The EAS is a campus-wide notification system that is activated by pendants worn by residents, pull cords, and motion detectors in the event that a resident requires emergency assistance.
Reliability of the care provided at residential care facilities is a major concern of residents and their families. Understanding and sharing this concern, one residential care facility contracted with PTC Windchill FMEA Professional Services to perform a failure mode and effects analysis (FMEA) on their emergency alert system (EAS) and its supporting processes.
A FMEA systematically identifies the potential failure modes of a system so that failures can either be prevented or the impact of their effects minimized. While FMEAs have long been used to mitigate the risks associated with medical device failure, their use can be extended to analyze the processes associated with providing medical care, particularly when a medical device is employed.
In this particular case, a FMEA was used to analyze the function failures of an emergency alert system (EAS), its supporting processes, and the human factors that might cause failures in these processes. Because of their flexible framework, FMEAs support identifying and categorizing not only product failures but also process and human failures, thereby allowing you to develop and implement an organized plan to address all of these elements and their interactions.
To provide actionable results from the FMEA, the following 4D approach to project management was utilized:
For this project, team members included FMEA analysts along with several managers and employees from the facility. Team members interviewed managers, employees, and residents to learn more about the EAS, current procedures, and resident usage. To streamline the analysis of the overall system, flowcharts were developed to show:
When an alert is triggered, the system notifies the main security station. The security guard then radios the facility staff to respond to the location from where the signal was transmitted. The EAS requires the proper operation of hardware and software components as well as the proper response of security personnel and facility staff.
The following observations and goals resulted from the discovery process:
In the PTC Windchill FMEA module, the FMEA worksheet is used to collect the data gathered for the analysis. For this project, the FMEA worksheet was created based on the comprehensive flowcharts and the following assumptions:
For FMEAs, prevention refers to ensuring that a failure mode does not occur; early detection refers to providing efficient design controls so that a deficiency or weakness in the system is revealed, detected, or eliminated. Controls are elements downstream from an error which allow for detection and correction before worst-case failure effects occur.
The flowcharts generated during discovery provided the team with a full understanding of the prevention and detection mechanisms already in place in the EAS and its supporting processes. For example, motion detectors in resident rooms were one type of system control. If no motion is detected in a room in a specified number of hours, an alert is triggered. This allows the facility to detect a situation where a resident might be unconscious and therefore unable to use the pendant or a pull cord.
Upon completion, the FMEA worksheet included not only functional failures of the EAS but also process and human failures that might lead to system failure. For each possible failure mode, a risk priority number (RPN) was calculated based on values assigned to its severity and detection. It is common in medical FMEAs to exclude occurrence in the RPN calculation, as failure modes high in severity and/or low in detection or prevention are considered high risk regardless of the occurrence rate.
RPN results revealed six high-risk failure modes:
For each high-risk mode, a root cause of failure and a recommendation for correction were determined. The table on page 4 summarizes the root causes and recommendations for the six modes with the highest RPNs.
The FMEA results for this project demonstrate how making a few changes to the EAS and its processes would significantly increase system reliability of the system, thereby significantly increasing the safety and well-being of residents. However, the recommendations provided for corrective actions are only a starting point for the facility’s management team. Once they reduce or eliminate occurrences of the six high-risk failure modes, they can identify root causes and recommendations for modes with lower risks. Additionally, when changes are made to the EAS or its processes, they can easily update the FMEA to see if additional system, procedure, and/or control changes are necessary. Because FMEAs can analyze product, process, and human factor components as well as their interactions, they are especially effective analysis tools for not only medical devices but also all types of health care providers.
|Alert not received||Security personnel unconscious||Notify a secondary person as a backup to the on-duty security guard by tying pagers into the EAS. Adding redundancy addresses the event that security guard is unable to respond.|
|Alarm perceived as false alarm||Security personnel misread the identity or location of the resident in distress||Add a step to the standard procedure for security personnel to confirm both the location and the identity of the resident who triggered the alert before clearing it.|
|Incorrect location due to interference||Location of the resident is inaccurate due to signal being received by a receiver other than the one closest to the resident||Add a step to the standard procedure for facility staff to check for the resident in rooms above, below, and adjacent to the room indicated if the resident is not found in the designated location.|
|Incorrect location due to resident being outside||Resident is outside of building but signal is picked up by an inside receiver nearby
||Install additional receivers along standard walking areas outside the building to provide clear indication of resident’s correct location.|
|No signal due to low sensitivity
||Sensitivity setting of receiver is set too low
||Modify the test procedures to test the pendant signal from the worst-case location within each living space to confirm that receiver sensitivity is not set too low.|
|No signal due to range limit
||Resident is outside of range of receiver||Build a coverage map of the facility and add receivers to areas that are considered dead zones. This test is to be performed with a pendant that has a weakened signal to simulate the worst-case condition where the pendant battery is low but not yet ready to be replaced.
"The Joint Commission for Accreditation of Healthcare Organizations requires hospitals to select one high risk process for proactive risk assessment each year."
— Quality Progress
"Risk analysis in the healthcare industry is unique in that it must combine analysis of product, process, and human factor components. FMEAs provide a flexible framework for analyzing these elements and their interactions."
— Karen Bowman, Senior PTC Windchill Quality Consulting Engineer, PTC
PTC Windchill FMEA is a software tool designed to handle your Failure Mode and Effects Analyses (FMEAs) with unsurpassed power and flexibility. With PTC Windchill FMEA you can quickly and easily analyze the potential failure modes of your system and the resulting effects of those failures, leading to improved designs for products and processes. PTC Windchill FMEA supports all widely used FMEA standards and methodologies coupled with extensive customization capabilities. Additionally, PTC Windchill FMEA supports both a Windows-based application and a Microsoft Silverlight-powered Web interface for enterprise-wide accessibility, providing unmatched capability for FMEA collaboration.