AAST grade of liver injury is not the single most important consideration in decision making for liver trauma.

BACKGROUND: The liver is one of the most injured organs in both blunt and penetrating trauma. The aim of this study was to identify whether the AAST liver injury grade is predictive of need for intervention, risk of complications and mortality in our patient population, and whether this differs between blunt and penetrating-trauma mechanisms. METHODS: Retrospective review of all liver injuries from a single high-volume metropolitan trauma centre in South Africa from December 2012 to January 2022. Inclusion criteria were all adults who had sustained traumatic liver injury. Patients were excluded if they were under 15 years of age or had died prior to operation or assessment. Statistical analysis was undertaken using both univariate and multivariate models. RESULTS: 709 patients were included, of which 351 sustained penetrating and 358 blunt trauma. Only 24.3 % of blunt compared to 76.4 % of penetrating trauma patients underwent laparotomy (p< 0.001). In blunt trauma, increasing AAST grade correlated directly with rates of laparotomy with an odds ratio of 1.7 (p < 0.001). In penetrating trauma, there was no statistical significance between increasing AAST grade and the rate of laparotomy. The rate of bile leak was 4.5 % (32/709) and of rebleed was 0.7 % (5/709). Five patients underwent ERCP and endoscopic sphincterotomy for bile leak, and three required angio-embolization for rebleeding. Increasing AAST grades were significantly associated with the odds of bile leak in both blunt and penetrating trauma. There was a statistically significant increase in the odds of a rebleed with increasing AAST grade in penetrating trauma. Five patients rebled, of which three died. Seven patients developed hepatic necrosis. Seventy-six patients died (10 %). There were 34/358 (9 %) deaths in the blunt cohort and 42 /351 (11 %) deaths in the penetrating trauma cohort. CONCLUSION: AAST grade in isolation is not a good predictor of the need for operation in hepatic trauma. Increasing AAST grade was not found to correlate with increased risk of mortality for both blunt and penetrating hepatic trauma. In both blunt and penetrating trauma, increasing AAST grade is significantly associated with increased bile leak. The need for ERCP and endoscopic sphincterotomy to manage bile leak in our setting is low. Similarly, the rate of rebleeding and of angioembolization was low.

Point of care ultrasound and sub-xiphoid window reduce uncertainty in the management of potential dual-cavity injuries in patients with torso stab wounds.

INTRODUCTION: This paper reviews our experiences with the management of patients with torso stab wounds and potential injuries in both the chest and abdomen over the last decade. The aim of the project is to clarify our approach and provide an evidence base for clinical algorithms. We hypothesize that there is room for our clinical algorithms to be further refined in order to address the diverse, life threatening injuries that can result from stab wounds to the torso. METHODS: Patients with one or more torso stab wounds, and a potential injury in both the chest and the abdomen were identified from a local database for the period December 2012 to December 2020. RESULTS: A total of 899 patients were identified. The mean age was 29 years (SD = 9) and 93% of patients were male. Amongst all patients, 686 (76%) underwent plain radiography, 207 (23%) a point of care ultrasound assessment, and 171 (19%) a CT scan. Following initial resuscitation, assessment and investigation, a total of 527 (59%) patients proceeded to surgery. A total of 185 patients (35%) underwent a semi elective diagnostic laparoscopy to exclude an occult diaphragm injury. Of the 342 who underwent an emergency operation, 9 patients (1%) required thoracotomy or sternotomy exclusively, 299 patients (33%) required a laparotomy exclusively and 34 patients (4%) underwent some form of dual cavity exploration. In total, there were 16 deaths, a mortality rate of 2%. The use of laparoscopy, point of care ultrasound and subxiphoid pericardial window increased over the period of this study. CONCLUSIONS: Patients with torso stab wounds and potential injuries above and below the diaphragm are challenging to manage. The highly structured clinical algorithm of the ATLS course should be complemented by the use of point of care ultrasound and sub-xiphoid window to assess the pericardium. These adjuncts reduce the likelihood of negative exploration and incorrect operative sequencing.

