Implementing a Hand Gesture Recognition System Based on Range-Doppler Map.

There have been several studies of hand gesture recognition for human-machine interfaces. In the early work, most solutions were vision-based and usually had privacy problems that make them unusable in some scenarios. To address the privacy issues, more and more research on non-vision-based hand gesture recognition techniques has been proposed. This paper proposes a dynamic hand gesture system based on 60 GHz FMCW radar that can be used for contactless device control. In this paper, we receive the radar signals of hand gestures and transform them into human-understandable domains such as range, velocity, and angle. With these signatures, we can customize our system to different scenarios. We proposed an end-to-end training deep learning model (neural network and long short-term memory), that extracts the transformed radar signals into features and classifies the extracted features into hand gesture labels. In our training data collecting effort, a camera is used only to support labeling hand gesture data. The accuracy of our model can reach 98%.

Doppler ultrasound findings in symptomatic pregnant women diagnosed with COVID-19.

The primary aim of this study was to investigate the potential impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on maternal and foetal Doppler findings. Doppler ultrasound findings were compared in 40 pregnant women diagnosed with COVID-19 disease who required hospitalisation (group 1) and 30 healthy pregnant women (group 2). Maternal characteristics and birth histories were recorded. Body mass index, gestational week at birth, type of delivery, oligihydroamnios, pre-term birth (<37 weeks), low birth weight (<10 percentile), perinatal death and f1st and 5th minute Apgar scores were recorded. Birth weights and foetal biophysical profile (BPP) scores in group 1 were significantly lower than those in group 2. There was a statistically significant between-group difference in the umbilical artery pulsatility index (PI), umbilical artery resistive index (RI), middle cerebral artery (MCA) PI, MCA RI, mean uterine artery (UtA) PI, mean UtA RI and cerebroplacental ratio (CPR), the parameters used to evaluate foetal-maternal blood flow. In the pregnant group diagnosed with COVID-19 and hospitalised, all foetal-maternal Doppler indicators of foetal-maternal blood flow were impaired, and birth weights and BPP scores in these patients were statistically significantly lower than those in the healthy controls.Impact statementWhat is already known on this subject? Foetal and maternal vascular malperfusion characterised by decidual arteriopathy have been reported in pathologies of placentas from pregnant women with SARS-CoV-2 infection.What the results of this study add? It was determined that COVID-19 disrupted foetal and maternal blood flow.What the implications are of these findings for clinical practice and/or further research? Foetal biometric measurements and foetal Doppler may be useful in the follow-up of perinatal outcomes in pregnant women with COVID-19.

Characteristics of deep vein thrombosis in the critically ill COVID-19 patient - an observational cohort study with Doppler ultrasound measurements.

OBJECTIVE: COVID-19 is associated with an increased prevalence of deep venous thrombosis (DVT), mainly in the lower limbs. However, the characteristics and rheological conditions, which contribute to facilitating DVT occurrence have been poorly investigated. We aimed to report DVT characteristics, vein diameters and peak blood flow velocities (PBFV) in the common femoral veins (CFVs) of critically ill COVID-19 patients. PATIENTS AND METHODS: We conducted a prospective single-center cohort study in March-October 2020 including all consecutive mechanically ventilated COVID-19 adults. Doppler ultrasound of the lower limbs was performed systematically during the first week of hospitalization. In DVT-free patients, a second Doppler ultrasound was performed seven days later. Data are expressed as medians (interquartile ranges) or percentages. Comparisons were performed using Mann-Whiney and Wilcoxon signed-rank tests or Fischer's exact tests, as appropriate. RESULTS: Fifty-five patients [age, 63 years (56-74); female/male ratio, 0.62; body-mass index, 29 kg/m2 (26-33); hypertension, 47%; diabetes, 38%; ischemic heart disease, 11%] were included. DVT was diagnosed in 19 patients (35%) including in 5 femoral (9%), 2 popliteal (4%) and 12 below-the-knee sites (22%). CFV diameter was increased to 12.0 mm (11.0-15.0) (normal range, 9.1-12) and PBFV reduced to 11.9 cm/s (8.8-15.8) (normal range, 21.3-49.2) [right-side values]. In four patients who had ultrasound before intubation, CFV diameter increased from 12.5 mm (11.8-13.3) before to 14 mm (13.6-15.3) after intubation (p = 0.008). CONCLUSIONS: DVT in the CFV occurred in 9% of the critically ill COVID-19 patients with an overall 35%-DVT prevalence. Venous return difficulty evidenced by larger than normal CFV diameters and lower than normal PBFVs may have facilitated proximal DVT occurrence.

