Epidemiology and estimated economic impact of musculoskeletal injuries in polytrauma patients in a level one trauma centre in Singapore

INTRODUCTION@#Musculoskeletal injuries are the most common reason for surgical intervention in polytrauma patients.@*METHODS@#This is a retrospective cohort study of 560 polytrauma patients (injury severity score [ISS] >17) who suffered musculoskeletal injuries (ISS >2) from 2011 to 2015 in National University Hospital, Singapore.@*RESULTS@#560 patients (444 [79.3%] male and 116 [20.7%] female) were identified. The mean age was 44 (range 3-90) years, with 45.4% aged 21-40 years. 39.3% of the patients were foreign migrant workers. Motorcyclists were involved in 63% of road traffic accidents. The mean length of hospital stay was 18.8 (range 0-273) days and the mean duration of intensive care unit (ICU) stay was 5.7 (range 0-253) days. Patient mortality rate was 19.8%. A Glasgow Coma Scale (GCS) score <12 and need for blood transfusion were predictive of patient mortality (p < 0.05); lower limb injuries, road traffic accidents, GCS score <8 and need for transfusion were predictive of extended hospital stay (p < 0.05); and reduced GCS score, need for blood transfusion and upper limb musculoskeletal injuries were predictive of extended ICU stay. Inpatient costs were significantly higher for foreign workers and greatly exceeded the minimum insurance coverage currently required.@*CONCLUSION@#Musculoskeletal injuries in polytrauma remain a significant cause of morbidity and mortality, and occur predominantly in economically productive male patients injured in road traffic accidents and falls from height. Increasing insurance coverage for foreign workers in high-risk jobs should be evaluated.

Landmark vessel in membrane anatomy-based colorectal surgery / 中华胃肠外科杂志

The theory of membrane anatomy has been widely used in the field of colorectal surgery. The key point to perform high quality total mesorectal excision (TME) and complete mesocolic excision (CME) is to identify the correct anatomical plane. Intraoperative identification of the various fasciae and fascial spaces is the key to accessing the correct surgical plane and surgical success. The landmark vessels refer to the small vessels that originate from the original peritoneum on the surface of the abdominal viscera during embryonic development and are produced by the fusion of the fascial space. From the point of view of embryonic development, the abdominopelvic fascial structure is a continuous unit, and the landmark vessels on its surface do not change morphologically with the fusion of fasciae and have a specific pattern. Drawing on previous literature and clinical surgical observations, we believe that tiny vessels could be used to identify various fused fasciae and anatomical planes. This is a specific example of membrane anatomical surgery.

Clinical characteristics and placental pathology analysis of 14 cases of pregnancy with aortic dissection/aortic aneurysm / 中华病理学杂志

Objective: To investigate the pathological changes of placenta in pregnant women with aortic dissection/aneurysm and their relationship with clinical features. Methods: The placental samples of 14 pregnant women with aortic dissection/aneurysm diagnosed from January 2012 to October 2021 and 10 normal placental samples of pregnant women from January 2021 to December 2021 at Beijing Anzhen Hospital Affiliated to Capital Medical University, Beijing, China were selected. Routine H&E staining and immunohistochemistry were used to analyze the histological features under light microscope. The clinical data were also analyzed. Results: The age of 14 pregnant patients with aortic dissection/aneurysm for placental examination ranged from 22 to 38 years (median, 28 years). The gestational ages ranged from 22 to 39 weeks (median, 34 weeks). The pregnancy of second trimester was noted in 2 cases, and the third trimester in 12 cases. All cases were singleton pregnancy. Seven cases were Stanford type A aortic dissection, 6 cases were Stanford type B aortic dissection, and one case was aortic root aneurysm. Four of the pregnant women underwent aortic dissection surgery after caesarean section, three underwent caesarean section after aortic dissection surgery, and seven underwent both caesarean section and aortic dissection procedures. Among the newborns, 2 cases were full-term birth, and 12 cases were premature birth. Twelve cases had alive newborns, and 2 cases stillbirths. Fetal/placental weight ratio (FPR)<10th percentile was in 5 cases and FPR>90th percentile in one case. Compared with the normal group, accelerated villus maturation and distal villus dysplasia were more frequently found in pregnancy with aortic dissection group (P<0.05). There was no significant difference in villi infarction and decidua vascular lesions between the two groups (P>0.05), nor was there correlation between the type of aortic dissection and distal villus dysplasia and accelerated villus maturation of placentas (P>0.05). The number of villous interstitial blood vessels in the placentas of pregnancy with aortic dissection group was significantly fewer than that in the normal control group (P<0.01). Conclusions: There are considerable pathological changes in the placentas of pregnant women with aortic dissection/aneurysm. The main histological features are accelerated villus maturation and distal villus dysplasia, which are manifestations of villous ischemia and hypoxia, and also a part of the placental pathological manifestations of maternal vascular dysperfusion.

