This paper introduces the preamplifier for the microcomputer-detecting system of 3-Channel ECG signals and its technical specifications. The practical experiments and clinical applications show that its performances conforms with all the requirements of the system.
Amplifiers, Electronic ; Electrocardiography ; instrumentation ; Equipment Design ; Heart Diseases ; diagnosis ; Humans ; Image Enhancement ; instrumentation ; Microcomputers ; Signal Processing, Computer-Assisted

This paper introduces double ultrasound pulse transmitting and receiving circuits used in ultrasound thermometry. Using the circuits, double ultrasound pulses could be made synchronously to satisfy the requirements of ultrasound thermometry, and the weak ultrasound echo signals are received successfully. The crux experiment waveform offered shows that the circuits have high reliability.
Equipment Design ; Humans ; Hyperthermia, Induced ; instrumentation ; Neoplasms ; therapy ; Pulse ; Temperature ; Transducers ; Ultrasonography ; instrumentation ; methods

OBJECTIVETo measure the effect of atorvastatin on COX-2 expression in monocytes in patients with acute myocardial infarction (AMI).

METHODSForty patients with AMI (AMI group) and 18 patients with stable coronary heart disease (control group) were enrolled, and patients with AMI were randomly given routine therapy (n = 20) and routine therapy plus atorvastatin (20 mg/day, n = 20) for a week. Peripheral blood monocytes for each participant including patients with AMI were isolated and cultured for 24 hours. During the culture, monocytes in patients with pretreatment AMI were incubated with celecoxib in different concentration (0, 0.1, 1 and 10 micromol/L). COX-2 mRNA expression in monocytes was measured by reverse transcription polymerase chain reaction (RT-PCR); concentrations of interleukin-6 (IL-6) in supernatant from monocytes and plasma hs-CRP levels were measured by using enzyme-linked immunosorbent assay (ELISA).

RESULTSCOX-2 expression in monocytes in patients with AMI (0.92 +/- 0.13) was significantly higher than that in the control subjects (0.19 +/- 0.08), and decreased by 66% after atorvastatin (compared with that on routine therapy, P < 0.05); IL-6 secretions of monocytes in the AMI group (204.8 +/- 45.6 ng/L) increased dramatically compared with those in the control group (40.9 +/- 1.2 ng/L, P < 0.05), and reduced dramatically by 58% when incubated with 10 micromol/L celecoxib (P < 0.05) in a concentration-dependent manner; plasma levels of CRP in the AMI group (43.3 +/- 14.9 mg/L) significantly increased compared with those in the control group (1.7 +/- 0.8 mg/L), and reduced by 62% after atorvastatin (compared with those in the routine therapy group, P < 0.05). COX-2 expression in monocytes in the AMI group was positively correlated with both secretions of IL-6 and plasma level of CRP (r = 0.636 and 0.662, respectively, both P < 0.05).

CONCLUSIONSThere is an inflammatory activation in peripheral blood monocytes in patients with early AMI, and the monocytes-derived COX-2 may play an important role in promoting early inflammatory process. Atorvastatin may decrease COX-2 expression in peripheral blood monocytes in patients with AMI and cyclooxygenase-dependent pathway might be correlated with the anti-inflammation mechanism of statin.

Aged ; Atorvastatin Calcium ; Cyclooxygenase 2 ; metabolism ; Female ; Heptanoic Acids ; therapeutic use ; Humans ; Inflammation ; Interleukin-6 ; metabolism ; Leukocytes, Mononuclear ; drug effects ; metabolism ; Male ; Middle Aged ; Myocardial Infarction ; drug therapy ; metabolism ; Pyrroles ; therapeutic use ; RNA, Messenger ; genetics

Mild cognitive impairment (MCI) is a prodromal stage of dementia.Predicting MCI's conversion to Alzheimer's disease (AD) plays critical roles in preventing the progression of AD.Alzheimer's disease neuroimaging initiative (ADNI) was introduced briefly,which was a widely used neuroimaging database for the study on AD related diseases,and the application of machine learning algorithm was reviewed in MCI classification.Deep learning network,which transforms the original data into a higher level and more abstract expression,has shown great promise in MCI conversion and classification.Two main kinds of deep learning approaches were described,including supervised learning and unsupervised learning,and their new application was discussed in MCI conversion and classification based on structural magnetic resonance imaging (sMRI).Finally,the current limitations and future trends of deep learning in this area were explored.

