Inside the Beltway: Zoll warning hints FDA wants user studies for wearable defibs
By Mark McCarty
Washington Editor
Zoll Medical (Chelmsford, Massachusetts) had an uncomfortable May-June inspection of its plant in Pittsburgh, the site of manufacture of the LifeVest wearable external defibrillator, which resulted in seven citations, including one addressing validation of the device's use. FDA said the device was not adequately validated under simulated or actual use conditions, but this was just one of several citations suggesting the agency is concerned that such devices have not been adequately tested in real-world use situations for the range of patients who will use the devices.
Zoll has snared only one other warning of recent vintage, a June 24, 2011, warning citing the firm's plant in Chelmsford for manufacture of external defibrillators. This warning contained two well-detailed citations addressing procedures for non-conforming product and verification of battery life, one of a series of FDA actions dealing with automated external defibrillators in the past few years.
The most recent letter to Zoll made mention of a redacted number of complaints of inappropriate shock "in which noise artifact and/or vibration were caused by various daily activities." However, the agency cited two other problems in addition to the validation issue associated with noise and vibrations, including a risk analysis that did not control for "lifestyle activities causing high noise artifact and/or vibration." The third sub-finding in this citation again took aim at the risk analysis, which the agency said did not "consider the use of the device in patients with cognitive and/or physical limitations," providing the example of "numerous complaints" in which "the device was supplied to patients even though they could not interact with the device as intended."
The problems cited in this context included complaints that patients "did not understand or know how to properly operate the device due to their physical and/or cognitive disabilities." In each case, FDA said the firm's response to the findings on the form 483 would be evaluated in a subsequent inspection, suggesting the agency found the responses reasonably assuring that Zoll addressed the problems.
The noise/vibration issue fed a citation for corrective and preventive action (CAPA), which stated that no CAPAs were undertaken to address those problems. The warning letter stated that Zoll had opened no CAPAs for the problems associated with patients who were unable to properly use the devices due to physical/cognitive disabilities as well. However, FDA also said Zoll had received "numerous complaints document that bystanders are interacting with the device, during cardiac events of patients, preventing treatment [from being] delivered."
Issues associated with medical device report (MDR) mandates also populated the warning letter, with the by-now commonplace citation that the company's procedures did not properly define the terms "became aware" and "caused or contributed." However, the term "malfunction" is now apparently on the list of confusing regulatory terminology for device makers as well. As was the case with the other citations, FDA said Zoll's response would be evaluated in the next inspection.
FDA cited Zoll for lack of documentation demonstrating that senior management had attended all management review meetings in 2013 and 2014. Zoll declined to comment for the record.