doppler signals
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2021 ◽  
Vol 14 (12) ◽  
pp. e247433
Author(s):  
Balamrit Singh Sokhal ◽  
Sowmya Prasanna Kumar Menon ◽  
Harrypal Panesar ◽  
Sriram Rajagopalan

A 44-year-old man was admitted after being found suspended by his ankles from a bridge for 5 days. The events leading to it was not clearly known initially. On examination, the patient was hypotensive and hypothermic, airway was oedematous and both lower limbs were mottled with dusky feet. Both foot pulses were impalpable, with prolonged capillary refill time and sensation barely present. Doppler signals were not heard in the feet, but groin pulses and popliteal signals were present. On CT, the patient had bilateral pneumothoraxes, extensive subcutaneous emphysema throughout the body from the subcutaneous tissue of the scalp to both lower limbs and pneumomediastinum and pneumoperitoneum. CT angiogram showed opacification up to proximal crural vessels and absence beyond. After multispeciality input and optimisation of his physiology, he underwent bilateral below knee amputations as they were non-salvageable.


Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 7314
Author(s):  
Huiling Hou ◽  
Zhiliang Yang ◽  
Cunsuo Pang

The micro-Doppler signal generated by the rotors of an Unmanned Aerial Vehicle (UAV) contains the structural features and motion information of the target, which can be used for detection and classification of the target, however, the standard STFT has the problems such as the lower time-frequency resolution and larger error in rotor parameter estimation, an FRFT (Fractional Fourier Transform)-FSST(STFT based synchrosqueezing)-based method for micro-Doppler signal detection and parameter estimation is proposed in this paper. Firstly, the FRFT is used in the proposed method to eliminate the influence of the velocity and acceleration of the target on the time-frequency features of the echo signal from the rotors. Secondly, the higher time-frequency resolution of FSST is used to extract the time-frequency features of micro-Doppler signals. Moreover, the specific solution methodologies for the selection of window length in STFT and the estimation of rotor parameters are given in the proposed method. Finally, the effectiveness and accuracy of the proposed method for target detection and rotor parameter estimation are verified through simulation and measured data.


Author(s):  
Wenchao Li ◽  
Gangyao Kuang ◽  
Zhenhua Chen ◽  
Jian Wang
Keyword(s):  

2021 ◽  
Vol 108 (Supplement_7) ◽  
Author(s):  
Mohamad Kamarizan ◽  
Anthony Da Silva

Abstract Aims Interpretation of Doppler audio signals among non-podiatrist has not been thoroughly investigated. This study analyses the accuracy of interpretation of Doppler audio signals among clinicians. Methods A single-centre prospective single blind study was used. Clinicians in the vascular department and with prior vascular experience in a district general hospital participated in interpreting 15 12-second Doppler audio signals (5 monophasic, 5 biphasic and 5 triphasic) into either ‘monophasic’, ‘biphasic’ and ‘triphasic’ using a Huntleigh’s Dopplex DMXTM digital hand-held Doppler ultrasound with visual waveform display covered. After all the audio signals were graded, the waveforms of each doppler signals are shown on the hand-held doppler display to reveal the correct responds. Results 8 clinicians were involved; 5 had less than 6 months of vascular experience. Out of 15 audio signals, the mean number correct grading of signals was 10.1. There is no difference in number of correct grading of the 3 waveforms (monophasic 3.5 out of 5, biphasic 3.25 out of 5, triphasic 3.5 out of 5). There is also no difference in responses between clinicians with less than 6 months and more than 6 months of vascular experience (p = 0.82). Conclusions There is a need for further ongoing education among clinicians in the use of hand held Doppler and interpretation of its audio signals. Reliability of Doppler examination in vascular assessment is also in contention, and further studies are required. The use of digital hand-held Doppler with visual wave form display will significantly improve accuracy of interpretation


2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Mathieu Alonzo ◽  
Anthony Lefebvre ◽  
Zhujun Huang ◽  
Stéphane Gluck ◽  
Cartellier Alain

Author(s):  
Mohit Mahajan ◽  
Madhumeet Singh ◽  
Akshay Sharma ◽  
Pravesh Kumar

Background: Embryonic mortality is one of the major factors leading to reproductive failure, decreased fertility and delayed pregnancy in cattle. Method: The study was aimed for investigating the incidence of embryonic mortality(EM), differentiate embryonic development and mortality based on color Doppler ultrasonographic characteristics. Different characteristics correlated were corpus luteum(CL) vascularity, embryonic development and EM features, monitored on day 21 post-insemination. Result: The overall incidence of EM was recorded to be 25%, with 15% and 10% mortality occurred between days 21-28 and 28-35 of gestation. Color Doppler analysis stated that, the CL in pregnant cows had a higher percentage of luteal tissue with positive Doppler signals on initial examination (day 21) differing significantly (P less than 0.01) from non-pregnant and consistently increased till the end of the examination. However, cows with EM had a significantly lower CL vascularity than pregnant (P less than 0.05) but significantly higher (P less than 0.05) than non-pregnant cows on day 21. Embryos from pregnant cows (detected by 28 days) increased in size along the days of examination. However, cows diagnosed with EM showed signs (day 28), which included reduced intra-uterine allantoic fluid, absence of embryo proper with an embryonic heartbeat, hyperechoic free-floating embryonic debris in the uterus and distorted allanto-chorionic membrane. In conclusion, the present study firmly supports color Doppler ultrasonography in diagnosis of pregnant cows based on CL vascularity, visualizing the different characteristics signs of EM, and detecting non-pregnant animals undergoing EM as early as day 21.


