radio frequency temperature sensor Using fiber optic sensors

Braiteoir teocht snáthoptaice, Intelligent monitoring system, Distributed fiber optic manufacturer in China

The role of radiofrequency ablation temperature sensors

In radio frequency systems, radio frequency electrodes are key devices used to contact or approach the treated human tissue and release radio frequency energy. Radio frequency electrodes are used to convert radio frequency signals into temperature fields and treat human tissues through thermal effects.
Due to the fact that the ablated tissue is generally located inside the body and is not as visible and touchable to doctors as traditional surgery, the measurement of tissue temperature and impedance plays a very important role in determining the ablated state of the tissue. In existing technologies, various radiofrequency ablation systems have one or more sensors installed near the radiofrequency electrodes, typical of which are temperature sensors and impedance sensors. Among them, temperature sensing is used to monitor the degree of tissue heating, in order to control the ablation process and judge the ablation effect. In addition to similar purposes, impedance monitoring can also assist in determining the contact status between the probe and internal tissues. For example, if the impedance is high during probe movement, it may be due to the detachment of the probe and tissue from contact, and doctors can adjust the position of the probe accordingly. The feedback of current and voltage is generally used in computer real-time closed-loop control systems to control the ablation process.

Types of RF ablation temperature sensors

Conventional temperature sensors, such as thermocouples and thermistors, are made of metal conductive materials. Conductive materials generate induced currents under high-frequency electromagnetic fields. Based on the principle of electromagnetic induction, they produce discharge phenomena or their own temperature increases, causing serious interference in temperature measurement, resulting in significant errors in temperature readings or inability to perform stable temperature measurements. In existing technologies, infrared temperature measurement can also be used for temperature measurement in radio frequency environments, but it has certain limitations. The measured temperature point must be within the visible range of the infrared sensor, and infrared temperature measurement can only measure the surface temperature of objects; The accuracy of infrared temperature measurement is affected by the emissivity of the surface material of the object. Different materials of the object being measured result in different infrared emissivity, leading to different measured temperature values. Fluorescence temperature measurement can overcome some of the shortcomings of the above methods. During measurement, the fluorescent material is placed in contact with the surface of the object being measured, and an excitation light source is input from the other end of the optical fiber. The excitation light is transmitted through the optical fiber to the head to activate the fluorescent material. After the excitation light pulse, the afterglow of the fluorescent material is exported from the original optical fiber, filtered out the spectrum, and its afterglow time constant is measured to convert the temperature of the object being measured.

RF fluorescence fiber optic temperature sensor

Technical parameters of fluorescent fiber optic temperature measurement device

Provide 1-8 position DIP switches
Provide two switch signal outputs
Temperature measurement range: -40 ℃~200 ℃
Temperature measurement accuracy: ± 1 ℃
Temperature measurement resolution: 0.1 ℃
Number of channels: 3 cainéil (can be expanded to 16 cainéil)
Communication interface: dual RS485 communication interface
Temperature measurement frequency: 1Hz

AC/DC universal power supply: wide voltage 100-300V/50Hz
Power consumption<6W
Communication protocol: Standard Modbus RTU
Installation size: 123.5mm x 48mm (length x width)
Operating temperature: -20 ℃~65 ℃
Storage temperature: -40 ℃~85 ℃
Fiber optic sensing probe with a withstand voltage of 100KV (40mm withstand length, 5min withstand time) and an inspection report issued