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The complexity defined by Lemple and Ziv (1976) represents the degree of the sequence randomness. In this paper, the complexity of EEG under different mental loads was measured and the relation between the brain active state and the EEG complexity was analyzed. The results showed a statistically strong relation between the mental load and the EEG complexity. Further study showed that the heavier the mental load was the smaller the EEG complexity became. This correlation was especially apparent in the frontal lobe, and the complexity of EEG might be regarded as one of the parameters representing the functional state of the brain. The results indicate that EEG complexity represents the active state of brain in processing information, and the measurement of EEG complexity may provide a new path to the research in the advanced cognitive function of the human brain.

Image space reconstruction algorithm (ISRA) is a new kind of method for ECT reconstruction. Unlike the ML-EM algorithm which maximizes likelihood function of Possion distribution, ISRA searches for the minimum non-negative mean square solution. In this paper, an improved ISRA (IISRA) algorithm is proposed. A comparison between the algorithms (ISRA and IISRA) demonstrates that the result of IISRA is closer to the test image than that of ISRA. In addition, the IIRSA inherits some properties of ISRA such as convergence.

This paper addresses the correlation dimension of R-R intervals under Heart Rate Variability (HRV) conditions according to chaos theory. We calculate the R-R interval dimensions of normal people's waking and sleeping status, and of different status of a 24-hour clinical Holter recording. The results show that the bigger the HRV is, the smaller the dimension of R-R interval is. This method needs small data and costs little time to calculate, so probably it can be of clinical use in the analysis of HRV.

In this paper, we have proposed a method for the dosage regimen evaluation of intrevenously infused drugs which obey first order clearance kinetics. An example of application is given.

Debilitating diseases such as osteo- and rheumatoid arthritis, trauma and bone cancer can be treated by using prostheses. The wear resistance of materials for joint replacement can affect the service-quality and service-life of prostheses. Materials for joint replacement and friction and wear were briefly reviewed in this paper.

The research on intelligent materials is a new advanced technology, which is much interested by many scientists and engineers in recent years. Some research results have been achieved and used in aeronautics, mecahanics, civil engineering, medicine and other associated fields. In this paper, we present the properties, functions and status of intelligent materials in modern medicine.

In this paper, four aspects of microrough surface of metallic biomaterials are reviewed: the preparation of microrough surface, the technology of surface roughness measurement, the parameters of roughness and the microrough surface bio-effect.

Functional Neuromuscular Stimulation (FNS) is a technique of restoring movements of paralyzed patients. This paper describes several respects of functional neuromuscular stimulation, such as stimulators, sensors, electrodes, muscle-skeletal models and control methods. Some novel control strategies are also discussed in this paper.

Vascular endothelial cells are most widely distributed of all cells in a living body, which have a complicated structure and many physiologic functions. It was reviewed in present paper that the structural and functional changes in the vascular endothelial cells were as a result of the stimulation from hemodynamics associated machanical factors, such as shear stress cyclic strain, and pressure in physical and pathophysical state.

In this paper, an omni-direction M-mode ultrasonic imaging method is introduced, in which M-mode sample line can rotate and move freely. In this way the measurement of parameters such as amplitude and speed of movement of organs can be conducted in any position or direction. We analyzed the sources of errors of the method and the way to overcome them.

In this paper, the tri-dimensional computer reconstruction and animated display from serial sections of the genuine crude drug Radix Aconitii have been addressed. Accordingly, some tridimensional image technique and information for the teaching and identification of pharmacognosy have also been offered.

It is well known that the scattered-radiation (SR) results in degradation of the images contrast in digital X-ray radiograph. The main reason affecting radiographic image quality is the SR arising from interaction of the photons with object being radiographed and veiling glare from detector system in the II-TV chai imaging system. With the aim of improving the image quality, we employed the Gaussian function to approximate the scattered point spread function (PSF) and determined the fraction of SR, rho and the parameter, sigma experimentally on an individual system; then we built an inverse filter to process the digital chest X-ray images, which were acquired with the same system and transformed in 2-D Fourier tansform operation. The images processed were corrected by using a variable weihting factor and the resulting images are shown in this paper. The method provides a useful way for solving the problem of correction of the SR in digital X-ray images.

