Doppler Machine Research Articles

Integrating Doppler LiDAR and machine learning into land-use regression model for assessing contribution of vertical atmospheric processes to urban PM2.5 pollution

Air pollution has been recognized as a global issue, through adverse effects on environment and health. While vertical atmospheric processes substantially affect urban air pollution, traditional epidemiological research using Land-use regression (LUR) modeling usually focused on ground-level attributes without considering upper-level atmospheric conditions. This study aimed to integrate Doppler LiDAR and machine learning techniques into LUR models (LURF-LiDAR) to comprehensively evaluate urban air pollution in Hong Kong, and to assess complex interactions between vertical atmospheric processes and urban air pollution from long-term (i.e., annual) and short-term (i.e., two air pollution episodes) views in 2021. The results demonstrated significant improvements in model performance, achieving CV R2 values of 0.81 (95 % CI: 0.75–0.86) for the long-term PM2.5 prediction model and 0.90 (95 % CI: 0.87–0.91) for the short-term models. Approximately 69 % of ground-level air pollution arose from the mixing of ground- and lower-level (105 m–225 m) particles, while 21 % was associated with upper-level (825 m–945 m) atmospheric processes. The identified transboundary air pollution (TAP) layer was located at ~900 m above the ground. The identified Episode one (E1: 7 Jan–22 Jan) was induced by the accumulation of local emissions under stable atmospheric conditions, whereas Episode two (E2: 13 Dec–24 Dec) was regulated by TAP under instable and turbulent conditions. Our improved air quality prediction model is accurate and comprehensive with high interpretability for supporting urban planning and air quality policies.

Assessment of Non-Alcoholic Hepatic Steatosis Disease and its Association with Hepatomegaly by Using Ultrasound

Background: Non-alcoholic hepatic steatosis disease (NAHSD) is increasingly recognized as a major global health concern, particularly due to its silent progression and significant impact on quality of life. The prevalence of NAHSD is particularly high in regions with widespread obesity and diabetes, conditions that are escalating in global incidence. Objective: This study aimed to evaluate the prevalence and severity of NAHSD and its association with hepatomegaly using ultrasonography in a Pakistani adult population. Methods: A cross-sectional study was conducted from November 2023 to March 2024 at the Department of Radiology, District Head Quarter’s Hospital, Swabi, Pakistan. A total of 70 adults presenting with clinical manifestations of hepatomegaly were enrolled. Ultrasonography was performed using a Toshiba Doppler machine equipped with a convex transducer (2.5—5.0 MH frequency). Liver size, shape, and echogenicity were assessed, and hepatic parenchyma was graded into three categories based on echogenicity. Data were analyzed using SPSS version 25, focusing on descriptive and inferential statistics. Results: The study comprised 41 females (58.6%) and 29 males (41.4%), with an age range from 19 to 69 years (mean age 43.79 ± 11.583 years). Hepatic steatosis was graded as mild in 20% (14), moderate in 5.7% (4), and severe in 1.4% (1) of patients with hepatomegaly. The majority, 72.9% (51), showed no signs of hepatic steatosis. Hepatomegaly was noted in 27% of patients (19). Conclusion: Ultrasonography is an effective diagnostic tool for assessing NAHSD and hepatomegaly, revealing a significant prevalence of these conditions among the studied population. Early screening and intervention are critical to managing and reducing the healthcare burden associated with NAHSD.

Detection of microemboli in patients with acute ischaemic stroke and atrial fibrillation suggests poor functional outcome.

