Measurements of cardiac efficiency and internal work of the left ventricle via reconstructed impedance cardiography.

. The aim of this study was to investigate methods for measuring the cardiac efficiency (CE) and internal work (IW) of the left ventricle via reconstructed impedance cardiography (RICG).On the basis of the physiological context and Bernoulli's equation in physics, methods of measuring the CE and IW were proposed.

Extraovarian Brenner tumor in the uterus: a case report and review of literature.

Background: Extraovarian Brenner tumors (EOBTs) are extremely rare and can be observed incidentally in both female and male patients, raising concerns regarding the origin of Brenner tumors.

Case Presentation: A 53-year-old postmenopausal woman presented with a nodular lesion in the left side of the corpus uteri, which was found at a routine health check. Macroscopically, the lesion appeared as a solid nodule with a yellowish-gray cut surface, approximately 6 cm in greatest diameter.

Waveform analysis of differential graphs of reconstructed impedance cardiography from healthy individuals.

Purpose: The aim is to measure and analyze the wave amplitudes and time intervals of differential graphs of reconstructed impedance cardiography (RICG).

Methods: 180 adults with normal cardiac function between the ages of 18-78 were included in the study. Six mingled impedance changes on chest surface were simultaneously detected for each subject.

Comparing square root method of measuring the cardiac output by means of aortic impedance change component to Kubicek's method.

Purpose: The aim of this study is to explore a calculated method used to measure the cardiac output using the aortic impedance change component of reconstructed impedance cardiography.

Methods: Routine impedance cardiography was measured using Kubicek's method with four ring electrodes. The thoracic mixed impedance changes were measured by six leads, which consisted of 15 electrodes.

Analyzing the formation of normal and abnormal O waves in thoracic impedance graph using the impedance change components for aorta, blood vessels in lung and ventricles.

Background: Many measurements of thoracic impedance graph show that the small C wave and big O wave appear often for patients with cardiac insufficiency, and the O/C ratio is bigger. And for the normal body, especially a younger one, the bigger O wave may also appear. But since the amplitude of the C wave of a normal body is bigger, the O/C ratio is smaller.

Thoracic impedance change equation deduced on the basis of parallel impedance model and Ohm's law.

Purpose: The aim of the present study is to investigate an impedance change equation suited with the measurement of the impedance cardiograph (ICG).

Methods: Based on a parallel impedance model and Ohm's law, an impedance change equation differed from Nyboer's equation is deduced. It is verified with the experiments of the impedance cardiography in 100 healthy adults.

Studies on separating the impedance change components of blood vessels and ventricles in thorax from mixed impedance signals on chest surface.

Purpose: The aim of the present study is to separate the impedance change components of the blood vessels and ventricles in thorax from the mixed impedance signals detected on the chest surface.

Methods: The mixed impedance signals on the chest surface are measured with a 15 electrode lead system. The thoracic impedance equations are established and solved iteratively with the algebraic reconstructed technique.

Mechanism of the formation for thoracic impedance change.

The purpose of this study is to investigate the mechanism of the formation for thoracic impedance change. On the basis of Ohm's law and the electrical field distribution in the cylindrical volume conductor, the formula about the thoracic impedance change are deduced, and they are demonstrated with the model experiment. The results indicate that the thoracic impedance change caused by single blood vessel is directly proportional to the ratio of the impedance change to the basal impedance of the blood vessel itself, to the length of the blood vessel appearing between the current electrodes, and to the basal impedance between two detective electrodes on the chest surface, while it is inversely proportional to the distance between the blood vessel and the line joining two detective electrodes.

[Evaluation of long-term therapeutic effects of ultrasound-guided percutaneous microwave ablation of liver metastases].

Objective: To explore therapeutic results of local microwave ablation for hepatic metastasis and the factors influencing the survival after percutaneous microwave ablation therapy.

Methods: From July 1995 to June 2005 128 patients with 282 hepatic metastases nodules with the primary diseases of upper gastrointestinal tumor (n = 26), colorectal tumor (n = 44), breast carcinoma (n = 19), pulmonary carcinoma (n = 15), and malignant tumor in other part of the body (n = 24), underwent percutaneous microwave ablation therapy and were followed up for 29.7 +/- 19.

[Ultrasound-guided percutaneous microwave coagulation therapy for hepatic metastases].

Objective: To analyze the therapeutic results and prognostic factors of hepatic metastases treated by ultrasound-guided percutaneous microwave coagulation.

Methods: Seventy-four patients with 149 nodules of hepatic metastases were given percutaneous microwave coagulation therapy. The longest diameter of the metastatic nodule ranged from 0.