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In this work we assessed the validity of the multi-frequency parameter (MFP) analysis method in distinguishing EIS false positive results. We chose 15 subjects with invasive duct carcinoma as the control group in which EIS results were all positive. In the experiment, three test groups-the Contact, the Skin and the Horm groups-were set to correspond to three common types of EIS false results. In the Contact group, false positive results were induced by poor contact of the measuring probe. In the Skin group, false positive results were induced by skin ridges. In the Horm group, false positive results were induced by a high hormone level. Based on the MFP analysis method, we obtained the Cole-Cole parameters of each subject in the control group and the test groups. Statistical analyses showed there was a significant difference in G(0N), G(infinity)N) or alpha(N) between the control group and the Contact or the Skin group. A significant difference between the control group and the Horm group existed only in alpha(N). These results suggested that by means of the MFP analysis method it was possible to distinguish between a false positive result and a positive result caused by breast cancer. In conclusion, the MFP analysis method appears to be a feasible means to improve the diagnosis accuracy of EIS for breast cancer detection.

Current medical imaging techniques are not effective for timely detection of internal hemorrhage when the bleeding is slow and in small quantities. In this study, electrical impedance tomography (EIT) was applied to monitor the intraperitoneal bleeding of an animal model. Five healthy pigs three months old were used. The process of intraperitoneal bleeding was simulated with the injection of anticoagulated blood which was controlled by an electronic syringe pump. The injected rate was no more than 100 ml h(-1) and the total injection volumes ranged from 300 ml to 500 ml. Sixteen electrodes were attached to the abdomen and used for electrical current excitation and surface voltage measurement. Dynamic changes in impedance distribution within the abdomen were calculated by the back-projection algorithm and a series of EIT images were displayed in a unified range. The monitoring was performed with EIT at a rate of one frame per second and continued for at least 4 h. Intraperitoneal blood volume changes could be identified by inspection of consecutive EIT images during the progression of blood injection. 30 ml of blood in the peritoneum could be detected. EIT was shown to be a promising technique for continuous monitoring of intraperitoneal bleeding over periods of time.

This paper designs one mobile physiological information monitor system based on the ZigBee protocol. The hardware structure is presented. The network communication characteristic of this system was analyzed. The paper points out the disadvantage of the connection method in the ZigBee protocol. One improved connection method is proposed. Through carries on the comparison and the simulation to the routing mechanism of the ZigBee protocol, we choose the Z-AODV routing mechanism. The experimental and simulation results show that the communicational efficiency and stability have been enhanced.

A movement during measurements can generate motion artifacts in photoplethysmography(PPG) signals. The motion artifacts reflect some information of tester's motion. If we can extract the relevant information from these interferences, it probable will be a new information collection method for portable physiological monitor. This paper first analyzes the relationship between the motion artifact and the PPG signals form the Beer-Lambert law. Then, compare the influence of PPG signals by different direction of movement. Finally, extract the information of motion through the reconstruction of wavelet transforms modulus maxima. Through compares the extracted signal and the real motional signals collected by accelerometer (ACQ), two signals have certain relativity. The extracted signal can basically reflect the tester's movement. It will be a new way of community and athletes medical care.

As a convenient, un-injurious and low cost method for women breast tumor diagnosis, Electrical Impedance Scanning (EIS) is being paid increasing attention. But EIS still has some problems. In theory the malignant tumor has higher electrical conductivity than normal tissue and benign tumor, so the cancer will be recognized in the EIS image as a bright spot. However, in practical the difference is not so obvious. In many cases it is difficult to judge whether a suspicious bright spot tells a malignant or benign tumor. This paper concerns a new method based on multi-frequency EIS measurement to solve this problem. A group of scanning results with various stimulating frequencies will be performed during an EIS measurement, which is automatically controlled by specially designed device and the location and pressure of the sensor will keep stable, so we will get a series of data at different stimulating frequencies through a measurement. Because the malignant and the benign tumor have different curves in electrical conductivity-frequency diagram, we can analyze the data at every frequency and find out the attribute of the tumor. Clinical trails have been carried out. Subjects were suspicious sufferers that were to receive histopathology examinations, and all analyses have been compared with histopathology results.