We investigated the burden of microembolic signals (MES) in patients with acute ischaemic stroke (AIS) and atrial fibrillation (AF), assessing their impact on functional outcomes. This multicentre international prospective cohort study involved patients with AIS and either a known or newly diagnosed anticoagulant-naïve AF. All centres utilised the same transcranial Doppler machine for 1-h monitoring with bilateral 2 MHz probes within 24 h of symptom onset. Recordings underwent MES analysis by a blinded central reader. The primary objectives were to ascertain the MES proportion and its association with functional outcomes assessed by the modified Rankin scale (mRS) score at 90 days. Between September 2019 and May 2021, we enrolled 61 patients, with a median age of 78 years (interquartile range 73-83) and a median stroke severity score of 11 (interquartile range 4-18). MES were observed in 14 patients (23%), predominantly unilateral (12/14, 86%), with a median rate of 6 counts/hour (interquartile range 4-18). MES occurrence was higher post-thrombectomy and among those with elevated brain natriuretic peptide levels (p < 0.05). A worse mRS score of 3-6 was more frequent in patients with MES, occurring in 11/14 (79%), compared to those without MES, 20/47 (43%), with an adjusted odds ratio of 5.04 (95% CI, 1.15-39.4), p = 0.04. Nearly a quarter of patients with AIS and AF exhibited silent microembolization after the index event. Detecting MES within 24 h post-stroke (using transcranial Doppler) could signify a marker of poor functional outcomes. Subsequent trials will assess if very early antithrombotic treatment might enhance outcomes in this highly selective group of cardioembolic stroke patients. (Clinicaltrials.gov ID: NCT06018090).

Assessment of Computed Tomography and Ultrasonography in Detection of Ureteric Calculi

Background: Urolithiasis, a common urological condition, presents diagnostic challenges. While CT scans are considered the gold standard for detecting ureteric calculi, the role of ultrasonography is also significant, especially in varied clinical scenarios. Objective: This study aims to assess the diagnostic accuracy of ultrasonography compared to CT scans in the detection of ureteric calculi. Methods: An observational study was conducted on 200 patients at the Combined Military Hospital, Peshawar. Participants included males and females aged 18-60 years, presenting with acute renal pain. Exclusion criteria included individuals without informed consent, multiple comorbidities, a history of kidney donations, or a family history of renal calculi. Ultrasonography was performed using an Ecoste Mylab 7 color Doppler machine with 3.5, 5, and 7.5 MHz probes. CT scans were conducted using the Siemens CT Somatom Sensation 64, without the administration of any contrast medium. Data were analyzed using SPSS version 26.0. Results: Ultrasonography detected ureteric calculi in 33% of patients (66 calculi), while CT scans detected 60% (118 calculi). The breakdown of calculi location for ultrasonography included 20 renal, 15 pelvic ureteric junction, 12 upper ureter, 8 lower ureter, 7 vesicoureteric junction obstruction, and 4 bladder. CT scan results showed 45 renal, 25 pelvic ureteric junction, 20 upper ureter, 11 lower ureter, 9 vesicoureteric junction obstruction, and 8 bladder calculi. The gender distribution in the study was 55% male and 45% female, with the mean age being 35 ± 16.79 years for males and 36 ± 17.24 years for females. The most common presenting complaints were flank pain (36%), lower back pain (25%), and burning micturition (15%). Conclusion: CT scans exhibit higher diagnostic accuracy for ureteric calculi compared to ultrasonography, thus reaffirming their role as the gold standard in this context. However, the radiation risks and economic implications of CT scanning necessitate a balanced approach to its use, emphasizing the importance of comprehensive patient evaluation and physician awareness of radiation risks.

Peripheral arterial disease among children with type 1 diabetes mellitus in a Nigerian teaching hospital

The study aimed to determine the prevalence of PAD in children with T1DM and to correlate PAD with clinical characteristics in children with T1DM. A comparative cross-sectional study was conducted involving 90 subjects (forty-five with T1DM and 45 apparently healthy comparative subjects that were matched for age and gender). Systolic blood pressure was measured in all limbs using the pocket Doppler machine (Norton Doppler scan machine). Ankle brachial index (ABI) was calculated as a ratio of ankle to arm systolic blood pressure. Peripheral arterial disease was defined as ABI less than 0.9. The prevalence of PAD was significantly higher in children with T1DM than in the matched comparison group (37.8% vs. 6.7%, p<0.001). Average values of waist circumference, hip circumference, weight, height and body mass index were comparable in subjects with TIDM and the comparison group (p>0.05). Subjects with PAD had a poorer glucose control evident by higher average values of glycated haemoglobin than those without PAD (13.47±3.2% vs. 8.16±2.3%, p<0.001). There is a strong negative correlation between ABI scores and glycated haemoglobin among subjects with T1DM (r=-0.626, p<0.001). With these findings, it is recommended that screening for PAD in children who have T1DM and poor glycaemic control should be doneearly to prevent cardiovascular complications before they arise.

