A STUDY OF FACTORS INFLUENCING FETAL MONITOR FAILURE

Technical Summary: A Study of Factors Influencing Fetal Monitor Failure

Problem Statement
Despite a high volume of fetal monitor usage in Mongolia's capital maternity hospital (27 units generating 30–35 service calls monthly), there is a documented lack of research regarding the specific causes of device damage, the factors influencing failure, and the organization of technical services. While pregnancy rates are decreasing, monitor usage remains high, yet the reliability of these critical devices is compromised by frequent malfunctions. The study addresses the gap in understanding the interplay between technical failures, human error, and environmental factors that lead to equipment downtime and potential risks to maternal-fetal safety.

Methodology
The research employed a cross-sectional, documentary-based, and descriptive observational design.

• Data Sources: The study aggregated quantitative data from technical passports, call logs, breakdown repair records, and annual workload data for 10 specific Toitu MT-610 fetal monitors commissioned in 2019 at the Urgo Maternity Hospital.
• Qualitative Analysis: Focus group interviews were conducted with biomedical engineers and technicians responsible for the equipment to identify root causes and practical difficulties.
• Scope: While the hospital utilizes six different monitor models (including Bionet, Contec, and Edan), the detailed evaluation focused on the MT-610 model to ensure data consistency.
• Variables: Key variables included device type, department location, daily operating hours, annual workload, failure type, root cause, repair method, maintenance frequency, user training levels, and environmental conditions.

Key Findings and Results
The study identified that fetal monitor failures are multifactorial, resulting from a combination of internal system degradation, external environmental stressors, and human operational errors.

1. Failure Distribution:

   • Main Unit (44.01%): The highest failure rate involved the main processing unit, including button jamming, calibration drift, loss of saved settings, probe socket damage, power supply faults, and screen failures.
   • Accessories (28.39%): Significant failures occurred in external connections, including power cord snapping, adapter output failures, and cable peeling/abrasion on UC/TOCO probes.
   • Printer Section (27.60%): Common issues included blank paper output, latch jamming, and damage to rollers and gears.

2. Root Causes:

   • Human Factors (65.6%): Improper handling was identified as the primary driver of failure. Specific behaviors included forceful plugging/unplugging of cables, excessive button pressing, abrupt closure of printer lids, and failure to dry devices after cleaning.
   • Workload Stress (18.8%): Continuous operation in high-traffic areas (particularly the Delivery Ward) led to accelerated mechanical wear on buttons, cables, and printers.
   • Environmental Factors (15.6%): Electrical fluctuations, humidity, dust, and lack of uninterrupted power sources negatively impacted adapters, main power modules, and internal batteries.

3. Specific Failure Mechanisms:

   • Sensor Degradation: Crystals in FHR and TOCO sensors cracked or lost sensitivity due to mechanical stress.
   • Configuration Loss: Frequent user interface changes and weak internal batteries led to the loss of standard settings.
   • Printer Overload: Continuous real-time recording caused mechanical wear on feed rollers and thermal heads.
   • Cascading Failures: The study noted that using replacement parts from previously broken monitors often resulted in repeated failures of the receiving unit.

Key Contributions

• Categorization of Failure Modes: The study provides a detailed classification of common breakdowns (Main Unit, Printer, Accessories) with specific annual failure counts, moving beyond general observations to quantified data.
• Identification of the "User-Device-Environment" Triad: The research explicitly links device reliability not just to age or manufacturing defects, but to the interaction between user habits, operational workload, and environmental stability.
• Operational Insights: The study highlights that "minor" repetitive breakdowns (e.g., configuration loss, cable peeling) significantly inflate aggregate maintenance expenditures and that unscheduled repairs vastly outnumber scheduled maintenance (2,083 unscheduled vs. 60 scheduled over five years).

Significance and Claims
The paper argues that the current "fix it when it breaks" maintenance policy is insufficient for ensuring maternal-fetal safety. Its primary significance lies in advocating for a shift toward a "preventive risk reduction" approach.

The authors conclude that to ensure reliable operation, hospitals must:

1. Implement regular, structured maintenance schedules that go beyond basic inspections.
2. Stabilize power supplies to protect sensitive electronics.
3. Improve the quality and handling of accessories (cables, probes).
4. Enhance the knowledge and skills of medical staff through targeted training on proper device handling and storage.

The study emphasizes that technical engineering support must be integrated with organizational quality management, risk assessment, and budget planning. By addressing human misuse and environmental factors alongside technical maintenance, the frequency of device failure can be significantly reduced.

Limitations
The authors acknowledge that the study is limited to a single institution and focuses heavily on one device model (MT-610), which may limit the generalizability of results to other hospitals or device types. Additionally, reliance on manual records introduced some variability in the accuracy of damage descriptions and repair cost data.