Compact and cost-effective laser-powered speckle contrast optical spectroscopy fiber-free device for measuring cerebral blood flow.

Significance: In the realm of cerebrovascular monitoring, primary metrics typically include blood pressure, which influences cerebral blood flow (CBF) and is contingent upon vessel radius. Measuring CBF noninvasively poses a persistent challenge, primarily attributed to the difficulty of accessing and obtaining signal from the brain. Aim: Our study aims to introduce a compact speckle contrast optical spectroscopy device for noninvasive CBF measurements at long source-to-detector distances, offering cost-effectiveness, and scalability while tracking blood flow (BF) with remarkable sensitivity and temporal resolution. Approach: The wearable sensor module consists solely of a laser diode and a board camera. It can be easily placed on a subject's head to measure BF at a sampling rate of 80 Hz. Results: Compared to the single-fiber-based version, the proposed device achieved a signal gain of about 70 times, showed superior stability, reproducibility, and signal-to-noise ratio for measuring BF at long source-to-detector distances. The device can be distributed in multiple configurations around the head. Conclusions: Given its cost-effectiveness, scalability, and simplicity, this laser-centric tool offers significant potential in advancing noninvasive cerebral monitoring technologies.

A compact and cost-effective laser-powered speckle visibility spectroscopy (SVS) device for measuring cerebral blood flow.

In the realm of cerebrovascular monitoring, primary metrics typically include blood pressure, which influences cerebral blood flow (CBF) and is contingent upon vessel radius. Measuring CBF non-invasively poses a persistent challenge, primarily attributed to the difficulty of accessing and obtaining signal from the brain. This study aims to introduce a compact speckle visibility spectroscopy (SVS) device designed for non-invasive CBF measurements, offering cost-effectiveness and scalability while tracking CBF with remarkable sensitivity and temporal resolution. The wearable hardware has a modular design approach consisting solely of a laser diode as the source and a meticulously selected board camera as the detector. They both can be easily placed on a subject's head to measure CBF with no additional optical elements. The SVS device can achieve a sampling rate of 80 Hz with minimal susceptibility to external disturbances. The device also achieves better SNR compared with traditional fiber-based SVS devices, capturing about 70 times more signal and showing superior stability and reproducibility. It is designed to be paired and distributed in multiple configurations around the head, and measure signals that exceed the quality of prior optical CBF measurement techniques. Given its cost-effectiveness, scalability, and simplicity, this laser-centric tool offers significant potential in advancing non-invasive cerebral monitoring technologies.

Power Budget of a Skull Unit in a Fully-Implantable Brain-Computer Interface: Bio-Heat Model.

The aim of this study is to estimate the maximum power consumption that guarantees the thermal safety of a skull unit (SU). The SU is part of a fully-implantable bi-directional brain computer-interface (BD-BCI) system that aims to restore walking and leg sensation to those with spinal cord injury (SCI). To estimate the SU power budget, we created a bio-heat model using the finite element method (FEM) implemented in COMSOL. To ensure that our predictions were robust against the natural variation of the model's parameters, we also performed a sensitivity analysis. Based on our simulations, we estimated that the SU can nominally consume up to 70 mW of power without raising the surrounding tissues' temperature above the thermal safety threshold of 1°C. When considering the natural variation of the model's parameters, we estimated that the power budget could range between 47 and 81 mW. This power budget should be sufficient to power the basic operations of the SU, including amplification, serialization and A/D conversion of the neural signals, as well as control of cortical stimulation. Determining the power budget is an important specification for the design of the SU and, in turn, the design of a fully-implantable BD-BCI system.

Development and Validation of a Novel Literature-Based Method to Identify Disparity-Sensitive Surgical Quality Metrics.