I Adore You

I Adore You Angela Yvonne Dahm My son, Theodore, was conceived after attending a cousin's wedding in Madison, WI. That cousin now has her own sons, one of whom is named Theodore. I found out I was pregnant on the first day of September and felt overwhelming excitement and anxiety, all at once. Would this pregnancy end happily for us? Two years earlier, we had lost our second pregnancy at 12 weeks because the fetus was not growing properly. The pregnancy was not viable, however the hospital was prohibited from performing a D&C because a heartbeat was still present. As a result, I remained hopelessly pregnant for three more long weeks waiting for that heartbeat to stop. Those three weeks were excruciating and traumatic. I grieved this loss deeply. Pregnant again, I cautiously took it one appointment at a time. Each whoosh whoosh whoosh of the heart doppler offered new hope and excitement that our baby was going to come to us. First trimester, then second trimester, then third trimester, but in the end a live birth would not be ours. The 27-week appointment went off without a hitch; a strong heartbeat, lots of baby kicks, round ligament pain, and complaints of swelling. I was anxious about traveling on an airplane for our upcoming babymoon1, so my doctor had me return in three weeks so we could check on baby boy before we flew to Dallas, TX. Three weeks later, a couple of days before my scheduled appointment, I noticed decreased fetal [End Page 199] movement and called my doctor's office. While initially telling me I might need to go to the hospital for fetal monitoring, the office called back to let me know that I was to count kick cycles that evening and come in first thing the next day. I had an anterior placenta with this pregnancy, which meant that the kicks were softer, as there was an entire placenta to send the kick movement through before it reached my belly button. I counted some kick cycles and fell asleep. Little did I know the devastation, pain and loss I was about to encounter. The next morning, cell phone in one hand, milk and decaf coffee in the other, I happily plopped down in the office, ready to get cozy, send some emails and listen to my baby's heartbeat. As the nurse tried to hook me up to the fetal monitoring machine, she struggled to find a heartbeat. After several minutes, she left the room to get help from the nurse practitioner. "She doesn't know what she's doing," I thought to myself. When the nurse practitioner couldn't find the heartbeat either, she left the room to grab a different doppler machine. When that proved fruitless, I told her, "This is bizarre. Dr. M always gets it on the very first try." She told me that I would need to go to the hospital for an ultrasound to check on the baby. She left the room to schedule the appointment and returned to let me know that I had an appointment and needed to go straight there. I broke down in tears in the elevator when I called my husband Jonathan to let him know that they couldn't find the baby's heartbeat and asked him to meet me at the hospital for an ultrasound. While driving, I called my mother, who was aware that I was going to the doctor to be monitored. She wanted to come join me at the hospital and I declined. I texted a couple of friends to let them know what was going on. When I got to the fourth floor at the hospital, I checked in and the receptionist told me I would need someone to accompany me for the ultrasound. That really set me off. I told her my husband was on the way and she asked that he check in at the front desk when he arrived. Why did I need someone to go back with me? I called my dear friend, Hannah, and cried and cried while sitting in the waiting room. Jonathan arrived, checked in, and they escorted...