Research and application of leek roots in medicinal field / 中草药·英文版

Some Chinese herbs have been used to prevent and treat diseases, and are also used as common food ingredients. These Chinese herbs are potential resource for research and development of new drugs. Leek roots is a typical medicine of food and medicine continuum. It has a long history of medicinal applications and edible food in China. In this paper, the origin, biological active components, pharmacological action and clinical application of leek roots were introduced. We hope that this review will contribute to the development of leek roots for pharmaceutical research and clinical applications, as well as related health products.

Thoracolumbar Injury Classification and Severity Score Is Predictive of Perioperative Adverse Events in Operatively Treated Thoracic and Lumbar Fractures

Methods@#We performed a retrospective review of 199 patients with surgically treated thoracolumbar fractures operated between January 2007 and January 2018. The potential risk factors for the development of AEs as well as the development of common complications were evaluated by univariate analysis, and a multivariate logistic regression analysis was performed to identify independent risk factors predictive of the above. @*Results@#The overall rate of AEs was 46.7%; 83 patients (41.7%) had nonsurgical AEs, whereas 24 (12.1%) had surgical adverse events. The most common AEs were urinary tract infections in 43 patients (21.6%), and hospital-acquired pneumonia in 21 patients (10.6%). On multivariate logistic regression, a Thoracolumbar Injury Classification and Severity (TLICS) score of 8–10 (odds ratio [OR], 6.39; 95% confidence interval [CI], 2.33–17.51), the presence of polytrauma (OR, 2.64; 95% CI, 1.17–5.99), and undergoing open surgery (OR, 2.31; 95% CI, 1.09–4.88) were significant risk factors for AEs. The absence of neurological deficit was associated with a lower rate of AEs (OR, 0.47; 95% CI, 0.31–0.70). @*Conclusions@#This study suggests the presence of polytrauma, preoperative American Spinal Injury Association score, and TLICS score are predictive of AEs in patients with surgically treated thoracolumbar fractures. The results might also suggest a role for minimally invasive surgical methods in reducing AEs in these patients.

Non-alcoholic fatty liver disease increases risk of carotid atherosclerosis and ischemic stroke: An updated meta-analysis with 135,602 individuals