An electrical impedance scanning (EIS) system was studied to meet the requirement of clinical breast screening. A quick examination, easy operation, safe electrical isolation and obvious diagnosis results are four main factors to a screening system. Basing on these considerations, a multi-frequency signal sampling system controlled by ARM chip was setup and the measuring data were transmitted to PC by an ethernet interface. For the measuring probe, three types of electrodes array were designed to adapt the different sizes of breast. Additionally, an imaging post-process algorithm was developed to assist the radiologist to have an obvious diagnosis results. Based on a saline-tank phantom and some satisfying results were got. The system has a character of high precision, real-time imaging and obvious results and can be used in the clinical study of EIS breast screening.

EIS (electrical impedance scanning) is a new technique used in the diagnosis of breast cancer. The impedance characteristics of the breast tissue are the fundamentals of the technique. In our experiment the four-electrode measurement was facilitated by means of the model 1255B impedance analyzer, which was used to measure the multi-frequency resistivities of Chinese women's breast carcinomas and their surrounding tissuwa in vitro. From the data obtained, it can be seen that there existed significant differences in resistivity between the breast carcinoma and its surrounding tissues. The resistivity of the fatty tissue was the highest among the measured samples, then came the resistivity of the breast carcinoma and that of the gland tissues. Pathological analysis and interpretation were followed. Some features of EIS imaging for Chinese women which are different from those of the Western women can be illustrated by the measured data.

Many reasons, such as traffic accident, abdomen post-operation, etc., may cause intraperitoneal bleeding. As a noninvasive imaging modality, electrical impedance tomography (EIT) may be applied for monitoring the intraperitoneal bleeding process of patient. In order to research the relationship between the bleeding and the monitoring processes, an EIT monitoring platform and a rabbit intraperitoneal bleeding model were desinged. The monitoring platform consists of hardware, software and 16 silver-electrode. Each silver-electrode was made of silver wire with diameter 2mm and length 50mm. All the 16 electrodes were embedded under the rabbit’s skin with equal space around its abdomen. The bleeding model was produced by hit the liver area with a self-made blunt iron shot from a nail-shooting gun. The distance between the rabbit and gun was adjusted to 70mm so that the skin was not injured but the liver was broken by the hitting. 15 anesthetic rabbits with liver bleeding were monitored by the EIT experiment platform, the bleeding volume of the broken liver ranged from 35ml∼50ml (41.9±3.1ml). Before hitting, the images was almost uniform. After hitting, the image became darker and the darker area enlarged as the bleeding process went on. This implies that as an image monitoring method, EIT is sensitive for monitoring the intraperitoneal bleeding.

A new post-processing algorithm was developed for EIS image in order to improve the accuracy of diagnosis. This algorithm automatically analyzes data and recognizes the light region in the EIS image basing on the data process criterions. The threshold criterion and the modality criterion were derived from the ideal saline-tank phantom experiment. And the filter criterion came from the analysis of 240 abnormal images. Filter criterion is first used to filter some influencing data in the algorithm process. Then the threshold criterion and the modality criterion are used to recognize the light region. In addition, the algorithm was verified on a test group including 540 EIS non-processed images. The performance obtained for this test group was an 8% increase of the accuracy. The algorithm provides a clear and objective interpretation for EIS recorded images.

Electrical impedance scanning (EIS) is a new adjunctive diagnostic method for women breast cancer examination. In clinic research, we found some influencing factors which can induce a bad EIS imaging results. In order to analyze the influencing factors on EIS imaging and find the solutions, we set up an EIS workbench which can simulate the influencing factors that may happen in a clinic. We studied the influencing factors from size, depth of the target; the influence from the poor contact; the influence from the unparallel current field. The experiment results show that the detectability of EIS system is a function of the depth, the size and the area of electrodes; a good contact between the probe and the skin can decrease the artificial imaging; using the imaging algorithm can calibrate the imaging induced by unparallel current field.

