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Medical RF Connectors: SMB, MCX, AMC, and Non-Magnetic Options

rf connector medical device magnetic resonance imaging wireless monitoring hospital equipment

This article explores various medical RF connectors, including SMB, MCX, AMC, and non-magnetic connectors specifically designed for medical RF applications. Let’s delve into the features of each type, as summarized in the table below.

Medical RF Connector Types and Features

Medical RF Connector TypeDescription
SMBIdeal for thicker layouts. Available in 50 Ohm impedance and offers 360 degrees of rotation. Designed for easy mating and un-mating.
MCX/MMCXSuitable for applications where physical space is limited. Available in both 50 Ohm and 75 Ohm versions.
AMCAMC cables are used for board-to-board connections in space-constrained medical devices. Typically available for 50 Ohm systems.
Non-MagneticThese coaxial connectors are specifically designed for carrying RF signals within the strong magnetic fields of MRI equipment. Critical for maintaining a high Signal-to-Noise Ratio (SNR). Available in 50 Ohm impedance and tested for magnetism before shipping. Supported interfaces include SMB, MMCX, and MCX.

Applications of Medical RF Connectors

These specialized RF connectors find use in several key medical technologies:

  • MRI (Magnetic Resonance Imaging): In this imaging technique, an RF signal is transmitted to the patient while they are under a strong magnetic field. This causes the hydrogen atoms within the body to align in the same direction, enabling the generation of detailed images. The received radio signal comes from the MRI coil, which makes direct contact with the body part being imaged.

    The underlying physics involves using a strong static magnetic field, B0B_0, to align the nuclear spins of hydrogen atoms. Radiofrequency pulses at the Larmor frequency, f0=γB0f_0 = \gamma B_0, where γ\gamma is the gyromagnetic ratio, are then used to excite these spins. The resulting signals are detected by the MRI coil and processed to create images.

  • Wireless Patient Monitoring: This increasingly popular method allows for the remote generation of patient vital signs reports, minimizing the need for patients to be physically present in the hospital unless absolutely necessary. This has led to significant cost reductions for healthcare providers and patients. Devices in this category often operate within the ISM (Industrial, Scientific, and Medical) frequency bands.

  • IMD (Implantable Medical Devices): These are medical devices surgically placed inside the human body, typically under the skin. Examples include neurostimulators, pacemakers, and glucose meters.

  • Hospital Equipment (RFID): RFID (Radio-Frequency Identification) technology is utilized by attaching RFID tags to hospital equipment. This enables efficient tracking and management of all equipment, ensuring they are easily accessible when needed.

Medical RF Connector Manufacturers

Several manufacturers specialize in producing medical RF connectors and cable assemblies for the medical market. Here are some prominent ones:

  • Amphenol RF
  • Molex
  • Radiall
  • IMS Connector System
  • BTC Electronic Components
  • Winchester Electronics