exchange. After 61 days in the ICU, the patient was successfully transferred to the Department of Urology and later discharged in stable condition. Conclusions. Bronchoscopic aspiration is a highly effective method for improving ventilation and oxygenation in patients on prolonged mechanical ventilation. It plays a crucial role in managing airway obstructions atelectasis, and enhancing microbiological diagnostics.

Interpretable prediction of 30-day mortality in patients with acute pancreatitis based on machine learning and SHAP.

Severe acute pancreatitis (SAP) can be fatal if left unrecognized and untreated. The purpose was to develop a machine learning (ML) model for predicting the 30-day all-cause mortality risk in SAP patients and to explain the most important predictors. This research utilized six ML methods, including logistic regression (LR), k-nearest neighbors(KNN), support vector machines (SVM), naive Bayes (NB), random forests(RF), and extreme gradient boosting(XGBoost), to construct six predictive models for SAP. An extensive evaluation was conducted to determine the most effective model and then the Shapley Additive exPlanations (SHAP) method was applied to visualize key variables. Utilizing the optimized model, stratified predictions were made for patients with SAP. Further, the study employed multivariable Cox regression analysis and Kaplan-Meier survival curves, along with subgroup analysis, to explore the relationship between the machine learning-based score and 30-day mortality. Through LASSO regression and recursive feature elimination (RFE), 25 optimal feature variables are selected. The XGBoost model performed best, with an area under the curve (AUC) of 0.881, a sensitivity of 0.5714, a specificity of 0.9651 and an F1 score of 0.64. The first six most important feature variables were the use of vasopressor, high Charlson comorbidity index, low blood oxygen saturation, history of malignant tumor, hyperglycemia and high APSIII score. Based on the optimal threshold of 0.62, patients were divided into high and low-risk groups, and the 30-day survival rate in the high-risk group decreased significantly. COX regression analysis further confirmed the positive correlation between high-risk scores and 30-day mortality. In the subgroup analysis, the model showed good risk stratification ability in patients with different gender, renal replacement therapy and with or without a history of malignant tumor, but it was not effective in predicting peripheral vascular disease. the XGBoost model effectively predicts the severity of SAP, serving as a valuable tool for clinicians to identify SAP early.

Construction and validation of a clinical prediction model for sepsis using peripheral perfusion index to predict in-hospital and 28-day mortality risk.

Sepsis is a clinical syndrome caused by infection, leading to organ dysfunction due to a dysregulated host response. In recent years, its high mortality rate has made it a significant cause of death and disability worldwide. The pathophysiological process of sepsis is related to the body's dysregulated response to infection, with microcirculatory changes serving as early warning signals that guide clinical treatment. The Peripheral Perfusion Index (PI), as an indicator of peripheral microcirculation, can effectively evaluate patient prognosis. This study aims to develop two new prediction models using PI and other common clinical indicators to assess the mortality risk of sepsis patients during hospitalization and within 28 days post-ICU admission. This retrospective study analyzed data from sepsis patients treated in the Intensive Care Unit of Peking Union Medical College Hospital between December 2019 and June 2023, ultimately including 645 patients. LASSO regression and logistic regression analyses were used to select predictive factors from 35 clinical indicators, and two clinical prediction models were constructed to predict in-hospital mortality and 28-day mortality. The models' performance was then evaluated using ROC curve, calibration curve, and decision curve analyses. The two prediction models performed excellently in distinguishing patient mortality risk. The AUC for the in-hospital mortality prediction model was 0.82 in the training set and 0.73 in the validation set; for the 28-day mortality prediction model, the AUC was 0.79 in the training set and 0.73 in the validation set. The calibration curves closely aligned with the ideal line, indicating consistency between predicted and actual outcomes. Decision curve analysis also demonstrated high net benefits for the clinical utility of both models. The study shows that these two prediction models not only perform excellently statistically but also hold high practical value in clinical applications. The models can help physicians accurately assess the mortality risk of sepsis patients, providing a scientific basis for personalized treatment.