BACKGROUND: Disparity in surgical care impedes the delivery of uniformly high-quality care. Metrics that quantify disparity in care can help identify areas for needed intervention. A literature-based Disparity-Sensitive Score (DSS) system for surgical care was adapted by the Metrics for Equitable Access and Care in Surgery (MEASUR) group. The alignment between the MEASUR DSS and Delphi ratings of an expert advisory panel (EAP) regarding the disparity sensitivity of surgical quality metrics was assessed. STUDY DESIGN: Using DSS criteria MEASUR co-investigators scored 534 surgical metrics which were subsequently rated by the EAP. All scores were converted to a 9-point scale. Agreement between the new measurement technique (ie DSS) and an established subjective technique (ie importance and validity ratings) were assessed using the Bland-Altman method, adjusting for the linear relationship between the paired difference and the paired average. The limit of agreement (LOA) was set at 1.96 SD (95%). RESULTS: The percentage of DSS scores inside the LOA was 96.8% (LOA, 0.02 points) for the importance rating and 94.6% (LOA, 1.5 points) for the validity rating. In comparison, 94.4% of the 2 subjective EAP ratings were inside the LOA (0.7 points). CONCLUSIONS: Applying the MEASUR DSS criteria using available literature allowed for identification of disparity-sensitive surgical metrics. The results suggest that this literature-based method of selecting quality metrics may be comparable to more complex consensus-based Delphi methods. In fields with robust literature, literature-based composite scores may be used to select quality metrics rather than assembling consensus panels.

Neural representations of economic decision variables in human posterior parietal cortex.

Decision making has been intensively studied in the posterior parietal cortex in non-human primates on a single neuron level. In humans decision making has mainly been studied with psychophysical tools or with fMRI. Here, we investigated how single neurons from human posterior parietal cortex represent numeric values informing future decisions during a complex two-player game. The tetraplegic study participant was implanted with a Utah electrode array in the anterior intraparietal area (AIP). We played a simplified variant of Black Jack with the participant while neuronal data was recorded. During the game two players are presented with numbers which are added up. Each time a number is presented the player has to decide to proceed or to stop. Once the first player stops or the score reaches a limit the turn passes on to the second player who tries to beat the score of the first player. Whoever is closer to the limit (without overshooting) wins the game. We found that many AIP neurons selectively responded to the face value of the presented number. Other neurons tracked the cumulative score or were selectively active for the upcoming decision of the study participant. Interestingly, some cells also kept track of the opponent's score. Our findings show that parietal regions engaged in hand action control also represent numbers and their complex transformations. This is also the first demonstration of complex economic decisions being possible to track in single neuron activity in human AIP. Our findings show how tight are the links between parietal neural circuits underlying hand control, numerical cognition and complex decision-making.

Disparity-Sensitive Measures in Surgical Care: A Delphi Panel Consensus.

BACKGROUND: In the US, disparities in surgical care impede the delivery of uniformly high-quality care to all patients. There is a lack of disparity-sensitive measures related to surgical care. The American College of Surgeons Metrics for Equitable Access and Care in Surgery group, through research and expert consensus, aimed to identify disparity-sensitive measures in surgical care. STUDY DESIGN: An environmental scan, systematic literature review, and subspecialty society surveys were conducted to identify potential disparity-sensitive surgical measures. A modified Delphi process was conducted where panelists rated measures on both importance and validity. In addition, a novel literature-based disparity-sensitive scoring process was used. RESULTS: We identified 841 potential disparity-sensitive surgical measures. From these, our Delphi and literature-based approaches yielded a consensus list of 125 candidate disparity-sensitive measures. These measures were rated as both valid and important and were supported by the existing literature. CONCLUSION: There are profound disparities in surgical care within the US healthcare system. A multidisciplinary Delphi panel identified 125 potential disparity-sensitive surgical measures that could be used to track health disparities, evaluate the impact of focused interventions, and reduce healthcare inequity.

Direct analysis in real time high-resolution mass spectrometry for authenticity assessment of lamb.

In comparison to more traditional methods of determining food authenticity, such as gas chromatography analysis, the primary advantages of DART-HRMS include its high speed and throughput of analysis. This study used a non-targeted metabolomics method based on real-time high-resolution mass spectrometry combined with chemometric analysis to distinguish lamb samples from four regions. Orthogonal least squares-discriminant analysis revealed a distinct difference between these four lamb regions. The potential markers were chosen based on the variable's importance in projection values, variance, and fold change. A total of 79 markers were identified using the matching chemistry database. These markers differed significantly between lambs in four regions according to heatmap analysis. The linear discriminatory analysis model had an initial classification rate of 100.0% and a cross-validation accuracy of 82.50% on the identified markers. The research demonstrates that DART-HRMS can perform a rapid authentication evaluation of lamb samples.

