Objective To compare the effects of high frequency oscillatory ventilation (HFOV) and conventional mechanical ventilation (CMV) whith or without pulmonary surfactant(PS) supplement on water vapour inhalation injury.Methods New Zealand rabbits model of severe acute lung injury with acute respiratory failure caused by steam inhalation was established.Then the animals were treated by CMV，HFOV，CMV+PS or HFOV+PS，respectively while animals in control group did not ventilated and supplemented with PS.Femoral arterial blood samples were obtained at 1，2，3，4 h after treatment for blood gas analysis.4 h after treatment ,the lowest lobe of right lung was weighed for calculating wet-to-dry weight ratio (W/D).Four different parts including dependent areas and non-dependent areas of the middle lobe of right lung were excised for histological observation.Results (A) After ALI established PaO2 in the five groups decreased below 60mmHg (Plt;0.01) but intergroup differences were found.Meanwhile the change of PaCO2 showd no statistical significance(Pgt;0.05).(B) PaO2 in the four treatment groups had increased since one hour after treatmentand sustained at favorite levels during treatment period.PaO2 in the HFOV and HFOV+PS groups were higher than those in CMV and CMV+PS groups,respectively (Plt;0.01，Plt;0.05).PaO2 in the CMV+PS group at 2 h and HFOV+PS group at 2 h and 3 h were significantly higher than those in corresponding non-PS groups at the same timepoints (Plt;0.05).P（A-a）O2 in the HFOV and HFOV+PS groups were lower than those in CMV and CMV+PS groups (Plt;0.05).P（A-a）O2 in the two groups with PS at 2 h，3 h and 4 h t were statistically lower than those in the two corresponding groups without PS (Plt;0.05).The pH and PaCO2 as well as circulatory function in the four groups were not significantly different at different treatment timepoints (Pgt;0.05).(C) Lung W/D was not different between CMV and HFOV groups (Pgt;0.05)，or CMV+PS and HFOV+PS.But lung W/D in the two groups treated with PS showed statistically decrement than that in non-PS groups (Plt;0.05).(D) Histological injury score was lowest in HFOV+PS group and highest in CMV group.Conclusion HFOV combined with exogenous PS supplement can improve arterial oxygenation and alleviate pulmonary edema and injury，which may be a optimal method for the treatment of acute lung injury with acute respiratory failure caused by water vapour inhalation.
Objective To investigate the effectiveness of high frequency color Doppler ultrasound for detecting perforators in the anterolateral thigh (ALT) flap surgery. Methods Between February 2011 and July 2012, 8 patients underwent high frequency color Doppler ultrasound to detect the perforator anatomy before ALT flap surgery. There were 5 males and 3 females, aged 21-46 years (mean, 34 years). Defects were caused by excision of squamous cell carcinoma in 2 cases, by scalp avulsion in 2 cases, by soft tissue necrosis after neck trauma in 1 case, by excision of groin fibrosarcoma in 1 case, by excision of groin melanoma in 1 case, and by malformation of the face in 1 case. The defect size varied from 12 cm × 7 cm to 22 cm × 18 cm. The perforator with wider caliber, faster flow speed, and shorter intramuscular trajectory was selected, and the flap was designed according to the observed results, which size varied from 14 cm × 9 cm to 25 cm × 20 cm. The donnor sites were repaired by free skin graft. Results Totally, 19 perforators in the flap area were detected by high frequency color Doppler ultrasound, and 18 were identified during operation, with an accuracy rate of 94.7%. The point going out muscle, the travel and direction of perforators observed during operation were basically in accordance with those detected by high frequency color Doppler ultrasound. The other flaps survived, and obtained healing by first intention except 1 flap which had partial fat necrosis with healing by second intention. The skin graft at donor site survived. All patients followed up 4-16 months (mean, 8 months). The flaps had good color and texture. Conclusion High frequency color Doppler ultrasound is a valuable imaging modality for the preoperative assessment of the vascular supply for ALT flap.