Cerebrovascular reactivity and response times describe recent ischemic symptomatology in patients with moyamoya

Abstract Moyamoya is a non-atherosclerotic intracranial steno-occlusive condition that places patients at high risk for ischemic stroke. Randomized trials of surgical revascularization demonstrating efficacy in ischemic moyamoya have not been performed, and as such, biomarkers of parenchymal hemodynamic impairment are needed to assist with triage and evaluate post-surgical response. In this prospective study, we test the hypothesis that parenchymal cerebrovascular reactivity (CVR) metrics in response to a fixed-inspired 5% carbon dioxide challenge correlate with recent focal ischemic symptoms. Hypercapnic reactivity blood oxygenation level-dependent (BOLD) MRI (echo time=35ms; spatial resolution=3.5x3.5x3.5mm) and catheter angiography assessments of cortical reserve capacity and vascular patency, respectively, in moyamoya disease and syndromic participants (n=73) were performed in sequence. Cerebrovascular reactivity uncorrected for response time (CVRRAW) was quantified, and time regression analyses were applied to quantify maximum cerebrovascular reactivity (CVRMAX) and cerebrovascular reactivity response time (CVRDELAY). Symptomatology was categorized by a stroke neurologist by hemisphere: symptomatic (lateralizing ischemic symptoms < 6 months) or asymptomatic (no ischemic symptom history). Values are presented as median [interquartile range]; logistic regression assessed the association of cerebrovascular reactivity metrics with symptoms, controlling for age and sex. A total of 109 hemispheres, including 39 symptomatic and 70 asymptomatic hemispheres, met inclusion criteria. Symptomatic hemispheres displayed reduced CVRRAW (p<0.01) (symptomatic=0.45 [0.28-0.70] z-statistic/ΔEtCO2 vs. asymptomatic=0.67 [0.44-0.98] z-statistic/ΔEtCO2), lengthened CVRDELAY (p<0.001) (symptomatic=47.6 [37.7-57.0] seconds vs. asymptomatic=37.7 [30.4-46.4] seconds), and reduced CVRMAX (p=0.037) (symptomatic=1.31 [0.99-1.94] z-statistic/ΔEtCO2 vs. asymptomatic=1.64 [1.29-2.12] z-statistic/ΔEtCO2). CVRDELAY (p<0.001) was found to be significantly related to age in asymptomatic hemispheres (0.33-unit increase/year). Of assessed measures, the receiver operating characteristic curves suggest that CVRDELAY is associated most closely with recent ischemic symptoms (p<0.001). Findings support that cerebrovascular reactivity metrics are uniquely altered in hemispheres with recent ischemic symptoms, further motivating their utilization as biomarkers of ischemic symptomatology and potential treatment efficacy in moyamoya disease and syndrome.

Stimulus-induced rotary saturation imaging of visually evoked response: A pilot study.

Spin-lock (SL) pulses have been proposed to directly detect neuronal activity otherwise inaccessible through standard functional magnetic resonance imaging. However, the practical limits of this technique remain unexplored. Key challenges in SL-based detection include ultra-weak signal variations, sensitivity to magnetic field inhomogeneities, and potential contamination from blood oxygen level-dependent effects, all of which hinder the reliable isolation of neuronal signals. This pilot study evaluates the performance of the stimulus-induced rotary saturation (SIRS) technique to map visual stimulation response in the human cortex. A rotary echo spin-lock (RESL) preparation followed by a 2D echo planar imaging readout was used to investigate 12 healthy subjects at rest and during continuous exposure to 8Hz flickering light. The SL amplitude was fixed to the target neuroelectric oscillations at that frequency. The signal variance was used as contrast metric, and two alternative post-processing pipelines (regression-filtering-rectification and normalized subtraction) were statistically evaluated. Higher variance in the SL signal was detected in four of the 12 subjects. Although group-level analysis indicated activation in the occipital pole, analysis of variance revealed that this difference was not statistically significant, highlighting the need for comparable control measures and more robust preparations. Further optimization in sensitivity and robustness is required to noninvasively detect physiological neuroelectric activity in the human brain.

Efficacy of Cytoreg in the treatment of diabetic foot disease.