Data resources for evaluating the economic and financial consequences of surgical care in the United States.

ABSTRACT: Evaluating the relationship between health care costs and quality is paramount in the current health care economic climate, as an understanding of value is needed to drive policy decisions. While many policy analyses are focused on the larger health care system, there is a pressing need for surgically focused economic analyses. Surgical care is costly, and innovative technology is constantly introduced into the operating room, and surgical care impacts patients' short- and long-term physical and economic well-being. Unfortunately, significant knowledge gaps exist regarding the relationship between cost, value, and economic impact of surgical interventions. Despite the plethora of health care data available in the forms of claims databases, discharge databases, and national surveys, no single source of data contains all the information needed for every policy-relevant analysis of surgical care. For this reason, it is important to understand which data are available and what can be accomplished with each of the data sets. In this article, we provide an overview of databases commonly used in surgical health services research. We focus our review on the following five categories of data: governmental claims databases, commercial claims databases, hospital-based clinical databases, state and national discharge databases, and national surveys. For each, we present a summary of the database sampling frame, clinically relevant variables, variables relevant to economic analyses, strengths, weaknesses, and examples of surgically relevant analyses. This review is intended to improve understanding of the current landscape of data available, as well as stimulate novel analyses among surgical populations. Ongoing debates over national health policy reforms may shape the delivery of surgical care for decades to come. Appropriate use of available data resources can improve our understanding of the economic impact of surgical care on our health care system and our patients. LEVEL OF EVIDENCE: Regular Review, Level V.

Improvements and Gaps in Financial Risk Protection Among Veterans Following the Affordable Care Act.

BACKGROUND: Despite public perception, most of the nearly 20 million US veterans have health coverage outside the Veterans Health Administration (VHA), and VHA eligibility and utilization vary across veterans. Out-of-pocket healthcare spending thus remains a potential source of financial hardship for veterans. The Affordable Care Act (ACA) aimed to expand health insurance access, but its effect on veterans' financial risk protection has not been explored. OBJECTIVE: To evaluate whether ACA implementation was associated with changes in veterans' risk of catastrophic health expenditures, and to characterize drivers of catastrophic health spending among veterans post-ACA. DESIGN: Using multivariable linear probability regression, we examined changes in likelihood of catastrophic health spending after ACA implementation, stratifying by age (18-64 vs 65+), household income tercile, and payer (VHA vs non-VHA). Among veterans with catastrophic spending post-ACA, we evaluated sources of out-of-pocket spending. PARTICIPANTS: Nationally representative sample of 13,030 veterans aged 18+ from the 2010 to 2017 Medical Expenditure Panel Survey. INTERVENTION: ACA implementation, January 1, 2014. MAIN MEASURES: Likelihood of catastrophic health expenditures, defined as household out-of-pocket spending exceeding 10% of household income. KEY RESULTS: Among veterans aged 18-64, ACA implementation was associated with a 26% decrease in likelihood of catastrophic health expenditures (absolute change, -1.4 percentage points [pp]; 95% CI, -2.6 to -0.2; p=0.03), which fell from 5.4% pre-ACA to 3.9% post-ACA. This was driven by a 38% decrease in catastrophic spending among veterans with non-VHA coverage (absolute change, -1.8pp; 95% CI, -3.0 to -0.6; p=0.003). In contrast, catastrophic expenditure rates among veterans aged 65+ remained high, at 13.0% pre- and 12.5% post-ACA. Major drivers of veterans' spending post-ACA include dental care, prescription drugs, and home care. CONCLUSIONS: ACA implementation was associated with reduced household catastrophic health expenditures for younger but not older veterans. These findings highlight gaps in veterans' financial protection and areas amenable to policy intervention.

Benchtop and bedside validation of a low-cost programmable cortical stimulator in a testbed for bi-directional brain-computer-interface research.

