Bioelectrical impedance measurement technology is a non-invasive detection technology for extracting human physiological and pathological information. The analysis method of the relationship between bioimpedance and human physiological parameters is an important part of this technology. In order to calculate the internal and external liquid volume of human cells more accurately, based on the Moissl equation for calculating the internal and external fluid volume of human cells, a segmented human bioimpedance spectrum measurement model and an improved calculation method of intracellular and external fluid capacity were proposed. The measurement and calculation experiments of the intracellular and extracellular fluid volume before and after the human body's water intake were designed and compared with the Moissl calculation method. The results show that the improved calculation method can calculate the intracellular and extracellular fluid volumes more effectively, and the relative error is less than 5%, which may provide new ideas or more accurate methods for the analysis of human body components, facilitating the diagnosis and treatment of diseases.
The injury of the knee joint is usually accompanied with the generation of hydrops. The volume of hydrops can be used as a reference to evaluate the extent of knee joint injuries. Based on the principle of bioimpedance detection, in this paper, a new method is proposed to detect knee joint hydrops. Firstly, a three-dimensional model of the knee joint was established according to the physiological and anatomical structure of the knee joint. Secondly, a knee impedance detection system was constructed based on the four-electrode theory, and the relationship between the knee impedance change and the volume of hydrops was calculated by linear regression. Finally, the model of rat knee joint hydrops was established, and the knee joint impedance was measured under different hydrops content to deduce the relationship between the fluid content and the knee joint impedance. The fluid volume in the joint was calculated by measuring the knee joint impedance, and the error rate was less than 10%. The experimental results show that the method proposed in this paper can establish the relationship between the impedance of the knee and the volume of fluid and realize the detection of the fluid volume.
Medical magnetic nanoparticles are nano-medical materials with superparamagnetism, which can be collected in the tumor tissue through blood circulation, and magnetic particle imaging technology can be used to visualize the concentration of magnetic nanoparticles in the living body to achieve the purpose of tumor imaging. Based on the nonlinear magnetization characteristics of magnetic particles and the frequency characteristics of their magnetization, a differential detection method for the third harmonic of magnetic particle detection signals is proposed. It was modeled and analyzed, to study the nonlinear magnetization response characteristics of magnetic particles under alternating field, and the spectral characteristics of magnetic particle signals. At the same time, the relationship between each harmonic and the amount of medical magnetic nanoparticle samples was studied. On this basis, a signal detection experimental system was built to analyze the spectral characteristics and power spectral density of the detected signal, and to study the relationship between the signal and the excitation frequency. The signal detection experiment was carried out by the above method. The experimental results showed that under the alternating excitation field, the medical magnetic nanoparticles would generate a spike signal higher than the background sensing signal, and the magnetic particle signal existed in the odd harmonics of the detected signal spectrum. And the spectral energy was concentrated at the third harmonic, that is, the third harmonic magnetic particle signal detection that meets the medical detection requirement could be realized. In addition, the relationship between each harmonic and the particle sample volume had a positive growth relationship, and the detected medical magnetic nanoparticle sample volume could be determined according to the relationship. At the same time, the selection of the excitation frequency was limited by the sensitivity of the system, and the detection peak of the third harmonic of the detection signal was reached at the excitation frequency of 1 kHz. It provides theoretical and technical support for the detection of medical magnetic nanoparticle imaging signals in magnetic particle imaging research.
Objective To evaluate clinical outcomes of complete video-assisted thoracoscopic surgery （VATS） lobectomy for patients with peripheral lung cancer.?Methods?We retrospectively analyzed clinical data of 90 consecutive patients with peripheral lung cancer who underwent complete VATS lobectomy from July 2009 to December 2011 in Provincial Hospital Affiliated to Anhui Medical University. There were 55 male patients and 35 female patients with their age of 33-79 （62.5 ±11.5） years. Lymph node dissection group and number, operation time, intraoperative blood loss, length of postoperative chest drainage, length of postoperative hospitalization, postoperative morbidity and pain score were analyzed.?Results?There was no hospital death in this group. Operation time was 135.0±32.5 min, intraoperative blood loss was 230.0±80.4 ml, length of postoperative chest drainage was 4.8±2.1 days, and pain score on the third postoperative day was 5.3±1.2. A total of 520 groups and 1 568 lymph nodes were dissected during the operation, with 5.8 groups and 17.4 lymph nodes dissected in each patient. There were 71 groups with lymph node metastasis, a positive rate of 13.7% （71/520）. Postoperatively, 2 patients had hoarseness and 3 patients had chylothorax, who were all cured after proper treatment. Ninety patients were followed up for 1-24 months. During follow-up, 4 patients died of tumor metastasis, and other patients were all alive with good quality of life.?Conclusion?Complete VATS lobectomy is a minimally invasive technique for patients with peripheral lung cancer with better postoperative recovery and reduced pain level. The safety and degree of radical resection of complete VATS lobectomy is similar to those of routine thoracotomy lobectomy. Complete VATS lobectomy can be recommended as a surgical treatment for patients with peripheral lung cancer.