To establish a high precision data acquisition system for multi-frequency electrical impedance tomography (EIT), a series of methods were introduced. Those methods include building a driving signal with up to four frequency components to diminish the effect of the dynamic change of tissues resistivity, extracting the impedance information by a digital demodulator that can improve the SNR by 8 times. The system that established can work at a wide range from 1.6 kHz to 380 kHz. Its CMRR is 74 dB at 100 kHz. The output impedance of current source is 2 MOmega at that frequency. And measurement precision on a 100 ohm resistor is better than -80 dB in full bandwidth. Both the quasi-static and the dynamic imaging results based on a saline tank can reflect the resistivity changes inside the phantom clearly. Therefore, the system was competent in multifrequency EIT research work

It is found that Electrical Impedance Tomography(EIT) is promising in its application to the clinical image monitoring and that the Back-Projection algorithm of EIT can meet the preliminary requirements of the real-time monitoring through our work. In order to improve the computed speed and the imaged resolution, different ways of completing the algorithm were tried in this paper. Moreover, it is shown that the impedance change due to physiological saline with the concentration of not more than 50 milliliter 0.9% can be detected and imaged by our system. The above result is helpful for our further work of image monitoring by EIT.

Developmental dysplasia of the hip (DDH) is a congenital hip joint malformation affecting the proximal femurs and acetabulum that are subluxatable, dislocatable, and dislocated. DDH is best treated during infancy. In this paper, we designed and implemented a computer aided system for treatment of this disease. In this system, we used a mixture-based PV partial-volume algorithm to perform bone segmentation on the patient's CT (computed tomography) or MRI (magnetic resonance imaging) image, then by three-dimensional (3D) reconstruction and display of the segmented image, we can easily get the quantitative measurement of Acetabular Index (AI) and Center-Edge Angle (CEA), which can help the clinic diagnosis and treatment. PC graphics-card GPU architecture was exploited to accelerate the 3D rendering and geometric manipulation. This system was implemented on PC/Windows environment.

To seek a single source drive pattern that is more suitable for brain electrical impedance tomography (EIT), a comparison between adjacent, cross, polar and newly proposed quasi-polar drive patterns was made in aspects of boundary voltages dynamic range, independent measurement number, Total boundary voltage changes and anti-noise performance based on an equivalent circuit of the brain resistivity distribution consisting of 7300-odd resistors. The results demonstrate that quasi-polar drive pattern is optimal in all the aspects except dynamic range. Polar and cross drive patterns come next, and adjacent drive pattern is the worst. Therefore, the quasi-polar drive pattern should be chosen for brain EIT.

A 16-channel magnetic induction imaging system is introduced briefly. Highly precise phase and magnitude detecting method is applied to the information acquisition. The resolution of phase detecting is 0.003deg. The results of magnitude detecting also provide us with useful information. The characteristic curves are smoother than that of our previous system. One dimension results in different positions of the measurement region demonstrate the trend of variation of the detected signals. The positions of the object affect the results greatly and the trend of variation is regular.

To improve dynamic EIT image quality, multiple meshes combination, a new method, was applied. The method was mainly based on sampling theory. First, a group of reconstruction models were made with different mesh schemes. Then EIT images were reconstructed with each model. Finally all the images were combined altogether to form the final image. This method was used to reconstruct images under computer simulative conditions and in physical phantoms. Two reconstruction algorithms were used: filtered spectral expansion algorithm (FSE) and general inversion algorithm (GIA) which was proposed by us. Results indicated that the method had a much smaller reconstruction error than the single mesh method. Besides, the ill-posed condition was not worsened in that the element number of each mesh didn't increase.