Introduction: Bi-directional brain-computer interfaces (BD-BCI) to restore movement and sensation must achieve concurrent operation of recording and decoding of motor commands from the brain and stimulating the brain with somatosensory feedback. Methods: A custom programmable direct cortical stimulator (DCS) capable of eliciting artificial sensorimotor response was integrated into an embedded BCI system to form a safe, independent, wireless, and battery powered testbed to explore BD-BCI concepts at a low cost. The BD-BCI stimulator output was tested in phantom brain tissue by assessing its ability to deliver electrical stimulation equivalent to an FDA-approved commercial electrical cortical stimulator. Subsequently, the stimulator was tested in an epilepsy patient with subcortical electrocorticographic (ECoG) implants covering the sensorimotor cortex to assess its ability to elicit equivalent responses as the FDA-approved counterpart. Additional safety features (impedance monitoring, artifact mitigation, and passive and active charge balancing mechanisms) were also implemeneted and tested in phantom brain tissue. Finally, concurrent operation with interleaved stimulation and BCI decoding was tested in a phantom brain as a proof-of-concept operation of BD-BCI system. Results: The benchtop prototype BD-BCI stimulator's basic output features (current amplitude, pulse frequency, pulse width, train duration) were validated by demonstrating the output-equivalency to an FDA-approved commercial cortical electrical stimulator (R 2 > 0.99). Charge-neutral stimulation was demonstrated with pulse-width modulation-based correction algorithm preventing steady state voltage deviation. Artifact mitigation achieved a 64.5% peak voltage reduction. Highly accurate impedance monitoring was achieved with R 2 > 0.99 between measured and actual impedance, which in-turn enabled accurate charge density monitoring. An online BCI decoding accuracy of 93.2% between instructional cues and decoded states was achieved while delivering interleaved stimulation. The brain stimulation mapping via ECoG grids in an epilepsy patient showed that the two stimulators elicit equivalent responses. Significance: This study demonstrates clinical validation of a fully-programmable electrical stimulator, integrated into an embedded BCI system. This low-cost BD-BCI system is safe and readily applicable as a testbed for BD-BCI research. In particular, it provides an all-inclusive hardware platform that approximates the limitations in a near-future implantable BD-BCI. This successful benchtop/human validation of the programmable electrical stimulator in a BD-BCI system is a critical milestone toward fully-implantable BD-BCI systems.

The Affordable Care Act's Insurance Marketplace Subsidies Were Associated With Reduced Financial Burden For US Adults.

Research suggests that the Affordable Care Act (ACA) Medicaid expansions improved financial protection for the poor. However, evidence is limited on whether subsidies offered through the ACA Marketplaces, the law's other major coverage expansion, were associated with reduced financial burden. Using national survey data from the period 2008-17, we examined changes in household health care spending among low-income adults eligible for both Marketplace premium subsidies and cost-sharing reductions (139-250 percent of the federal poverty level) and middle-income adults eligible only for premium subsidies (251-400 percent of the federal poverty level), using high-income adults ineligible for subsidies (greater than 400 percent of the federal poverty level) as controls. Among low-income adults, Marketplace subsidy implementation was associated with 17 percent lower out-of-pocket spending and 30 percent lower probability of catastrophic health expenditures. In contrast, middle-income adults did not experience reduced financial burden by either measure. These findings highlight the successes and limitations of Marketplace subsidies as debate continues over the ACA's future.

Impact of the Affordable Care Act Insurance Marketplaces on Out-of-Pocket Spending Among Surgical Patients.

