Hello everyone, welcome to the RF Academy. When it comes to RF, the first things that come to mind are usually mobile communications, base stations, radar, and satellites. However, few people know that RF coils, signal transceiving, and near-field high-sensitivity reception are the "heart" of modern medical imaging. On May 1, 2026, a groundbreaking patent from the US company Neuro42 was officially published in China: Intracranial RF Coil for Intraoperative Magnetic Resonance Imaging (Patent CN121969304A)
It does not rely on complex theories, but uses an extremely small RF coil to solve the pain points that have plagued neurosurgery for decades: poor visibility, inaccessible areas, and inaccurate positioning during surgery. In this article, I will explain this cross-disciplinary RF breakthrough in the most fluent and accessible way, combined with the patent drawings, so we can learn about it together.
Three Major Pain Points of Traditional Intraoperative MRI
In neurosurgery, Magnetic Resonance Imaging (MRI) serves as the surgeon's "eyes." However, traditional high-field MRI has three unavoidable problems: The magnetic field is too strong and too dangerous: The 1.5T/3T high magnetic field acts like a giant magnet, attracting surgical instruments and robots, posing extremely high safety risks. Enclosed cylinder, impossible to operate: Once the patient is inside the machine, surgeons cannot perform minimally invasive procedures during the scan. Coils are outside the body, images are not clear enough: The RF receiving coils are placed on the outside of the scalp, far from the deep brain, resulting in significant signal loss and blurry needle tip imagery.
To solve all these issues, Neuro42 has proposed a simple yet revolutionary solution: miniaturize the RF receiving coil to the millimeter scale, mount it directly on the surgical needle, and insert it into the brain.
What Does the Entire System Look Like? (Combined with Patent Drawings)
The entire system revolves around a dome-shaped head magnet (Figures 1, 4, and 5). 1. Dome Open Magnet: Surgically Compatible MRI. Unlike traditional enclosed equipment, it is a dome that covers the head: It uses a Halbach permanent magnet array to generate anultra-low magnetic field below 0.3T, with no attractive force and higher safety; it does not require a shielded room and can be used in a standard operating room; the housing is equipped with surgical access ports, allowing surgeons to directly insert needles, scalpels, and catheters (Figures 2 and 3). Simply put, this is an MRI that allows surgeons to scan and operate simultaneously.
2. Electrical System: External Transmission, Intracranial Reception (Figure 6)
The system adopts a transceiver-separated RF architecture: External coil: Responsible only for transmitting signals to excite brain protons; Gradient coil: Responsible for spatial positioning; Micro coil: Responsible only for receiving signals, placed closest to the lesion. This is the key to clear imaging for the entire device.
Core Breakthrough Technology: 1.2mm Intracranial RF Coil (Figures 9 to 12)
The most impressive aspect of this patent is the micro RF receiving coil mounted at the tip of surgical tools. 1. Ultimate Miniaturization: Outer diameter: 1mm–2mm, preferably 1.2mm, which can be directly integrated into: biopsy needles, scalpels, microcatheters, and electrodes, truly realizing: the instrument is the antenna, and the needle tip is the sensor.
2. Two Dedicated Coil Structures: The patent designs two types of coils for different surgical needs: (1) Dual Opposed Solenoid Coil (Figure 10): The two segments are mirror-symmetric and wound in opposite directions to deliver low mutual interference and uniform signal response. suitable for: cerebral blood vessel wall imaging.
(2) Dual Orthogonal Solenoid Coil (Figure 11):Two sets of solenoids are nested and rotated 90 degrees relative to each other, creating a forward-facing sensitive region.(Figure 12). Wherever the needle tip goes, it prioritizes clear visualization. Suitable for: intraoperative navigation, avoiding cardiovascular and functional areas.
3. Why Does It Make Images Clearer? the coil sits directly adjacent to brain tissue, creating the shortest signal path; high filling factor, with a signal-to-noise ratio far exceeding that of external coils; it only receives signals and does not transmit them, resulting in lower interference; even under low magnetic field strength, it can still capture ultra-high-resolution local images.
Surgical Robots Can Also Be Used in Coordination (Figure 8)
This system can be directly integrated with surgical robots: The robotic arm passes through the magnet port into the cranial cavity; the end effector carries the 1.2mm RF coil; MRI provides real-time positioning of the needle tip; the robot precisely performs biopsies, tumor resections, and electrode implantations.
How Is a Surgery Completed? (Reviewing the Patent Flowchart)
The entire process is clear and easy to understand: Place the dome magnet over the patient's head to establish a <0.3T low-field static magnetic field; insert the surgical needle with the micro coil into the brain; transmit RF pulses externally to excite proton signals; the needle tip coil receives signals in the near field with ultra-strong signals; the computer reconstructs ultra-high-definition brain images, tracks the needle tip position in real time, and fuses local images with global images, allowing surgeons to see more accurately.
To summarize in one sentence: External transmission, intracranial reception, millimeter-scale coils, and real-time navigation.
What Exactly Makes This Patent So Outstanding?
From the perspective of an RF engineer, it achieves four breakthroughs: Transceiver separation significantly improves the signal-to-noise ratio; the 1.2mm coil enables truly minimally invasive procedures; low-field + near-field reception uses design to bridge the performance gap; open magnet + surgical ports achieve true intraoperative MRI. It is not just an RF technology, but an upgrade for neurosurgery: Brain biopsy: Real-time visualization of the needle tip without touching blood vessels; Tumor resection: Clear boundaries for cleaner resection; Deep brain stimulator implantation: Sub-millimeter precise positioning; Minimally invasive surgery: Safer, less tissue damage, and faster recovery.
Conclusion
RF technology is no longer exclusive to the communications field. Neuro42 tells us with a 1.2mm intracranial RF coil: the best receiving antenna should be placed as close to the signal source as possible. From mobile communications to medical imaging, from the outside of devices to the inside of the human body, RF is redefining the future of healthcare using the most fundamental physical principles. This is the power of RF.
Note: The patent is from the China Patent Publication Website. To download the full text, please scan the Baidu Netdisk QR code below.