Portable through-metal ultrasonic power transfer using a dry-coupled detachable transmitter

Ultrasonic waves can be used to transfer power and data efficiently through metallic enclosures when feedthroughs are not practical due to structural or electromagnetic shielding considerations. Previous implementations of ultrasonic power transfer (UPT) used a piezoelectric transducer permanently bonded to the metal for efficient ultrasonic coupling. For portable operation, it is essential to have a detachable transmitter (charger) that is only attached to the enclosure while transferring power. This requirement presents several design challenges; notably, detachable ultrasonic coupling typically relies on liquid or gel couplant, which may become inconvenient or less robust during repeated attachment and detachment. Thus, this work develops a dry-coupled detachable UPT system to transfer power efficiently through a metallic enclosure without the need for a liquid couplant. Low attenuation soft elastomers are experimentally tested with a magnetic setup to evaluate their dry-coupled efficiency. Samples with different materials and thicknesses are experimentally tested to select the best configuration for dry ultrasonic coupling. The softest elastomer tested yielded the best ultrasonic efficiency (AC-to-AC) of 68% at 1 MHz. A full DC-to-DC portable (battery-operated) UPT system was then developed and experimentally characterized. The system was capable of delivering up to 3 W of DC power to a resistive load with a total efficiency of 50%.

Endometrial Cancer: Analysing Patterns of Recurrence and Real-Life Outcome Data Using the 2020 ESGO-ESTRO-ESP Risk Stratification System

AIMS

To evaluate patterns of recurrence and explore the prognostic differences between the 2018 FIGO staging system and the 2020 ESGO-ESTRO-ESP risk stratification system of endometrial cancer with an emphasis on early-stage disease.

BACKGROUND

The incidence of endometrial cancer has risen by around 60% since the 90's. It is projected that by 2035 endometrial cancer will be the sixth most common cause of cancer-related death amongst females.

METHODS

This was a retrospective cohort study which included patients treated between 2010 and 2017. Primary endpoints were overall survival (OS) and recurrence-free survival (RFS). Kaplan-Meyer survival analysis was used to assess OS and RFS across different risk groups. Cox proportional hazards regression was used to evaluate prognostic risk factors implicated in recurrence. Different recurrence patterns across the subgroups were analysed with Pearson's chi-square test.

RESULTS

The study included 692 patients with a recurrence rate of 14.9%. The median time to recurrence was 17.1 months (IQR:8.8-28.4). The mean OS varied between 97.2 months in the low-risk group to 63.1 months in the high-risk group (p < 0.001). Mean RFS was 96.1 in the low-risk group and 58.9 in the high-risk group (p < 0.001). RFS was predicted by the following factors; high risk group (OR=3.87; p = 0.041), LVSI (OR=2.54, p = 0.005), carcinosarcoma (OR=2.20, p = 0.021) and serous subtype (OR=1.91, p = 0.01). Logistic regression was used to evaluate risk factors for loco-regional and distant recurrence. Patients in the low-risk group were less likely to have distant recurrence (OR=0.08, p = 0.004). Similarly, negative LVSI and Grade 1 cancers were associated with decreased risk of distant recurrence (OR=0.34, p = 0.006 and OR=0.33, p = 0.007, respectively). There were no significant risk factors for loco-regional recurrence.

CONCLUSIONS

The 2020 ESGO-ESTRO-ESP risk stratification provides accurate estimates of recurrence risk and survival. Those treated in line with current guidance have significantly better outcomes.

National Survey of Current Follow-up Protocols for Patients Treated for Endometrial Cancer in the UK

AIMS

The aim of this study was to establish a baseline of national practice for follow-up after treatment for endometrial cancer in the UK.

MATERIALS AND METHODS

An online cross-sectional survey was developed and distributed through the Royal College of Radiologists via an email link to the audit leads of radiotherapy centres in the UK. The survey was conducted from November 2021 to 5 January 2022. The main themes assessed in the survey were the form, frequency and duration of follow-up practices.