OBJECTIVE: To evaluate the association between the introduction of the Affordable Care Act (ACA) Health Insurance Marketplaces ("Marketplaces") and financial protection for patients undergoing surgery. BACKGROUND: The ACA established Marketplaces through which individuals could purchase subsidized insurance coverage. However, the effect of these Marketplaces on surgical patients' healthcare spending remains largely unknown. METHODS: We analyzed a nationally representative sample of adults aged 19-64 who underwent surgery in 2010-2017, using the Medical Expenditure Panel Survey. Low-income patients eligible for cost-sharing and premium subsidies in the Marketplaces [income 139%-250% federal poverty level (FPL)] and middle-income patients eligible only for premium subsidies (251%-400% FPL) were compared to high-income controls ineligible for subsidies (>400% FPL) using a quasi-experimental difference-in-differences approach. We evaluated 3 main outcomes: (1) out-of-pocket spending, (2) premium contributions, and (3) likelihood of experiencing catastrophic expenditures, defined as out-of-pocket plus premium spending exceeding 19.5% of family income. RESULTS: Our sample included 5450 patients undergoing surgery, representing approximately 69 million US adults. Among low-income patients, Marketplace implementation was associated with $601 lower [95% confidence interval (CI): -$1169 to -$33; P = 0.04) out-of-pocket spending; $968 lower (95% CI: -$1652 to -$285; P = 0.006) premium spending; and 34.6% lower probability (absolute change: -8.3 percentage points; 95% CI: -14.9 to -1.7; P = 0.01) of catastrophic expenditures. We found no evidence that health expenditures changed for middle-income surgical patients. CONCLUSIONS: The ACA's insurance Marketplaces were associated with improved financial protection among low-income surgical patients eligible for both cost-sharing and premium subsidies, but not in middle-income patients eligible for only premium subsidies.

Epidemiologic Assessment of Concussions in an NCAA Division I Women's Soccer Team.

BACKGROUND: Among collegiate sports, ice hockey and wrestling have been reported to have the highest rates of concussion injury. Recent literature has shown that among all sports, female soccer players had the highest rate of concussion injury at the high school level. Sport-specific analysis will increase our knowledge of epidemiologic characteristics of this serious injury in young soccer players, where "heading" is commonly involved during participation. HYPOTHESIS: Heading during soccer will be associated with increased frequency of concussion injury in collegiate female players compared with other mechanisms of injury, and concussion injury mechanism and rates will differ by setting of injury (practice or match) and player position. STUDY DESIGN: Descriptive epidemiologic study. METHODS: This was a retrospective review and epidemiologic analysis of all concussions documented from a single National Collegiate Athletic Association (NCAA) Division I female collegiate soccer team between 2004 and 2017. A total of 381 participants were reviewed, and concussion injury mechanism, setting (practice or match), player position, and number of games and practices missed due to injury were analyzed. RESULTS: Overall, 25 concussions in 22 players from the 2004 to 2017 seasons were identified, for an annual rate of 1.79 concussions per year. Collisions (36%) followed by headers (20%) were the most common mechanisms. Forwards sustained the most concussions (32%). Injuries were more common in games (56%) than practice (40%). Of note, the most common cause of concussion during practice was headers (40%). Of the concussions documented, 20 (91%) were the player's first concussion. On average, each concussion resulted in a player missing 3.96 games and 12.46 practices. CONCLUSION: Our results demonstrate that concussion rates in female NCAA soccer players vary by position and occur with different frequencies and mechanisms in practice and games. Interventions for concussion avoidance should aim to limit exposure to high-risk activity, including player-to-player contact in games and headers in practice. Although gameplay and collisions can be unpredictable and difficult to control, practice settings can be modified in an attempt to decrease risk.

Catastrophic expenditures in California trauma patients after the Affordable Care Act: reduced financial risk and racial disparities.

BACKGROUND: Hospital charges due to major injury can result in high out-of-pocket expenses for patients. We analyzed the effect of the Affordable Care Act (ACA) on catastrophic health expenditures (CHE) among trauma patients. METHODS: We identified trauma patients aged 19-64 admitted to a safety-net Level 1 trauma center in California from 2007 to 2017. Out-of-pocket expenditures and income were calculated using hospital charges, insurance status, and ZIP code. CHE was defined using the World Health Organization definition of out-of-pocket spending exceeding 40% of inflation-adjusted income minus food and housing expenditures. Multivariable logistic regression was performed to assess odds of CHE post-ACA (2014-2017) vs. pre-ACA (2007-2013). RESULTS: Of 7519 trauma patients, 20.6% experienced CHE, including 89.0% of uninsured patients. There was a 74% decrease in odds of CHE post-ACA (aOR: 0.26, 95% CI: 0.22-0.30), with greater decreases among Black (aOR: 0.09, 95% CI: 0.04-0.18) and Hispanic (aOR: 0.23, 95% CI: 0.19-0.29) patients. CONCLUSIONS: ACA implementation was associated with markedly decreased odds of catastrophic expenditures and decreased racial disparities in financial protection among trauma patients in our study.

