I-Corps: Acousto-optical RF Field Sensor for Magnetic Resonance Imaging

该I-Corps项目的更广泛影响/商业潜力是通过在介入和诊断程序期间感测射频（RF）信号来提高磁共振成像（MRI）程序的安全性。在介入手术期间，特别是对于无法使用X射线成像的儿童至关重要，该传感器可提供患者体内器械（如导管）的位置和方向，以指导医生。由于使用了声光传感器，因此实现了这种信息传递，而没有不利影响，例如RF加热。在诊断过程中，传感器可以帮助实时量化患者的射频场暴露，防止组织过度发热。此外，由于安全问题，它可以使目前未通过MRI成像的具有医疗植入物的患者成像。作为一种商业产品，传感器将潜在地降低医疗行业（医院、保险公司、政府机构等）中所有医疗保险持有者的成本。该I-Corps项目基于射频（RF）安全声光传感器，用于在磁共振成像（MRI）中局部测量RF场，从而在MRI介入手术期间提供信号以跟踪介入器械（如导管和针头），并测量患者的RF能量暴露。MRI的主要安全问题是射频加热，因为需要金属电缆将信号从天线传输到外部系统。这里的解决方案是用光纤玻璃纤维取代所有的金属电缆，这消除了RF加热。为了将RF信号转换为光调制，使用紧凑型声光传感器作为天线和光纤之间的中间介质。这是通过用微型MRI线圈和天线产生的RF信号激励光纤上的压电换能器来实现的，所述RF信号又在光纤中产生声波。由于信号是在没有任何导体的情况下通过光纤生成并传输到MRI系统，因此消除了RF加热安全问题。该传感器原型已经成功地进行了台架测试，并证明了介入程序的原理。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估。

The broader impact/commercial potential of this I-Corps project is to improve the safety of magnetic resonance imaging (MRI) procedures by sensing the radio frequency (RF) signals during interventional and diagnostic procedures. During interventional procedures, especially critical for children who cannot be imaged using X-rays, this sensor provides the location and orientation of devices, such as catheters, inside the patient's body to guide the physicians. Since an acousto-optical sensor is used, this information transfer is achieved with no adverse effects, such as RF heating. During diagnostic procedures, the sensor can help quantify the RF field exposure of the patient in real-time, preventing excessive tissue heating. Furthermore, it may enable imaging of patients with medical implants who are not currently imaged by MRI due to safety concerns. As a commercial product, the sensor will potentially decrease the costs for all the stake-holders within the health industry (hospitals, insurance companies, governmental institutions, etc.) while decreasing the risk to the patients and improving health outcomes.This I-Corps project is based on a radio frequency (RF) safe acousto-optical sensor to locally measure the RF field in magnetic resonance imaging (MRI) which in turn provides the signals to track the interventional devices like catheters and needles during interventional procedures under MRI as well as to measure RF energy exposure of the patient. The main safety concern with MRI is RF heating due to metal cables required to carry the signal from an antenna to the outside system. The solution here is replacing all the metal cables with optical glass fiber, which eliminates the RF heating. To convert the RF signal into optical modulation, a compact acousto-optic sensor is used as an intermediate medium between the antenna and the optical fiber. This is achieved by exciting a piezoelectric transducer on an optical fiber with the RF signal generated by miniature MRI coils and antennas which in turn generates acoustic waves in the optical fiber. Since the signal is generated and transmitted over an optical fiber to the MRI system without any conductors, this eliminates the RF heating safety issue. The sensor prototype has been successfully bench tested and proof of principle for interventional procedures has been demonstrated.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.