RESULTS

There were a total of 43/61 (70%) complete responses. 93% of centres had a standard follow-up protocol and 7% who did not have a follow-up protocol discharged patients after the post-operative review. Five centres (13%) used molecular profiling to inform follow-up practices. Patient-initiated follow-up was mainly used in the cohort of patients who had surgery alone with no adjuvant treatment (68%, (19/28)). In the cohort who had face-to-face follow-up, the majority had pelvic examinations as part of their review and total follow-up for five years. 93% of respondents are interested in a national follow-up protocol.

CONCLUSION

Our data shows that there is national variation in practise with regard to follow-up of women treated for endometrial cancer. Many of the follow-up practises are based on conventional follow-up regimens and these may fail to address the more holistic needs of cancer survivors. Recent publication of updated guidance from the British Gynaecological Cancer Society may help standardise practise and provide a more relevant approach to follow-up for women treated for endometrial cancer.

Viewing the immune checkpoint VISTA: landscape and outcomes across cancers

BACKGROUND

Optimizing immune checkpoint inhibitor (ICI) therapy may require identification of co-targetable checkpoint pathways via immune profiling. Herein, we analyzed the transcriptomic expression and clinical correlates of V-domain immunoglobulin suppressor of T-cell activation (VISTA), a promising targetable checkpoint.

PATIENTS AND METHODS

RNA sequencing was carried out on 514 tissues reflecting diverse advanced/metastatic cancers. Expression of eight immune checkpoint markers [lymphocyte-activation gene 3 (LAG-3), tumor necrosis factor receptor superfamily 14 (TNFRSF14), programmed cell death protein 1 (PD-1), programmed death-ligand 1 (PD-L1), programmed death-ligand 2 (PD-L2), B- and T-lymphocyte attenuator (BTLA), T-cell immunoglobulin and mucin domain-containing protein 3 (TIM-3), cytotoxic T-lymphocyte antigen 4 (CTLA-4)], in addition to VISTA, was analyzed, along with clinical outcomes.

RESULTS

High VISTA RNA expression was observed in 32% of tumors (66/514) and was the most common highly expressed checkpoint among the nine assessed. High VISTA expression was independently correlated with high BTLA, TIM-3, and TNFRSF14, and with a diagnosis of pancreatic, small intestine, and stomach cancer. VISTA transcript levels did not correlate with overall survival (OS) from metastatic/advanced disease in the pan-cancer cohort or with immunotherapy outcome (progression-free survival and OS from the start of ICI) in 217 ICI-treated patients. However, in ICI-treated pancreatic cancer patients (n = 16), median OS was significantly shorter (from immunotherapy initiation) for the high- versus not-high-VISTA groups (0.28 versus 1.21 years) (P = 0.047); in contrast, VISTA levels were not correlated with OS in 36 pancreatic cancer patients who did not receive ICI.

CONCLUSION

High VISTA expression correlates with high BTLA, TIM-3, and TNFRSF14 checkpoint-related molecules and with poorer post-immunotherapy survival in pancreatic cancer, consistent with prior literature indicating that VISTA is prominently expressed on CD68+ macrophages in pancreatic cancers and requiring validation in larger prospective studies. Immunomic analysis may be important for individualized precision immunotherapy.

'Low' faecal immunochemical test (FIT) colorectal cancer: a 4-year comparison of the Nottingham '4F' protocol with FIT10 in symptomatic patients

AIM

The aim of this work was to evaluate colorectal cancer (CRC) outcomes after 'low' (sub-threshold) faecal immunochemical test (FIT) results in symptomatic patients tested in primary care.

METHOD

This work comprised a retrospective audit of 35 289 patients with FIT results who had consulted their general practitioner with lower gastrointestinal symptoms and had subsequent CRC diagnoses. The Rapid Colorectal Cancer Diagnosis pathway was introduced in November 2017 to allow incorporation of FIT into clinical practice. The local '4F' protocol combined FIT results with blood tests and digital rectal examination (DRE): FIT, full blood count, ferritin and finger [DRE]. The outcome used was detection rates of CRC, missed CRC and time to diagnosis in local 4F protocols for patients with a subthreshold faecal haemoglobin (fHb) result compared with thresholds of 10 and 20 μg Hb/g faeces.

