Application of Fiber Bragg Grating Sensor Temperature Monitoring System in Medical Nuclear Magnetic Resonance

Sensor o le vevela o le vaai mamao, Faiga atamai e mataituina ai, Falegaosimea o le optic o le vaai i Saina

Medical sensors are sensors applied in the biomedical field, which can convert physiological signals of the human body into easily readable digital image information. They are important tools used by doctors for diagnosis and treatment. Due to the application of medical sensors in the human body, the design and application of medical sensors must consider the specificity and complexity of biological signals, while also considering biocompatibility, reliability, and safety. I tausaga talu ai nei, researchers have found that the characteristics of fiber optic gratings can meet the special needs of medical sensors, so a large number of medical sensors based on fiber optic gratings have been proposed by researchers. O lea, it is necessary to introduce the basic sensing principles of fiber optic gratings, analyze the application characteristics of fiber optic grating sensors, and summarize their application progress in medical equipment fields such as heart monitoring, respiratory monitoring, temperature monitoring, ultrasound, and surgical medicine.

Due to the application of medical equipment to the human body, it needs to comply with various complex physiological structural characteristics of the human body, and the characteristics of fiber optic grating sensors can meet the special requirements of sensors in the field of medical equipment. The characteristics of fiber Bragg gratings ensure the safety of their actual use and are very suitable for the sensing field of medical equipment.

Application Analysis of Fiber Bragg Grating in Medical Equipment Field

Application in the field of cardiac monitoring

Cardiac efficiency is one of the important parameters for cardiac monitoring, and a fiber optic grating sensor for measuring cardiac efficiency was proposed in 1997. In this measurement method, the user inserts a directional thermal dilution catheter into the right atrium of the subject and injects a frozen liquid. By measuring the temperature and pulsation rate of the subject’s pulmonary artery blood, the measurement of cardiac pumping volume is ultimately achieved.
A fiber optic grating sensor is used to measure human heart sound and heartbeat frequency. The fiber optic grating is packaged in a textile as a sensing head. When the textile is tightly attached to the human body, the heart sound and heartbeat act on the fiber optic grating sensing head, realizing the modulation process of sound strain light signals. Finally, by monitoring the changes in the center, the sensing of human heart sound and heartbeat frequency is achieved.

Application in respiratory monitoring field

A respiratory monitoring system based on fiber optic grating, which fixes the fiber optic grating strain sensor to the chest of the subject through elastic tape. The sensor measures the respiratory process spectrum by monitoring changes in the chest cavity. In the process of using high-voltage electrodes to assist patients in artificial respiration, high-voltage discharge is usually used to stimulate the diaphragm nerve to help patients breathe. O lea, the patient’s chest needs to be equipped with high-voltage electrodes. Ordinary electrical sensors are not suitable for this high-voltage environment, and fiber Bragg grating has anti high-voltage interference characteristics. O lea, based on fiber Bragg grating sensors, it can be used in this high-voltage environment. In this type of process of using high-voltage electrodes to assist patients in artificial respiration, it is used to control the triggering of high-voltage discharge and achieve real-time monitoring of the patient’s breathing situation.
Develop a wearable sensor system for real-time monitoring of user breathing conditions. This sensor uses fiber optic gratings to sew into textiles, which are worn on the user’s chest and abdomen. By monitoring changes in chest and abdominal pressure, real-time respiratory movement monitoring is achieved. This wearable sensor facilitates real-time monitoring of the user’s breathing by medical institution staff.

Application in the field of ultrasound

A certain research unit detects ultrasonic fields based on fiber optic grating sensors. Propose a 1mm long fiber optic grating as the sensing head to measure a 2 MHz high-frequency ultrasonic field, with a pressure resolution of 10-3Hz.

There are many ultrasound diagnostic devices in medical equipment, such as ultrasound lithotripsy, ultrasound hyperthermia, and ultrasound surgery. When ultrasonic equipment is used, its output power usually needs to be monitored in real-time by sensors, while conventional piezoelectric devices are sensitive to electromagnetic fields, but the probe size does not match it, making it difficult to accurately measure the ultrasonic field inside the body. Fiber optic grating sensors have the characteristics of small size and resistance to electromagnetic interference, which are suitable for sensing medical ultrasound diagnostic equipment and can achieve multi-point measurement of ultrasound fields.

Application in temperature monitoring field

A fiber optic grating temperature sensing system applied to monitor the actual temperature of the nuclear magnetic resonance machine. The sensing head of the system is composed of four fiber optic gratings connected in series. During use, the sensing head is placed in a container of the nuclear magnetic resonance machine, with a magnetic field value of 4.7 T. A 25 meter long fiber optic cable is used to connect the probe and demodulator. The temperature resolution of the sensing system is 0.1 °C, the accuracy is ± 0.5 °C, and the measurement range is 25-60 °C. This sensing system fully embodies the advantages of fiber optic grating sensors in resisting electromagnetic interference, achieving temperature monitoring that traditional thermocouple sensors cannot be applied to strong magnetic field environments.
A new type of medical temperature sensing fiber Bragg grating sensing system applied to temperature monitoring during medical hyperthermia.

The temperature measurement results of this sensing system are consistent with those of traditional thermocouple sensors, with a resolution of 0.1 °C, an accuracy of ± 0.2 °C, and a measurement range of 30-60 °C. The stable physical characteristics of fiber optic grating sensors are very suitable for their application in some medical fields with complex detection environments.

Based on the basic sensing principle of fiber Bragg grating, the application characteristics of fiber Bragg grating sensors are small volume, mamafa, tetee atu i le pala, high temperature and high pressure resistance, magnetic field interference resistance, high sensitivity and accuracy. The application of fiber Bragg grating sensors in medical equipment fields such as heart monitoring, respiratory monitoring, temperature monitoring, ultrasound, and surgery are summarized. Ae peitai, the application of fiber optic grating sensors in the field of actual medical equipment still needs to consider the complexity and specificity of medical applications. Currently, most research is only in the laboratory research stage. It is believed that with more research and experimentation by researchers, fiber optic grating medical sensors that can truly be applied in the field of medical equipment will be developed.