[Development and application of extremely low frequency multi-waveform electromagnetic field generator].

In th is paper, an Extremely Low Frequency Multi-waveform Electromagnetic Field Generator has been developed with single chip computer, which provides pulsed, rectangular, triangular and sinusoidal magnetic field with the frequency range from 0-150 Hz and the intensity range from 0-50 mT. The application shows that the device is easy to operate and the parameters of magnetic fields are stable. It has provided successful application in the experiments on biological effects of magnetics and has obtained valuable result.

[The effects of extremely low-frequency electromagnetic fields on rat osteoblast].

The performance of extremely low-frequency electromagnetic fields (ELEF) can change the response of osteoblasts. In this study a kind of ELEF stimulator, which can radiate sinusoidal, rectangular, triangular and pulsed burst ELEF with frequency of 0-300 Hz and strength of 0-40 mT was developed. The neonatal rat calvarial osteoblasts were treated with the device. The effects of various ELEF stimulation on the osteoblast were evaluated by its proliferation and differentiation. The results demonstrated that rectangular and pulsed burst radiation (15Hz, 5mT) can positively change the proliferation of the osteoblast and inhibit its differentiation, but the sinusoidal one can significantly enhance its differentiation and decrease its proliferation.

Effects of different extremely low-frequency electromagnetic fields on osteoblasts.

It is well known that the extremely low-frequency electromagnetic field (EMF) can promote the healing of bone fractures, but its mechanism remains poorly understood. The purpose of this study was to examine the response of neonatal rat calvarial bone cells to the rectangular electromagnetic field (REMF), triangular electromagnetic field (TEMF), sinusoidal electromagnetic field (SEMF), and pulsed electromagnetic field (PEMF). The stimulatory effects of EMF were evaluated by the proliferation (methyltetrazolium colorimetric assay), differentiation (alkaline phosphatase (ALP) activity), and mineralization (area of mineralized nodules of the cells). REMF treatment of osteoblasts increased cellular proliferation and decreased ALP activity (p < 0.05). TEMF had an accelerative effect on the cellular mineralized nodules (p < 0.05). SEMF treatment of osteoblasts decreased the cellular proliferation, increased ALP activity, and suppressed mineralized nodules formation (p < 0.05). PEMF promoted the proliferation of osteoblasts, inhibited their differentiation, and increased the mineralized nodules formation (p < 0.05). Moreover, the effects of PEMF on osteoblasts were concerned with the extracellular calcium, P2 receptor on the membrane, and PLC pathway, but the response of osteoblasts on SEMF was only related to PLC pathway. The results suggested that the waveforms of EMF were the crucial parameters to induce the response of osteoblasts.

[Design of MC-III low frequency pulsed strong magnetic fields generator].

In this paper, We designed and accomplished a low frequency pulsed strong magnetic fields generator, which provides a pulsed magnetic field with the intensity range from 0.1-2.5 T and the adjusted time interval of pulse. This device is easy to operate and performs reliably. It can work steady for a long time and has been successful used in the experiments of biological effects of electromagnetics.

[Development of the coaxial-cylinders-type coagulometer].

Through the detection of the change of shear stress in blood, four coagulation parameters (t(r), delta tau/delta t, tau(max), S) can be automatically determined. The instrument can be used to automatically detect the process of blood coagulation and print coagulation curves. There is a great difference between different samples while there is a good repeatability with the same sample.