Association of the US Affordable Care Act With Out-of-Pocket Spending and Catastrophic Health Expenditures Among Adult Patients With Traumatic Injury.

Importance: Trauma is an expensive and unpredictable source of out-of-pocket spending for American families. The Patient Protection and Affordable Care Act (ACA) sought to improve financial protection by expanding health insurance coverage, but its association with health care spending for patients with traumatic injury remains largely unknown. Objective: To evaluate the association of ACA implementation with out-of-pocket spending, premiums, and catastrophic health expenditures (CHE) among adult patients with traumatic injury. Design, Setting, and Participants: Data from a nationally representative sample of US adults aged 19 to 64 years who had a hospital stay or emergency department visit for a traumatic injury from January 2010 to December 2017 were analyzed using the Medical Expenditure Panel Survey. Multivariable generalized linear models were used to evaluate changes in spending after ACA implementation. Additionally, 4 income subgroups were evaluated based on ACA thresholds for program eligibility: lowest-income patients (earning 138% or less of the federal poverty level [FPL]), low-income patients (earning 139% to 250% of the FPL), middle-income patients (earning 251% to 400% of the FPL), and high-income patients (earning more than 400% of the FPL). Data were analyzed from February to December 2019. Exposures: Implementation of the ACA, beginning January 1, 2014. Main Outcomes and Measures: Out-of-pocket spending, premium spending, out-of-pocket plus premium spending, and likelihood of experiencing CHE, defined as out-of-pocket plus premium spending exceeding 19.5% of family income. Results: Of the 6288 included patients, 2995 (weighted percentage, 51.3%) were male, and the mean (SD) age was 41.4 (12.8) years. Implementation of the ACA was associated with 31% lower odds of CHE (adjusted odds ratio, 0.69; 95% CI, 0.54 to 0.87; P = .002). Changes were greatest in lowest-income patients, who experienced 30% lower out-of-pocket spending (adjusted percentage change, -30.4%; 95% CI, -46.6% to -9.4%; P = .01), 26% lower out-of-pocket plus premium spending (adjusted percentage change, -26.3%; 95% CI, -41.0% to -8.1%; P = .01), and 39% lower odds of CHE (adjusted odds ratio, 0.61; 95% CI, 0.44 to 0.84; P = .002). Low-income patients experienced decreased out-of-pocket spending and out-of-pocket plus premium spending but no changes in CHE, while middle-income and high-income patients experienced no significant changes in any spending outcome. In the post-ACA period, 1 in 11 of all patients with traumatic injury and 1 in 5 with the lowest incomes continued to experience CHE each year. Conclusions and Relevance: Implementation of the ACA was associated with improved financial protection for US adults with traumatic injury, especially lowest-income individuals targeted by the law's Medicaid expansions. Despite these gains, injured patients remain at risk of financial strain.

Understanding how the concentration of neighborhood advantage and disadvantage affects spina bifida risk among births to non-Hispanic white and Hispanic women, Texas, 1999-2014.