Background/Aims@#Non-alcoholic fatty liver disease (NAFLD) is associated with the development of cardiovascular disease. While existing studies have examined cardiac remodeling in NAFLD, there has been less emphasis on the development of carotid atherosclerosis and stroke. We sought to conduct a meta-analysis to quantify the prevalence, risk factors, and degree of risk increment of carotid atherosclerosis and stroke in NAFLD. @*Methods@#Embase and Medline were searched for articles relating to NAFLD, carotid atherosclerosis, and stroke. Proportional data was analysed using a generalized linear mixed model. Pairwise meta-analysis was conducted to obtain odds ratio or weighted mean difference for comparison between patients with and without NAFLD. @*Results@#From pooled analysis of 30 studies involving 7,951 patients with NAFLD, 35.02% (95% confidence interval [CI], 27.36–43.53%) had carotid atherosclerosis with an odds ratio of 3.20 (95% CI, 2.37–4.32; P<0.0001). Pooled analysis of 25,839 patients with NAFLD found the prevalence of stroke to be 5.04% (95% CI, 2.74–9.09%) with an odds ratio of 1.88 (95% CI, 1.23–2.88; P=0.02) compared to non-NAFLD. The degree of steatosis assessed by ultrasonography in NAFLD was closely associated with risk of carotid atherosclerosis and stroke. Older age significantly increased the risk of developing carotid atherosclerosis, but not stroke in NAFLD. @*Conclusions@#This meta-analysis shows that a stepwise increment of steatosis of NAFLD can significantly increase the risk of carotid atherosclerosis and stroke development in NAFLD. Patients more than a third sufferred from carotid atherosclerosis and routine assessment of carotid atherosclerosis is quintessential in NAFLD.

The effect of diabetes and prediabetes on the prevalence, complications and mortality in nonalcoholic fatty liver disease

Background/Aims@#Nonalcoholic fatty liver disease (NAFLD) is closely associated with diabetes. The cumulative impact of both diseases synergistically increases risk of adverse events. However, present population analysis is predominantly conducted with reference to non-NAFLD individuals and has not yet examined the impact of prediabetes. Hence, we sought to conduct a retrospective analysis on the impact of diabetic status in NAFLD patients, referencing non-diabetic NAFLD individuals. @*Methods@#Data from the National Health and Nutrition Examination Survey 1999–2018 was used. Hepatic steatosis was defined with United States Fatty Liver Index (US-FLI) and FLI at a cut-off of 30 and 60 respectively, in absence of substantial alcohol use. A multivariate generalized linear model was used for risk ratios of binary outcomes while survival analysis was conducted with Cox regression and Fine Gray model for competing risk. @*Results@#Of 32,234 patients, 28.92% were identified to have NAFLD. 36.04%, 38.32% and 25.63% were non-diabetic, prediabetic and diabetic respectively. Diabetic NAFLD significantly increased risk of cardiovascular disease (CVD), stroke, chronic kidney disease, all-cause and CVD mortality compared to non-diabetic NAFLD. However, prediabetic NAFLD only significantly increased the risk of CVD and did not result in a higher risk of mortality. @*Conclusions@#Given the increased risk of adverse outcomes, this study highlights the importance of regular diabetes screening in NAFLD and adoption of prompt lifestyle modifications to reduce disease progression. Facing high cardiovascular burden, prediabetic and diabetic NAFLD individuals can benefit from early cardiovascular referrals to reduce risk of CVD events and mortality.

Symptomatic Construct Failure after Metastatic Spine Tumor Surgery

Methods@#We conducted a retrospective analysis on 288 patients (246 for final analysis) who underwent MSTS between 2005–2015. Data collected were demographics and peri/postoperative clinical and radiological features. Early and late radiological SF were defined as presentation before and after 3 months from index surgery, respectively. Univariate and multivariate models of competing risk regression analysis were designed to determine the risk factors for SF with death as a competing event. @*Results@#We observed 14 SFs (5.7%) in 246 patients; 10 (4.1%) underwent revision surgery. Median survival was 13.4 months. The mean age was 58.8 years (range, 21–87 years); 48.4% were women. The median time to failure was 5 months (range, 1–60 months). Patients with SF were categorized into three groups: (1) SF when the primary implant was revised (n=5, 35.7%); (2) peri-construct progression of disease requiring extension (n=5, 35.7%); and (3) SFs that did not warrant revision (n=4, 28.5%). Four patients (28.5%) presented with early failure. SF commonly occurred at the implant-bone interface (9/14) and all patients had a spinal instability neoplastic score (SINS) >7. Thirteen patients (92.8%) who developed failure had fixation spanning junctional regions. Multivariate competing risk regression showed that preoperative Eastern Cooperative Oncology Group score was a significant risk factor for implant failure (adjusted sub-hazard ratio, 7.0; 95% confidence interval, 1.63–30.07; p7 and fixations spanning junctional regions were associated with SF. Majority of construct failures occurred at the implant-bone interface.

