Aiming at the increasing application of RFID technology in the medical environment, this study introduces the foreign requirements for RFID immunity test of medical devices, compares them with the current immunity test requirements of medical devices in China, and puts forward the necessity of establishing relevant test specifications in China.
Radio Frequency Identification Device ; Electromagnetic Fields ; Radio Waves ; Equipment Safety ; Technology

The series of YY/T 0987 standards converted from the corresponding ASTM (American Society for Testing and Materials) standards regulate the marking medical devices and testing methods for passive implants in the magnetic resonance environment. Along with the advancement of scientific cognition and the development of technology, the ASTM continuously amends and updates standards. This article studies the new version of ASTM standards and analyzes the advancing parts newly added as compared to the current YY/T 0987-2016 standard and eventually pinpoints some problems that remained to be solved. Except for the standard for image artifacts, this study found out that other standards had also been constantly updated, such as the standard of ASTM F2503 for marking medical devices extends its referenced documents and adds some ISO standards in, meanwhile, the test method on magnetically induced displacement force, radio frequency induced heating and magnetically induced torque also had been significantly adjusted and improved accordingly. This article recommends that domestic standards need to keep pace with the latest edition of ASTM F standards and to supplement new research achievements timely, just in order to provide a better normalization, guidance and support to the development of Chinese passive implants industry.
Magnetic Resonance Imaging ; Magnetic Resonance Spectroscopy ; Prostheses and Implants ; Radio Waves ; Torque ; United States

Objective: To detect the effects of shortwave radiation on dose-dependent cardiac structure and function in rats after radiation and to elucidate the mechanism of shortwave radiation induced cardiac injury to identify sensitive indicators and prophylactic treatment. Methods: One hundred Wistar rats were either exposed to 27 MHz continuous shortwave at a power density of 5, 10, and 30 mW/cm for 6 min or undergone sham exposure for the control (the rats had to be placed in the exposure system with the same schedules as the exposed animals, but with an inactive antenna). The Ca , glutamic oxaloacetic transaminase (AST), creatine kinase (CK) and lactate dehydrogenase (LDH) content in the peripheral serum of the rats were detected by an automatic blood biochemical analyser. The electrocardiogram (ECG) of standard lead II was recorded by a multi-channel physiological recording and analysis system. The cardiac structure of rats was observed by light and electron microscopy. Results: The results showed that the 5, 10, and 30 mW/cm shortwave radiation caused a significant increased in the levels of Ca , AST, CK, and LDH in the peripheral serum of rats. The cardiac structure was damaged by radiation and showed a disordered arrangement of myocardial fibres, the cavitation and swelling of myocardial mitochondria. These injuries were most significant 7 d after radiation and were not restored until 28 d after radiation. Conclusion Shortwave radiation of 5, 10, and 30 mW/cm can damage rat cardiac function, including damage to the tissue structure and ultrastructure, especially at the level of the myocardial fibres and mitochondria. Shortwave radiation at 5, 10, and 30 mW/cm induced damage to rat heart function and structure with a dose-effect relationship, i.e., the greater the radiation dose was, the more significant the damage was.
Animals ; Dose-Response Relationship, Radiation ; Heart ; radiation effects ; Heart Diseases ; ethnology ; pathology ; physiopathology ; Male ; Myocardium ; pathology ; Radio Waves ; adverse effects ; Random Allocation ; Rats ; Rats, Wistar

