Fault detection and diagnostics in ventilation units using linear regression virtual sensors

Buildings represent a significant portion of global energy consumption. Ventilation units are one of the largest components in buildings systems and are responsible for large part of energy consumption. Ventilation units are complex components, often customized for the specific building. Their faults impact buildings' energy efficiency and occupancy comfort. In order to ensure their correct operation, proper Fault Detection and Diagnostics methods must be applied. Hardware redundancy, an effective approach to detect faults, leads to increased costs and space requirements. We propose to exploit physical relations inside the unit to create virtual sensors from other sensors' readings, introducing redundancy in the system. We create linear regression models for three sensors using other sensors related through physical laws as inputs. We use two different measures to detect when a virtual sensor deviates from the actual one: coefficient of determination and acceptable range. We test our method on a real building at the University of Southern Denmark. Our method detects a fault in temperature sensor, where its readings have an abnormal trend and fall outside acceptable ranae for one day.Postprint (author's final draft

A method for fault detection and diagnostics in ventilation units using virtual sensors

Buildings represent a significant portion of global energy consumption. Ventilation units are complex components, often customized for the specific building, responsible for a large part of energy consumption. Their faults impact buildings’ energy efficiency and occupancy comfort. In order to ensure their correct operation, proper fault detection and diagnostics methods must be applied. Hardware redundancy, an effective approach to detect faults, leads to increased costs and space requirements. We propose exploiting physical relations inside ventilation units to create virtual sensors from other sensors’ readings, introducing redundancy in the system. We use two different measures to detect when a virtual sensor deviates from the physical one: coefficient of determination for linear models, and acceptable range. We tested our method on a real building at the University of Southern Denmark, developing three virtual sensors: temperature, airflow, and fan speed. We employed linear regression models, statistical models, and non-linear regression models. All models detected an anomalous strong oscillation in the temperature sensors. Readings fell outside the acceptable range and the coefficient of determination dropped. Our method showed promising results by introducing redundancy in the system, which can benefit several applications, such as fault detection and diagnostics and fault-tolerant control. Future work will be necessary to discover thresholds and set up automatic fault detection and diagnostics.Peer ReviewedPostprint (published version

The impact of fasciotomy on inpatient outcomes in lower leg fracture management.

BACKGROUND While lower extremity fractures are common injuries, concomitant compartment syndrome can lead to significant implications and surgical release (fasciotomy) is essential. The aim of this study was to identify potential predictors of compartment release and risk factors related to complications. Using a large nationwide cohort, this study compared patients suffering from lower extremity fractures with and without compartment syndrome during their primary in-hospital stay following trauma. METHODS A retrospective analysis was conducted using the prospective surgical registry of the working group for quality assurance in surgery in Switzerland, which collects data from nearly 85% of all institutions involved in trauma surgery. Inclusion criteria Patients who underwent surgical treatment for tibia and/or fibula fractures between January 2012 and December 2022 were included in the study. Statistics Statistical analysis was performed using Chi-square, Fisher's exact test, and t test. Furthermore, a regression analysis was conducted to determine the independent risk factors for fasciotomy and related complications. In the present study, a p value less than 0.001 was determined to indicate statistical significance due to the large sample size. RESULTS The total number of cases analyzed was 1784, of which 98 underwent fasciotomies and 1686 did not undergo the procedure. Patients with fasciotomies were identified as significantly younger (39 vs. 43 years old) and mostly male (85% vs. 64%), with a significantly higher American Society of Anesthesiologists (ASA) score (ASA III 10% vs. 6%) and significantly more comorbidities (30% vs. 20%). These patients had significantly longer duration of surgeries (136 vs. 102 min). Furthermore, the total number of surgical interventions, the rate of antibiotic treatment, and related complications were significantly higher in the fasciotomy group. Sex, age, comorbidities, and fracture type (both bones fractured) were identified as relevant predictors for fasciotomy, while ASA class was the only predictor for in-hospital complications. Outcomes Patients who underwent fasciotomy had a significantly longer hospital stay (18 vs. 9 days) and a higher complication rate (42% vs. 6%) compared to those without fasciotomy. While fasciotomy may have played a role, other factors such as variations in patient characteristics and injury mechanisms may also contribute. Additionally, in-house mortality was found to be 0.17%, with no patient death recorded for the fasciotomy group. CONCLUSIONS Fasciotomy is vital. The knowledge about the further course is, however, helpful in resource allocation. We found significant differences between patients with and without fasciotomy in terms of age, sex, complication rate, length of stay, comorbidities, duration of operations, and use of antibiotics during their primary in-hospital stay. While the severity of the underlying trauma could not be modulated, awareness of the most relevant predictors for fasciotomy and related complications might help mitigate severe consequences and avoid adverse outcomes

Is there an impact of surgeon's experience on in-hospital outcome in patients with operatively treated proximal humerus and humerus shaft fractures?