RESULTS

A single threshold of 10 μg Hb/g faeces identifies a population in whom the risk of CRC is 0.2%, but this would have missed 63 (10.5%) of 599 CRCs in this population. The Nottingham 4F protocol would have missed fewer CRCs [42 of 599 (7%)] despite using a threshold of 20 μg Hb/g faeces for patients with normal blood tests. Subthreshold FIT results in patients subsequently diagnosed with a palpable rectal tumour yielded the longest delays in diagnosis.

CONCLUSION

A combination of FIT with blood results and DRE (the 4F protocol) reduced the risk of missed or delayed diagnosis. Further studies on the impact of such protocols on the diagnostic accuracy of FIT are expected. The value of adding blood tests to FIT may be restricted to specific parts of the fHb results spectrum.

Prevalence and Causes of Diagnostic Errors in Hospitalized Patients Under Investigation for COVID-19

BACKGROUND

The COVID-19 pandemic required clinicians to care for a disease with evolving characteristics while also adhering to care changes (e.g., physical distancing practices) that might lead to diagnostic errors (DEs).

OBJECTIVE

To determine the frequency of DEs and their causes among patients hospitalized under investigation (PUI) for COVID-19.

DESIGN

Retrospective cohort.

SETTING

Eight medical centers affiliated with the Hospital Medicine ReEngineering Network (HOMERuN).

TARGET POPULATION

Adults hospitalized under investigation (PUI) for COVID-19 infection between February and July 2020.

MEASUREMENTS

We randomly selected up to 8 cases per site per month for review, with each case reviewed by two clinicians to determine whether a DE (defined as a missed or delayed diagnosis) occurred, and whether any diagnostic process faults took place. We used bivariable statistics to compare patients with and without DE and multivariable models to determine which process faults or patient factors were associated with DEs.

RESULTS

Two hundred and fifty-seven patient charts underwent review, of which 36 (14%) had a diagnostic error. Patients with and without DE were statistically similar in terms of socioeconomic factors, comorbidities, risk factors for COVID-19, and COVID-19 test turnaround time and eventual positivity. Most common diagnostic process faults contributing to DE were problems with clinical assessment, testing choices, history taking, and physical examination (all p < 0.01). Diagnostic process faults associated with policies and procedures related to COVID-19 were not associated with DE risk. Fourteen patients (35.9% of patients with errors and 5.4% overall) suffered harm or death due to diagnostic error.

LIMITATIONS

Results are limited by available documentation and do not capture communication between providers and patients.

CONCLUSION

Among PUI patients, DEs were common and not associated with pandemic-related care changes, suggesting the importance of more general diagnostic process gaps in error propagation.

Emergency versus semi-elective management of mandible fractures: a Maxillofacial Trainee Research Collaborative (MTReC) study

INTRODUCTION

Recent evidence suggests that acute emergency management of mandible fractures does not improve surgical outcomes yet is associated with increased financial burden. Current NHS policy advocating for increased adoption of day-case and semi-elective surgical procedures to reduce bed strain must be balanced with providing timely, effective treatment. Our research aims to determine patient groups currently managed via semi-elective admission and whether this can be extended to other groups to provide safe and effective management of mandible fractures.

METHODS

A multi-national trainee-led audit of mandibular fractures across 49 units was completed by the Maxillofacial Trainee Research Collaborative (MTReC). Each unit prospectively collected data on fractures on admission and at follow-up. Data collected included patient demographics, behaviour, health, injury, timing to intervention and surgical complications.

RESULTS

Data were collected on 947 mandibular fractures. Of the surgically managed patients, 649 (90%) were managed via acute emergency admission at the time of presentation, while 68 (10%) were managed semi-electively. Patient demographics, injury pattern and mechanism appeared to significantly affect timing of management, whereas patient behaviour, health status, timing of injury and presentation did not. Semi-elective management was associated with a significantly shorter inpatient duration (0.9 versus 1.9 days, p=0.000) with no differences in readmission, antibiotic usage or surgical complications (p=1.000, RR 1.030).

