Anti-interference hemoglobin analysis system by high performance liquid chromatography / 生物医学工程学杂志

High performance liquid chromatography (HPLC) is currently the mainstream technology for detecting hemoglobin. Glycated hemoglobin (HbA1c) is a gold indicator for diagnosing diabetes, however, the accuracy of HbA1c test is affected by thalassemia factor hemoglobin F (HbF)/hemoglobin A2 (HbA2) and variant hemoglobin during HPLC analysis. In this study, a new anti-interference hemoglobin analysis system of HPLC is proposed. In this system, the high-pressure three-gradient elution method was improved, and the particle size and sieve plate aperture in the high-pressure chromatography column and the structure of the double-plunger reciprocating series high-pressure pump were optimized. The system could diagnose both HbA1c and thalassemia factor HbF/HbA2 and variant hemoglobin, and the performance of the system was anti-interference and stable. It is expected to achieve industrialization. In this study, the HbA1c and thalassemia factor HbF/HbA2 detection performance was compared between this system and the world's first-line brand products such as Tosoh G8, Bio-Rad Ⅶ and D10 glycosylated hemoglobin analysis system. The results showed that the linear correlation between this system and the world-class system was good. The system is the first domestic hemoglobin analysis system by HPLC for screening of HbA1c and thalassemia factor HbF/HbA2 rapidly and accurately.

The follow-up value of D/S ratio in CHF patients with treatment / 重庆医学

Objective To explore the follow-up value of phonocardiogram D/S ratio in CHF patients with treatment.Methods Forty-eight CHF patients who had never under-went regular treatment were collected in our hospital,given the regular anti-heart failure treatment for 3 months.NYHA heart failure classification,resting heart rate(RHR),and D/S ratio of phonocardiogram were recorded,six-minutes walk distance(6MWD),Left ventricular end diastolic diameter(LVEDd),the left ventricular ejection(LVEF) were tested before and after treatment.After 3-month treatment,the resting heart rate 65 times as the watershed,the patients were classified into two groups:one was up to standard,and the other was not up to standard.D/S ratio,RHR,6MWD,LVEDD,LVEF and the improvement of the heart function were compared between the two group.Results Exception the resting heart rate,the in-dicators had no significant improvement in the group of not up to standard compared with the before treatment,and D/S ratio, 6MWD,LVEF was improved significantly after three months treatment(P <0.05).In the group of up to standard,the D/S ratio was improved significantly after one months treatment(P <0.05),while after three months treatment all indicators were improved significantly(P <0.05).Comparison between the two groups,the RHR,D/S ratio were significantly improved(P <0.05 ),LVEF was significantly improved after three months treatment(P <0.05).At the same time,the D/S ratio,6MWD and NYHA classifica-tion of cardiac function was significant negatively correlated(P <0.05).Conclusion The D/S ratio could reflect heart functional im-provements in patients with CHF after anti-heart failure treatment,and it could reflect the heart functional improvement earlier and more significant in the group up to standard,it has a good clinic follow-up value in CHF patients with anti-heart failure treatment.

Research on biometric method of heart sound signal based on GMM / 中国医疗器械杂志

<p><b>OBJECTIVE</b>Extraction of cepstral coefficients combined with Gaussian Mixture Model (GMM) is used to propose a biometric method based on heart sound signal.</p><p><b>METHODS</b>Firstly, the original heart sounds signal was preprocessed by wavelet denoising. Then, Linear Prediction Cepstral Coefficients (LPCC) and Mel Frequency Cepstral Coefficients (MFCC) are compared to extract representative features and develops hidden Markov model (HMM) for signal classification. At last, the experiment collects 100 heart sounds from 50 people to test the proposed algorithm.</p><p><b>RESULTS</b>The comparative experiments prove that LPCC is more suitable than MFCC for heart sound biometric, and by wavelet denoising in each piece of heart sound signal, the system achieves higher recognition rate than traditional GMM.</p><p><b>CONCLUSION</b>Those results show that this method can effectively improve the recognition performance of the system and achieve a satisfactory effect.</p>

Analysis of the heart sound with arrhythmia based on nonlinear chaos theory / 生物医学工程学杂志

In this paper, a new method based on the nonlinear chaos theory was proposed to study the arrhythmia with the combination of the correlation dimension and largest Lyapunov exponent, through computing and analyzing these two parameters of 30 cases normal heart sound and 30 cases with arrhythmia. The results showed that the two parameters of the heart sounds with arrhythmia were higher than those with the normal, and there was significant difference between these two kinds of heart sounds. That is probably due to the irregularity of the arrhythmia which causes the decrease of predictability, and it's more complex than the normal heart sound. Therefore, the correlation dimension and the largest Lyapunov exponent can be used to analyze the arrhythmia and for its feature extraction.