BACKGROUND: Proximal humerus and shaft fractures are common, comprising 10-11 % of all fractures. Progress in their management includes refined surgical techniques and implants, coupled with a deeper understanding of fracture patterns. AIMS: This study examines the effect of surgical education on in-hospital outcomes for operatively treated proximal and humerus shaft fractures, aiming to enhance patient care and results. MATERIAL AND METHODS: This study analyzed cases from 1st of January 2010 until the 31st of December 2021 using data extracted from the Swiss working group for quality assurance in surgery, including patients with proximal humerus and shaft fractures who underwent surgical procedures like open reduction with internal fixation (ORIF), closed reduction with internal fixation (CRIF), external fixation, or prosthesis. Analysis included patient demographics, procedure details, and outcomes, comparing those with and without teaching of the surgical procedures. Binary logistic regression identifie

Retrospective Registry-Based Nationwide Analysis of the COVID-19 Lockdown Effect on the Volume of General and Visceral Non-Malignant Surgical Procedures

Introduction Coronavirus disease 2019 (COVID-19) is an acute virus infection, which was declared a pandemic by the World Health Organization. The Swiss government decreed a public lockdown to reduce and restrict further infections. The aim of this investigation was to analyze the impact of the first COVID-19 lockdown on the performance of general and visceral surgery procedures. Materials and Methods A retrospective study was performed on the basis of the surgical registry of the working group for quality assurance in surgery (“Arbeitsgemeinschaft für Qualitätssicherung in der Chirurgie” or AQC). All patients with specific surgical diagnoses (complicated gastric or duodenal ulcer, acute appendicitis, hernia, diverticular disease, gallstone disease, pilonidal sinus, cutaneous and perianal abscess) were analyzed during 2019 and the corresponding lockdown period of March 14 through April 26, 2020. Data regarding patients’ characteristics, diagnoses, and treatments were analyzed. Results In total, 3,330 patients were analyzed, with 2,203 patients treated in 2019 and 1,127 patients treated in 2020. There was a reduction in the number of all investigated diagnoses during the pandemic period, with statistically significant differences in acute appendicitis, hernia, diverticular disease, gallstone disease, pilonidal sinus (all p < 0.001), and cutaneous abscess (p = 0.01). The proportion of complicated appendicitis (p = 0.02), complicated hernia (p < 0.001), and complicated gallstone disease (choledocholithiasis p = 0.01; inflammation, p = 0.001) was significantly higher during the lockdown period. The surgical urgency rate in all patients was higher during the lockdown period compared to the control period (p < 0.001). Conclusions The socioeconomic lockdown significantly impacted the number of general and visceral surgery procedures in Switzerland. The reasons for the reduction are multifactorial

Impact of the first COVID-19 shutdown on traumatological patient volumes in Switzerland

Background The coronavirus has caused a worldwide pandemic with serious impacts on our healthcare systems. Many countries experienced a decline in traumatological patient volume. The aim of this study is to evaluate the impact of the first lockdown on traumatological patient volume in Switzerland. Methods We retrospectively used a prospective national quality measurement database. We compared the period of the first lockdown in Switzerland from March 17 to April 26, 2020 to the same period in the years 2018 and 2019. Included were all adult patients with any S-code (trauma) according to the International Classification of Diseases. Results In total, we assessed 3874 patients (1779 in the year 2018, 1303 in the year 2019, and 792 in the year 2020) with a mean age of 61 ± 21 years. The patients during the lockdown period had significantly more injuries to the hip and forearm, had more comorbidities, and were more likely to have statutory insurance. During the lockdown period, more thromboembolism prophylaxis or anticoagulation was applied, and more patients needed antibiotic treatment. Conclusions The present study demonstrated a 40–55% reduction in patient volume during the lockdown period in Switzerland compared to the previous years. The in-hospital mortality and complication rate during the lockdown period remained stable. This study suggests that in-hospital care for trauma patients in Switzerland was not substantially affected by the first lockdown