Complications from diabetic foot wounds, including bacterial infection, ulceration and gangrene, are major causes of hospitalisation and are responsible for 85% of amputations in patients with diabetes. Given that orally administered investigational therapeutic Cytoreg (Cytorex de Venezuela SA, Venezuela), a defined aqueous mixture of hydrofluoric, hydrochloric, sulfuric, phosphoric, citric and oxalic acids, has been shown to increase levels of arterial blood oxygen in a Wistar rat model, oral and oral+topical Cytoreg were tested on patients with diabetic foot ulcers (DFUs) under a humanitarian, compassionate-use protocol. All patients received oral Cytoreg (5.0 ml concentrate in fruit juice) for 30 days; half also received weekly wound washing with Cytoreg concentrate in isotonic saline (1:50 volume/volume) (oral+topical group). In addition to standard clinical observations, wounds were monitored against the Saint Elian checklist system for the diabetic foot. A total of 10 patients took part in the study. Complete wound closure was observed in 4/5 patients in the oral+topical group; in the remaining patient, necrotic and fibrin tissues on the wound edges were eliminated. Half (2/4) of the patients receiving oral-only Cytoreg experienced complete wound closure; one patient in this group was removed prematurely because of an unrelated illness and was not replaced. During the study, no significant differences were observed between groups in either the oxygen saturation of the affected tissues or in insulin and glycaemia levels (p<0.05). Significant increases in arterial haemoglobin and arterial oxygen partial pressure (p<0.05) were observed, and significant decreases were measured in the levels of glycosylated haemoglobin, aspartate aminotransferase, glutamic-pyruvic transaminase, creatine and urea (p<0.05). The results of this study justify an expanded clinical study for the treatment of DFUs with Cytoreg.

Quantitative BOLD (qBOLD) imaging of oxygen metabolism and blood oxygenation in the human body: A scoping review.

There are many approaches to the quantitative BOLD (qBOLD) technique described in the literature, differing in pulse sequences, MRI parameters and data processing. Thus, in this review, we summarized the acquisition methods, approaches used for oxygenation quantification and clinical populations investigated. Three databases were systematically searched (Medline, Embase, and Web of Science) for published research that used qBOLD methods for quantification of oxygen metabolism. Data extraction and synthesis were performed by one author and reviewed by a second author. A total of 93 relevant papers were identified. Acquisition strategies were summarized, and oxygenation parameters were found to have been investigated in many pathologies such as steno-occlusive diseases, stroke, glioma, and multiple sclerosis disease. A summary of qBOLD approaches for oxygenation measurements and applications could help researchers to identify good practice and provide objective information to inform the development of future consensus recommendations.

Internet based highly secure data transmission system in health care monitoring system

&lt;span&gt;The health care systems in our contemporary countries are advancing rapidly in terms of maturity and professionalism. In an effort to alleviate the current burden on the public health system and boost the popularity of regular health self-checks, this method has been developed for producing prediagnoses that are easier to use, quicker, and more accurate. To ascertain how well the heart is circulating oxygen throughout the body, a pulse test, a painless examination that measures an individual's degree of oxygen saturation, is used. It can be used to evaluate the state of any patient with a disease, particularly those with pulmonary problems. Diseases in these patients could need ongoing observation and care. Our system comes to the rescue in order to resolve this problem. This portable system is simple to use and may be taken anywhere by the subject. The internet of things (IoT) will update the pertinent parameters. This health monitoring system's controller is made up of an adaptor, a saturation of peripheral oxygen (SPO2 ) sensor (a blood oxygen meter), a temperature sensor, a heart rate sensor, a WiFi module, and a liquid crystal display (LCD).&lt;/span&gt;

Prefrontal cortex engagement during an fMRI task of emotion regulation as a potential predictor of treatment response in borderline personality disorder.

Borderline personality disorder (BPD) is a severe mental illness, with high rates of co-morbid depression and suicidality. Despite the importance of optimizing treatment in BPD, little is known about how neural processes relate to individual treatment response. This study examines how baseline regional brain blood oxygen level dependent (BOLD) activation during a functional magnetic resonance imaging (fMRI) task of emotion regulation is related to treatment response following a six-month randomized clinical trial of Dialectical Behavior Therapy (DBT) or Selective Serotonin Reuptake Inhibitor (SSRI) treatment. Unmedicated females with BPD (N = 37), with recent suicidal behavior or self-injury, underwent an fMRI task in which negative personal memories were presented and they were asked to distance (i.e., downregulate their emotional response) or immerse (i.e., experience emotions freely). Patients were then randomized to DBT (N = 16) or SSRI (N = 21) treatment, with baseline and post-treatment depression and BPD severity assessed. BOLD activity in prefrontal cortex, anterior cingulate, and insula was associated with distancing. Baseline BOLD during distancing in dorsolateral, ventrolateral, and orbital prefrontal cortex (dlPFC, vlPFC, OFC) differentially predicted depression response across treatment groups, with higher activity predicting better response in the SSRI group, and lower activity predicting better response in the DBT group. All female samples. Findings indicate that greater prefrontal engagement during emotion regulation may predict more antidepressant benefit from SSRIs, whereas lower engagement may predict better response to DBT. These results suggest different mechanisms of action for SSRI and DBT treatment, and this may allow fMRI to guide individualized treatment selection.