Three cases of acute venous thromboembolism in females after vaccination for coronavirus disease 2019.

Since December 2020, four vaccines for SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) have been developed, and three have been approved for immediate use in the United States. Two are mRNA vaccines, and one uses a viral vector mechanism. Thrombotic complications have been reported after vaccine administration, which were primarily cerebral sinus thromboses after administration of the viral vector vaccines. To the best of our knowledge, we are the first to report venous thrombotic complications within days of administration of the mRNA-1273 (Moderna) vaccine. We present a series of three women who developed venous thromboembolism after RNA-1273 vaccination at a single healthcare system.

Fetal pulmonary artery Doppler evaluation in pregnant women after recovery from COVID-19.

OBJECTIVE: To evaluate fetal lung development using pulmonary artery Doppler in pregnant women who had recovered from COVID-19. METHODS: The prospective case-control study included 41 pregnant women who had recovered from COVID-19 and 43 healthy pregnant women (control group). All the women in the study group had been diagnosed with COVID-19 and had completed a quarantine period. RESULTS: The demographic data of patients were similar in the groups (P > 0.05). Main pulmonary artery peak systolic velocity was higher and pulsatility indices were lower in pregnant women who recovered from COVID-19 compared to the controls (P < 0.001, P = 0.001). Acceleration time, ejection time, and acceleration/ejection time ratio (PATET) of the fetal MPA Doppler were significantly decreased in pregnant women who recovered from COVID-19 (P < 0.001, P = 0.036, and P = 0.002, respectively). The patients who had recovered from COVID-19 were divided into two groups: those treated with expectant management and those treated in hospital. The pulmonary artery acceleration time and PATET ratio were significantly lower in the group treated in the hospital (P = 0.023 and P = 0.045, respectively). CONCLUSION: Detailed Doppler evaluations of the pulmonary artery may help in evaluating the fetal adverse effects of COVID-19 disease.

Vascular alterations among young adults with SARS-CoV-2.

While SARS-CoV-2 primarily affects the lungs, the virus may be inflicting detriments to the cardiovascular system, both directly through angiotensin-converting enzyme 2 receptor and initiating systemic inflammation. Persistent systemic inflammation may be provoking vascular dysfunction, an early indication of cardiovascular disease risk. To establish the potential effects of SARS-CoV-2 on the systemic vasculature in the arms and legs, we performed a cross-sectional analysis of young healthy adults (control: 5 M/15 F, 23.0 ± 1.3 y, 167 ± 9 cm, 63.0 ± 7.4 kg) and young adults who, 3-4 wk prior to testing, had tested positive for SARS-CoV-2 (SARS-CoV-2: 4 M/7 F, 20.2 ± 1.1 y, 172 ± 12 cm, 69.5 ± 12.4 kg) (means ± SD). Using Doppler ultrasound, brachial artery flow-mediated dilation (FMD) in the arm and single passive limb movement (sPLM) in the leg were assessed as markers of vascular function. Carotid-femoral pulse wave velocity (PWVcf) was asvsessed as a marker of arterial stiffness. FMD was lower in the SARS-CoV-2 group (2.71 ± 1.21%) compared with the control group (8.81 ± 2.96%) (P < 0.01) and when made relative to the shear stimulus (SARS-CoV-2: 0.04 ± 0.02 AU, control: 0.13 ± 0.06 AU, P < 0.01). The femoral artery blood flow response, as evidenced by the area under the curve, from the sPLM was lower in the SARS-CoV-2 group (-3 ± 91 mL) compared with the control group (118 ± 114 mL) (P < 0.01). PWVcf was higher in the SARS-CoV-2 group (5.83 ± 0.62 m/s) compared with the control group (5.17 ± 0.66 m/s) (P < 0.01). Significantly lower systemic vascular function and higher arterial stiffness are evident weeks after testing positive for SARS-CoV-2 among young adults compared with controls.NEW & NOTEWORTHY This study was the first to investigate the vascular implications of contracting SARS-CoV-2 among young, otherwise healthy adults. Using a cross-sectional design, this study assessed vascular function 3-4 wk after young adults tested positive for SARS-CoV-2. The main findings from this study were a strikingly lower vascular function and a higher arterial stiffness compared with healthy controls. Together, these results suggest rampant vascular effects seen weeks after contracting SARS-CoV-2 in young adults.