CONCLUSION

Our study demonstrates the efficacy of planned admissions and semi-elective management of mandibular fractures. Simple mandibular fractures in compliant patients are suitable for semi-elective treatment. Holistic patient assessment and tailored surgical planning is crucial in determining admission modality to effectively manage mandibular trauma.

Health Disparities in Multiple Sclerosis among Hispanic and Black Populations in the United States

Multiple sclerosis (MS) is an acquired demyelinating disease of the central nervous system (CNS). Historically, research on MS has focused on White persons with MS. This preponderance of representation has important possible implications for minority populations with MS, from developing effective therapeutic agents to understanding the role of unique constellations of social determinants of health. A growing body of literature involving persons of historically underrepresented races and ethnicities in the field of multiple sclerosis is assembling. Our purpose in this narrative review is to highlight two populations in the United States: Black and Hispanic persons with multiple sclerosis. We will review the current understanding about the patterns of disease presentation, genetic considerations, response to treatment, roles of social determinants of health, and healthcare utilization. In addition, we explore future directions of inquiry as well as practical methods of meeting these challenges.

Analytical validation of a multi-protein, serum-based assay for disease activity assessments in multiple sclerosis

PURPOSE

To characterize and analytically validate the MSDA Test, a multi-protein, serum-based biomarker assay developed using Olink^® PEA methodology.

EXPERIMENTAL DESIGN

Two lots of the MSDA Test panel were manufactured and subjected to a comprehensive analytical characterization and validation protocol to detect biomarkers present in the serum of patients with multiple sclerosis (MS). Biomarker concentrations were incorporated into a final algorithm used for calculating four Disease Pathway scores (Immunomodulation, Neuroinflammation, Myelin Biology, and Neuroaxonal Integrity) and an overall Disease Activity score.

RESULTS

Analytical characterization demonstrated that the multi-protein panel satisfied the criteria necessary for a fit-for-purpose validation considering the assay's intended clinical use. This panel met acceptability criteria for 18 biomarkers included in the final algorithm out of 21 biomarkers evaluated. VCAN was omitted based on factors outside of analytical validation; COL4A1 and GH were excluded based on imprecision and diurnal variability, respectively. Performance of the four Disease Pathway and overall Disease Activity scores met the established acceptability criteria.

CONCLUSIONS AND CLINICAL RELEVANCE

Analytical validation of this multi-protein, serum-based assay is the first step in establishing its potential utility as a quantitative, minimally invasive, and scalable biomarker panel to enhance the standard of care for patients with MS.

Impact of Remote Patient Monitoring on Length of Stay for Patients with COVID-19

Background: Remote patient monitoring (RPM) can be deployed as part of a tiered approach to open up hospital bed availability by allowing earlier discharge of patients with continued virtual monitoring. We describe the impact of RPM on length of stay (LOS) for patients with COVID-19. Methods: We deployed RPM during two COVID-19 surges at a tertiary academic hospital from March to June 2020 as a feasibility pilot to establish the infrastructure for RPM including electronic health record changes and virtual health center (VHC) protocols, and October 2020 to February 2021, during the second surge of COVID-19. Discharging patients received a wearable vital sign monitoring device, allowing real-time data transmission to the VHC using a smart phone application. The data, monitored 24 h a day for 8 days by a technician, had built-in escalation protocols to nurses and/or attending physicians. Results: We compared patients discharged with RPM with those discharged without RPM during both phases using a two-to-one-matched case-control design including age, sex, Charlson comorbidity index, and limited English proficiency. After including discharge with home oxygen therapy as an effect modifier, there was a significant association between shorter LOS and RPM for patients discharging without home oxygen (p = 0.0075) compared with patients not discharging on RPM. Discussion: Our study shows a strong association between a reduction in LOS for patients discharging with RPM but without home oxygen therapy, which can assist with hospital capacity. Conclusions: Home telemonitoring after discharge for patients with COVID-19 may reduce LOS.