Usefulness of perfusion index derived parameters in dogs undergoing interventional cardiology

Usefulness of perfusion index derived parameters in dogs undergoing interventional cardiology

Changes in portal pulsatility index induced by a fluid challenge in patients with haemodynamic instability and systemic venous congestion: a prospective cohort study

BackgroundIt is uncertain whether fluid administration can improve patients with systemic venous congestion and haemodynamic instability. This study aimed to describe the changes in systemic venous congestion and peripheral perfusion parameters induced by a fluid challenge in these patients, and to analyse the influence of the fluid responsiveness status on these changes.MethodsThe study is a single-centre prospective cohort study of 36 critically ill ICU patients with haemodynamic instability and a maximum vena cava diameter ≥ 20 mm. Changes in cardiac index during a fluid challenge (4 mL/kg of lactated Ringer’s solution during 5 min) assessed by pulse contour analysis, central venous pressure, ultrasound systemic congestion parameters (portal venous flow pulsatility index, supra hepatic and intrarenal venous Doppler), and peripheral perfusion parameters (capillary refill time and peripheral perfusion index) were assessed in the overall population. All these data were compared between patients presenting a cardiac index increase > 10% during the fluid challenge (fluid responders) and the others (fluid non-responders).ResultsTwenty-eight (78%) patients were admitted for postoperative care following cardiac surgery; their mean ± SD left ventricular ejection fraction was 42 ± 9% and right ventricular dysfunction was found in at least 61% of the patients. The mean ± SD SOFA score was 9 ± 3. Thirteen (36%) patients were fluid responders. The fluid challenge administration induced a significant increase in portal pulsatility index, VExUS score, and central venous pressure without significant difference of these changes between fluid responders and non-responders. No significant change in perfusion parameters was observed.ConclusionFluid administration in patients with haemodynamic instability and systemic venous congestion worsens venous congestion regardless of the fluid responsiveness status, without improving perfusion parameters.

Normal Value of Perfusion Index in Healthy Neonates Born in Iran

Normal Value of Perfusion Index in Healthy Neonates Born in Iran

Suratentorial Tümör Cerrahisinde %20 Mannitol ve %3 Hipertonik Salin Kullanımlarının Beyin Relaksasyonu, Hemodinamik Parametreler, Serum Osmolaritesi ve Elektrolitleri Üzerine Etkilerinin Değerlendirilmesi

Objective: Different drugs or methods can be applied to provide brain relaxation in supratentorial tumor surgery. In our study, we aimed to evaluate effects of 20% Mannitol and 3% Hypertonic Saline (HS) used during supratentorial tumor surgery on brain relaxation, hemodynamic parameters, urine flow, fluid volume, pulse pressure variability (PPV), pleth variability index (PVI), serum osmolarity and electrolytes. Methods: The study included 60 patients aged 18-65 years, ASA I-II class, who were scheduled to undergo supratentorial tumor surgery. General anesthesia was administered with sevoflurane and remifentanil to achieve a state entropy of 40-60. Patients were allocated into two groups, with Group Mannitol receiving 20% mannitol (2.5 mL kg-1) and Group Hypertonic Saline receiving 3% HS (2.5 mL kg-1). In all patients, PPV and PVI values were planned to be ≤13%. After the dura was opened, brain relaxation scores were evaluated. Perioperative hemodynamic variables, blood gases, PVI, PPV values were recorded. Na+, K+ values, urine volume and administered fluid were recorded at 30, 45 and 60 minutes and 2-3 hours after the end of the infusion. Preoperative and postoperative BUN, creatinine and osmolarity values were recorded. Results: No statistical difference was found between demographic characteristics, brain relaxation and hemodynamic data. In HS group, PVI and PPV values were higher than Mannitol group from the beginning of infusion. In mannitol group, urine and administered fluid amounts were higher. Decrease in Na+ values was detected with Mannitol and increase with HS. It was determined that BUN and creatinine values were similar, serum osmolarity did not change at postoperative period in mannitol group and increased HS. Average intensive care and length of hospital stay were similar. Conclusion: In supratentorial tumor surgery, effective brain relaxation was achieved with Mannitol and HS, without affect to hemodynamics. Pulse pressure variability and PVI decreased with Mannitol. Blood gases, Na+, K+, BUN creatinine, osmolarity levels did not show serious changes. It was concluded that HS could be an alternative to mannitol in supratentorial surgery. Keywords: Hypertonic saline,mannitol, serum osmolarity, supratentorial tumor surgery