Identity Authentication in Two-Subject Environments Using Microwave Doppler Radar and Machine Learning Classifiers

Identity authentication based on Doppler radar respiration sensing is gaining attention as it requires neither contact nor line of sight and does not give rise to privacy concerns associated with video imaging. Prior research demonstrating the recognition of individuals has been limited to isolated single-subject scenarios. When two equidistant subjects are present, identification is more challenging due to the interference of respiration motion patterns in the reflected radar signal. In this research, respiratory signature separation techniques are functionally combined with machine learning (ML) classifiers for reliable subject identity authentication. An improved version of the dynamic segmentation algorithm (peak search and triangulation) was proposed, which can extract distinguishable airflow profile-related features (exhale area, inhale area, inhale/exhale speed, and breathing depth) for medium-scale experiments of 20 different participants to examine the feasibility of extraction of an individual’s respiratory features from a combined mixture of motions for subjects. Independent component analysis with the joint approximation of diagonalization of eigenmatrices (ICA-JADE) algorithm was employed to isolate individual respiratory signatures from combined mixtures of breathing patterns. The extracted hyperfeature sets were then evaluated by integrating two different popular ML classifiers, k-nearest neighbor (KNN) and support vector machine (SVM), for subject authentication. Accuracies of 97.5% for two-subject experiments and 98.33% for single-subject experiments were achieved, which supersedes the performance of prior reported methods. The proposed identity authentication approach has several potential applications, including security/surveillance, the Internet-of-Things (IoT) applications, virtual reality, and health monitoring.

Exploratory study to assess feasibility of intracerebral hemorrhage detection by point of care cranial ultrasound

BackgroundLimited studies have evaluated the use of ultrasound for detection of intracerebral hemorrhage (ICH) using diagnostic ultrasound Transcranial Doppler machines in adults. The feasibility of ICH detection using Point of care Ultrasound (POCUS) machines has not been explored. We evaluated the feasibility of using cranial POCUS B mode imaging performed using intensive care unit (ICU) POCUS device for ICH detection with a secondary goal of mapping optimal imaging technique and brain topography likely to affect sensitivity and specificity of ICH detection with POCUS.Materials and methodsAfter obtaining IRB approval, a blinded investigator performed cranial ultrasound (Fujifilm, Sonosite® Xporte, transcranial and abdominal presets) through temporal windows on 11 patients with intracerebral pathology within 72 h of last CT/MRI (computed tomography scan/magnetic resonance imaging) brain after being admitted to a neurocritical care unit in Aug 2020 and Nov 2020–Mar 2021. Images were then compared to patient’s CT/MRI to inform topography. Inferential statistics were reported.ResultsMean age was 57 (28–77 years) and 6/11 were female. Six patients were diagnosed with ICH, 3 with ischemic stroke, 1 subarachnoid hemorrhage, and 1 brain tumor. The sensitivity and specificity of point of care diagnosis of ICH compared to CT/MRI brain was 100% and 50%, respectively. Mean time between ultrasound scan and CT/MRI was 13.3 h (21 min–39 h). Falx cerebri, choroid calcification and midbrain-related artifacts were the most reproducible hyperechoic signals. Abdominal preset on high gain yielded less artifact than Transcranial Doppler preset for cranial B mode imaging. False positive ICH diagnosis was attributed to intracerebral tumor and midbrain-related artifact.ConclusionsOur exploratory analysis yielded preliminary data on use of point of care cranial ultrasound for ICH diagnosis to inform imaging techniques, cranial topography on B mode and sample size estimation for future studies to evaluate sensitivity and specificity of cranial POCUS in adult patients. This pilot study is limited by small sample size and over representation of ICH in the study. Cranial POCUS is feasible using POCUS machines and may have potential as a screening tool if validated in adequately powered studies.

Prevalence and determinants of peripheral arterial disease in children with nephrotic syndrome.