Bioimpedance is an electrical character of living tissue, organ, cell or living body. When direct or alternating current of effective value below the exitation threshold passes through the living tissue, bioimpedance can be measured indirectly by voltage. It has been studied both theoretically and experimentally by many researchers. In this paper, the bioimpedance measurement theory and technologies are reviewed.

In this paper we discuss the elastic light scattering techniques used in blood cell counting and classification and expound the principles of elastic light scattering techniques and four theoretical scattering models of blood cell and the applicable areas. Also we analyze their application in recent years and point out the problems to be solved.

This paper introduces the present situation of research and methods of 3-D ultrasonic medicine imaging. An extensive summary of the clinical application of 3-D ultrasonic images is also presented. At last this paper discusses the factors influencing the quality of 3-D image reconstruction and some cynosure of research directions.

Evoked potentials (EP) is an important bioelectric signal for studying the neural processes, but it is immersed in very strong background noise. Extraction of EP from a single trial has been a topic of great theoretical and clinical interest. In this paper, a new signal processing method--wavelet transform is introduced and several applications are given.

The control of fluid pressure during continuous ventricular drainage was reevaluated by hydromechanical analysis. Auditory meatuses form a good datum plane for the measurement of the fluid height in the ventricular drainage tube. The arrangement of the drainage tubes should not only restrict ventricular pressure of stable state to physiological range, but also have buffer effect on fluctuations of the pressure. The height of the peak point and that of the tube end are both primary factors controlling ventricular fluid pressure. If tube end or central section of the tube is laid too low, the ventricular fluid pressure could decrease markedly under certain situations. An ideal pattern of the tube arrangement was proposed in the paper.

We have adopted the TPD (thermal pulse decay) technique for determining the conductivity and blood perfusion of living tissue in vivo by using a self-heated sphere thermistor probe, which is based on the classical bioheat equation suggested by Pennes. This paper intends to discuss conduction in living tissue, to provide foundamental information for clinical medicine, and to extend application of the trapping probe measuring method.

In this paper, a new method of estimating bone age is reported that is based on the use of spatial description parameters and fourier frequential descriptors, which presents the boundary shapes detected in finger bones X-ray films of 0-, 3-, 6-, 9-month baby according to their bone shape changes in different stages.

In this paper we introduce a method and an implementation of blood flow imaging by means of backscattered Doppler ultrasound power. Compared with Color Flow Map technique based on autocorrelation, this technique is relatively angle independent, aliasing free and more sensitive to blood flow signal with noise background. We present the theory, experimental system and in-vitro experimental results. The realization of this technique means a new stage of color Doppler ultrasound imaging technique in our country is coming.

A method of dual-energy separation of bone and soft tissue images of chest based on an X-ray direct digital imaging system has been investigated. In this paper, the optimal thickness of the filter for high energy X-ray beam is discussed. An algorithm of correction of scattered radiation is employed before the separation algorithm. The separated images will be shown in the paper. The result shows that it is possible to use an ordinary broad spectral X-ray beam to acquire the dual-energy images for routine X-ray diagnosis.

Since 1979, many cases of paraganliomas in the neck have been successfully treated in Tianjin Cancer Hospital. All patients who would be subjected to this operation should undergo preoperative compressing exercises of the carotid artery to promote better circulation of collateral cerebral crossflow. Therefore, a reliable and compact instrument is necessary for the compressing exercises of the carotid artery and the long-term ambulatory monitoring of the compressing effect. This paper introduces our developed instrument, Adjustable and Digital Carotid compressor, which is based on the principle of volume-oscillometric method. During the gradual change in cuff pressure, the amplitude of consecutive arterial volume pulsation associated with pulse pressure shows change characteristically due to the nonlinearity of arterial pressure-volume (P-V) relation. Arterial pressure can be determined by detecting this change in the amplitude, while the arterial volume change can be noninvasively obtained as a function of this transmural pressure, provided that the state of blood flow are determined during this pressure measurement. Considering the simplicity and practicability of this instrument, we have designed a new portable one which consists of pulse pressure transducer, signal amplifier, peak voltage locking circuit and liquid crystal displayer. The validity and accuracy of this instrument and a few examples of its clinical application are presented.

