Device companies urge FDA to refine guidance on PCLC devices

Regulatory NewsRegulatory News | 01 March 2022 |  By 

Medical devices companies urged the US Food and Drug Administration (FDA) to expand the scope of its recent guidance on assessing physiologic closed-loop control (PCLC) technology to cover non-invasive devices and to incorporate additional standards when outlining patient hazards.
Other companies suggested that FDA include additional examples of sensor performance risks.
The comments were in response to FDA’s draft guidance for manufacturers on developing medical devices with physiologic closed-loop control (PCLC) technology issued in early January. (RELATED: FDA issues draft guidance on assessing physiologic-closed-loop control devices, Regulatory Focus 6 January 2022)
FDA said these devices “can enable automation in a variety of medical device types including infusion systems, ventilators, extracorporeal systems, and stimulation systems.” These devices can provide automated delivery to patients for fluid resuscitation, ventilation, and anesthesia and, which are “emerging applications for the critical and emergency care environments.” The devices consist of a sensor that measures a physiologic variable from the patient, a controller/control algorithm, and an actuator that delivers, or removes energy or an article such as a drug to the patients.
The deadline for commenting closed on 22 February. Seventeen comments from medical device companies, a hospital, and a clinical research organization (CRO) were available at the time of publication.
BD: Expand scope of guidance
Becton, Dickinson and Company (BD) recommended that FDA expand the scope of the guidance to include hypo- and hyperthermia systems used to adjust patient body temperature for certain types of treatments. The company also urged FDA to include short-term drug delivery systems such as those systems for subcutaneous treatment delivery.
BD writes that “currently, the guidance appears to be mostly focused on invasive, interventional and internally operated medical devices.”
BD also urged FDA to recognize other standards, such as ISO 149741, in describing patient hazards. The draft says that “the response of the patient to the energy or article being delivered or removed (i.e., the patient transfer element as defined in IEC 60601-1-10) is a critical factor to consider in the design.”
GE recommends format for URRA risk analysis
GE Healthcare recommended FDA specify a format and examples for manufacturers to use in conducting use-related risk analysis (URRA).
FDA recommends manufacturers use the URRA in assessing “the potential harm that could arise during step-by-step use of the device” but does not provide examples of the format and content of such analyses.
“Due to the emphasis on URRA within the draft guidance, inclusion of format and content examples would be helpful to ensure manufacturers consider the appropriate PCLC risks as part of risk analysis and provide information in the preferred FDA format,” says GE.
More examples of sensor risks
GE and Medtronic Respiratory Interventions suggested that FDA include additional examples of sensor performance risks.
The guidance lists eight factors that manufacturers consider in evaluating risks related to inadequate sensor performance within the PCLC device.
GE suggested FDA add a ninth risk that includes “any changes in sensor performance due to calibration drift over time.” The company writes that “inclusion of normal-use scenarios where sensor accuracy may change over time will provide additional clarity and guidance for manufacturers regarding design or selection of physiologic-measuring sensors to be used as part of a PCLC device and for the agency during premarket or post-market assessments.”
Medtronic recommended that sensor failure should also be listed as a risk. The company writes “for some PCLC devices, it may be necessary to monitor sensor performance so that the system can detect failures related to the sensor and revert to backup sensors or to state estimation, as appropriate.”
What is not considered physiologic variable?
Medtronic also suggested FDA amend the definition of a physiologic variable to include what is not considered a physiologic variable.
The guidance defines a physiologic variable as a “quantity or condition, from a patient, whose value is subject to change and can usually be measured.”
“We suggest adding a note to explain what would not be considered a physiologic variable and using ventilator as an example. When a ventilator is used on a patient, the adjustment of respiratory pressure by the ventilator will directly affect the respiratory volume. In this case, neither respiratory pressure nor volume should be considered as a physiologic variable,” writes Medtronic.


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Tags: CDRH, devices, FDA, PCLC

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