Study on the thermal field distribution of cholangiocarcinoma model by magnetic fluid hyperthermia / 生物医学工程学杂志

Cholangiocarcinoma is a highly malignant tumor. It is not sensitive to radiotherapy and chemotherapy and has a poor prognosis. At present, there is no effective treatment. As a new method for treating cancer, magnetic fluid hyperthermia has been clinically applied to a variety of cancers in recent years. This article introduces it to the cholangiocarcinoma model and systematically studies the effect of magnetic fluid hyperthermia on cholangiocarcinoma. Starting from the theory of magnetic fluid heating, the electromagnetic and heat transfer models were constructed in the finite element simulation software COMSOL using the Pennes biological heat transfer equation. The Helmholtz coil was used as an alternating magnetic field generating device. The relationship between the magnetic fluid-related properties and the heating power was analyzed according to Rosensweig's theory. After the multiphysics coupling simulation was performed, the electromagnetic field and thermal field distribution in the hyperthermia region were obtained. The results showed that the magnetic field distribution in the treatment area was uniform, and the thermal field distribution met the requirements of hyperthermia. After the magnetic fluid injection, the cholangiocarcinoma tissue warmed up rapidly, and the temperature of tumor tissues could reach above 42 °C, but the surrounding healthy tissues did not heat up significantly. At the same time, it was verified that the large blood vessels around the bile duct, the overflow of the magnetic fluid, and the eddy current heat had little effect on thermotherapy. The results of this article can provide a reference for the clinical application of magnetic fluid hyperthermia for cholangiocarcinoma.

Simulation of the relationship between magnetic medium parameters and heating temperature in magnetic fluid hyperthermia / 生物医学工程学杂志

In this paper, we established magnetic fluid hyperthermia (MFH) model for rat tumor using the finite element software COMSOL based on the linear response theory. By analyzing four kinds of magnetic medium within relaxation mechanism, such as Fe O 、FeCo、fccFePt and L1 FePt, we studied the influence of the change of magnetic medium radius on dissipation power and temperature field, respectively. At the same time, the optimization method for the parameters of several magnetic medium is proposed, and the applications of four kinds of magnetic medium are given as well. By increasing the dissipation power of the magnetic medium as much as possible, the dose of magnetic medium used in the treatment can be reduced, meanwhile, the adverse effects on health tissue surrounding the tumor will be minimized. The conclusions of this paper can provide reference for magnetic medium preparation applied to MFH.

Hardware Implementation of Numerical Simulation Function of Hodgkin-Huxley Model Neurons Action Potential Based on Field Programmable Gate Array / 生物医学工程学杂志

Neuron is the basic unit of the biological neural system. The Hodgkin-Huxley (HH) model is one of the most realistic neuron models on the electrophysiological characteristic description of neuron. Hardware implementation of neuron could provide new research ideas to clinical treatment of spinal cord injury, bionics and artificial intelligence. Based on the HH model neuron and the DSP Builder technology, in the present study, a single HH model neuron hardware implementation was completed in Field Programmable Gate Array (FPGA). The neuron implemented in FPGA was stimulated by different types of current, the action potential response characteristics were analyzed, and the correlation coefficient between numerical simulation result and hardware implementation result were calculated. The results showed that neuronal action potential response of FPGA was highly consistent with numerical simulation result. This work lays the foundation for hardware implementation of neural network.