A single-centre, retrospective study on the impact of omitting preoperative antibiotic prophylaxis on wound infections in minor orthopedic implant removals

Background: The use of preoperative antibiotic prophylaxis (POAP) in elective implant removal (IR) is controversial due to a lack of evidence-based recommendations. First-generation cephalosporins, which are commonly used in orthopedic IR, are believed to reduce wound infection risks. However, the potential for serious side effects had raised concerns about their necessity. This study was intended to evaluate whether omitting POAP in small IR increases the risk of wound infections. Methods: This retrospective, single-centre cohort study was conducted at a level I trauma centre in Switzerland, including patients who underwent IR between January 1, 2016, and December 31, 2021. The IR procedures involved the upper extremities (UEs), such as the clavicle, olecranon, radius and ulna, as well as the lower extremities (LEs), such as the patella, tibia, fibula, (bi)malleolar and foot. Postoperative follow-up included clinical and radiological evaluations 6 weeks after surgery. The outcomes assessed were deep wound infections, wound healing complications, refractures, persistent pain, bleeding, neurovascular injuries and muscle hernias. Results: Of the 273 patients (mean age: 42.1 ± 14.5; 44% female), 117 (42.9%) received POAP. In the LE group (n = 141), 51.1% received POAP; in the UE group (n = 132), 34.1% received POAP. Eleven (4.0%) wound-healing disorders were documented, with five (4.3%) in the POAP group and six (3.8%) in the non-POAP group (p = 1). No deep wound infections were observed. Conclusion: Withholding POAP in elective IR procedures does not significantly increase wound infection rates, suggesting it may be unnecessary in uncomplicated cases

Influence of Age on Outcome Following Rib Fractures - A Case-Control Analysis

BACKGROUND Thoracic injuries are a very common entity throughout all age groups. With rising numbers of geriatric patients, characteristics of this patient group need to be better defined. The aim of this study was to investigate the impact of age on the outcome of thoracic trauma. In this project we provide a stratification of differentiated age groups regarding outcome parameter on rib fractures. METHODS The study employed a retrospective design using data from patients who sustained thoracic trauma and received treatment at a level I trauma center over a 5-year period. Patients with the same pattern of injury and gender but different age (above and below 70 years) were matched. RESULTS The mean age of the study population was 57 ± 19 years, 69% were male, 54% of patients had preexisting comorbidities. Hemothorax was present in 109 (16%), pneumothorax in 204 (31%) and lung contusions in 136 patients (21%). The overall complication rate was 36%, with a mortality rate of 10%. The matched pair analysis of 70 pairs revealed a higher prevalence of comorbidities in the older age group. They had significantly fewer pulmonary contusions and pneumothoraces than the younger patients and a shorter length of stay. However, the older age group had a significantly higher mortality rate. CONCLUSIONS Geriatric patients with rib fractures exhibit different patterns of intrathoracic injuries compared to their younger counterparts. Although numeric age may not be the most accurate predictor of adverse outcome, we found that higher age was associated with a clear trend towards an increased mortality rate. Our findings build a basis for further research to evaluate the outcome of age for instance with the tool of a rib fracture scoring system within stratified age groups in order to identify patients at major risk

A Randomized Clinical Trial to Evaluate the Efficacy and Safety of the ACTLIFE Exercise Program for Women with Post-menopausal Osteoporosis: Study Protocol

Osteoporosis (OP) is a systemic disease of the skeleton characterized by increased risk of fracture. There is a general consensus on the efficacy of physical activity in the prevention of bone loss, falls and fractures, but there is no agreement on the best setting to exercise. The aim of the study is to evaluate the efficacy of a 12-months exercise protocol for women with post-menopausal OP when administered as individual home training (IHT) versus gym group training (GGT). The study is a randomized trial with two parallel groups. Sedentary patients with primary post-menopausal osteoporosis are recruited at the Istituto Ortopedico Rizzoli of Bologna. In the first group, the 12-month ACTLIFE program is performed as IHT, while in the second as GGT. The program is aimed at improving joint mobility, muscle force, balance, motor coordination and endurance. The study is single blinded. Patients are assessed at baseline and after 6 and 12 months. The primary outcome is the modification of quality of life measured with the Short Osteoporosis Quality of Life Questionnaire (ECOS-16). The findings of this study will highlight advantages and disadvantages of exercising in the two different settings and provide evidence on how to increase physical activity in osteoporotic women