Risk Factors Associated with Chemotherapy-Induced Nausea and Vomiting Among Women with Breast Cancer Receiving Highly Emetogenic Chemotherapy: Individual Patient-Based Analysis of Three Prospective Antiemetic Trials.

Purpose: Although risk factors related to chemotherapy-induced nausea and vomiting (CINV) have been identified in previous studies, only a few studies have evaluated the risk factors associated with contemporary antiemetic prophylaxis, including olanzapine/aprepitant- or NEPA-containing regimens. This study aimed to identify the risk factors associated with CINV development in Chinese breast cancer patients receiving doxorubicin and cyclophosphamide chemotherapy. Methods: Data from 304 patients enrolled in 3 previously reported prospective antiemetic studies were included. Multivariate logistic regression models were used to predict risk factors associated with CINV occurrence. Additionally, the likelihood of treatment failure in relation to the number of risk factors in individual patients was evaluated. Results: Multivariate analysis of the entire study group revealed that obesity status (defined as body mass index/= 25.0 kg/m2) and the use of olanzapine/aprepitant- or NEPA-containing anti-emetic regimens were associated with a high likelihood, while a history of motion sickness was associated with a lower likelihood, complete response (CR), and "no nausea" in the overall phase. A history of vomiting during pregnancy was also associated with a lower likelihood of an overall CR. Patients with an increasing number of risk factors had a higher likelihood of treatment failure and shorter time to first vomiting. Those who did not achieve CR and "no nausea" in the first cycle were less likely to achieve these parameters in the subsequent cycle of chemotherapy. Conclusion: The present study confirmed previously reported risk factors for CINV in Chinese breast cancer patients receiving doxorubicin and cyclophosphamide. Further optimization of CINV control is required for patients with identifiable risk factors; olanzapine/aprepitant- or NEPA- containing prophylaxis are the preferred contemporary anti-emetics regimens for Chinese breast cancer patients undergoing doxorubicin and cyclophosphamide chemotherapy.

Management of thoracoabdominal gunshot wounds - Experience from a major trauma centre in South Africa.

INTRODUCTION: The management of thoracoabdominal (TA) gunshot wounds (GSW) remains challenging. This study reviewed our experience with treating such injuries over a decade. MATERIALS AND METHODS: A retrospective study was conducted at a major trauma centre in South Africa over a ten-year period from December 2012 to January 2022. RESULTS: Two hundred sixteen cases were included (male: 85 %, mean age: 33 years). Median RTS: 8 and median ISS: 17 (IQR: 10-19). The mean value of physiological parameters: Heart Rate (HR): 98/min, Systolic Blood Pressure (SBP): 119 mmHg, Temperature (T): 36.2 °C, pH: 7.35, Lactate 3.7 mmol/l. Ninety-nine (46 %) underwent a CT scan of the torso. One hundred fifty-four cases (69 %) were managed operatively: thoracotomy only [5/154 (3 %)], laparotomy only [143/154 (93 %)], and combined thoracotomy and laparotomy [6/154 (4 %)]. Those who had surgery following preoperative CT had a lower rate of dual cavity exploration (2 % vs 4 %, p = 0.51), although it did not reach statistical significance. The overall morbidity was 30 % (69). 82 % required intensive care (ICU) admission. The mean length of hospital stay was 14 days. The overall mortality was 13 % (28). Over the 10-year study period, there was a steady increase in the number of cases of TA GSWs managed at our institution. Over the study period, an increasing use of CT was noted, along with a steady reduction in the proportion of operations performed. CONCLUSIONS: Thoraco-abdominal GSWs remain challenging to manage and continue to be associated with significant morbidity and mortality. The increased use of CT scans has reduced the degree of clinical confusion around which body cavity to prioritize, leading to an apparent decrease in dual cavity exploration, and has allowed for the increased use of minimalistic and non-operative approaches.

The "weekend effect" does not impact on outcome of trauma laparotomy - Experience from a level 1 trauma centre in New Zealand.