Objective To explore the effect of enriched environmental stimulation on mouse brain cognitive reserve to enhance the sensitivity of brain age gap estimation (BrainAGE).Methods Twenty-one healthy adult C57BL / 6J male mice,15 months old,were divided into a group with a standard environment and two groups with enriched environments.All the groups underwent magnetic resonance microcopy.Scaled subprofile model was used to analyze the features reflecting the changes of brain cognitive reserve.Results There were significant differences between the mean BrainAGE of the two groups with enriched environments and that of the remained standard environment group,then it's proved that some assumption might be reasonable that brain cognitive reserve could be estimated based on BrainAGE.Optim ized BrainAGE model made explanations for 58.9％ differences during stimulus phase in enriched environment.Conclusion Improved BrainAGE model gains high sensitivity when used to measure the redundancy of brain cognitive reserve.

Objective To propose an algorithm to extract fetal ECG signals from mixed signals of maternal abdominal wall with high signal-to-noise ratio and clear waveforms by combining kernel principal component analysis(KPCA),fast independent component analysis(FastICA)and singular value decomposition(SVD).Methods Firstly,KPCA was used to downscale the maternal ECG signals,and then the improved negative entropy-based FastICA was applied to processing the downscaled data to obtain the independent components.Subsequently,sample entropy was introduced for signal channel selection,and the signal channel containing the most maternal information was selected.SVD was performed on the selected maternal channel to get an approximate estimate of the maternal ECG signals,which was then subtracted from the abdominal wall source signals to obtain a preliminary estimate of the fetal ECGs.Finally,the pure fetal ECG signals were successfully separated using a modified negentropy-based FastICA.The proposed algorithm was validated in the Abdominal and Direct Fetal Electrocardiogram Database(ADFECGDB)and the PhysioNet 2013 Challenge database.Results The proposed algorithm gained advantages in both subjective visualization and objective evaluation metrics,which had the sensitivity,positive predictive value and F1 value of fetal QRS compound wave respectively being 99.74％,98.85％and 99.30％for the ADFECGDB database,and 99.10％,97.87％and 98.48％for the PhysioNet 2013 Challenge database.Conclusion The fetal ECG signal extraction algorithm incorporating KPCA,FastICA and SVD effectively handles the additional noise while extracting fetal ECG signals,which provides strong support for the early diagnosis of fetal diseases.[Chinese Medical Equipment Journal,2024,45(7):1-7]

Objective To detect and analyze of residual ethanol in abandoned flaps after laser subepithelial keratomileusis (LASEK) with ethanol infiltration methods.Methods Together 20 patients (40 eyes) undergoing LASEK were recruited in the study.After infiltrated with 20％ ethanol and rinsed in equilibration solution,the corneal epithelial free flap was isolated and removed in time for sealing,and then procedures were continuously completed.Finally,observation of the skin flap production,postoperative irritation symptoms,epithelial healing,visual recovery and postoperative haze situation was performed,and then the amount of ethanol in the epithelial flap was measured.Results There was no failure in making the intact corneal flaps.The sensory score of postoperative irritation was 2.52 ± 1.46.Neonatal epithelial with 1 grade was observed in 32 eyes,2 grade in 8 eyes 5 days after surgery,while corneal haze with 0.5 grade was occurred in 3 eyes,1 grade in 2 eyes 12 weeks after surgery.There were ethanol residues in corneal epithelium in the abandoned flaps,with the amount of ethanol residues of (0.205 2 ± 0.041 0) μL in each flap.Conclusion It is found that a certain amount of ethanol residue in the corneal epithelium after LASEK with ethanol infiltration equilibration solution rinse,which may be one reason of the corneal irritation symptoms and corneal haze.