Acute upper limb ischemia in a patient with COVID-19: A case report.

The novel pandemic of coronavirus infection (COVID-19) has been linked with coagulopathy and thromboembolic events, causing limb loss and finally death. The present report describes a case of upper limb ischemia in a patient with COVID-19 infection, who lacked conventional risk factors for acute limb ischemia (ALI).mAn 83 year-old man with intraluminal thrombus and the occlusion of the axillary and brachial arteries, ceasing blood supply to the distal part of the body, was tested positive for the COVID-19 infection. The patient received therapeutic anticoagulation and underwent open thromboembolectomy, which failed to save the patient's life. The link between COVID-19 and thromboembolism remains unknown and needs further studies to be disclosed.

Investigation and management of pulmonary embolism 2: specific clinical conditions.

Pulmonary embolism remains a common and potentially deadly disease, despite advances in diagnostic imaging, treatment and prevention. Managing pulmonary embolism requires a multifactorial approach involving risk stratification, determining appropriate diagnostics and selecting individualised therapy. The first part of this article reviewed the pathophysiology, risk factors, clinical presentation, diagnostic evaluation and therapeutic management and early outpatient management of pulmonary embolism. This second part summarises pulmonary embolism in the setting of pregnancy, COVID-19, recurrent disease and chronic thromboembolic pulmonary hypertension.

Renal Resistive Index: Not Only for Kidney Clinics.

Renal Resistive Index (RRI) is a measurement of the resistance of the renal blood flow. A value higher than 0.70 is a marker of increased resistance and is correlated with kidney injury and its severity. Additionally, it may be associated with the mortality rate in the post-surgery population. In COVID-19 subjects, we found that high RRI has been associated with high levels of serum C-reactive protein, a marker of systemic inflammatory reaction syndrome. Finally, we propose RRI not only as a marker of kidney injury, but also as a tool to evaluate the course of critical illness.

A Comparison of Thrombosis and Hemorrhage Rates in Patients With Severe Respiratory Failure Due to Coronavirus Disease 2019 and Influenza Requiring Extracorporeal Membrane Oxygenation.

OBJECTIVES: Extracorporeal membrane oxygenation is a lifesaving therapy for patients with severe acute respiratory distress syndrome refractory to conventional mechanical ventilation. It is frequently complicated by both thrombosis and hemorrhage. A markedly prothrombotic state associated with high rates of venous thromboembolism has been described in patients with severe acute respiratory syndrome coronavirus 2 (coronavirus disease 2019) infection. These rates have currently not been described during extracorporeal membrane oxygenation in comparison to other viral pneumonias. DESIGN: Retrospective observational study. SETTING: Single high-volume tertiary critical care department at a university hospital. PATIENTS: Patients 16 years old or greater receiving venovenous extracorporeal membrane oxygenation between March 1, 2020, and May 31, 2020, with coronavirus disease 2019 were compared with a cohort of patients with influenza pneumonia between June 1, 2012, and May 31, 2020. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The rates of venous thromboembolism and hemorrhage were compared in patients with coronavirus disease 2019 against a historic population of patients with influenza pneumonia who required extracorporeal membrane oxygenation. There were 51 patients who received extracorporeal membrane oxygenation due to coronavirus disease 2019 and 80 patients with influenza. At cannulation for extracorporeal membrane oxygenation, 37% of patients with coronavirus disease 2019 compared with 8% of patients with influenza had filling defects on CT pulmonary angiography (p = 0.0001). Catheter-associated deep vein thrombosis shown on ultrasound Doppler after decannulation was present in 53% with coronavirus disease 2019 versus 25% with influenza (p = 0.01). The rates of intracranial hemorrhage at the time of cannulation were 16% with coronavirus disease 2019 and 14% with influenza (p = 0.8). Elevated d-dimer levels were seen in both conditions and were significantly higher in those with pulmonary thromboembolism than those without in coronavirus disease 2019 (p = 0.02). Fibrinogen and C-reactive protein levels were significantly higher in those with coronavirus disease 2019 than influenza (p < 0.01). CONCLUSIONS: Significant rates of pulmonary thromboembolism and of catheter-associated deep vein thrombosis were seen in both viral infections but were greater in those requiring the use of extracorporeal membrane oxygenation in coronavirus disease 2019 than for influenza.

Diagnosis and resection of a giant ovarian cyst presenting in a young patient with contralateral back pain and lower limb deep vein thrombosis.

