Development of 3D-printed mouse head holder for use in VsEPs system
The Mouse Auditory Testing Core within NIDCD provides investigators with assistance in testing auditory function in rodents. In addition to the standard auditory testing (such as auditory brainstem response), NIDCD is expanding core capabilities to include the often-needed testing of vestibular sensory evoked potentials (VsEPs). VsEPs are used to assess the vestibular system, which is a critical component associated with a sense of balance. Current and previous projects utilizing VsEPs include gene therapy, blast exposure, and ototoxicity. The VsEPs are induced by forcing a rapid motion of the rodent head and measuring the electrophysiological response using electrodes placed under the skin. No commercial system or solution is available, therefore SPIS has assisted NIDCD in duplicating a standard VsEPs testing platform developed by an outside researcher who pioneered the technique. While originally focused on establishing the basic VsEP testing capability, SPIS staff have taken initiative in debugging and improving the system design. Improvements include adjustments to the mechanical setup to significantly reduce motion noise artifacts, modifications to the rodent head mount to improve fit and translation of the desired movement, and modifications aimed at enhancing the VsEP signals.
A key component of the system is the mouse head holder which translates mechanical motion from a lab shaker to the mouse head. Proper translation of this mechanical motion to the head is essential to producing a VsEP response. The existing system uses a modified hair clip based on previous work by the leading expert in the field. While the clip is effective, placing the mouse head properly is cumbersome, and the clip is prone to breakage and can be difficult to source replacements parts. The BESIP student will working closely with the Pohida and Fitzgerald labs to design a 3D-printed head holder to improve clip fabrication, head fit, and overall usability of the device. The student will:
- Use Solidworks 3D CAD software to design a new head holder to firmly grasp the mouse head without requiring permanent attachments (e.g., attachments to the skull) or restricting normal breathing.
- The student will select an appropriate 3D printing technology available through the Pohida lab to fabricate the holder for testing. The student will integrate the new holder into the existing system and work with the Fitzgerald staff on evaluating the fit and usability of the design.
- The student will work with the Fitzgerald staff to run comparison studies between the new design and the established design. Based on these results, the student will refine the design as needed.
- Based on results and time, the student may design and evaluate several different designs. In addition to the head holder, the student will work with the Pohida and Fitzgerald labs to design and implement any additional devices or methods to assist in proper setup of an experiment.
Fitzgerald lab: The mission of the Mouse Auditory Testing Core Facility is to assist the NIDCD’s principal investigators and their collaborators with tests of auditory and vestibular function in rodents. We specialize in performance of auditory brainstem response (ABR) testing to estimate hearing sensitivity, distortion-product otoacoustic emission (DPOAE) testing for evaluation of cochlear (inner ear) function, and vestibular sensory evoked potential (VsEP) testing to evaluate vestibular function. We can also perform noise exposures. We offer consultation on and training in these techniques.
Pohida lab: Provides electrical, electronic, electro-optical, mechanical, computer, and software engineering expertise to NIH projects that require in-house technology development. Collaborations involve advanced signal transduction and data acquisition; real-time signal and image processing; control and monitoring systems (e.g., robotics, process automation); and rapid prototype development. Collaborations result in the design of first-of-a-kind biomedical/clinical research systems, instrumentation, and methodologies.