Making a Traditional Spine Surgery Clinic Telemedicine-Ready in the “New Normal” of Coronavirus Disease 2019

Methods@#We reviewed the evidence behind telemedicine and described our clinical protocol, patient selection criteria, and workflow for telemedicine. We discussed a simple methodology to convert pre-existing traditional clinic resources into telemedicine tools, along with future challenges. @*Results@#Our methodology was successfully and easily applied in our clinical practice, with a streamlined workflow allowing our spine surgery service to implement telemedicine as a consultation modality in line with the national recommendations of social distancing. @*Conclusions@#Telemedicine was well incorporated into our outpatient practice using the above workflow. We believe that the use of telemedicine via videoconferencing can become part of the new normal and a safe strategy for healthcare systems as both a medical and an economic countermeasure against COVID-19.

Asymptomatic Construct Failure after Metastatic Spine Tumor Surgery: A New Entity or a Continuum with Symptomatic Failure?

Methods@#We conducted a retrospective analysis of 288 patients (246 for final analysis) who underwent MSTS between 2005–2015. Data collected were demographics and peri/postoperative clinical and radiological features. Early and late radiological AsCF were defined as presentation before and after 3 months, respectively. We analyzed patients with AsCF for risk factors and survival duration by performing competing risk regression analyses where AsCF was the event of interest, with SF and death as competing events. @*Results@#We observed AsCF in 41/246 patients (16.7%). The mean time to onset of AsCF after MSTS was 2 months (range, 1–9 months). Median survival of patients with AsCF was 20 and 41 months for early and late failures, respectively. Early AsCF accounted for 80.5% of cases, while late AsCF accounted for 19.5%. The commonest radiologically detectable AsCF mechanism was angular deformity (increase in kyphus) in 29 patients. Increasing age (p<0.02) and primary breast (13/41, 31.7%) (p<0.01) tumors were associated with higher AsCF rates. There was a non-significant trend towards AsCF in patients with a spinal instability neoplastic score ≥7, instrumentation across junctional regions, and construct lengths of 6–9 levels. None of the patients with AsCF underwent revision surgery. @*Conclusions@#AsCF after MSTS is a distinct entity. Most patients with early AsCF did not require intervention. Patients who survived and maintained ambulation for longer periods had late failure. Increasing age and tumors with a better prognosis have a higher likelihood of developing AsCF. AsCF is not necessarily an indication for aggressive/urgent intervention.

Symptomatic Construct Failure after Metastatic Spine Tumor Surgery

Methods@#We conducted a retrospective analysis on 288 patients (246 for final analysis) who underwent MSTS between 2005–2015. Data collected were demographics and peri/postoperative clinical and radiological features. Early and late radiological SF were defined as presentation before and after 3 months from index surgery, respectively. Univariate and multivariate models of competing risk regression analysis were designed to determine the risk factors for SF with death as a competing event. @*Results@#We observed 14 SFs (5.7%) in 246 patients; 10 (4.1%) underwent revision surgery. Median survival was 13.4 months. The mean age was 58.8 years (range, 21–87 years); 48.4% were women. The median time to failure was 5 months (range, 1–60 months). Patients with SF were categorized into three groups: (1) SF when the primary implant was revised (n=5, 35.7%); (2) peri-construct progression of disease requiring extension (n=5, 35.7%); and (3) SFs that did not warrant revision (n=4, 28.5%). Four patients (28.5%) presented with early failure. SF commonly occurred at the implant-bone interface (9/14) and all patients had a spinal instability neoplastic score (SINS) >7. Thirteen patients (92.8%) who developed failure had fixation spanning junctional regions. Multivariate competing risk regression showed that preoperative Eastern Cooperative Oncology Group score was a significant risk factor for implant failure (adjusted sub-hazard ratio, 7.0; 95% confidence interval, 1.63–30.07; p7 and fixations spanning junctional regions were associated with SF. Majority of construct failures occurred at the implant-bone interface.

