Biomedical subjects

K Hagisawa

Publications and source records attributed to K Hagisawa.

3 recordsLinked to original sources

PubMed1997

A case of acute massive pulmonary thromboembolism treated by mechanical clot fragmentation using a percutaneous transluminal angioplasty balloon.

Large, bilateral central pulmonary thromboemboli (PTE) led to cor pulmonale and severe hypoxemia in a patient who had undergone Hardy's operation. After several unsuccessful efforts (thrombolysis using a percutaneous catheter and aspiration of the emboli), mechanical clot fragmentation using a percutaneous transluminal angioplasty (PTA) balloon was attempted. This procedure was successful, resulting in a decrease in pulmonary artery pressure from 58/22 (mean 34) mmHg to 20/10 (mean 13) mmHg together with an increase in aortic pressure from 64/36 (mean 45) mmHg to 112/60 (mean 77) mmHg. Thus, mechanical clot fragmentation using a PTA balloon is a promising method for reducing pulmonary artery pressure and increasing aortic pressure in patients with acute PTE.

Aged↗

PubMedDate not supplied

Determining the temperature distribution of swine aorta with simulated atheromatous plaque under pulsed laser irradiation: an experimental attempt to detect the vulnerability of atherosclerosis.

We developed a method to determine the temperature distribution of swine aortas with simulated atheromatous plaques in order to measure the temperature of atherosclerotic lesions. The inflammation associated with temperature elevation is considered to be one of the aggravating mechanisms of atherosclerosis resulting in fissuring or rupture of atheromatous plaques. The temperature distribution of plaques covered by fibrous caps cannot be measured by conventional thermistors. Indocyanine green (ICG) solution was injected into the subintima of swine aorta to simulate the light absorption coefficient of human atheromatous plaques. The temperature distribution was calculated from measured temperature changes of the aortic intima under pulsed laser irradiation. The aorta was heated from the adventitial side with a halogen lamp to simulate the temperature elevation derived from inflammation. The temperature distribution of the aorta was obtained by solving the heat transfer equation using the surface layer thickness (corresponding to the fibrous cap thickness). The surface layer thickness can be calculated using the following working formula: D(microm)=1363-398DeltaTs+35DeltaTs(2), where AT, denotes intimal surface temperature change under pulsed laser irradiation. The calculated temperature of the ICG layer (corresponding to the atheromatous core) correlated well with the measured temperature (r=0. 97, p<0.0001).

Animals↗

PubMedDate not supplied

Development of a continuous temperature mapping system using a deep body thermometer.

To determine continuous body temperature distribution, an inexpensive temperature mapping system was developed using a deep body thermometer adopting the finite-element method. A stripe with 16 thermocouples was wrapped around the waist of rats to measure body surface temperatures (the boundary conditions). The abdominal deep temperature of the rats was measured from the dorsum using the thermal compensation probe of a deep body thermometer. The abdominal temperature of the rats was mapped by solving a heat conduction equation using surface and deep temperatures obtained in real time. The temperature measured with a thermocouple inserted into the abdominal centre of the rats correlated well with the calculated temperature (r = 0.93, p < 0.01). The system is low cost and simple to use compared with the magnetic resonance temperature mapping system. Our temperature mapping system could potentially result in improved management of patients in critical care medicine.

Abdomen↗