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FDA finalizes brain-computer interface guidance, issues draft for glycemic control devices

Posted 20 May 2021 | By Kari Oakes 

FDA finalizes brain-computer interface guidance, issues draft for glycemic control devices

The US Food and Drug Administration (FDA) has issued four medical device-related guidance documents. The new guidances address brain-computer interfaces, considerations in medical device design for the magnetic resonance imaging environment, clinical studies for devices to improve glycemic control and premarket notification submissions for peripheral atherectomy devices.
 
The four documents, one in draft and three in final form, were part of a larger swath of guidances announced by FDA in Wednesday’s Federal Register.  
 
Implanted brain-computer interfaces
The first final guidance from FDA’s Center for Devices and Radiological Health (CDRH) provides device developers with clinical and non-clinical testing considerations for implanted brain-computer interface (BCI) devices intended for use by patients with paralysis or amputation. These devices, explains FDA in the introduction to the guidance, are “neuroprostheses that interface with the central or peripheral nervous system to restore lost motor and/or sensory capabilities in patients with paralysis or amputation.”
 
This guidance was made available in draft form in February 2019; it debuted FDA’s “leapfrog” guidance process. Scott Gottlieb, FDA commissioner at the time the draft guidance was released, explained then that the BCI draft guidance “helps bridge where we are today with innovations of tomorrow, providing our initial thoughts about regulatory considerations for an emerging health technology with the understanding that our recommendations are likely to evolve as the FDA works to finalize the guidance to account for public comments, technological developments and new information.” (RELATED: CDRH issues guidance on brain-computer interface devices, Regulatory Focus 22 February 2019)
 
In the interval since the release of the draft guidance, FDA took into consideration the comments it received and made some adjustments to the final guidance. Among these is the addition of a section addressing human factors that recommends early and iterative attention to usability information; the final guidance also describes training for home use of implanted BCIs, including how to evaluate the effectiveness of the training.
 
The final guidance also advises developers to submit a pre-submission to receive feedback from FDA when developing “any BCI devices with technological characteristics, components, or indications for use or patient population not described in the guidance.”
 
The 30-page guidance document takes developers through considerations in the pre-submission and investigational device exemption processes, with special attention given to non-clinical bench testing considerations. An appendix provides stimulation output specifications.
 
The guidance strongly encourages developers to avail themselves of feedback from FDA early in the BCI development process through the agency’s Q-submission program.
 
Safety in the magnetic resonance environment
FDA also finalized guidance on testing and leveling medical devices for safe use in the magnetic resonance environment. The strong magnetic forces used in magnetic resonance imaging (MRI) and other MR work can result in catastrophe if ferromagnetic materials come too close to the magnets. (RELATED: FDA updates guidance on device in the magnetic resonance environment, Regulatory Focus 01 August 2019)
 
After reviewing relevant consensus standards and guidance documents, the final guidance goes through how to address a variety of hazards that medical devices may post in the MR environment. These range from magnetically induced displacement force and torque to unintended heating, gradient-induced vibration, unintended stimulation and medical device malfunction.
 
The final guidance clarified approaches to be used in assessing radiofrequency heating; further revisions provided more detail “about when gradient induced vibration and heating assessments are needed and to include the possibility of magnetically induced force and torque causing equipment to tip over,” according to the Federal Register entry announcing the availability of the final guidance.
 
The guidance also discusses how to assess the MR image artifact or corruption that actively operating medical devices can cause; another section instructs developers how to report their testing results.
 
For MRI safety labeling of devices, FDA sets out four categories: MR Safe, MR Unsafe, MR Conditional and a final category for devices whose MRI safety has not been evaluated. Developers seeking to use the last category should “provide a rationale as to why the labeling is appropriate for your medical device in your premarket submission;” a Q-submission engagement with the agency is also recommended if developers are unsure whether this category best fits their device.
 
The 23-page final guidance has two accompanying appendices; one gives an example of a test result summary that could be included in a regulatory submission, and the second gives examples of MR conditional labeling. The new MR testing and labeling guidance supersedes a 2014 guidance.
 
Premarket submissions for atherectomy devices
FDA also finalized a 2018 draft guidance that contained select updates for premarket notification submissions related to peripheral vascular atherectomy devices. This guidance, meant both for industry and FDA staff, lays out the scope of information that should be included in premarket notifications; in the 32-page final document, these include “descriptive characteristics, labeling, biocompatibility, sterility, nonclinical, animal, and clinical performance testing,” according to the Federal Register announcement of the guidance.
 
No public comments were submitted on the draft guidance, and FDA made no substantive changes from the draft version. (RELATED: FDA drafts 510(k) submission guidance n peripheral atherectomy devices, Regulatory Focus 26 July 2018)
 
Draft guidance for non-insulin glycemic control devices
A new draft guidance is intended to guide developers of devices intended to therapeutically improve glycemic control in patients with type 2 diabetes (T2DM).
 
The scope of this guidance is meant to include devices such as “neurostimulators, and those that mimic or result in anatomical changes similar to those made by bariatric surgical procedures, alter the anatomy and/or physiology of the small intestines, or manipulate the sympathetic nervous system,” according to the draft guidance. No such devices are currently cleared or approved by FDA, though the draft document notes that devices in this arena “have become an increasing area of interest.”
 
Specifically excluded from the scope of this guidance are devices to measure or monitor blood glucose, those that dose or deliver insulin or calculate insulin doses, and software as a medical device (SaMD) to improve glycemic control in T2DM patients.
 
The draft guidance gives specific recommendations for early-phase clinical studies of devices to improve glycemic control, including how to select the appropriate study design, duration and follow-up schedule, what sample size is appropriate and who should be included and excluded from clinical studies, patient demographic considerations, and treatment parameters.
 
The draft guidance gives specific recommendations about the upper and lower limits of glycated hemoglobin (HbA1c) levels for participants in feasibility studies, and recommends that aside from their T2DM, patients participating in these early-stage studies should be “otherwise healthy under optimal medical management.”
 
Medication management plans for study of a novel device are also outlined in the draft guidance. Change in HbA1c is recommended as the key effectiveness endpoint for both early feasibility and feasibility clinical studies, “as this is a widely recognized objective measure of glycemic control.”
 
Also addressed are appropriate safety and effectiveness endpoints and which data should be collected in support of claims for both safety and effectiveness, and considerations in the statistical analysis of study data.
 

 

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Tags: devices, FDA, medical, MRI, US

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