Research and application of cardiac reserve data processing and information management system / 中国组织工程研究

BACKGROUND: Cardiac reserve indicators obtained under quiescent condition are used as evaluating index for cardiac reserve functions. However, most important aspect of cardiac dysfunction in heart failure is not the depressed cardiac performance noted at basal resting states, but rather the loss of cardiac reserve. OBJECTIVE: To develop a data processing and information management system for detecting cardiac reserve indicator with the widely used B mode ultrasound instrument in the ultrasonography field, and to provide guidance for B mode ultrasound instrument perfection. METHODS: General B mode ultrasound instrument as peripherals was connected with the pc by image acquisition card; ultrasound heart image diagnosis and management system including professional heart image acquisition and process and perfect data bank was develop. RESULTS AND CONCLUSION: An efficient and flexible mini picture archiving and communication system system was achieved, which realized image enhancement, geometric parameter measuring, convenient diagnosis report output, archive management and print function. Results demonstrated that with the powerful data process ability of PC, the system could improve the performance of the traditional ultrasound instrument in detecting cardiac reserve, which provide a powerful support for the further study.

A clinical study of cardiac reserve mobilizing condition for pregnant women / 生物医学工程学杂志

This study was conducted on the basis of informed consent of subjects and was approved by the ethical review committee concerned. 527 pregnant women voluntarily participated in this project for the investigation of cardiac reserve mobilizing condition. Using the digital technique of heart sound signal processing, we measured the heart rate (HR), the ratio of the first heart sound to the second heart sound (S1/S2)and the ratio of diastolic to systolic duration (D/S) during pregnancy. There was significant difference of HR and S1/S2 between the group of non-pregnant (G1), the group of 28-36 pregnant weeks (G2), and the group of 37-42 pregnant weeks (G3) (HR, S1/S2: G1 vs G2, G1 vs G3: P < 0.01). HR of the pregnant women increased with the increase of pregnant weeks. D/S decreased with the increase of pregnant weeks. There was significant difference of D/S between G1, G2, and G3 (G1 vs. G2: P < 0.01; G1 vs. G3: P < 0.01). There was also significant difference of D/S between G2 and G3 (G2 vs. G3: P < 0.05). Everybody in the non-pregnant women group was found to have D/S > or = 1.30; 64.33% of pregnant women were found to have 1.00 < D/S < 1.30, whereas 3.05% of pregnant women were found to have D/S < 1.00. These data revealed that the heart burden of the pregnant woman increased with the increase of pregnant weeks and the mobilization of cardiac reserve.

Clinical analysis of cardiac reserve function and outcome of preeclampsia / 中华妇产科杂志

Objective To investigate cardiac reserve function and pregnant results of preeclampsia.Methods Pregnant women chosen by randomized table and hospitalized in the department of obstetrics of the first affiliated hospital of Chongqing MedicaI University were involved in this study from January to December,2008.Sixty-nine cases of normal pregnant women were divided into 3 groups:normal group 1(20cases),normal group 2(26 cases)and normal group 3(23 cases).The normal group number 1 to number 3 were paired to gestational hypertension(20 cases),mild preeclampsia(26 cases)and severe preeclampsia (23 cases),respectively.The digital technique of heart sound signal processing WaS used to measure cardiac reserve function parameters including the heart rate(HR),the ratio of the amplitude of the first heart sound to the second heart sound(S1/S2)and the ratio of diastolic to systolic duration(D/S)of pregnant women.The pregnant results were also recorded.Results (1)The ratio of S1/S2 in the group of severe preeclampsia 4.5±3.2 was significantly bigher than the group of gestational hypertension 2.2±1.1 and normal group 32.2±1.1(P＜0.01).The ratio of D/S of the group of severe preeclampsia 1.1±0.3 Was significantly lower than the group of gestational hypertension 1.4±0.3 and normal group 31.4±0.2(P＜0.01).(2)All cases of the normal group number 1 to number 3 and the group of gestational hypertension were found the ratio of D/S≥1.00,whereas 1 case(1/26,4%)of the group of mild preeclampsia and 4 cases(4/23.17%)of the group of severe preeclampsia were found the ratio of D/S＜1.00.(3)The two cases of the pregnant wornen(including one woman died of cardiac arrest)with S1/S2＞5.00 and D/S＜1.00,who were in the group of severe preeclampsia,were sent to Intensive Care Unit after delivery.There were 4 cases(4/26,15%)and 6 cages(6/23,26%)of 1 minute Apgar score less than 7,7 cases(7/26,27%)and 6 cases(6/23,26%)sent to neonatal Intensive Care Unit,2 cases(2/26,8%)and 4 cases(4/23,17%)of neonatal death in the group of mild preeclampsia and in the group of severe preeclampsia,respectively.All newborns in the normal group number 1 to number 3 and the group of gestational hypertension were normal.Conclusions The cardiac reserve function of a pregnant woman with preeelampsia is decreased with the severity of preeclampsia and the parturient and neonatal results get worse.The distal technique of heart sound signal processing is a safe,harmless,simple and effective tool to measure cardiac reserve funotion of preeclampsia,and is worthy of widely used clinically.