To improve the accuracy of oscillometric blood pressure measurement, an artifact rejection method for oscillations detection called R wave-relative method was developed. It was mainly based on the correlation between ECG R wave and oscillation. Combining with identification of oscillation characteristics this method can distinguish valid signals from interference. This algorithm has been implemented in 8098 microcontroller. Its program flowchart has also been presented in this paper.

This paper introduces a new apparatus and method that suits to measuring the water vapor transmission rate (WVTR) of wound covering materials. WVTR of synthetic materials, amniotic membrane, porcine and cadaveric skin was measured under different conditions of four temperatures, three mediums, and "water cup" or "inverted water cup". The temperature was in close relationship with the WVTR except Omiderm, amniotic membrane, and cadaveric skin between 30 degrees C and 37 degrees C groups. The medium did not affect the WVTR (P > 0.05). There was significant difference between the "water cup" and "inverted water cup" groups(P < 0.01). This study suggests that the apparatus is easy-to-operate, reliable and suitable for the measurement of WVTR of burn wound coverings and other membranous materials.

This paper introduces a biomaterial torque experiment apparatus which consists of AST486 computer, photodiode array, code device interface circuit, and magnetoelectric motional coil structure. According to experimental conditions, the computer sends out signal to the coil which under the magnetic field is activated to produce a series of desired torque and bring the sample to deflect. Angular displacement is measured by photodiode array and code device system. The whole system has good dynamics and high precision and could finish a series of torque experiment for biomaterials, and AST486 computer can automatically conduct signals analyzing and data processing.

In the light of solid mechanics as well as thermal physics, the physical factors causing thermal injury are correlated and a new thermomechanical model is established to quantitatively describe the injury process in living tissues under heat striking. The three-stage mode of thermal injury to living tissue is interpreted. The paper reflects our preliminary effort to further study this clinical phenomenon in point of micro mechanics and thermal science. It is of significance in revealing the mechanisms of subcutaneous bubble formation, development as well as tissue's thermal mechanical disruption.

The FEM analysis of Casson fluid flow in flow chamber under all wall conditions was made in this paper, and the result was compared with that of Newton and that of Casson fluid flow with plane hypothesis.

Cardiac contractile proteins are the material basis of cardiac contractility. This paper introduces the Structures of two major cardiac contractile proteins: myosin and actin, especially the details of the two proteins' structure relevant to their function. At the same time, it describes the myosin and actin proteins' changes in normal and abnormal hearts so as to enrich our mind with knowledge of cardiac hypertrophy and heart failure at the molecular level.

In this paper a filtering method for ECG signal is introduced which decomposes original ECG signals into detail signals on different frequency bands by using Wavelet Transform(WT). According to ECG signal feature, some detail signals are discarded, and the retained signals are reconstructed by inverse WT, so three main interferences in ECG signal can be removed. Our experimental results demonstrate that this is an efficient filtering method.

Cardiac simulation model is a frontier topic in the theoretical field of cardiac simulation. In this paper, dissipating energy model is presented to solve element equation and hence to reveal the rule of activities of heart.

The observational results of bone interface of titanium-coated 317L plate screw and 317L plate screw under light microscope are reported in the present paper. Osseointegration was formed in both kinds of screws after implanting. In the titanium-coated 317L plate screw group, the inflammatory reaction was slighter, the new bone formed earlier in the interface and the bone was combined with the metal tightly, whereas in the uncoated 317L plate screw group, the relationship between the bone and metal was only a state of contact. These indicate that the bone interface and tissue compatibility of titanium-coated 317L plate screw may be better than that of the 317L plate screw.

In this paper, the relaxation process of RBC in the suspending medium of medium viscosity was studied with the Erythrocyte Rheometer(Electric Resistive method) developed by ourselves. On the basis of Fricke-Velick conductive theory of RBC suspension, the experimental results were discussed. The results demonstrate that delta R/R0-t curve can really reflect the deformability of RBCs and the viscoelasty of RBCs after their deformation.

This paper describes a method based on the theory of stochastic recursive identification for lossless compression of medical images detail. The performances of this method are compared with the existing method of DPCM through ten X-ray chest images. The experimental results clearly indicate that this method is very valid to realize lossless compression of medical images.