Peripheral arterial disease (PAD) is the least studied complication of nephrotic syndrome (NS). Risk factors which predispose children with NS to developing PAD include hyperlipidaemia, hypertension and prolonged use of steroids. The development of PAD significantly increases the morbidity and mortality associated with NS as such children are prone to sudden cardiac death. The ankle brachial index (ABI) is a tool that has been proven to have high specificity and sensitivity in detecting PAD even in asymptomatic individuals. We aimed to determine the prevalence of PAD in children with NS and to identify risk factors that can independently predict its development. A comparative cross-sectional study was conducted involving 200 subjects (100 with NS and 100 apparently healthy comparative subjects that were matched for age, sex and socioeconomic class). Systolic blood pressures were measured in all limbs using the pocket Doppler machine (Norton Doppler scan machine). ABI was calculated as a ratio of ankle to arm systolic blood pressure. PAD was defined as ABI less than 0.9. The prevalence of PAD was significantly higher in children with NS than matched comparison group (44.0% vs 6.0%, p < 0.001). Average values of waist and hip circumference were significantly higher in subjects with PAD than those without PAD (61.68± 9.1cm and 67.6± 11.2 cm vs 57.03 ± 8.3cm and 65.60± 12.5cm respectively, p< 0.005). Serum lipids (triglyceride, very low density lipoprotein, total cholesterol and low density lipoprotein) were also significantly higher in subjects with PAD than those without PAD [106.65mg/dl (67.8–136.7) vs 45.72mg/dl (37.7–61.3), 21.33mg/dl (13.6–27.3) vs 9.14mg/dl (7.5–12.3), 164.43mg/dl (136.1–259.6) vs 120.72mg/dl (111.1–142.1) and 93.29mg/dl (63.5–157.3) vs 61.84mg/dl (32.6–83.1), respectively p< 0.05]. Increasing duration since diagnosis of NS, having a steroid resistant NS and increasing cumulative steroid dose were independent predictors of PAD in children with NS; p< 0.05 respectively. With these findings, it is recommended that screening for PAD in children with NS should be done to prevent cardiovascular complications before they arise.

Disparity in association of obesity measures with ankle and brachial systolic blood pressures in Europeans and South Asians

Obesity causes increases in brachial systolic-blood-pressures (SBP), risks of type 2 diabetes (T2DM) and cardiovascular diseases (CVD). Brachial and ankle SBPs have differential relationship with T2DM and CVD. Our objective was to study the relationship of obesity measures with brachial and ankle SBPs. A population of 1098 adults (South Asians n = 699; 41.70% male and 58.3% female) were recruited over 5 years from primary care practices in England. Their four limbs SBPs were measured using Doppler machine and body-mass-index (BMI) and waist-to-height-ratio (WHtR) calculated. Linear regressions were performed between SBPs and obesity measures, after adjustments for sex, age, ethnicity, T2DM and CVD. The mean age of all participants was 51.3 (SD = 17.2), European was 57.7 (SD 17.2) and South Asian was 47.8 (SD = 16.1). The left posterior tibial [Beta = 1.179, P = 4.559 × 10−15] and the right posterior tibial SBP [Beta = 1.178, P = 1.114 × 10−13] most significantly associated with the BMI. In South Asians, although the left brachial [Beta = 25.775, P = 0.032] and right brachial SBP [Beta = 22.792, P = 0.045] were associated to the WHtR, the left posterior tibial SBP [Beta = 39.894, P = 0.023], association was the strongest. For the first time, we have demonstrated that ankle SBPs had significant association with generalised obesity than brachial systolic blood pressures (SBP), irrespective of ethnicity. However, with respect to visceral obesity, the association with ankle SBP was more significant in South Asians compared to Europeans.

CEREBRAL BLOOD FLOW ASSESSMENT BY TRANSCRANIAL DOPPLER TO EVALUATE THE PERCENTAGE OF HIGH RISK OF STROKES IN SICKLE CELL ANEMIA PATIENTS – A CROSS SECTIONAL OBSERVATIONAL STUDY