PURPOSE: Trauma centres have been proven to provide better outcomes in developed countries for overall trauma, but there is limited literature on the systematic factors that describe any discrepancies in outcomes for trauma laparotomies in these centres. This study was conducted to examine and interrogate the effect of systematic factors on patients undergoing a trauma laparotomy in a developed country, intending to identify potential discrepancies in the outcome. METHODS: This was a retrospective study of all laparotomies performed for trauma at a level 1 trauma centre in New Zealand. All adult patients who had undergone an index laparotomy for trauma between February 2012 and November 2020 were identified and laparotomies for both blunt and penetrating trauma were included. Repeat laparotomies and trauma laparotomies in children were excluded. The primary clinical outcomes reviewed included morbidity, length of hospital stay, and mortality. All statistical analysis was performed using R v.4.0.3. RESULTS: During the 9-year study period, 204 trauma laparotomies were performed at Waikato hospital. The majority (83.3%) were performed during office hours (170/204), and the remaining 16.7% were performed after hours (34/204). And 61.3% were performed on a weekday (125/204), whilst 38.7% were performed on the weekend/public holiday (79/204). Most of the parameters in office hours and after hours groups had no statistically significant difference, except lactate (p = 0.026). Most of the variables in weekday and weekend groups had no statistically significant difference, except pH, lactate, length of stay, and gastrointestinal complications (p = 0.012, p < 0.001, p = 0.003, p = 0.020, respectively). CONCLUSION: The current trauma system at Waikato hospital is capable of delivering care for trauma laparotomy patients with the same outcome regardless of working hours or after hours, weekday or weekend. This confirms the importance of a robust trauma system capable of responding to the sudden demands placed on it.

Penetrating buttock trauma is morbid but rarely fatal - A South African experience.

BACKGROUND: Penetrating injuries to the buttock are relatively rare but are associated with significant morbidity. This study aimed to review our experience in managing penetrating trauma to the buttocks to contextualize the injury, document the most common associated injuries, and generate an algorithm to assist with the management of these patients. METHODS: A retrospective study was conducted at a major trauma center in South Africa over 8 years (January 2012 to January 2020). All patients presenting with a penetrating buttock injury were included. RESULTS: Our study included 40 patients. Gunshot wounds accounted for 93% (37/40), stab wounds accounted for 5% (2/40), and 1 case was gored by a cow. The majority (98%) underwent further investigation in the form of imaging or endoscopy. Forty percent (16/40) required surgical intervention. Of these 16 cases, 14 required a laparotomy, and 2 required gluteal exploration. Fifty-six percent (9/16) required a stoma. Five percent (2/40) experienced one or more complications, both of whom had stomas. The median length of stay for all patients was 3 days, whereas for the patients with stomas was 7 days. There were no ICU admissions or mortality in this study. Only 3 of the 9 stomas were reversed, and the median time to reversal was 16 months. CONCLUSION: Penetrating trauma to the buttock may result in injuries to surrounding vital structures, which must be actively excluded. Rectal injury was the most common injury, and most required a defunctioning colostomy as part of the management resulting in significant morbidity.

Double Jeopardy Injuries: Improved Clinical Outcomes With FAST Imaging and Subxiphoid Pericardial Window for Combined Cardiac and Abdominal Stab Wounds.

BACKGROUND: This study reviews our experience with combined cardiac and abdominal stab wounds over 12 years and reviews how changes in technology and clinical approaches have impacted our management of these patients. MATERIALS AND METHODS: A retrospective cohort study was conducted from January 2008 to January 2020 at a major trauma centre in South Africa. All patients with concurrent SWs to the chest and the abdomen and required both a thoracotomy for cardiac injury and a laparotomy for an intra-abdominal injury at the same setting were included. RESULTS: Twenty-two cases were identified (100% male, mean age: 27 years). Mean values of admission physiology: systolic blood pressure (SBP): 85 mmHg, pH: 7.2, base excess: -10.2 mmol/L and serum lactate 6.7 mmol/L. Thirty-two percent (7/22) of cases underwent a Focused Assessment with Sonography in Trauma (FAST) scan (5 positive and 2 negative). All 7 cases had intraoperatively confirmed cardiac injuries. The thoracotomy first approach was used in 18 cases (82%), and the laparotomy first approach was used in the remaining 4 cases (18%). Nineteen (86%) of the 22 laparotomies were positive. A total of 6 patients (27%) experienced one or more complications. The mean length of hospital stay was 9 days. The overall mortality was 18% (4/22) and all mortality occurred prior to 2013. DISCUSSION: Double jeopardy is still associated with an increased risk of mortality. The use of FAST and Subxiphoid Pericardial Windows (SPWs) have reduced clinical uncertainty, decreasing the need for concomitant thoracotomy and laparotomy to be performed.