Vision Disturbance (not vision loss) following Epinephrine Injection

Patients with severe acute respiratory distress syndrome require supportive treatment with mechanical ventilation with or without extracorporeal membrane oxygenation to maintain optimal oxygenation. Persistent inefficient blood oxygenation can be related to severity of clinical presentation, technical issues, or concomitant diseases. In this case report, man previously suffering from chronic myeloid leukemia received extracorporeal membrane oxygenation for influenza A virus subtype H1N1. Despite invasive oxygenation therapy, it was not possible to achieve amelioration of arterial blood oxygenation. After a differential diagnosis, pathological hyperleukocytosis was identified as a potential reason of oxygenation impairment, which improved after introduction of concomitant chemotherapy that lowered leukocytes count.

CMOS Pulse Oximeter

Abstract: This paper presents the design and implementation of a non-invasive pulse oximeter based on Complementary MetalOxide-Semiconductor (CMOS) technology, aimed at enhancing the accuracy and accessibility of blood oxygen saturation measurements. Pulse oximetry is a critical tool in clinical and personal health monitoring, providing vital information about respiratory function. The integration of CMOS technology allows for miniaturization and energy efficiency, facilitating the development of compact, wearable devices capable of continuous monitoring. The proposed system utilizes advanced signal processing techniques, including lock-in detection and dual-wavelength illumination, to improve the reliability of photoplethysmographic (PPG) signal acquisition under various conditions. Experimental validation demonstrates the device's capability to deliver accurate SpO2 readings even in the presence of motion artifacts and ambient light interference. Furthermore, the calibration methods employed ensure that measurements are consistent and precise across different users. By leveraging the advantages of CMOS technology, this study not only highlights the potential for improved patient comfort and compliance but also opens new avenues for the application of pulse oximetry in diverse environments. The findings underscore the effectiveness of CMOS-based pulse oximeters in advancing non-invasive health monitoring solutions, ultimately contributing to enhanced patient care and outcomes.

Spirometry Results in Children over Five Years Old with COVID-19 at Least Six Months after Discharge

Introduction: Since it is necessary to detect changes in lung function for the follow-up of the patients with respiratory and functional complications caused by COVID-19, in this study, we decided to examine the results of spirometry in children over 5 years old with Covid-19. Methods: In this cross-sectional study, 52 over-five-year-old children, hospitalized due to COVID-19 for at least six past months, were examined. The participants’ demographic information, respiratory symptoms, underlying diseases, severity of COVID-19 according to WHO, severity of lung involvement in CT scan, type of lung involvement, oxygen saturation at admission as well as FEV1, FVC, and FEV1/FVC were collected and analyzed, the results were analyzed using SPSS version 16 software and t-test and Chi-square tests. Results: Of all investigated patients،, 26 were boys (50%) and 38 (73.1%) were 5-12 years old. The minimum age of the children was 5 years and the maximum was 18 years. The mean age of children was 3.41±10 years. The FEV1/FVC ranged from 61% to 79% in five patients (9.6%) and from 80% to 100% in 47 patients (90.4%). The FEV1 was lower than 80% in 28 and higher than 80% in 24 patients. FEV1/FVC had no significant relationship with the participants’ age, gender, clinical manifestations, and disease severity in terms of pulmonary involvement, but it had a significant association with blood oxygen saturation level (P: 0.001). Conclusion: The changes in pulmonary function tests vary in different months following contamination with COVID-19. In the present study, 9% of the patients, who were examined in the sixth month after infection, had abnormal pulmonary function test results. Based on the findings, the pulmonary function test results had no significant relationship with the patients’ age, gender, and clinical symptoms, while it was significantly associated with their blood oxygen saturation intensity.