BACKGROUND: This is the first study to utilize the index of concentration at the extremes (ICE) to examine risk factors for spina bifida in Texas. The ICE is a useful measure for providing the degree to which residents in a certain area are concentrated into groups at the extremes of disadvantage and privilege. We introduce two novel ICE measures (language and nativity), and three existing ICE measures (race/ethnicity, income, and education), which we applied specifically to Texas residents. METHODS: We used multivariable mixed-model Poisson regression analyses to estimate spina bifida birth prevalence and prevalence ratios among singleton live births in Texas, 1999-2014, for each of our ICE measures. Maternal census tract at delivery was included in the models as a random effect. Analyses were stratified by maternal race/ethnicity (Hispanics and non-Hispanic whites). Live births served as denominators for each category. RESULTS: Among non-Hispanic white women, those in the most disadvantaged versus the advantaged census tract quintile had adjusted relative risk between 1.6 and 8.5 for having a baby affected by spina bifida. However, Hispanic women in the most disadvantaged versus advantaged census tract quintile for four ICE measures had a 33% to 87% lower risk of having an affected pregnancy. CONCLUSIONS: Findings suggest spina bifida risk is associated with neighborhood disadvantage or advantage, and that relationship seems to vary by race-ethnicity. The varied associations between ICE measures and spina bifida by race/ethnicity highlights the importance of using targeted interventions in the prevention of spina bifida.

Brief surgical procedure code lists for outcomes measurement and quality improvement in resource-limited settings.

BACKGROUND: The lack of a classification system for surgical procedures in resource-limited settings hinders outcomes measurement and reporting. Existing procedure coding systems are prohibitively large and expensive to implement. We describe the creation and prospective validation of 3 brief procedure code lists applicable in low-resource settings, based on analysis of surgical procedures performed at Mbarara Regional Referral Hospital, Uganda's second largest public hospital. METHODS: We reviewed operating room logbooks to identify all surgical operations performed at Mbarara Regional Referral Hospital during 2014. Based on the documented indication for surgery and procedure(s) performed, we assigned each operation up to 4 procedure codes from the International Classification of Diseases, 9th Revision, Clinical Modification. Coding of procedures was performed by 2 investigators, and a random 20% of procedures were coded by both investigators. These codes were aggregated to generate procedure code lists. RESULTS: During 2014, 6,464 surgical procedures were performed at Mbarara Regional Referral Hospital, to which we assigned 435 unique procedure codes. Substantial inter-rater reliability was achieved (κ = 0.7037). The 111 most common procedure codes accounted for 90% of all codes assigned, 180 accounted for 95%, and 278 accounted for 98%. We considered these sets of codes as 3 procedure code lists. In a prospective validation, we found that these lists described 83.2%, 89.2%, and 92.6% of surgical procedures performed at Mbarara Regional Referral Hospital during August to September of 2015, respectively. CONCLUSION: Empirically generated brief procedure code lists based on International Classification of Diseases, 9th Revision, Clinical Modification can be used to classify almost all surgical procedures performed at a Ugandan referral hospital. Such a standardized procedure coding system may enable better surgical data collection for administration, research, and quality improvement in resource-limited settings.

Performance Assessment of a Custom, Portable, and Low-Cost Brain-Computer Interface Platform.

OBJECTIVE: Conventional brain-computer interfaces (BCIs) are often expensive, complex to operate, and lack portability, which confines their use to laboratory settings. Portable, inexpensive BCIs can mitigate these problems, but it remains unclear whether their low-cost design compromises their performance. Therefore, we developed a portable, low-cost BCI and compared its performance to that of a conventional BCI. METHODS: The BCI was assembled by integrating a custom electroencephalogram (EEG) amplifier with an open-source microcontroller and a touchscreen. The function of the amplifier was first validated against a commercial bioamplifier, followed by a head-to-head comparison between the custom BCI (using four EEG channels) and a conventional 32-channel BCI. Specifically, five able-bodied subjects were cued to alternate between hand opening/closing and remaining motionless while the BCI decoded their movement state in real time and provided visual feedback through a light emitting diode. Subjects repeated the above task for a total of 10 trials, and were unaware of which system was being used. The performance in each trial was defined as the temporal correlation between the cues and the decoded states. RESULTS: The EEG data simultaneously acquired with the custom and commercial amplifiers were visually similar and highly correlated ( ρ = 0.79). The decoding performances of the custom and conventional BCIs averaged across trials and subjects were 0.70 ± 0.12 and 0.68 ± 0.10, respectively, and were not significantly different. CONCLUSION: The performance of our portable, low-cost BCI is comparable to that of the conventional BCIs. SIGNIFICANCE: Platforms, such as the one developed here, are suitable for BCI applications outside of a laboratory.