Foley Catheter Balloon Tamponade for Actively Bleeding Wounds Following Penetrating Neck Injury is an Effective Technique for Controlling Non-Compressible Junctional External Haemorrhage.

BACKGROUND: The foley catheter balloon tamponade (FCBT) has been widely employed in the management of trauma. This study reviews our cumulative experience with the use of FCBT in the management of patients presenting with a penetrating neck injury (PNI). METHODS: A retrospective study was conducted at a major trauma centre in South Africa over a 9-year period from January 2012 to December 2020. All patients who presented with a PNI who had FCBT were included. RESULTS: A total of 1581 patients with a PNI were managed by our trauma centre, and 44 (3%) patients had an FCBT. Of the 44 cases of FCBT, stab wounds accounted for 93% (41/44) and the remaining 7% were for gunshot wounds. Seventy-five per cent of all FCBT (33/44) were inserted at a rural hospital prior to transfer to our trauma centre; the remaining 25% (11/44) were inserted in our resuscitation room. The success rate of FCBT was 80% (35/44), allowing further CT with angiography (CTA) to be performed. CTA findings were: 10/35 (29%) positive, 18/35 (51%) negative, and 7/35 (20%) equivocal. Fifteen patients required additional intervention (open surgery or endovascular intervention). The overall morbidity was 14% (6/44). Eighteen per cent required intensive care unit admission. The median length of stay was 1 day. The overall mortality rate was 11% (5/44). CONCLUSION: FCBT is a simple and effective technique as an adjunct in the management of major haemorrhage from a PNI. In highly selective patients, it may also be used as definitive management.

The Management of Penetrating Neck Injury With Retained Knife: 15-Year Experience From a Major Trauma Center in South Africa.

BACKGROUND: This study reviews our cumulative experience with the management of patients presenting with a retained knife following a penetrating neck injury (PNI). METHODS: A retrospective cohort study was conducted at a major trauma center in South Africa over a 15-year period from July 2006 to December 2020. All patients who presented with a retained knife in the neck following a stab wound (SW) were included. RESULTS: Twenty-two cases were included: 20 males (91%), mean age: 29 years. 77% (17/22) were retained knives and 23% (5/22) were retained blades. Eighteen (82%) were in the anterior neck, and the remaining 4 cases were in the posterior neck. Plain radiography was performed in 95% (21/22) of cases, and computed tomography (CT) was performed in 91% (20/22). Ninety-five percent (21/22) had the knife or blade extracted in the operating room (OR). Formal neck exploration (FNE) was undertaken in 45% (10/22) of cases, and the remaining 55% (12/22) underwent simple extraction (SE) only. Formal neck exploration was more commonly performed for anterior neck retained knives than the posterior neck, although not statistically significant [56% (10/18) vs 0% (0/18), P = .096]. There were no significant differences in the need for intensive care admission, length of hospital stay, morbidities, or mortalities between anterior and posterior neck retained knives. DISCUSSION: Uncontrolled extraction of a retained knife in the neck outside of the operating room may be dangerous. Retained knives in the anterior neck commonly required formal neck exploration but not for posterior neck retained knives.

HDP-101, an Anti-BCMA Antibody-Drug Conjugate, Safely Delivers Amanitin to Induce Cell Death in Proliferating and Resting Multiple Myeloma Cells.