ObjectiveTo retrospectively compare the clinical effects of high frequency oscillatory ventilation (HFOV) and conventional ventilation (CV) on patients with acute respiratory distress syndrome (ARDS) induced by smoke inhalation injury. MethodsForty-three patients with smoke inhalation induced ARDS were admitted in the Center Hospital of Hu Ludao between October 2004 and June 2015.Among the patients, 19 cases were treated with CV (CV group) and 24 cases were treated with HFOV (HFOV group).The clinical data were collected and compared between two groups including blood gas at certain time points (6 h, 24 h, 48 h, 96 h, and 7 d) as well as complications and prognosis. ResultsThere was no significant difference in arterial blood gas between two groups before treatment (P > 0.05).After ventilation treatment, there were significant differences in arterial blood gas parameters between two groups except arterial carbon dioxide partial pressure at 48 and 96 h.And the patients in the HFOV group improved more obviously.The hospitalization time and ventilation time in the HFOV group were significantly shorter than those in the CV group (P < 0.05).No significant difference was found between two groups in the incidences of mortality, complications or 30-day survival rate (P > 0.05). ConclusionsBoth high frequency oscillatory ventilation and conventional ventilation can improve the clinical status in patients with smoke inhalation induced ARDS.These two ventilation modes do not present any difference with respect to prognosis by present evidence.
ObjectiveTo analyze the current situation and international research focuses on the study of medical device risk management. MethodsTo retrieve medical device risk management literature information cited from 2002 to 2011 in PubMed such as high-frequency MeSH; analyze current situation and research focuses of medical device risk management by using bibliometrics, bibliographic item co-occurrence matrix builder (BICOMB), and graphical clustering toolkit (gCluto) for quantitative analysis, high-frequency MeSH term papers cluster visualization analysis. ResultsA total of 7 073 published studies were retrieved, basically suggesting a gradually increasing trend of the number of published papers. The top 3 numbers of first authors' papers referred to three countries: the United States, Britain and Germany, while China ranked twelfth. The top 3 numbers of journal articles referred to the United States, Britain and Holland, while China ranked twenty-second. Twenty journals published more than 50 papers, and all these journals were clinical journals. Thirty-three authors published no less than 5 papers, with the maximum of 18 articles. Totally, there were 124 highfrequency MeSHs. The high-frequency MeSHs were classified into 6 categories by using double cluster analysis: kinds 0 to 4 included risk report, risk analysis, risk assessment and methodology of heart valve prosthesis, coronary stents, peripheral vascular stents, implantable defibrillators and other life support device, surgical repair surgical flaps and minimal invasion surgical device such as laparoscopy; kind 5 focused on safety management, risk control, organization and implementation and other related research based on prevention and control of medical device adverse reaction, medical errors, occupation exposure, and equipment failure. ConclusionThe analysis on international literature on medical device risk management basically shows a gradually increasing trend; most studies published in the clinical medicine journals; research focus on risk assessment, safety management and quality improvement in the application such as angioplasty, artificial prosthesis replacement, plastic surgery, minimally invasive surgery and critical care medicine, and radiology diagnosis and treatment; implantable, life-supported invasive and radiological devices as the main research subject; and characteristics include closely combination between medical device risk management and the application of safe and effective, quality improvement systems for clinical diagnosis and treatment.
ObjectiveTo investigate the application of high frequency color Doppler ultrasound (HFCDU) combined with wide-field imaging in the preoperative navigation of anterolateral thigh perforator flap graft.MethodsBetween January 2017 and March 2018, 28 patients with skin and soft tissue defects were treated, including 22 males and 6 females, with an average age of 33.5 years (range, 17-66 years). The causes of injury included 2 cases of scald scar, 7 cases of heavy object crushing injury, 12 cases of traffic accident injury, 4 cases of fall injury, 2 cases of machine injury, and 1 case of infection ulcer. Injury sites included 6 cases of hand and wrist, 12 cases of lower leg, 10 cases of foot. After debridement, the wound area ranged from 6.0 cm×3.5 cm to 24.0 cm×9.0 cm, and all patients were treated with free circumflex femoral artery perforator flap graft. Combo of HFCDU and wide-field imaging navigation were done preoperatively to detect the origin, quantity, course, surface location, hemodynamic characteristics, and the relationship with body area of perforator branch of lateral circumflex femoral artery. According to the perforator information displayed by wide-field imaging of source artery, the dominant perforator was determined to be a pedicle for designed flap. The flap size ranged from 7.0 cm×4.5 cm to 26.0 cm×7.0 cm. The flap donor area was sutured directly.ResultsThe dominant perforator was successfully detected by HFCDU combined with wide-field imaging in 28 patients before operation. The existence of the perforator was confirmed during operation, and the location was accurate. The course characteristics of the perforate were consistent with the results of wide-field imaging. The grafted flaps survived completely among 27 patients after operation. Necrosis at the edge of the flap was observed in 1 patient, which healed after dressing change. All patients were followed up 3-12 months, with an average of 9 months. All the flaps have good blood supply, good elasticity and shape. The donor areas healed perfectly.ConclusionUsing HFCDU and wide-field imaging navigation for designing of anterolateral thigh perforator flaps can clearly show the characteristics of perforators, hemodynamic information, and the relationship with body area, so that the surgeons can understand the perforators more accurately and intuitively, and improve the success and efficiency of flap graft surgery.