Making a Traditional Spine Surgery Clinic Telemedicine-Ready in the “New Normal” of Coronavirus Disease 2019

Methods@#We reviewed the evidence behind telemedicine and described our clinical protocol, patient selection criteria, and workflow for telemedicine. We discussed a simple methodology to convert pre-existing traditional clinic resources into telemedicine tools, along with future challenges. @*Results@#Our methodology was successfully and easily applied in our clinical practice, with a streamlined workflow allowing our spine surgery service to implement telemedicine as a consultation modality in line with the national recommendations of social distancing. @*Conclusions@#Telemedicine was well incorporated into our outpatient practice using the above workflow. We believe that the use of telemedicine via videoconferencing can become part of the new normal and a safe strategy for healthcare systems as both a medical and an economic countermeasure against COVID-19.

Japanese encephalitis virus: Biological clones from a clinical isolate quasispecies show differing neurovirulence in vitro and in a mouse model

@#The Japanese encephalitis virus (JEV), a leading cause of encephalitis, exists as quasispecies in clinical isolates. Using a limiting dilution method combined with immunohistochemistry to detect viral antigens, 10 biological clones were isolated and purified from a clinical JEV isolate (CNS138/9) derived from an autopsy brain. These biological clones were tested for neurovirulence in SK-N-MC and NIE-115 neuronal cells, and a 2-week-old, footpad-infected, JE mouse model. Nine clones were found to be neurovirulent; one clone neuroattenuated. Although further studies are needed to determine genotypic differences, if any, in these clones, the limiting dilution purification and neurovirulence testing methods described herein should be useful for phenotypic studies of quasispecies of neurotropic viruses in general, and JEV and other flaviviruses in particular.

Mutation analysis of a family affected with isolated proteinuria / 中华医学遗传学杂志

OBJECTIVE@#To analyze the clinical characteristics and genetic features of a family affected with isolated proteinuria.@*METHODS@#Clinical data of the family was collected. Mutations of 191 renal disease-related genes in the proband were screened with next generation sequencing (NGS). Sanger sequencing was used to verify suspected mutations in his family members and 100 healthy controls. The impact of the mutation was predicted with online software SIFT. Frequency of the mutation was searched in databases including 1000 Genomic Project, ESP and ExAC.@*RESULTS@#NGS and Sanger sequencing showed that the proband harbored compound heterozygous mutations of ADCK4 gene including c.748C>G (p.Asp250His) and c.1041G>T (p.Cys347*), which were respectively inherited from his mother and father whom were both non-symptomatic.@*CONCLUSION@#The proband may have ADCK4-associated glomerulopathy due to the compound heterozygous mutations of the ADCK4 gene.

Repair soft tissue defects of extremities with the perforator flap based on the first perforating artery of Profunda artery / 中华整形外科杂志