Despite major treatment advances in recent years, patients with multiple myeloma inevitably relapse. The RNA polymerase II complex has been identified as a promising therapeutic target in both proliferating and dormant cancer cells. Alpha-amanitin, a toxin so far without clinical application due to high liver toxicity, specifically inhibits this complex. Here, we describe the development of HDP-101, an anti-B-cell maturation antigen (BCMA) antibody conjugated with an amanitin derivative. HDP-101 displayed high efficacy against both proliferating and resting myeloma cells in vitro, sparing BCMA-negative cells. In subcutaneous and disseminated murine xenograft models, HDP-101 induced tumor regression at low doses, including durable complete remissions after a single intravenous dose. In cynomolgus monkeys, HDP-101 was well tolerated with a promising therapeutic index. In conclusion, HDP-101 safely and selectively delivers amanitin to myeloma cells and provides a novel therapeutic approach to overcome drug resistance in this disease.

Resting Borg score as a predictor of safe discharge of chronic obstructive pulmonary disease from the emergency department observation unit.

BACKGROUND: Chronic obstructive pulmonary disease exacerbations (eCOPD) can be life-threatening and costly. Emergency department (ED) observation units (ED-Obs) offer short-term care to safely reduce preventable hospitalizations. Accurately identifying eCOPD patients who can be discharged safely will improve outcomes. OBJECTIVES: The objective were to: I) evaluate utility of conventional clinical variables as predictors of safe discharge and II) assess utility of serial resting Borg score and novel Dyspnea Assessment Score (DAS) for identifying eCOPD patients who can be safely discharged from ED-Obs. METHODS: This study was carried out in a 680-bed tertiary, academic hospital with >700 annual eCOPD ED encounters and a 16-bed ED-Obs. A two-phase study of eCOPD patients admitted to ED-Obs was performed. Objective I was a retrospective study including all eCOPD admits from April 2016 to May 2017. Predictor variables (demographics, COPD severity, comorbid conditions, exacerbation severity, clinical care in ED) and outcome variables (ED-Obs disposition, ED revisits) were obtained through electronic medical records. Safe discharge was defined as home disposition from ED-Obs without 7-day revisit. A stepwise regression was performed for predictors of safe discharge. Objective II was a prospective observation study for change in every 4-hour serial resting Borg score and DAS as identifiers of safe discharge. Comparative and receiver operating characteristic (ROC) analyses were performed. A p-value of <0.05 was considered significant. RESULTS: In Objective I, 171 patients with age, FEV1 %, and body mass index of 59.8 (±9.5) years, 35 (±24)%, and 28.8 (±8) m2 /kg were included. After ED-Obs treatment 78 (45.6%) were hospitalized and 93 (54.4%) were discharged home, of whom 11 (6.4%) had 7-day ED revisit. Safe discharge occurred in 82 (48%). None of the predictor variables correlated with safe discharge. In Objective II, of 38 patients included, 20 (52.6%) had safe discharge. Among others, 16 (42%) were hospitalized and two (5.2%) had 7-day ED revisit. The admission Borg scores and DASs were similar in both groups. The predisposition Borg score was significantly lower in patients with safe discharge (2.75 vs. 5.28, p < 0.001) and had the highest area under curve on ROC (0.77) for safe discharge. DAS was not significantly different between groups. CONCLUSIONS: Routine clinical variables do not identify eCOPD patients who can be safely discharged from ED-Obs. Change in resting Borg score during the course of ED-Obs treatment safely identifies patients for discharge. Prospective, external validation is needed to incorporate serial Borg scores in ED-Obs disposition decision for improved safety.

Lossy wavefront sensing and correction of distorted laser beams.