A study on the four modes for transmitting heart sound signal / 生物医学工程学杂志

As an important human body sound signal, heart sound is of great value in the researches on diagnostics of heart diseases. This study sought to explore the methods of transmitting heart sound through the telephone correspondence system for simultaneous telemetering cardiac contractility and heart rate. Heart sounds were transmitted from a phone to another phone with 4 modes, the wirelessly transmitted distance between the two phones being 5 m, 10 km, and 1000 km, respectively. The results of experiments show that telemetering cardiac contractility and heart rate can be realized by the telephone correspondence system. Such methods have the advantages of being noninvasive, inexpensive, rapid and convenient; moreover, they can be used repeatedly and be available for in-home use.

Development of heart sound signal detection system based on USB interface / 生物医学工程学杂志

This paper introduces a type of heart sound recording, analysis and processing system based on USB interface. The system consists of high performance sensor sampling heart sounds, the preprocessing circuit, the A/D conversion module and the USB based high-speed computer communications interface. The experiments show that it is noninvasive, convenient, inexpensive and rapid in detecting the cardiac contractility of patients with heart disease as well as of healthy subjects. This system has provided a reliable technical platform for evaluating the cardiac contractility reserve.

Heart sound recognition algorithm based on PNN for evaluating cardiac contractility change trend / 生物医学工程学杂志

This paper discusses the recognition of heart sound for evaluating the cardiac contractility change trend, which includes heart sound samples recorded at different exercise condition. Especially, focused on the recognition of heart sound recorded after high intensity exercise workload. The algorithm proposed consisted of two correlative methods. The first was to recognize heart sound recorded at rest and after low intensity exercise workloads by probabilistic neural network and the second was to recognize heart sound recorded after high intensity exercise workloads based on the characteristic of heart sound. Both methods have two consecutive phases. Firstly, all peaks, including the peaks of both heart sounds and noise, are marked by a repetitive threshold detecting algorithm. Secondly, probabilistic neural network is employed to classify the peaks detected in the first phase into Si, S2, and noise. Finally, the performance of the algorithm was evaluated using 45 digital heart sound recordings including normal and abnormal heart sound, which were recorded at rest and after low intensity exercise workloads, and 28 digital heart sound recordings recorded after high intensity exercise workloads. The results showed that over 94% of heart sound samples were classified and recognized correctly. Moreover, the reasons for the wrong classification, of which omitting and misdetection are two main problems, are also discussed and solutions are proposed. So this method can be improved and refined in following studies. In conclusion, this algorithm is a reliable approach to detect and classify heart sounds, providing a solid basis for further heart sound analysis.

Design of multifocal visual electrophysiology examining system based on fast m-transform / 生物医学工程学杂志

The multifocal visual electrophysiology is an objective and non-invasive method to examine visual function. It can examine many tiny areas of retina at the same time and have a particular advantage in diagnosing the early diseases of ocular fundus. This paper introduces the design of multifocal visual electrophysiology examining system. The system uses multidisplay technology exclusively owned by Windows 98 or above operating system to control graphics stimulator which generates specified hexagonal array. The white or black transition of each hexagon controlled by a binary m-sequence stimulates corresponding area of retina. The specified Burian-Allen electrode is used to extract the mixed signal originated from many areas of retina. The signal is amplified and A/D transformed. The computer separates the mixed signal through fast m-transform and gets the response of each area of retina. The fast m-transform is a fast computation of cross-correlations with binary m-sequences and can reduce cross-correlation computation to a single Fast Walsh Transform. So a lot of time can be saved.