Objective@#To investigate the feasibility of repairing soft tissue defects of extremities with the perforator flap based on the first perforating artery of profunda artery.@*Methods@#From January 2015 to December 2018, 9 patients with soft tissue defects of extremities were treated in the Department of Burns and Plastic Surgery, Affiliated Hospital of Zunyi Medical University. 5 males and 4 females; aged 29-48 years, average 36 years old. The causes of injury were traffic accident injury (4 cases), heavy object crush injury (3 cases) and mechanical injury (2 cases). There were 3 cases of soft tissue defect of upper limb, 6 cases of soft tissue defect of lower extremity, 2 cases of tendon and nerve rupture, 2 cases of fracture, 1 case of tendon and 1 case of bone exposure. All soft tissue defects were repaired with the perforator flap based on the first perforating artery of Profunda artery. After debridement, The range of soft tissue defect was 10 cm×5 cm-16 cm×10 cm. The intraoperative flap area was 12 cm×6 cm-18 cm×11 cm. The vascular anastomosis was performed in the area, the flap covered the wound surface and the donor site directly pulled the suture or grafted skin.@*Results@#All flaps survived completely and there were no complications such as vascular crisis. Follow-ups were performed in various forms for 6 to 12 months. These flaps were satisfactory in appearance and function and had a good texture.@*Conclusions@#The perforator flap based on the first perforating artery of profunda artery can repair the defects of the limbs in the soft group. The donor site of the flap is hidden, the amount of tissue available is relatively large and the repair effect is good.

Comparison between Single and Double Cleavage-Stage Embryo Transfers, Single and Double Blastocyst Transfers in a South East Asian In Vitro Fertilisation Centre

INTRODUCTION@#This study investigated the differences in clinical pregnancy rate (CPR), live birth rate (LBR) and multiple pregnancy rate (MPR) between double cleavage-stage embryo transfers compared to single and double blastocysts stage embryo transfers in a single academic medical centre.@*MATERIALS AND METHODS@#This was a retrospective cohort study performed at the KK Women's and Children's Hospital In Vitro Fertilisation (KKIVF) Centre of all women who underwent fresh-cycle in vitro fertilisation/intracytoplasmic sperm injection (IVF/ICSI) cycles over a 5-year period. The outcome measures were CPR, LBR and MPR. The study included 5294 cycles, of which 539 patients underwent single embryo transfer (SET); 4533 patients underwent double embryo transfer (DET); 84 patients underwent double blastocyst embryo transfer (DBT); and 65 patients underwent single blastocyst embryo transfer (SBT).@*RESULTS@#The mean age of patients undergoing single blastocysts stage embryo transfer was lower than the other 2 groups. The DET, single and double blastocysts stage embryo transfer groups achieved similar LBR (33.9%, 38.7%, 35.4%, >0.05) and CPR (42.4%, 46.2%, 46.9%).@*CONCLUSION@#We found that single blastocysts stage embryo transfer is associated with similar LBR and CPR compared to double blastocysts stage embryo transfer and DET, with lower MPRs, and should be offered as standard practice, where possible.

A comparison of Streptococcus agalactiae septic arthritis and non-Streptococcus agalactiae septic arthritis

<p><b>INTRODUCTION</b>Streptococcus agalactiae (Group B Streptococcus, GBS) is an uncommon cause of septic arthritis in the adult population. In recent years, there has been an increase in the incidence of GBS septic arthritis. This study aims to compare the clinical presentation, investigations, microbiology and outcome of management in patients with GBS and non-GBS septic arthritis.</p><p><b>METHODS</b>Retrospective review of hospital surgical records was done to identify all patients treated surgically at our institution from January 2011 to January 2016 for primary septic arthritis. Patients were categorised into two groups: those with culture-proven GBS septic arthritis and those with causative pathogens that were not GBS. Patients who were medically unfit for surgical intervention as well as those who declined interventional procedures were excluded from the study.</p><p><b>RESULTS</b>A total of 83 patients were included in the study: 62 (74.7%) had non-GBS septic arthritis and 21 (25.3%) had GBS septic arthritis. Patients with GBS septic arthritis were more likely to have polyarticular involvement (p < 0.001) and involvement of less common sites such as the elbow joint. They were also more likely to have elevated inflammatory markers (C-reactive protein > 150 mg/L; p = 0.017) and positive blood cultures (p = 0.02), and were typically healthy adults with no medical comorbidities (p = 0.012).</p><p><b>CONCLUSION</b>Patients with GBS septic arthritis were more likely to present with polyarticular involvement, positive blood cultures and higher levels of C-reactive protein on admission, and tended to be healthier individuals with no medical comorbidities.</p>

