NIMH Instrumentation Core Facility

National Institute Of Mental Health

Investigators

Linked publications & trials

Abstract

This past year, our Section had the unique opportunity to support the research of various Labs & Sections within NIMH, NINDS, NICHD, and NCCIH. During the past twelve months, investigators from these labs and branches requested 482 formal projects from our staff, an increase of 41% from the previous year. Each of these requests was documented, and the time recorded to complete the job. In addition to the formal requests, we are available daily for numerous walk-in, phone call or e-mail requests for assistance. In general, our technical support this past year can be divided into the following research areas: Human and Clinical: The following are a subset of SI Clinical projects this past year: NIRS Sleep Wearable Pulse Oximeter SI developed a mechanism to hold a novel pulse oximeter device during subject sleep studies. The design had to minimize the contact of the sensor and case with the patient’s skin and uses commercially available, single-use materials to maintain compatibility with patient safety protocols. Linearly Driven Ultrasound Transducer SI designed a custom servo-driven ultrasound transducer system to allow for automatic scanning of nerves in subject’s forearms. MRI Compatible Stretcher SI developed modifications to a patient transfer board to allow research staff to transfer a patient in and out of a novel mobile MRI unit. Head Holder for TMS Coil (side) SI developed a system to hold the TMS coil on the side of the head of a patient to better acquire different signals for depression studies. Optically Pumped Magnetometer (OPM) System Over the past year, the Instrumentation Team has delivered a series of custom-engineered solutions that have directly enabled the NIMH MEG Core to ramp up operation of its new Optically Pumped Magnetometer (OPM) suite. From magnetic-field–safe seating and sensor mounts to precision calibration arrays and adaptable fixtures, these innovations have solved space, safety, and usability challenges that off-the-shelf equipment could not address. The MEG core recently opened its OPM suite, housed in a compact magnetically shielded room. Because of the limited space and strict material requirements, the team designed and built modular, multi-purpose components that maximize functionality while maintaining a safe, uncluttered environment. There were several separate systems for the OPM System: 1. Height-Adjustable, Metal-Free Chair A custom, sturdy, height-adjustable chair was built entirely from non-metallic materials to meet the magnetic environment requirements. Starting from CNC CAD files provided by the MEG Core, the Instrumentation Team modified the design to fit the core’s specifications and water-jetted the components from PVC. Because the sensor array cannot be suspended from the ceiling, the chair was adapted to incorporate a vertically adjustable, rotatable sensor holder. This holder can also support calibration phantoms for quality assurance testing. 2. Calibration Array A flat fixture was designed to hold 64 OPM sensors, distributed over two vertically adjustable levels: - Bottom Level: A central 7×7 grid of vertically oriented sensors, spaced as closely as possible, arranged in a checkerboard pattern with alternating 90° rotations. Surrounding this grid are three horizontally oriented sensors on each side, also rotated alternately by 90° along their longitudinal axes. The sensing volumes of the horizontal sensors are co-planar with those in the grid. The bottom level is adjustable over a 25 mm range. - Top Level: Three orthogonally arranged reference sensors, centered above the bottom grid, following the orientation of the previous reference bridge design. This level is also vertically adjustable over 25 mm, with a minimum clearance of approximately 57 mm to accommodate sensor sleeves and heat dissipation. To allow both V2 and HEDscan sensors to be used with the same array, the team developed 3D-printed adapter sleeves for the V2 sensors, based on manufacturer CAD files that required substantial modifications through iterative test prints. 3. Support Arms For brain recordings, HEDscan sensors are placed in a manufacturer-supplied helmet, while V2 sensors are positioned using a custom fixture built previously by the Instrumentation Team. Due to the new room’s ceiling restrictions, a 3D-printed coupler was designed to connect an extendable PVC arm to support the V2 array. At the arm’s end, a custom PVC connector was designed to hold a brass bar that supports the OPM array on participants’ heads, allowing limited rotation while maintaining load stability. In addition, two other OPM sensors in the room are mounted on fixed vertical PVC pipes with 3D-printed holders. The team designed a modification enabling these mounts to swing approximately 90°, allowing them to rest parallel to the ceiling. This adjustment provides better access for setup while minimizing handling of the sensors. 