Fatigue analysis system with HR and HRV as indexes / 医疗卫生装备

In this paper,heart rate (HR) and heart rate variability (HRV) are extracted from ECG,and the five indexes in both time and frequency domains are analyzed.The result shows that the standard deviation (SDNN) of R-R intervals,the value of total power (TP),the power value of low frequency (LF) of HRV and the value of LF/HF increase obviously,while the power value of high frequency (HF) decreases markedly after fatigue.The physical fatigue level is classified according to the rate of increase and decrease of the indexes above.It is suggested that these five ECG indexes be used to reflect and evaluate the degree of physical fatigue quantitatively.

Improved method of gray correction for the medical ultrasonic image / 医疗卫生装备

The general theories of gray correction methods for the medical ultrasonic image are introduced in this paper, including gray level correction, gray level transformation and histogram correction. The dominant histogram equalization method is expatiated and modified against its disadvantages including inapparent enhancement of partial detail and non-interactivity. Series connections of several gray correction methods are used to treat with the ultrasonic image, and thus its utility is improved through the selective enhancement of the contrast of certain gray scope.

Implementation of physiological electrical signal transmission based on Bluetooth protocol / 医疗卫生装备

Bluetooth is a new widely accepted standard of short distance communication in personal area networks (PANs). By analyzing the communication process based on Bluetooth protocol and requirements of physiological electrical signal transmission, such operations are performed as the design of Bluetooth model for measurement of heart sound, the development of Bluetooth network communication library and the implementation of the model by programming.

Development of Portable Multi-function Heart-Sound Auscultating System / 医疗卫生装备

Objective To overcome the disadvantages of the traditional auscultating method and design the electro-auscultating visual system integrating the monitoring and recording functions.Methods The portable system consisted of the module pre-gathering and electro-auscultating heart-sound signal,the circuit of A/D converting and MCU,as well as the device of signal LCD-displaying in real-time and the USB mass storage device.Results Portable electro-auscultating system was realized,which integrated the functions of watching,monitoring and recording.Conclusion The portable system is more convenient for clinical doctors to get correct information from patients,benefiting to the clinical pathology-statistics and profound development of the related data.

Study on difference of noninvasive blood pressure measurement method based on oscillometric and auscultatory / 医疗卫生装备

This paper introduces and compares several blood pressure measurements, among which two noninvasive blood pressure measurements based on oscillometric and auscultatory methods are mainly compared. It also analyses the characteristics and advantages of oscillometric method as well as introduces a noninvasive blood pressure measurement monitor based on oscillometric. By using this monitor and a common auscultory method, we conducted a public survey. The result for statistical data analysis showed that the difference between oscillometric and auscultatory methods are quite small, and the accuracy of them are both quite good .This paper also previews the future of the noninvasive blood pressure measurement

A study of ECG combination detection algorithm based on wavelet transform and morphological method / 生物医学工程学杂志

In order to deal with the disadvantages in ECG waveform detection by wavelet harr transform at level 3, we put forward a new set of algorithm which combines wavelet transform (WT) and morphological peak and valley detection. The combination algorithm can make up the limitation in detecting ECG swing by WT and improve the accuracy of ECG waveform detection effectively.

Heart sound recognition algorithm based on mathematical morphology / 生物医学工程学杂志

In this paper, a new method was put forward for automatic recognition of the first heart sounds (S1) and the second heart sounds (S2). After the original heart sound signal was preprocessed, the heart sound envelope was extracted by using the mathematical morphology. Then on the heart sound envelope, S1 and S2 were recognized. Eighty heart sound samples collected were used for testing the algorithm. The accuracy of recognition was 86%, and was 100% for the normal heart sound. The result showed that the algorithm proposed in this paper had high performance, which could be used as a basis for further analysis of heart sound.

Database design of multi-focal visual electric-physiological examining system / 医疗卫生装备

The database design of multi-focal visual electric-physiological examining system is introduced in this paper.Microsoft Access 97 is used to design the database.VC++ can append,query or delete records of the database through DAO interface.It reflects such advantages that the database is easy to be managed and convenient to be queried.The design pattern can be transplanted to other medical devices' design.

Implementation of serial communication between personal computer and C8051F000 in sampling of heart sound / 医疗卫生装备

This paper analyses the requirements of serial data communication interface between upper and lower hosts in a heart sound sampling system, and then introduces the system design scheme, schematic of hardware interface and source codes of upper and lower hosts. C8051F000 and personal computer adopted as the lower host and upper host respectively, C++ Builder and Windows API functions are also used to implement the applications.