The art of rectifying a laser beam carrying amplitude and phase distortions has been demonstrated through several competing methods. Both wavefront sensor and wavefront sensor-less approaches show that the closed-loop correction of a laser beam can be accomplished by exploiting high-resolution sampling of the beam distortion in its spatial or time domain, respectively. Moreover, machine-learning-based wavefront sensing has emerged recently, and uses training data on an arbitrary sensing architecture to map observed data to reasonable wavefront reconstructions. This offers additional options for beam correction and optical signal decoding in atmospheric or underwater propagation. Ideally, wavefront sensing can be achieved through any resolution in spatial samples, provided that more frequent sampling in the time domain can be achieved for a reduced number of spatial samples. However, such trade-offs have not been comprehensively studied or demonstrated experimentally. We present a fundamental study of lossy wavefront sensing that reduces the number of effective spatial samples to the number of actuators in a deformable mirror for a balanced performance of dynamic wavefront corrections. As a result, we show that lossy wavefront sensing can both simplify the design of wavefront sensors and remain effective for beam correction. In application, this concept provides ultimate freedom of hardware choices from sensor to sensorless approaches in wavefront reconstruction, which is beneficial to the frontier of study in free-space optical communication, lidar, and directed energy.

COPD Care Bundle in Emergency Department Observation Unit Reduces Emergency Department Revisits.

BACKGROUND: COPD exacerbations lead to accelerated decline in lung function, poor quality of life, and increased mortality and cost. Emergency department (ED) observation units provide short-term care to reduce hospitalizations and cost. Strategies to improve outcomes in ED observation units following COPD exacerbations are needed. We sought to reduce 30-d ED revisits for COPD exacerbations managed in ED observation units through implementation of a COPD care bundle. The study setting was an 800-bed, academic, safety-net hospital with 700 annual ED encounters for COPD exacerbations. Among those discharged from ED observation unit, the 30-d all-cause ED revisit rate (ie, the outcome measure) was 49% (baseline period: August 2014 through September 2016). METHODS: All patients admitted to the ED observation unit with COPD exacerbations were included. A multidisciplinary team implemented the COPD bundle using iterative plan-do-study-act cycles with a goal adherence of 90% (process measure). The bundle, adopted from our inpatient program, was developed using care-delivery failures and unmet subject needs. It included 5 components: appropriate inhaler regimen, 30-d inhaler supply, education on devices available after discharge, standardized discharge instructions, and a scheduled 15-d appointment. We used statistical process-control charts for process and outcome measures. To compare subject characteristics and process features, we sampled consecutive patients from the baseline (n = 50) and postbundle (n = 83) period over 5-month and 7-month intervals, respectively. Comparisons were made using t tests and chi-square tests with P < .05 significance. RESULTS: During baseline and postbundle periods, 410 and 165 subjects were admitted to the ED observation unit, respectively. After iterative plan-do-study-act cycles, bundle adherence reached 90% in 6 months, and the 30-d ED revisit rate declined from 49% to 30% (P = .003) with a system shift on statistical process-control charts. There was no difference in hospitalization rate from ED observation unit (45% vs 51%, P = .16). Subject characteristics were similar in the baseline and postbundle periods. CONCLUSIONS: Reliable adherence to a COPD care bundle reduced 30-d ED revisits among those treated in the ED observation unit.

Pragmatic Challenge of Sustainability: Long-Term Adherence to COPD Care Bundle Maintains Lower Readmission Rate.

Long-term sustainability of successful improvement initiatives remains a pragmatic challenge with limited literature guidance. A chronic obstructive pulmonary disease (COPD) care bundle was developed and implemented to mitigate care-delivery failures and unmet patient needs at University of Cincinnati Medical Center that led to a 35% reduction in 30-day all-cause readmissions. Here, two-year outcomes and the method of achieving sustainability are presented. METHODS: After implementation of the COPD care bundle, 30-day all-cause readmissions reduced from 22.7% to 14.7%. In 2016 the project transitioned from implementation to the sustainability phase. A four-member sustainability team was formed (pulmonologist, hospitalist, respiratory therapist, and pharmacist) with clearly defined roles for monitoring and facilitating sustainability actions. The process of bundle delivery was purposefully designed for higher reliability. Staff education and daily operations were updated to incorporate the new process. Outcome (readmission rate) and process (bundle adherence) measures were monitored monthly. Any significant drop (special cause variation) would be reviewed by the team and further action taken, if needed. The National Health Service sustainability model was used, with adjustments made to meet our contextual needs. RESULTS: The 30-day all-cause readmission rate remained the same as during the initial implementation phase (14.9%). Adherence to COPD care bundle components was 87.7%. During the two-year period, three occasions triggered a team discussion and detailed review. CONCLUSION: Sustainability requires a purposefully designed, resilient process; standard work; engagement of the team and leadership; and a monitoring system of key process and outcome measures. Application of sustainability models should be adjusted for specific contextual needs.