Ÿ 1. AIMS AND OBJECTIVES :To assess the proportion of high risks of stroke in sickle cell disease patients using Transcranial Doppler ndings. Ÿ To assess the abnormal time average mean of maximum velocity in cerebral blood vessels so as we can prevent future stroke by giving proper treatment. 2. Materials and Methods: In our cross-sectional- observational study, 164 patients of age group 2 to 16 years have sickle cell disease were referred to radiology department. After taking informed consent, Transcranial Doppler of the patients was done either transtemporal or transforamenal approach. Data obtained from the study will be subjected to appropriate statistical analysis so as to facilitate interpretation and P-Values were found out. P-Value&lt;0.05 was considered to be statistically signicant. Ÿ 3. Results: Among 164 patients, 106 are male and 58 are female, from which 37 % of male and 27% of female are at high risk, considering the haemoglobin level in normal range. Ÿ In Transcranial Doppler study, we found out that from 164 patients, 108 are normal, 39 are conditional risk and 17 are at high risk of stroke. Ÿ After interpretation, the patients how have the values of TAMMV of MCA and/or ICA more than 200 are in the high risk of stroke with P-Value &lt;0.05; which was statistically signicant. 4. Conclusion: Prevalence of abnormal cerebral blood ow velocity is high in children with Sickle Cell Anemia which require more availability of transcranial Doppler machine for routine screening of children with SCD. This will help in early identication of children at risk of a Cardio-Vascular Accident for prompt intervention that can avert the deadly complication

Sleep Posture Recognition With a Dual-Frequency Microwave Doppler Radar and Machine Learning Classifiers

An automated, robust, noncontact sleep posture recognition technique is proposed in this letter, which uses optimizable (Bayesian hyperparameter tuning) machine learning (ML) classifiers applied to dual-frequency (2.4 GHz, 5.8 GHz) monostatic continuous-wave radar-measured effective radar cross section and chest displacement. The technique is demonstrated to accurately recognize three different key sleep postures categories for 20 participants, with greater accuracy and computational efficiency than prior published research involving either a custom ML model or threshold-based assessment. Three ML classifiers (K-nearest neighbor, support vector machine (SVM), and decision tree) were assessed, with an SVM using a quadratic kernel achieving an accuracy of 85 and 80%, at 2.4 and 5.8 GHz, respectively, and the decision tree classifier recognizing sleep postures in less than 2 min with 98.4% accuracy for dual-frequency combined measurements.

Association of folic Acid deficiency with Central Nervous System Anomalies, Anencephaly, Spina bifida and Hydrocephalous Diagnosed by Ultrasonography during Embryonic and Fetal period

Aim: To see central nervous system anomaly during pregnancy (anencephaly, hydrocephalus and spina bifida) by ultrasonography associated with folic acid deficiency/ low intake. Study design: cross sectional Site and duration: one year from Jan 2021 to Dec 2021 at Pak Red Crescent Medical &amp; Dental College and teaching Hospital Dina Nath Multan Road Kasur. Method: There was convenient sampling. Written Consent was taken from mothers for participation in study. Pregnant mothers were examined by ultrasonography and color Doppler Machine. Designated proforma was filled by taking history of pregnant mother. Results: The mean age of mothers was 25.oo + 5.00. Most of mothers were in 3rd trimester and Gravida 2. In eleven percent cases CNS anomalies were seen among these 6% were anencephaly and 5% were Spina bifida and hydrocephalus. Conclusion: Central nervous system anomalies were found associated with folic acid low intake by mothers during pregnancy. Keywords: Anencephaly, Hydrocephalus, Spina bifida, Folic acid intake, Ultrasonography.

Heartbeat Detection by Laser Doppler Vibrometry and Machine Learning.

Background: Heartbeat detection is a crucial step in several clinical fields. Laser Doppler Vibrometer (LDV) is a promising non-contact measurement for heartbeat detection. The aim of this work is to assess whether machine learning can be used for detecting heartbeat from the carotid LDV signal. Methods: The performances of Support Vector Machine (SVM), Decision Tree (DT), Random Forest (RF) and K-Nearest Neighbor (KNN) were compared using the leave-one-subject-out cross-validation as the testing protocol in an LDV dataset collected from 28 subjects. The classification was conducted on LDV signal windows, which were labeled as beat, if containing a beat, or no-beat, otherwise. The labeling procedure was performed using electrocardiography as the gold standard. Results: For the beat class, the f1-score () values were 0.93, 0.93, 0.95, 0.96 for RF, DT, KNN and SVM, respectively. No statistical differences were found between the classifiers. When testing the SVM on the full-length (10 min long) LDV signals, to simulate a real-world application, we achieved a median macro- of 0.76. Conclusions: Using machine learning for heartbeat detection from carotid LDV signals showed encouraging results, representing a promising step in the field of contactless cardiovascular signal analysis.