Ultrasonic Backscattered Signal(UBSS) from tissues is fundamentally a statistical signal. The statistics of UBSS provide information relating to the number, mean spacing and the scattering cross sections of the scatterers constituting the tissue. Mean scatterer spacing(MSS) is an important parameter for describing the biological tissues microstructural features and tissues ultrasonic scattering characteristics. This paper reviews the methods of MSS estimation as well as ultrasonic imaging based on the scatterer spacing.

This paper introduces an experimental appliance which drives rabbits running and jumping by means of electric stimulation with the aid of this device to train rabbits, the pathologic modes of stress fracture of femur and tibia of rabbits were imitated successfully.

In this paper, an ECG pre-amplifier portable monitor is given, which has many functions, i.e., 50 Hz notch, lead-off alarm and pacer pulse inhibition. The amplifier only consists of 3 chips of 8 pin ICs, and consumes current less than 1.4 mA.

X-ray machine mA circuits are generally composed by mA Pre-set circuits and mA detect circuits. To effectively control the tube current, there are many safety circuits and auxiliary circuits in mA control circuits. The trouble of mA circuits of HD150B-10 displays "mA Trouble" promptly on the plasma display; however, it is difficult to discover the actual trouble in the circuits because the mA control circuits are interconnected. In this paper, the question we discuss is how to check and shoot quickly and correctly the trouble of mA circuits, after the prompt appearance of "mA Trouble" on the plasma display.

Biphasic selective stimulation is an effective electrical stimulation mode for preventing nerve fibers against electrochemical damage, for muscle to contract smoothly, and decreasing muscle's fatigue. By use of computer simulation, this paper presents three biphasic stimulation modes respectively using monopolr, bipolar and tripolar electrodes, which can effectively stimulate nerve fibers in a selective way. The results are helpful to the clinical application of neuroelectrical stimulation.

In this paper, we propose the concept of standardization of brain CT image and introduce a kind of standardization method based on geometry correction technique. To work out the method, first we preprocessed the raw CT image, second automatically searched the control points which were used for establishing the correction equation, and last we completed the standardization of the CT image. The result of the experiments demonstrated the pracficability efficiency of this kind of method which conld provide theoretical foundation and experimental means for the diagnosis of brain disease.

A novel concept of cardiopulmonary-cerebral resuscitation (CPCR) has been proposed, in which a combination of technologies of the membrane artificial lung, mild hypothermia, centrifugal blood pump, heparin coated surfaces and blood shunting have been used. The present paper introduces the modern conception, history of CPCR, with emphasis on the brain(cerebral) resuscitation. Importance of extracorporeal membrane oxygenation, mild hypothermia and centrifugal blood pump in cerebral resuscitation has been emphasized. Thereupon the new idea of the novel CPCR has been proposed and the design and laboratory manufacture of the equipment of CPCR will be carried out.

The mechanical isocentre positional accuracy of the X Knife system is a very important technological parameter in the course of the X Knife therpy. In this paper, a film-concentric circle method for measuring the mechanical isocentre positional accuracy is introduced. A simulation ball set at the isocentre of the X Knife mechanical positional system, as a substitute for target, was imaged on a film (the simulation ball's image is a circle and its diameter is 8 mm), and a collimator was imaged on the same film (the collimator's image is also a circle and its diameter is 30 mm). The distance between these two circles' centres is the error of the isocentric system. This method has been used in our work.

This paper presents the biomechanical property changes of long bone in goats at 180 days after ovariectomy. 10 female goats at the age of 1.5 +/- years(average body wight 22 kg) were randomly divided into the control group and ovariectomized group. These goats were sacrificed at 180 days after ovariectomy and the femora, tibiae, metatarsus, humeri, radius and metacarpus were taken out bilaterally. The structural mechanical properties of these bones were measured with the three-point bending method. The material mechanical properties of flexura, compress and tensile in the compact bone specimens taken from the two broken ends were also measured. The results showed that the bone density, bone thickness in broken ends, and the break load of three-point bending for the long bones in the OVX group were obviously lower than those in the control group (P < 0.05). And compared with the control group all the long bones in the OVX group, except the femur, had significantly lower ultimate bending strength, bending elastic modulus; ultimate flexural strength, flexural elastic modulus; ultimate compressing strength, and compressing elastic moduus. Some long bones in the OVX group had significantly decreased ultimate tensile strength (P < 0.05). These indicated that the mechanical properties of long bone in OVX group at 180 days after ovariectomy were reduced in varying degrees and were liable to fracture. This result is in accord with the clinical findings in osteoporosis resulting from post-menopausal estrogen fall and is also consistent with the osteoporotic model of ovariectomized rats. The authors conclude that the bone biomechanical properties are important parameters in assessing osteoporosis and the ovariectomized goat can possible be a good big animal model of osteoporosis.