OBJECTIVE: To estimate the detrimental effects of shortwave exposure on rat hippocampal structure and function and explore the underlying mechanisms. METHODS: One hundred Wistar rats were randomly divided into four groups (25 rats per group) and exposed to 27 MHz continuous shortwave at a power density of 5, 10, or 30 mW/cm2 for 6 min once only or underwent sham exposure for the control. The spatial learning and memory, electroencephalogram (EEG), hippocampal structure and Nissl bodies were analysed. Furthermore, the expressions of N-methyl-D-aspartate receptor (NMDAR) subunits (NR1, NR2A, and NR2B), cAMP responsive element-binding protein (CREB) and phosphorylated CREB (p-CREB) in hippocampal tissue were analysed on 1, 7, and 14 days after exposure. RESULTS: The rats in the 10 and 30 mW/cm2 groups had poor learning and memory, disrupted EEG oscillations, and injured hippocampal structures, including hippocampal neurons degeneration, mitochondria cavitation and blood capillaries swelling. The Nissl body content was also reduced in the exposure groups. Moreover, the hippocampal tissue in the 30 mW/cm2 group had increased expressions of NR2A and NR2B and decreased levels of CREB and p-CREB. CONCLUSION Shortwave exposure (27 MHz, with an average power density of 10 and 30 mW/cm2) impaired rats' spatial learning and memory and caused a series of dose-dependent pathophysiological changes. Moreover, NMDAR-related CREB pathway suppression might be involved in shortwave-induced structural and functional impairments in the rat hippocampus.
Animals ; Cyclic AMP Response Element-Binding Protein ; genetics ; metabolism ; Dose-Response Relationship, Radiation ; Electroencephalography ; radiation effects ; Hippocampus ; radiation effects ; Male ; Memory ; radiation effects ; Nissl Bodies ; physiology ; radiation effects ; Radio Waves ; adverse effects ; Random Allocation ; Rats ; Rats, Wistar ; Receptors, N-Methyl-D-Aspartate ; genetics ; metabolism ; Spatial Learning ; radiation effects

This paper explored the feasibility of using ultrasonic Nakagami statistic parameter imaging to evaluate the thermal lesion induced by microwave ablation (MWA) in porcine models. In this paper, thermal lesions were induced in livers and kidneys in 5 swines using a clinical MWA system. During this treatment progress, ultrasonic radiofrequency (RF) data were collected. The dynamic changes of Nakagami parameter in the thermal lesion were calculated, and the ultrasonic B-mode images and Nakagami images were reconstructed simultaneously. The contrast-to-noise ratio (CNR) between the thermal lesion and the surrounding normal tissue was calculated over the MWA procedure. After MWA, a bright hyperechoic region appeared in the ultrasonic Nakagami image as an indicator of the thermal lesion and this bright spot enlarged with lesion development during MWA exposure. The mean value of Nakagami parameter in the liver and kidney increased from 0.78 and 0.79 before treatment to 0.91 and 0.92 after treatment, respectively. During MWA exposure, the mean values of CNR calculated from the Nakagami parameter increased from 0.49 to 1.13 in the porcine liver and increased from 0.51 to 0.85 in the kidney, which were both higher than those calculated from the B-mode images. This study on porcine models suggested that the ultrasonic Nakagami imaging may provide an alternative modality for monitoring MWA treatment.
Animals ; Kidney ; diagnostic imaging ; Liver ; diagnostic imaging ; Microwaves ; Radio Waves ; Radiofrequency Ablation ; Swine ; Ultrasonography

Ablation Techniques ; adverse effects ; methods ; Humans ; Lung Neoplasms ; diagnostic imaging ; radiotherapy ; surgery ; Postoperative Complications ; prevention & control ; therapy ; Radio Waves ; therapeutic use ; Radiotherapy, Image-Guided ; adverse effects ; methods ; Treatment Outcome

OBJECTIVE: This paper aimed to evaluate the effectiveness of the 3D printing puncture navigation template-guided percutaneous radiofrequency thermocoagulation for V2 trigeminal neuralgia treatment. METHODS: A total of 52 patients with V2 trigeminal neuralgia were treated with radiofrequency thermocoagulation. A total of 32 patients were treated under the guidance of the 3D printing puncture navigation template (guide plate group), while 20 patients underwent puncture via pterygopalatine fossa routinely (routine treatment group). The puncture time, operation time, puncture success rate, and immediate postoperative pain were recorded. The degree of immediate postoperative pain was indicated by visual analogue scale (VAS). Barrow Neurological Institute (BNI) classification criteria were used to evaluate the efficacy, and the postoperative complications were observed. All patients were followed up for 1 year. RESULTS: The two groups showed significant decrease in VAS after the operation (P<0.05). The puncture and operation times of the guide plate group were significantly lower than those of the routine treatment group (P<0.05). The difference in terms of the clinical effects and recurrence rate between the two groups was insignificant (P>0.05). CONCLUSIONS 3D printing puncture navigation template-guided radiofrequency thermocoagulation may increase the operation success rate and reduce complication incidence. Therefore, this technique possesses clinical promotional value.
Electrocoagulation ; Humans ; Postoperative Complications ; Printing, Three-Dimensional ; Radio Waves ; Treatment Outcome ; Trigeminal Neuralgia