Transcranial Doppler in children with sickle cell disease: Five years of screening experience.

Sickle cell disease (SCD) is an autosomal recessive, inherited disorder of haemoglobin. Children with sickle cell disease (SCD) are at risk of vascular occlusions. If this occurs in the brain, it can result in stroke. Stroke is the leading cause of death and disability in children with SCD.Transcranial Doppler (TCD) has been shown to accurately predict those children at risk of stroke so appropriate preventative treatment can commence. TCD screening with a non-imaging Doppler machine to assess stroke risk has been in operation at our institution for 5years. Eighty-eight patients attending the haematology clinic for SCD are scanned annually. If abnormal velocities are found, repeat scans are performed at close interval to ensure results are reproducible. No child has had a stroke since the start of our screening. Seven of the eighty-eight patients have shown high velocities on annual screening. The introduction of a TCD programme at out institution has identified children at risk of stroke so they can be closely monitored and potentially receive prophylactic treatment.

The correlation between the preoperative measurement of estimated cerebral perfusion pressure and estimated intracranial pressure as obtained by trans cranial doppler with modified fisher grade as seen in computed tomography scan head in patients with acute sub arachnoid hemorrahage undergoing surgical clipping

Background: In Aneurysmal Sub Arachnoid haemorrhage, precise Cerebral Perfusion Pressure (CPP) and Intracranial Pressure (ICP) measurement can only be achieved by an invasive monitoring device. The study aimed at non-invasively estimating the preoperative values of CPP and ICP by use of validated formulae. These estimated flow velocities (estimated CPP or eCPP and estimated ICP or eICP) of the Middle Cerebral Artery were obtained by Trans Cranial Doppler ultrasound and comparing it with the preoperative CT Head Fisher Scale. In the Institute Rimed Digi-Lite Trans Cranial Doppler machine was used for research and Siemens (Somatom) 64 CT Scanner from GE (Signa) was used to perform CT scan of patients.Methods: It is a prospective, observational study which was studied between July 2017 and December 2018 in Post Graduate Institute of Medical Education and Research, Chandigarh, India. This study is a secondary analysis of a prospective observational study which was primarily designed to evaluate the neurological outcome related to the effect of estimated Intracranial Pressure and estimated Cerebral Perfusion Pressure as measured by Trans Cranial Doppler in patients with a SAH. A total of 100 patients were recruited in this study.Results: There was significant correlation between estimated CPP and Fisher Grading. There was no strong correlation between the modified Fisher Grade and estimated ICP.Conclusions: This study was able to give a statistically significant correlation between eCPP and Fisher Grading (p value- 0.047), as the Modified Fisher grading increased, so did the eCPP, this observation was unique, and it went against the hypothesis. However, no statistically significant co-relation was seen during comparison of eICP and Fisher Grading (p value- 0.069).

A New Application in Dermatological Ultrasound

As the high-resolution multifrequency transducers and multichannel color Doppler machines have been developed, dermatologic ultrasound imaging has been rapidly growing...