Elements Influencing Recruitment and Retention of Millennial Hospitalists Born in or after 1982: a Survey-Based Study

BACKGROUND

Hospitalist turnover is exceedingly high, placing financial burdens on hospital medicine groups (HMGs). Following training, many begin their employment in medicine as early-career hospitalists, the majority being millennials.

OBJECTIVE

To understand what elements influence millennial hospitalists' recruitment and retention.

DESIGN

We developed a survey that asked participants to rate the level of importance of 18 elements (4-point Likert scale) in their decision to choose or remain at an HMG.

PARTICIPANTS

The survey was electronically distributed to hospitalists born in or after 1982 across 7 HMGs in the USA.

MAIN MEASURES

Elements were grouped into four major categories: culture of practice, work-life balance, financial considerations, and career advancement. We calculated the means for all 18 elements reported as important across the sample. We then calculated means by averaging elements within each category. We used unpaired t-tests to compare differences in means for categories for choosing vs. remaining at an HMG.

KEY RESULTS

One hundred forty-four of 235 hospitalists (61%) responded to the survey. 49.6% were females. Culture of practice category was the most frequently rated as important for choosing (mean 96%, SD 12%) and remaining (mean 96%, SD 13%) at an HMG. The category least frequently rated as important for both choosing (mean 69%, SD 35%) and remaining (mean 76%, SD 32%) at an HMG was career advancement. There were no significant differences between respondent gender, race, or parental status and ratings of elements for choosing or remaining with HMGs.

CONCLUSION

Culture of practice at an HMG may be highly important in influencing millennial hospitalists' decision to choose and stay at an HMG. HMGs can implement strategies to create a millennial-friendly culture which may help improve recruitment and retention.

The utilization and mortality benefits of pulmonary artery catheterization in patients with cardiogenic shock

Introduction

Pulmonary artery catheterization (PAC) can provide essential hemodynamic data to assist in managing critical patients with cardiogenic shock. The use of PAC has been controversial as clinical studies have shown a lack of benefit. However, with the recent widespread availability of mechanical circulatory assists devices, the application and benefits of PAC are expected to rise.

Purpose

To determine the impact of PAC on inpatient outcomes and the utilization of advanced heart failure devices in these patients.

Methods

The National Inpatient Sample from 2016 to 2018 was queried to identify patients with cardiogenic shock. Of these patients, we compared those who received invasive hemodynamic monitoring (IHM) with PAC to those who did not receive PAC. Patients under age 18 and those undergoing surgical or transcatheter cardiac procedures during the same admission were excluded. Multivariate logistic regression was used to select matched samples between groups accounting for patient/hospital demographics and medical comorbidities. The primary endpoint was a comparison of in-hospital mortality, length of hospitalization, and medical costs. The secondary endpoints compared the utilization of mechanical circulatory assists devices: percutaneous ventricular assist devices (pVAD), extracorporeal membrane oxygenation (ECMO), and left ventricular assist device (LVAD), and the incidence of post-PAC complications: pneumothorax, sepsis, and hemorrhage/hematoma.

Results

We identified a total of 279,619 patients admitted with cardiogenic shock, of these patients 25,166 (9%) received IHM with PAC. Patients who had PAC had decreased in-hospital mortality (22.3% vs 29.7%; p&lt;0.001), increased length of hospitalization (12 days vs 9 days; p&lt;0.001), and increased medical costs ($65,884 vs $47,983; p&lt;0.001). Furthermore, in patients with PAC there was increased utilization of pVAD (4.5% vs 1.9%; p&lt;0.001), ECMO (0.07% vs 0.01%; p&lt;0.001), and LVAD (2.2% vs 0.3%; p&lt;0.001). There was no difference in the prevalence of post-PAC complications between both groups.

Conclusions

The use of IHM with PAC was associated with improved mortality and utilization of mechanical circulatory assist devices in patients with cardiogenic shock without increasing risk for post-procedural complications. Therefore, the increased average duration and medical costs of hospitalization with PAC patients likely resulted from improved patient survival. Therefore, the present study indicated that IHM with PAC is safe and beneficial for patients with cardiogenic shock.