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 1415.4-1416
Author(s):  
S. Mahadevan ◽  
B. Navaneethan ◽  
N. Gopalakrishnapillai Syamala ◽  
M. Mamadapur ◽  
R. S ◽  
...  

Background:Progressive pseudorheumatoid dysplasia(PPRD) is considered as a degenerative genetic bone disorder. It is caused by loss of function mutation in WNT-1 inducible signaling pathway protein-3(WISP-3)1. WISP-3 gene function is required for the normal function of cartilage and skeletal development. The patients are normal at birth and start developing symptoms around 3-6 years of age2. The disease is characterised by stiffness, pain, deformity due to enlargement of the ends of short and long bones. Often, such patients are misdiagnosed as Juvenile idiopathic arthritis(JIA). In general, PPRD being considered as non-inflammatory disease, immunosuppressants or disease modifying anti rheumatic drugs(DMARDS) like methotrexate treatment are not used for treatment.Objectives:We report a patient with characteristic findings of PPRD but with coexisting clinical and imaging evidence of inflammation.Methods:16 year old male boy born of third degree consanguineous asymptomatic parents presented with progressive swelling, deformity of bilateral small and large joints of upper and lower limbs. He also had pain in both hip and knee for past two years. Pain is associated with difficulty in walking and squatting. On examination he had bony enlargement around bilateral elbow, wrist, proximal and distal interphalangeal joints(Figure 1A). He also had restriction of bilateral hip movements and swelling of bilateral knee with effusion. He had exaggerated lumbar lordosis and flexion deformity of bilateral hip, knee. His blood counts, ESR, CRP were normal. Analysis of Knee joint synovial fluid showed cell count of 200/mm3 with no crystals and sterile culture. USG knee showed evidence of synovial thickening with increased power Doppler signals. Skeletal survey showed typical findings of PPRD with enlargement of epiphysis and osteoarthritis changes(Figure 1B). MRI hip showed minimal effusion, synovial thickening, edema with STIR hyperintensity and enlargement of bilateral femoral epiphysis. MRI knee showed minimal effusion, marrow edema in patella(Figure 1C, arrow head), femoral condyle, diffuse synovial thickening with contrast enhancement(Figure 1D, arrow) and deformed patellar contour. Immunological tests showed negative RF, ACPA and positive ANA(Hep2) speckled 4+. Immunoblot for ENA was negative. His ophthalmological evaluation showed no evidence of uveitis.Figure 1.Clinical picture showing typical hand deformity and swelling at bone ends(A), hand radiograph showing epiphyseal enlargement(B), MRI knee T2 STIR showing bone marrow edema(arrow head) in patella(C) and synovial thickening(arrow) with contrast enhancement in fat saturated T1 MRI with contrast.Results:Patient tested positive for homozygous mutation in WISP-3 gene. He was treated with ibuprofen and supportive measures. Orthopedic consultation obtained and planned for hip, knee replacement during follow up. Follow up imaging and acute phase response was advised after three months.Conclusion:Although PPRD was classically described as a degenerative disease, the findings presented in our case show coexisting inflammation. Bone marrow edema in weight bearing areas, synovial effusion may be explained as part of cartilage degeneration like in osteoarthritis but synovial hypertrophy with contrast enhancement, power Doppler signals in ultrasound, ANA positivity may be signs of coexisting inflammatory or autoimmune phenomenon.References:[1]Hurvitz JR, Suwairi WM et al. Mutations in the CCN gene family member WISP3 cause progressive pseudorheumatoid dysplasia. Nat Genet. 1999 Sep;23(1):94-8. doi: 10.1038/12699. PMID: 10471507.[2]Garcia Segarra N, Mittaz L et al. The diagnostic challenge of progressive pseudorheumatoid dysplasia (PPRD): a review of clinical features, radiographic features, and WISP3 mutations in 63 affected individuals. Am J Med Genet C Semin Med Genet. 2012 Aug 15;160C(3):217-29. doi: 10.1002/ajmg.c.31333. Epub 2012 Jul 12. PMID: 22791401.Disclosure of Interests:None declared


Diagnostics ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 358
Author(s):  
Su-Min Kim ◽  
Soo-Young Ye

The myocardial performance index is widely used as an indicator of the heart’s performance. However, due to the subjective nature of ultrasonic testing, there are differences in the measurements among inspectors, requiring a quantitative and objective assessment. In this study, an automated program was developed to quantitatively evaluate the myocardial performance index (MPI) and the cardiac time intervals in the left ventricle for each trimester. One hundred and thirty-three pregnant women who visited the hospital for prenatal examinations were studied, and skilled inspectors obtained left ventricular blood flow waveforms from 47 fetuses in the 12 weeks, 54 fetuses in the 22 weeks, and 32 fetuses in the 31 weeks of pregnancy using a pulse Doppler mode of ultrasound equipment. The acquired images automatically measured the isovolumetric contraction time (IVCT), isovolumetric relaxation time (IVRT,) ejection time (ET), and filling time (FT), and calculated the Tei index (TI) and the K-index (KI); each interval was manually measured during the actual inspection for comparison. In this study, the ultrasonic Doppler waveform was objectively analyzed and measured by the automated program, and it will help with the evaluation of fetal heart function.


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