Simulating birth to investigate clinician-applied loads on newborns

Area of Science:

• Medical Simulation
• Biomechanical Engineering
• Obstetrics

Background:

• Shoulder dystocia is a critical obstetric emergency requiring skilled management.
• Accurate measurement of forces during delivery is crucial for understanding potential infant injury.
• Existing methods for assessing delivery forces lack precision.

Purpose of the Study:

• To design, develop, and test a novel force-measuring birth simulator.
• To quantify forces exerted by clinicians during simulated routine, difficult, and shoulder dystocia deliveries.
• To compare simulated forces with known thresholds for birth trauma, such as clavicle fracture.

Main Methods:

• Development of the Shoulder Dystocia Birth Model (SDBM), incorporating a maternal manikin, adjustable jack, and overhung beam.
• Instrumentation of the SDBM with strain gauges and a commercial sensor for real-time force and moment measurement.
• Data acquisition system for precise measurement of axial force, vertical force, and end-moment during simulated deliveries by 15 clinicians.

Main Results:

• The SDBM achieved high accuracy: 2% for forces and 5% for end-moment.
• Average peak forces recorded were 68 N (routine), 118 N (difficult), and 172 N (shoulder dystocia).
• Average peak moments were 138 N.cm (routine), 384 N.cm (difficult), and 621 N.cm (shoulder dystocia).

Conclusions:

• The SDBM provides accurate, real-time force and moment data during simulated deliveries.
• Significant variation in clinician-applied forces highlights the need for standardized training.
• Peak forces in simulated shoulder dystocia deliveries frequently exceed the force required to cause clavicle fracture.