Funding Acknowledgement

Type of funding sources: None.

A nationwide analysis of cardiac sarcoidosis and related in-hospital outcomes

Introduction

Sarcoidosis is a multisystem disorder characterized by an autoimmune response to an unidentified antigen in genetically susceptible persons. Despite clinically detectable cardiac manifestations of sarcoidosis occurring in approximately 5% of patients, recent studies have revealed cardiac involvement to be at 25% in patients with the disease, highlighting the fact that cardiac involvement in sarcoidosis is much more common than was once thought to be.

Purpose

With cardiac involvement in sarcoidosis being increasingly recognized due to the availability of advanced cardiac imaging, large scale data regarding in-hospital mortality and clinical outcomes of patients admitted with cardiac sarcoidosis (CS) is lacking. Our study aimed to fill this knowledge gap by analyzing demographics and in-hospital outcomes of a large cohort of patients admitted with CS across the United States (US).

Methods

We analyzed data from the national inpatient sample (NIS) database between October 2015 to December 2018 to identify patients who had been admitted with primary and secondary diagnoses of CS. The NIS is an administrative database sponsored by the Agency for Healthcare Research and Quality consisting of data from 46 participating states, representing more than 95% of the US population and providing nationwide estimates of over 35 million hospitalizations annually. The NIS uses de-identified hospital discharges as samples and hence no additional ethical committee approval was required. International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) code D86.85 was used to identify hospitalizations with CS in patients aged 18 years or older. SAS 9.4 (SAS Institute, Inc, Cary, NC) was used for statistical analyses.

Results

A total of 4275 patients were included in the analysis. A higher proportion of patients with CS were females (62.43% vs. 37.57%). Hypertension was the most common comorbidity (43.99%), followed by hyperlipidemia (39.21%) and chronic kidney disease (26.95%). All-cause in-hospital mortality was 2.57%. Atrial fibrillation (AF) was the most common arrhythmia (28.12%), followed by ventricular tachycardia (VT) (22.52%). About 16% of CS patients underwent implantable cardioverter-defibrillator (ICD) implantation during hospital stay. About 42% of patients had concurrent heart failure, out of whom 33.84% had heart failure with reduced ejection fraction (HFrEF). Mean length of hospital stay was 5 days (3–8 days), and the mean cost of hospitalization was $14,177 ($7,121–35,993).

Conclusion

Given the low prevalence of CS, most of the available studies have been retrospective in nature, based on small sample sizes. Despite being retrospective and cross-sectional, our study has the advantage of being based on a nationally representative sample population, providing key formation on the demographics and in-hospital outcomes of patients with CS.

Funding Acknowledgement

Type of funding sources: None.

Ultrasonic testing of thick and thin Inconel 625 alloys manufactured by laser powder bed fusion

Additive manufacturing of alloys enables low-volume production of functional metallic components with complex geometries. Ultrasonic testing can ensure the quality of these components and detect typical defects generated during laser powder bed fusion (LPBF). However, it is difficult to find a single ultrasonic inspection technique that can detect defects in the large variety of geometries generated using LPBF. In this work, phased array ultrasonic testing (PAUT) is suggested to inspect thick LPBF components, while guided waves are explored for thin curved ones. PAUT is used to detect cylindrical lack of fusion defects in thick LPBF rectangular parts. Practical defects are generated by reducing the laser power at prespecified locations in the samples. The defects' shape and density are verified using optical microscopy and X-ray computed tomography. Partially fused defects down to 0.25 mm in diameter are experimentally detected using a 10 MHz PAUT probe with the total focusing method post-processing. The experimental results are compared to defect images predicted by finite element simulations. For thin components with curved geometry, guided waves are used to detect powder-filled cylindrical defects. The waves are generated using piezoelectric transducers, and the spatiotemporal wavefield is measured using a scanning laser Doppler vibrometer. Using root-mean-square imaging of the wavefield, defects down to 1 mm are clearly detected despite the complex internal features in the samples.