Objective To plan microwave antenna puncture direction effectively and realize personalized preoperative simulation by exploring microwave ablation(MWV)outcomes of lung cancer based on real anatomical model.Methods Firstly,a personalized MWA simulation model consisting of the lung tissue,tumor and vascular system was constructed based on the lung CT data of real patients.Secondly,the MWA effect was simulated by coupling 2 physical fields including an electromagnetic field and a biological heat transfer field,so as to determine the volume of the ablation thermocoagulation zone and the temperature distribution of the lung tissue.Finally,the effects of the vascularized network on the ablation results were quantitatively evaluated in terms of conductivity and blood perfusion,and the ablation results were analyzed with different distances between the large vessels and the antennae(5 and 10 mm from the antennae tips)and puncture angles(large vessels parallelling or intersecting with the antennae tips).Results The vascularized network reduced the volume of the thermocoagulation zone by 0.5％to 3.7％,and blood perfusion made the ablation temperature and the volume of the thermocoagulation zone decreased significantly.The cooling effect gradually diminished with the increase of the distance between the large vessels and the antenna.With the same treatment parameters,the thermocoagulation zone formed when the large vessels paralleled with the antenna was obviously larger than that when the vessles intersected with the antenna.Conclusion Personalized MWA simulation analysis based on real CT data contributes to clarifying the temperature distribution and damage estimation close to the actual situation,which provides guidance and reference for precise treatment of the lung tumor and determination of microwave antenna puncture direction.[Chinese Medical Equipment Journal,2024,45(9):27-34]

OBJECTIVESTo study the occurrence of different anomalies associated with hypospadias and to instruct relevant treatment in clinical practice.

METHODSThree hundred and forty-one cases of hypospadias were investigated, all treated respectively corresponding to their specific anomalies.

RESULTSThe morbidity of associated anomalies in cases of hypospadias was as high as 21.1%. Most of the anomaly cases were undescended testes and inguinal hernia, and the incidence of associated anomalies was related to the degree of hypospadias.

CONCLUSIONSHypospadias is not just a local dysmorphic problem but rather a local manifestation of a systemic disease. It is necessary to take those associated anomalies as a systemic whole and attach enough importance to their clinical treatment.

Adolescent ; Adult ; Child ; Child, Preschool ; Humans ; Hypospadias ; complications ; surgery ; Male ; Urogenital Abnormalities ; complications ; surgery ; Urogenital Surgical Procedures ; methods

AIMTo establish a suitable condition for extraction of phenylalanine (Phe), 5-hydroxytryptophan (5-OH-Trp) and four diastereomeric salts, (1R,2S)-ephedrine- (2S,3S)-tartaric acid, (1R,2S)-ephedrine-(2R,3R)-tartaric acid, (1S,2S)-pseudoephedrine-(2S,3S)-tartaric acid, (1S,2S)-pseudoephedrine- (2R,3R)-tartaric acid in supercritical fluid extraction and to assess the solubilities of Phe, 5-OH-Trp and the four diastereomeric salts in CO2.

METHODSSingle-pass method and HPCE.

RESULTSThe solubilities of Phe, 5-OH-Trp and the four diastereomeric salts in CO2 were determined over temperature and pressure ranges of 25-50 degrees C and 6.32-34.03 MPa respectively. The experimental results showed that the solubilities of Phe, 5-OH-Trp and the four diastereomeric salts do not increase with density of CO2. There existed a maximum in the critical region of CO2.

CONCLUSIONThe dramatically high solubilities in the pressure of 6.32-7.78 MPa show a critical behavior, which can be explained by critical characteristic through thermodynamics analysis. The results suggest that the separation of Phe, 5-OH-Trp and the four diastereomeric salts is more efficient in critical region of CO2.

5-Hydroxytryptophan ; chemistry ; Ephedrine ; chemistry ; Phenylalanine ; chemistry ; Pressure ; Solubility ; Stereoisomerism ; Tartrates ; chemistry ; Temperature