We present a case of a giant ovarian cyst in a 20-year-old woman who presented atypically at our Emergency Department with left-sided back pain followed by acute left leg swelling. Blood tests showed significantly raised C-Reactive Protein and D-Dimer. CT-Abdomen-Pelvis demonstrated a large mass in the region of the right ovary with suspicious heterogeneous filling defects in the left external iliac vein, confirmed as a left-sided deep-vein thrombosis on ultrasound Doppler. MRI revealed the lesion to be cystic and the deep venous thrombosis was treated with twice-daily Clexane. Prior to removal of the cyst, an Inferior Vena Cava Filter was placed to reduce thromboembolic risk. The cyst was resected without complication and the postoperative period was uneventful. This case occurred while face-to-face services were limited by COVID-19 and illustrates the need for robust systemic measures to safeguard patients against the emergency sequelae of insidious gynaecological pathology.

Assessment of fetal Doppler parameters in pregnant women with COVID-19 infection: a prospective case-control study.

OBJECTIVES: To investigate the effect of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on fetal Doppler parameters. METHODS: This was a prospective case-control study conducted in Ankara City Hospital with confirmed SARS-CoV-2 infected pregnants between August 1, 2020 and October 1, 2020. There were 54 COVID-19 confirmed pregnant women and 97 age-matched pregnant women as a control group between 28 and 39 weeks. Infection was confirmed based on positive real-time polymerase-chain reaction results. Demographic features, uterine artery (right, left), umblical artery, middle cerebral artery, ductus venosus, cerebro-placental ratio, and cerebral-placental-uterine ratio Doppler parameters were investigated in both groups. RESULTS: Two groups were similar in terms of demographic features and no difference was found for fetal Doppler parameters. CONCLUSIONS: COVID-19 seems to have no adverse effect on fetoplacental circulation in mild and moderate patients during the acute phase of the infection.

Doppler assessment of the fetus in pregnant women recovered from COVID-19.

OBJECTIVE: The aim of this study was to evaluate the maternal-fetal Doppler patterns in pregnant women recovered from COVID-19. METHODS: This prospective case-control study was conducted in Ankara City Hospital between July 1, 2020 and August 30, 2020. Thirty pregnant women who were diagnosed with COVID-19 and completed the quarantine process were compared with 40 healthy pregnant women in terms of the fetal Doppler parameters. All pregnant women diagnosed with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection were followed up in our clinic and their diagnoses have been confirmed in nasopharyngeal and oropharyngeal samples by quantitative real time reverse transcriptase polymerase chain reaction (RT-PCR) method. Doppler ultrasonographic assessment of the uterine arteries (UtA) and middle cerebral artery (MCA) were used in addition to umbilical artery (UA) Doppler between 23 and 40 weeks of gestation. Also, cerebroplacental ratio (CPR) was calculated according to gestational age. RESULTS: The pulsatility and resistance indices of umbilical and UtA showed a significant increase in pregnant women in the study group compared to the control group (p < 0.05). Multivariable logistic regression analysis revealed that pulsatility and resistance indices of the mean UtA were independently associated with disease (OR > 1000, 95%CI 9.77 to >1000, p = 0.009; OR 0,000 95%CI 0,000-0,944, p = 0,049), respectively. Medical treatment was given to 16/30 (53%) of pregnant women diagnosed with COVID-19. CONCLUSION: In conclusion, uterine artery Doppler indices in the third trimester may have clinical value in pregnant women recovered from COVID-19.

Maternal and fetal effects of COVID-19 virus on a complicated triplet pregnancy: a case report.