Bioresorbable pressure sensors protected with thermally grown silicon dioxide for the monitoring of chronic diseases and healing processes.

Pressures in the intracranial, intraocular and intravascular spaces are clinically useful for the diagnosis and management of traumatic brain injury, glaucoma and hypertension, respectively. Conventional devices for measuring these pressures require surgical extraction after a relevant operational time frame. Bioresorbable sensors, by contrast, eliminate this requirement, thereby minimizing the risk of infection, decreasing the costs of care and reducing distress and pain for the patient. However, the operational lifetimes of bioresorbable pressure sensors available at present fall short of many clinical needs. Here, we present materials, device structures and fabrication procedures for bioresorbable pressure sensors with lifetimes exceeding those of previous reports by at least tenfold. We demonstrate measurement accuracies that compare favourably to those of the most sophisticated clinical standards for non-resorbable devices by monitoring intracranial pressures in rats for 25 days. Assessments of the biodistribution of the constituent materials, complete blood counts, blood chemistry and magnetic resonance imaging compatibility confirm the biodegradability and clinical utility of the device. Our findings establish routes for the design and fabrication of bioresorbable pressure monitors that meet requirements for clinical use.

Using turbulence scintillation to assist object ranging from a single camera viewpoint.

Image distortions caused by atmospheric turbulence are often treated as unwanted noise or errors in many image processing studies. Our study, however, shows that in certain scenarios the turbulence distortion can be very helpful in enhancing image processing results. This paper describes a novel approach that uses the scintillation traits recorded on a video clip to perform object ranging with reasonable accuracy from a single camera viewpoint. Conventionally, a single camera would be confused by the perspective viewing problem, where a large object far away looks the same as a small object close by. When the atmospheric turbulence phenomenon is considered, the edge or texture pixels of an object tend to scintillate and vary more with increased distance. This turbulence induced signature can be quantitatively analyzed to achieve object ranging with reasonable accuracy. Despite the inevitable fact that turbulence will cause random blurring and deformation of imaging results, it also offers convenient solutions to some remote sensing and machine vision problems, which would otherwise be difficult.

Phase and amplitude beam shaping with two deformable mirrors implementing input plane and Fourier plane phase modifications.

We find that ideas in optical image encryption can be very useful for adaptive optics in achieving simultaneous phase and amplitude shaping of a laser beam. An adaptive optics system with simultaneous phase and amplitude shaping ability is very desirable for atmospheric turbulence compensation. Atmospheric turbulence-induced beam distortions can jeopardize the effectiveness of optical power delivery for directed-energy systems and optical information delivery for free-space optical communication systems. In this paper, a prototype adaptive optics system is proposed based on a famous image encryption structure. The major change is to replace the two random phase plates at the input plane and Fourier plane of the encryption system, respectively, with two deformable mirrors that perform on-demand phase modulations. A Gaussian beam is used as an input to replace the conventional image input. We show through theory, simulation, and experiments that the slightly modified image encryption system can be used to achieve arbitrary phase and amplitude beam shaping within the limits of stroke range and influence function of the deformable mirrors. In application, the proposed technique can be used to perform mode conversion between optical beams, generate structured light signals for imaging and scanning, and compensate atmospheric turbulence-induced phase and amplitude beam distortions.

Multi-aperture laser transmissometer system for long-path aerosol extinction rate measurement.