4. Projector Holder A custom 3D-printed clamp was produced to attach the projector securely to a new aluminum mounting plate. The aluminum plate, patterned similarly to the existing steel version that came with the magnetically shielded room but with a shifted hole pattern, allows researchers to align the projector more precisely with the waveguide, providing improved positioning flexibility. These solutions, all custom-designed for the constraints of a compact, magnetically shielded OPM environment, have been critical to ensuring that the MEG Core can carry out high-quality, reliable measurements in support of ongoing neuroscience research CGMP Radiotracer Facility: Currently, NIMH produces virtually all of its short-lived radiotracers for research studies in human subjects with positron emission tomography (PET) from its own laboratory suite. The CGMP laboratory was created in the Clinical PET Center to produce all radiotracers for PET studies in human subjects on the NIH campus according to a high common standard in compliance with regulatory needs. The Section on Instrumentation continues to provide a substantial amount of engineering support to the Section on PET Radiopharmaceutical Sciences in the Molecular Imaging Branch (MIB) to implement the CGMP and other radiotracer facilities. Electrophysiology: The Section on Instrumentation staff continuously strives to improve the utility of various components that comprise electrophysiology. We have continued to improve the engineering and 3D-Printed fabrication of multiple-hole grid arrays and integrated bases that allow precise and repeatable placement of a single or multiple electrodes over a wide area. fMRI/MRI: The Section on Instrumentation (SOI) provides a wide range of support for fMRI-related research. Fabrication of devices for use in MRI environments is a specialized area of expertise, with great attention given to design without ferrous metals and minimization of all metal components. In addition, commercial industrial fiber optic components and systems are evaluated and integrated into many designs and devices we fabricate. SOI continues to provide considerable effort in the design and fabrication of primate chair systems to incorporate new features as requested by researchers. Non-Human Primate (NHP): Our group is responsible for providing a wide range of engineering and fabrication services to support non-human primate research. Many of the mechanical assemblies that are necessary for this type of research are engineered and fabricated in-house. Our group provides a diverse array of custom systems and components to many different investigators, such as custom primate chairs, high-strength restraints, MRI positioning systems, custom head coils, reward systems, data acquisition and analysis, optical response systems, plus a wide range of small mechanical components. Behavioral: Several different types of mazes are used to study spatial learning and memory in rodents. These studies have been used to help understand general principles about learning that can be applied to humans, and to determine how different treatments affect learning and memory in mice. We continue to produce a variety of custom T and Y mazes for behavioral testing. These mazes may be passive fixed passages or selectable passages controlled by an electro-mechanical interface. SI also continues development of a custom behavioral testing system for studying plasticity in the mouse brain. Neuroplasticity in sensory brain areas supports adaptation after nerve injury and fundamentally impacts sensation and movement. However, limited neuroplasticity in somatosensory areas due to the early critical period makes determining the role of thalamocortical (TC) inputs in sensorimotor signal processing challenging. SI built a custom automated behavioral testing system in a sound isolated chamber to allow for research into the reactivation of TC neuroplasticity to provide crucial evidence that TC inputs can alter the neural activity of sensory-motor pathways even after the critical period. The enormous changes in sensorimotor circuit activity are important for adaptation following an injury such as limb loss, stroke, or other forms of neural injury. Imaging: SOI continues to produce a variety of equipment that supports two-photon microscopy, such as novel titanium headposts and stereotaxic frames, faraday cages for electronic and light shielding and custom mirror mounts. In addition, behavioral testing equipment such as low-inertia mouse wheels are fabricated for use with two-photon microscopy. SI also provided engineering expertise in fabricating a high frame-rate video capturing system for mouse eye tracking in behavioral experiments. Technology: The Section on Instrumentation continues to incorporate cutting-edge 3D printing technology at the NIH. By using the latest technology in CAD/CAM programming, Rapid Prototyping techniques, and reverse engineering, SOI is able to increase productivity and effectiveness while at the same time decreasing the amount of time needed to engineer and machine the components. Rapid Prototyping, or 3D printing, is revolutionizing the worlds of engineering and product development by accelerating the design process and producing otherwise impossible parts. 3D printing allows engineers to produce parts quickly and without additional user manufacturing time, as the parts self-build once the CAD file is sent to the printer. This speed in production allows for quick revision changes and improvement to the parts, while simultaneously allowing for increased output. In addition to accelerating the production of traditional parts, 3D printing allows for the creation of parts that would be otherwise impossible to produce. Because the material is added layer by layer, complex structures can be produced that are not possible with any other technique. This advantage is particularly suited to SOI as the vast majority of our projects involve very small runs of extremely specialized designs. 3D printing has allowed us to quickly and effectively produce specialized parts necessary for biomedical experimentation, and we are in the process of adding new technology to our 3D capabilities.