BACKGROUND: Coronavirus disease 2019 (COVID-19), the global pandemic that has spread throughout the world, is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Given the limited scientific evidence on the manifestations and potential impact of this virus on pregnancy, we decided to report this case. CASE PRESENTATION: The patient was a 38 year-old Iranian woman with a triplet pregnancy and a history of primary infertility, as well as hypothyroidism and gestational diabetes. She was hospitalized at 29 weeks and 2 days gestational age due to elevated liver enzymes, and finally, based on a probable diagnosis of gestational cholestasis, she was treated with ursodeoxycholic acid. On the first day of hospitalization, sonography was performed, which showed that biophysical scores and amniotic fluid were normal in all three fetuses, with normal Doppler findings in two fetuses and increased umbilical artery resistance (pulsatility index [PI] > 95%) in one fetus. On day 4 of hospitalization, she developed fever, cough and myalgia, and her COVID-19 test was positive. Despite mild maternal symptoms, exacerbated placental insufficiency occurred in two of the fetuses leading to the rapid development of absent umbilical artery end-diastolic flow. Finally, 6 days later, the patient underwent cesarean section due to rapid exacerbation of placental insufficiency and declining biophysical score in two of the fetuses. Nasopharyngeal swab COVID-19 tests were negative for the first and third babies and positive for the second baby. The first and third babies died 3 and 13 days after birth, respectively, due to collapsed white lung and sepsis. The second baby was discharged in good general condition. The mother was discharged 3 days after cesarean section. She had no fever at the time of discharge and was also in good general condition. CONCLUSIONS: This was a complicated triplet pregnancy, in which, after maternal infection with COVID-19, despite mild maternal symptoms, exacerbated placental insufficiency occurred in two of the fetuses, and the third fetus had a positive COVID-19 test after birth. Therefore, in cases of pregnancy with COVID-19 infection, in addition to managing the mother, it seems that physicians would be wise to also give special attention to the possibility of acute placental insufficiency and subsequent fetal hypoxia, and also the probability of vertical transmission.

Effect of SARS-CoV-2 infection during the second half of pregnancy on fetal growth and hemodynamics: A prospective study.

INTRODUCTION: Our objective was to compare the fetal growth velocity and fetal hemodynamics in pregnancies complicated and in those not complicated by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. MATERIAL AND METHODS: Prospective case-control study of consecutive pregnancies complicated by SARS-CoV-2 infection during the second half of pregnancy matched with unaffected women. The z scores of head circumference, abdominal circumference, femur length, and estimated fetal weight were compared between the two groups. Fetal growth was assessed by analyzing the growth velocity of head circumference, abdominal circumference, femur length, and estimated fetal weight between the second- and third-trimester scans. Similarly, changes in the pulsatility index of uterine, umbilical, and middle cerebral arteries, and their ratios were compared between the two study groups. RESULTS: Forty-nine consecutive pregnancies complicated, and 98 not complicated, by SARS-CoV-2 infection were included. General baseline and pregnancy characteristics were similar between pregnant women with and those without SARS-CoV-2 infection. There was no difference in head circumference, abdominal circumference, femur length, and estimated fetal weight z scores between pregnancies complicated and those not complicated by SARS-CoV-2 infection at both the second- and third-trimester scans. Likewise, there was no difference in the growth velocity of all these body parameters between the two study groups. Finally, there was no difference in the pulsatility index of both maternal and fetal Doppler scans throughout gestation between the two groups. CONCLUSIONS: Pregnancies complicated by SARS-CoV-2 infection are not at higher risk of developing fetal growth restriction through impaired placental function. The findings from this study do not support a policy of increased fetal surveillance in these women.

High prevalence of occult thrombosis in cases of mild/moderate COVID-19.

BACKGROUND AND PURPOSE: An increasing number of reports have observed thrombosis in severe cases of COVID-19. The aim of this study was to evaluate the incidence of thromboembolism in mild/moderate cases of COVID-19. All of the patients had normal coagulation tests and none had any overt thrombotic complications. Our findings indicate that it is important to screen the thrombotic status of cases with mild/moderate COVID-19. METHODS: Between 11 June and 8 July 2020, 23 patients with mild/moderate COVID-19 pneumonia consented to having computed tomography pulmonary angiography (CPTA) and computed tomography venography (CTV) scans of the lungs and extremity veins. Doppler ultrasound (DUS) was also performed in all patients for screening. The incidence, clinical manifestations, laboratory examinations, imaging features, and prognosis, of patients with venous thromboembolism (VTE) were analyzed and compared with those of patients with COVID-19 pneumonia without VTE. RESULTS: Nineteen patients (82.6%) had VTE, mainly distal limb thrombosis. Only one of the VTE patients was positive when screened by DUS; the other VTE patients were negative by DUS. All of the mild/moderate patients with VTE were screened by CTPA + CTV. Blood tests for inflammatory, coagulation, and biochemical, parameters were all within the normal range, except for WBC and LDH. CONCLUSIONS: When using CTV screening for DVT, we found that the incidence of thrombosis in patients with mild/moderate COVID-19 markedly increased to 82.6% (19/23). Screening for thrombosis is therefore important in patients with COVID-19. CTV is more sensitive than DUS for the detection of thrombosis. More research is now needed to evaluate the significance of thrombosis in COVID-19 pneumonia.