ECG data compression has been greatly improved since 1960 s. Although the error of compression can be controlled accurately, the reported algorithm at present can not be processed in real-time with a microcomputer. In this paper an algorithm for ECG data compression is expounded which can be realized in real-time with a single chip computer. The algorithm has not only adjustable precision but also an average compression rate of 10.34, especially a pretty high compression ratio for frequent arrhythmic patients.

A new approach to extracting single-trail event-related potential(ERP) in combination with the correlation analysis has been proposed. This approach, called time-frequency filter, is based on the concept that multiresolution wavelet transforms. At first, an investigation of the properties in time and frequency domain was carried out on the ERP. On the basis of the findings, the time-frequency filter of wavelet was designed and used for single-trail ERP extracting. The results and related discussion are presented in this paper.

A new method of recognizing ECG P waves based on approximating function is presented in this paper. The result of experiment demonstrates that the method based on the second order approximating functions to recognize P waves in useful and easy to do. The rate of correctness for recognizing P waves is higher than 99% according to MIT/BIH ECG Datebase.

This paper introduces a monitoring system of musle relaxant in action during the operation under general anaesthesia. The design of the monitor is based on measurement of acceleration. It consists of an acceleration transducer, a nerve stimulator and a microcomputer unit. The transducer can be fastened to the thumb, and the signal of the thumb movement in response to ulnar nerve stimulation is measured and registered in the computing unit. In clinical practice, it has been proved that this new apparatus can achieve reliable evaluation of nuromuscular transmission function and improve the quality of anesthesia in patients care during surgical operation.

The results on the agreement between microcomputer and experts for the diagnosis of pneumoconiosis from X-ray films are presented in this paper. On a set of 200 films, the diagnoses made by the computer and by five experts were compared; From 100 films, the agreement rates were 83.5% for the normal/abnormal, 73.0% for the four categories of profusion and 70.5% for the four categories of pneumoconiosis. From 100 films, the rates of agreament between the computer and the basic-level consultation group were 86.0%, 82.0% and 63.0% respectively. From 300 films for screening pneumoconiosis, the rate of agreement between the computer and the experts was 89.3%. The results demonstrate that the automatic diagnosis by computer is closer to the diagnosis made by experts.

The design and laboratory manufacture of "SUU-TYPE I" extra-luminal flow(ELF) hollow fibre membrane oxygenator are presented. The design is based on the O2 and CO2 transfer models in the cross-flow membrane oxygenator of Mockros and Pei. This paper also introduces the sketch of the membrane oxygenator, the structure of housing, the bundle of hollow fibres and the procedure of centrifugal potting. The self-made potting equipment and process of centrifugal potting are emphasized. The key know-how of centrifugal potting includes: (1) assuring the quality of the hollow fibre membrane material and the bundle; (2) calculating the quantity of potting material, polyurethane; (3) controlling reaction temperature; (4) removing gas from potting ends; (5) controlling rotation speed; (6) inserting the bundle in the house; (7) mastering the time of demoudling and cutting.

This paper integrates qualitativ analysis with quantitative grey relation analysis in the comprehensive evaluation for solving medical problems, especially diagnostic problems, and good results are obtained. In it, some new medical concepts such as diagnostic value, diagnostic grey degree and information cover rate are defined. The given example demonstrates that when used in clinical diagnosis, this diagnostic model makes a feature of high diagnostic coincidence rate as well as low misdiagnosis rate and it overcomes the common disability of general medical diagnostic model in quantitative analysis.

This paper describes the design of a safety interlock used by X-knife system for preventing the linear accelerator gantry colliding with the treatment couch and the patient when the accelerator is rotating and irradiating X-rays. How to install and adjust the unit is also addressed in this paper. The unit has been successfully used in JX-100 X-knife system developed by the First Military Medical University.