We present the theory, design, simulation, and experimental evaluations of a new laser transmissometer system for aerosol extinction rate measurement over long paths. The transmitter emits an ON/OFF modulated Gaussian beam that does not require strict collimation. The receiver uses multiple point detectors to sample the sub-aperture irradiance of the arriving beam. The sparse detector arrangement makes our transmissometer system immune to turbulence-induced beam distortion and beam wander caused by the atmospheric channel. Turbulence effects often cause spatial discrepancies in beam propagation and lead to miscalculation of true power loss when using the conventional approach of measuring the total beam power directly with a large-aperture optical concentrator. Our transmissometer system, on the other hand, combines the readouts from distributed detectors to rule out turbulence-induced temporal power fluctuations. As a result, we show through both simulation and field experiments that our transmissometer system works accurately with turbulence strength Cn2 up to 10-12 m-2/3 over a typical 1-km atmospheric channel. In application, our turbulence- and weather-resistant laser transmissometer system has significant advantages for the measurement and study of aerosol concentration, absorption, and scattering properties, which are crucial for directed energy systems, ground-level free-space optical communication systems, environmental monitoring, and weather forecasting.

Reliable adherence to a COPD care bundle mitigates system-level failures and reduces COPD readmissions: a system redesign using improvement science.

BACKGROUND: Readmissions of chronic obstructive pulmonary disease (COPD) have devastating effects on patient quality-of-life, disease progression and healthcare cost. Effective interventions to reduce COPD readmissions are needed. OBJECTIVES: Reduce 30-day all-cause readmissions by (1) creating a COPD care bundle that addresses care delivery failures, (2) using improvement science to achieve 90% bundle adherence. SETTING: An 800-bed academic hospital in Ohio, USA. The COPD 30-day all-cause readmission rate was 22.7% from August 2013 to September 2015. METHOD: We performed a cross-sectional study of COPD 30-day readmissions from October 2014 to March 2015 to identify care delivery failures. We interviewed readmitted patients with COPD to identify their needs after discharge. A multidisciplinary team created a care bundle designed to mitigate system failures. Using a quasi-experimental study and 'Model for Improvement', we redesigned care delivery to improve bundle adherence. We used statistical process control charts to analyse bundle adherence and all-cause 30-day readmissions. RESULTS: Cross-sectional review of the index (first-time) admissions revealed COPD was the most common readmission diagnosis and identified 42 system-level failures. The most prevalent failures were deficient inhaler regimen at discharge, late or non-existent follow-up appointments, and suboptimal discharge instructions. Patient interviews revealed confusing discharge instructions, especially regarding inhaler use. The COPD care-bundle components were: (1) appropriate inhaler regimen, (2) 30-day inhaler supply, (3) inhaler education on the device available postdischarge, (4) follow-up within 15 days (5) standardised patient-centred discharge instructions. The adherence to completing bundle components reached 90% in 5.5 months and was sustained. The COPD 30-day readmission rate decreased from 22.7% to 14.7%. Patients receiving all bundle components had a readmission rate of 10.9%. As a balancing measure for the targeted reduction in readmission rate, we assessed length of stay, which did not change (4.8 days before vs 4.6 days after; p=0.45). CONCLUSION: System-level failures and unmet patient needs are modifiable risks for readmissions. Development and reliable implementation of a COPD care bundle that mitigates these failures reduced COPD readmissions.

Comparison of the plenoptic sensor and the Shack-Hartmann sensor.

Adaptive optics has been successfully used for decades in the field of astronomy to correct for atmospheric turbulence. A well-developed example involves sensing the slightly distorted wavefronts with a Shack-Hartmann sensor and then correcting them with a phase conjugate device. While the Shack-Hartmann sensor has proven effective for astronomical purposes, it has been less successful for use in deep turbulence conditions often found in ground-to-ground-based optical systems. We have studied an alternative way to sense and correct distorted wavefronts using a plenoptic sensor. We review the design of the plenoptic sensor and directly compare it with the well-known Shack-Hartmann sensor. An experimental comparison of the plenoptic sensor and the Shack-Hartmann sensor is performed to highlight their differences in real-world atmospheric turbulence conditions.