Tissue Oxygenation Sensor and an ActiveIn VitroPhantom for Sensor Validation

A free flap is a tissue reconstruction procedure where healthy tissue is harvested to cover up vital structures after wound debridement. Microvascular anastomoses are carried out to join the arteries and veins of the flap with recipient vessels near the target site. Continuous monitoring is required to identify the flap failure and enable early intervention to salvage the flap. Although there are medical instruments that can assist surgeons in monitoring flap viability, high upfront costs and time-consuming data interpretation have hindered the use of such technologies in practice. Surgeons still rely largely on the clinical examination to monitor flaps after operations. This paper presents a low-cost, low-power (6.6 mW), and miniaturized Hamlyn StO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> (tissue oxygen saturation) sensor that can be embodied as a plaster and attached to a flap for real-time monitoring. Similar to the design of oxygen saturation (SpO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /SaO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) sensors, the Hamlyn StO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> sensor was designed based on photoplethysmography (PPG), but with a different target of quantifying tissue perfusion rather than capturing pulsatile flow. To understand the spectral response to oxygenation/deoxygenation and vascular flow, an active in vitro silicone phantom was developed. The new sensor was validated using the silicone phantom and compared with a commercially available photospectroscopy and laser Doppler machine (O2C, LEA, Germany). In addition, in vivo experiments were conducted using a brachial pressure cuff forearm ischemia model. The experiment results have shown a high correlation between the proposed sensor and the O2C machine (r = 0.672 and p <; 0.001), demonstrating the potential value of the of the proposed low-cost sensor in post-operative free flap monitoring.

Machine Learning Classification for Assessing the Degree of Stenosis and Blood Flow Volume at Arteriovenous Fistulas of Hemodialysis Patients Using a New Photoplethysmography Sensor Device

The classifier of support vector machine (SVM) learning for assessing the quality of arteriovenous fistulae (AVFs) in hemodialysis (HD) patients using a new photoplethysmography (PPG) sensor device is presented in this work. In clinical practice, there are two important indices for assessing the quality of AVF: the blood flow volume (BFV) and the degree of stenosis (DOS). In hospitals, the BFV and DOS of AVFs are nowadays assessed using an ultrasound Doppler machine, which is bulky, expensive, hard to use, and time consuming. In this study, a newly-developed PPG sensor device was utilized to provide patients and doctors with an inexpensive and small-sized solution for ubiquitous AVF assessment. The readout in this sensor was custom-designed to increase the signal-to-noise ratio (SNR) and reduce the environment interference via maximizing successfully the full dynamic range of measured PPG entering an analog–digital converter (ADC) and effective filtering techniques. With quality PPG measurements obtained, machine learning classifiers including SVM were adopted to assess AVF quality, where the input features are determined based on optical Beer–Lambert’s law and hemodynamic model, to ensure all the necessary features are considered. Finally, the clinical experiment results showed that the proposed PPG sensor device successfully achieved an accuracy of 87.84% based on SVM analysis in assessing DOS at AVF, while an accuracy of 88.61% was achieved for assessing BFV at AVF.

Prevalence of left ventricular diastolic dysfunction by echocardiography in type II diabetes mellitus patients

Background: Epidemiological data indicates a greater risk of cardiovascular morbidity and mortality, particularly congestive heart failure in diabetic patients, compared with nondiabetic patients. Heart failure in many patients is due to left Ventricular Diastolic Dysfunction (LVDD), but its prevalence among diabetic adults is still not known, especially in the primary health care settings. Present study aims to evaluate the prevalence of LVDD by Echocardiography in Type II Diabetes Mellitus (DM).Methods: Authors did a prospective study, from May 2012 to August 2014, in Department of Medicine, Dr. D. Y. Patil Hospital, Kolhapur which included 100 randomly selected patients of Type II DM. The diagnosis of Type II DM was done according to the criteria laid down by American Diabetes Association 2012. A detailed clinical history was taken using a structured questionnaire prepared by us and all patients were evaluated for left ventricular function by Echocardiography. Equipment used for echocardiography-Mind ray DC USG, Doppler machine Probe used-7.5MHz.Results: On Echocardiography, Diastolic Dysfunction was found to be prevalent among individuals with Type 2 DM. Duration of DM and increasing age were found to be significantly associated with presence of Diastolic Dysfunction among individuals with Type 2 DM. Maximum number of patients were observed in the age group 51-60 years in our institute. 45% of the patients were asymptomatic, rest of the patients had predominantly cardiac symptoms.Conclusions: It is essential to screen diabetic patients with Echocardiography at an early stage to prevent future cardiovascular complications.