ObjectiveTo analyze the feasibility and effectiveness of elastic intramedullary nail fixation for the fifth metacarpal neck fracture under the guidance of high frequency ultrasound.MethodsThe clinical data of 30 patients with the fifth metacarpal neck fractures who were treated with elastic intramedullary nails fixation under the guidance of high frequency ultrasound and met the selection criteria between May 2013 and September 2017 were retrospectively analysed. There were 24 males and 6 females, the age ranged from 18 to 58 years, with an average of 31.4 years. The head-shaft angle of the fifth metacarpal was (55.6±11.3)°. The time from injury to operation was 12 hours to 8 days, with an average of 2.4 days. The operation time, number of intraoperative fluoroscopy, fracture reduction, complications, and fracture healing time were recorded. The head-shaft angle of the fifth metacarpal on the affected side after fracture healing were measured and compared with the healthy side. At last follow-up, the active range of motion of the fifth metacarpophalangeal joint of both sides were measured, and the function was evaluated by using the total active movement (TAM) evaluation standard of the Hand Surgery Association of Chinese Medical Association.ResultsThe operation time was 22-40 minutes, with an average of 32.4 minutes; the intraoperative fluoroscopy was performed once; ultrasound images and X-ray fluoroscopy showed that the fracture was well reduced and no adjustment was required. The incisions healed well after operation, without tendon adhesion or local numbness. All 30 patients were followed up 8-16 months, with an average of 11.7 months. The fracture healing time was 4-8 weeks, with an average of 5.6 weeks. The head-shaft angle of the fifth metacarpal was (13.2±1.4)°, which was significantly improved when compared with preoperative value (t=−20.02, P=0.00); and there was no significant difference (t=1.94, P=0.06) when compared with the healthy side [(12.6±1.0)°]. At last follow-up, the active range of motion of the fifth metacarpophalangeal joint on the affected side was (89.4±2.4)°, showing no significant difference (t=−1.58, P=0.13) when compared with the healthy side [(90.3±2.0)°]. According to the TAM evaluation standard of the Hand Surgery Association of Chinese Medical Association, all patients were considered to be excellent.ConclusionThe effectiveness of elastic intramedullary nail fixation for the fifth metacarpal neck fracture under the guidance of high frequency ultrasound is definite. It can dynamically observe the fracture reduction from different angles, reduce ionizing radiation and postoperative complications.
Steady-state visual evoked potential (SSVEP) has been widely used in the research of brain-computer interface (BCI) system in recent years. The advantages of SSVEP-BCI system include high classification accuracy, fast information transform rate and strong anti-interference ability. Most of the traditional researches induce SSVEP responses in low and middle frequency bands as control signals. However, SSVEP in this frequency band may cause visual fatigue and even induce epilepsy in subjects. In contrast, high-frequency SSVEP-BCI provides a more comfortable and natural interaction despite its lower amplitude and weaker response. Therefore, it has been widely concerned by researchers in recent years. This paper summarized and analyzed the related research of high-frequency SSVEP-BCI in the past ten years from the aspects of paradigm and algorithm. Finally, the application prospect and development direction of high-frequency SSVEP were discussed and prospected.
In this paper, the differences between air probe and filled probe for measuring high-frequency dielectric properties of biological tissues are investigated based on the equivalent circuit model to provide a reference for the methodology of high-frequency measurement of biological tissue dielectric properties. Two types of probes were used to measure different concentrations of NaCl solution in the frequency band of 100 MHz–2 GHz. The results showed that the accuracy and reliability of the calculated results of the air probe were lower than that of the filled probe, especially the dielectric coefficient of the measured material, and the higher the concentration of NaCl solution, the higher the error. By laminating the probe terminal, liquid intrusion could be prevented, to a certain extent, to improve the accuracy of measurement. However, as the frequency decreased, the influence of the film on the measurement increased and the measurement accuracy decreased. The results of the study show that the air probe, despite its simple dimensional design and easy calibration, differs from the conventional equivalent circuit model in actual measurements, and the model needs to be re-corrected for actual use. The filled probe matches the equivalent circuit model better, and therefore has better measurement accuracy and reliability.