Current trauma care system and trauma care training in China / 中华创伤杂志(英文版)

Trauma is a life-threatening "modern disease". The outcomes could only be optimized by cost-efficient and prompt trauma care, which embarks on the improvement of essential capacities and conceptual revolution in addition to the disruptive innovation of the trauma care system. According to experiences from the developed countries, systematic trauma care training is the cornerstone of the generalization and the improvement on the trauma care, such as the Advance Trauma Life Support (ATLS). Currently, the pre-hospital emergency medical services (EMS) has been one of the essential elements of infrastructure of health services in China, which is also fundamental to the trauma care system. Hereby, the China Trauma Care Training (CTCT) with independent intellectual property rights has been initiated and launched by the Chinese Trauma Surgeon Association to extend the up-to-date concepts and techniques in the field of trauma care as well to reinforce the generally well-accepted standardized protocols in the practices. This article reviews the current status of the trauma care system as well as the trauma care training.

The Uneven Distribution of Mating Type Genes in Natural and Cultivated Truffle Orchards Contributes to the Fructification of Tuber indicum

The aim of this study was to investigate the pattern of distribution of mating type (MAT) genes of Tuber indicum in ectomycorhizosphere soils from natural T. indicum-producing areas and cultivated truffle orchards and ascocarp samples from different regions. Quantitative real-time PCR and multiplex PCR were used to weight the copy numbers of MAT1-1-1 and MAT1-2-1 in natural truffle soils and cultivated orchard soils. The effect of limestone on the pattern of truffle MAT genes and the correlation between soil properties and the proportion of MAT genes were also assessed. These results indicated that an uneven and nonrandom distribution of MAT genes was common in truffle-producing areas, cultivated truffle orchards, and ascocarps gleba. The competition between the two mating type genes and the expansion of unbalanced distribution was found to be closely related to truffle fructification. Limestone treatments failed to alter the proportion of the two mating type genes in the soil. The content of available phosphorus in soil was significantly correlated with the value of MAT1-1-1/MAT1-2-1 in cultivated and natural ectomycorhizosphere soils. The application of real-time quantitative PCR can provide reference for monitoring the dynamic changes of mating type genes in soil. This study investigates the distributional pattern of T. indicum MAT genes in the ectomycorhizosphere soil and ascocarp gleba from different regions, which may provide a foundation for the cultivation of T. indicum.

Feasibility study on magnetic coupling-driven pulsate blood pump / 医用生物力学

Objective To propose the design of a pulsate blood pump driven by magnetic coupling and verify its feasibility. Methods The blood pump was designed based on the magnetic transmission reciprocating force model and the push-and-pull structure, and the coupling force was calculated by building the magnetic force-driven model. The prototype of the blood pump was then manufactured, on which the extracorporeal circulation simulation test was conducted to obtain the pressure and flow rate. Results Physiological saline was used as the circulation medium. When the afterload was fixed and increase the preload, the output of the blood pump would decrease, but showing no obvious linear trend. While the preload was fixed and increase the afterload, the output of the blood pump was reduced, showing a linear trend. With the driving frequency set as 75 per minute, and the preload and afterload adjusted in the range of 0.665-3.990 kPa (5-30 mmHg) and 5.320-11.970 kPa (40-90 mmHg), respectively, the output of the blood pump could reach 2.0-3.1 L/min while guaranteeing the linear relationship. Conclusions The proposed magnetic coupling-driven pulsate blood pump can basically meet the need of extracorporeal membrane pulmonary circulation, while it still needs further improvement. The research results have a valuable application prospect, especially with great significance in replacement of blood pump currently used in the extra-corporeal membrane oxygenation (ECMO) equipment in clinic.