Smart Compression Sock for Early Detection of Diabetic Foot Ulcers

The prevention of diabetic foot ulcers remains a critical challenge. This study evaluates a smart compression sock designed to address this issue by integrating temperature, plantar pressure, and blood oxygen sensors and monitoring data recorded by these sensors. The smart sock, developed with input from a certified Pedorthist, was tested on 20 healthy adult participants aged 16 to 53. It includes four temperature sensors and pressure sensors at common ulcer sites (first and fifth metatarsal heads, calcaneus, and hallux), and a blood oxygen sensor on the hallux. The sensors are monitored, and their transduced data are collected and stored through an app installed on a personal cell phone. The mobile app interface is user-friendly, providing intuitive navigation and easy access to the sensors’ data. Using repeated measures ANOVA and post hoc tests, we analyzed the impact of various physical activities on physiological changes in the foot. The device effectively detected significant variations in blood oxygen, temperature, and pressure across six activities. Statistical analyses revealed significant differences based on activity type and sensor location. These results highlight the smart sock’s sensitivity and accuracy, suggesting its potential to prevent diabetic foot ulcers. Further clinical trials are needed to evaluate its efficacy in a larger, more diverse population.

Effects of FOLFOX Chemotherapy on Tumor Oxygenation and Perfused Vasculature: An InVivo Study by OpticalTechniques.

The effects of cytotoxic chemotherapy on tumor vasculature and oxygenation are in the focus of modern investigations becausevascular structure and distribution of oxygen influence tumor behavior and treatment response. The aim of ourstudywas to monitor changes in the vascular component of colorectal tumor xenografts induced by a clinical combination of chemotherapy drugs FOLFOX invivo using two complementary techniques: diffuse reflectance spectroscopy (DRS) and optical coherence tomography-based microangiography (OCT-MA). These techniques revealed a slower decrease in tumor blood oxygenation in treated tumors as compared to untreated ones, faster suppression of tumor vasculature perfusion and increase in water content as a result of treatment, and decrease in total hemoglobin in untreated tumors. Immunohistochemical analysis of hypoxia-inducible factor HIF-2α detected tissue hypoxia as a consequence of inappropriate oxygen supply in the treated tumors. The obtained results show the prospects for monitoring of treatment efficacy using DRS and OCT-MA.

The Relative Indirect Effects of Technology Bias and Implicit Bias on Racial Disparity in Service Delivery and Sepsis Mortality

Racism at the individual and societal levels has been identified as a cause of disparity in healthcare outcomes in the United States but reducing disparity has been slow. This study disentangles the relative effects of two types of racism on inpatient service delivery and hospital mortality: technology bias and implicit bias. Drawing on clinical data from intensive care unit (ICU) patients with sepsis, we use propensity score matching to balance groups of White and nonwhite patients and run a causal mediation analysis to test our model, which links patient race to hospital mortality through two mediating variables related to service delivery: (1) discrepancies in blood oxygen saturation measurements due to technology bias embedded in the medical device (i.e., pulse oximeter) and (2) administration of supplemental oxygen, which could be impacted by clinicians’ implicit bias. We first replicate prior findings that (a) higher discrepancies between oximeter readings and laboratory tests for nonwhite patients compared to Whites and (b) a higher discrepancy lowers the likelihood of patients receiving supplemental oxygen during the ICU stay. We make a unique contribution by finding that nonwhite patients with sepsis have a 79% higher risk of hospital mortality in the ICU compared to Whites, with nearly half of the racial disparity in mortality stemming from technology bias and less than a fifth from clinicians’ implicit bias. Eliminating these two biases would help save thousands of lives annually among racial/ethnic minorities with sepsis in the United States. Our findings indicate that technology bias exerts a greater negative impact on mortality than does implicit bias, highlighting the importance of device approval standards and clinicians' ability to customize decision criteria for supplemental oxygen.