OBJECTIVE: To evaluate the effect of prenatal mobile phone exposure on the expression of proliferating cell nuclear antigen (PCNA) and doublecortin (DCX) in dentate gyrus of offspring rats. METHODS: The rat model of prenatal mobile phone exposure was established and there were three groups including control group, short term maternal exposure group and long term maternal exposure group(=6). From pregnant day 1 to day 17, pregnant rats in long term and short term maternal exposure group were exposed to an mobile phone in talking mode for 6 h/d and 24 h/d, respectively. Length of pregnancy, maternal body weight gain, litter size and pup's body weight were observed. The cell morphology in dentate gyrus of offspring rats at the age of 1 month was studied by cresyl violet staining. The immunohistochemical expression of PCNA and DCX in dentate gyrus of rat offspring were detected, and the expression of DCX and brain derived neurotrophic factor (BDNF) in hippocampus of rat offspring were evaluated by Western blot. RESULTS: There was no difference in length of pregnancy, maternal body weight gain, litter size and pup's body weight among three groups. The morphological changes of pyramidal cells in the polymorphic layer and DCX-positive cells in the dentate gyrus were obvious in rat offspring of long term maternal exposure group. There were less PCNA-positive cells in dentate gyrus and decreased expression of DCX and BDNF in hippocampus by Western blot in long term maternal exposure group compared with control and short term maternal exposure group (all <0.05). CONCLUSIONS Long term prenatal mobile phone exposure might inhibit the expression of PCNA and DCX in dentate gyrus of rat offspring by down-regulating BDNF.
Animals ; Brain-Derived Neurotrophic Factor ; metabolism ; Cell Phone ; Dentate Gyrus ; metabolism ; Female ; Hippocampus ; metabolism ; Microtubule-Associated Proteins ; metabolism ; Neuropeptides ; metabolism ; Pregnancy ; Prenatal Exposure Delayed Effects ; Proliferating Cell Nuclear Antigen ; metabolism ; Radio Waves ; Rats

In order to support study of new radiofrequency ablation treatments and finally realize of precise conformal ablation of targeted tissue, this paper proposed a system which is able to generate radio frequency currents at different frequencies. The designed system bases on the basic principle of Class E power amplifier and uses MSP430 microcontroller as a controller and uses a touch screen as human-machine interface to design a frequency-selectable radiofrequency ablation treatment system,. The RF signals at frequencies of 230 kHz, 460 kHz, 920 kHz, and 2 000 kHz were tested to verify the feasibility of the system, and by using a tissue phantom, tested the heating ability of the RF signals at frequencies of 460 kHz, 920 kHz, and 2 000 kHz. The results show the device could well heat the tissue at the three frequencies. The study has also found that both the highest temperature and the ablation area decreases with RF frequency, when using the constant power control mode.
Catheter Ablation ; instrumentation ; Hot Temperature ; Humans ; Hyperthermia, Induced ; Phantoms, Imaging ; Radio Waves

A 25-year-old man presented with chronic low back pain and occasional radiation to the right lower limb. Magnetic resonance imaging and computed tomography (CT) of the lumbar spine showed an osteolytic expansile lesion with a central sclerotic nidus in the right superior facet of the L5 vertebra and surrounding marrow oedema. The diagnosis of osteoblastoma was made based on imaging findings and confirmed after CT-guided biopsy. Radiofrequency ablation of the lesion was successfully performed. The patient tolerated the procedure well and showed symptomatic relief. The imaging features and management of osteoblastoma are discussed.
Adult ; Catheter Ablation ; Chronic Pain ; diagnostic imaging ; Humans ; Image Processing, Computer-Assisted ; Image-Guided Biopsy ; Low Back Pain ; diagnostic imaging ; Lumbar Vertebrae ; diagnostic imaging ; Magnetic Resonance Imaging ; Male ; Osteoblastoma ; diagnostic imaging ; Osteolysis ; Osteoma ; diagnostic imaging ; Radio Waves ; Tomography, X-Ray Computed