When managing major adverse cardiovascular events (MACEs) in patients facing life-threatening conditions, standard therapies may need to be complemented with advanced mechanical assistance solutions. Intra-Aortic Balloon Pumping (IABP) and Ventricular Assist Devices (VADs), also known as Temporary Mechanical Circulatory Support (tMCS), are among these modern, life-supporting therapies utilized in critical care settings to stabilize patients with severe cardiac dysfunction.
Accurate and Continuous Pressure Measurement: Vital in Advanced Cardiac Therapies
IABP, VADs, and tMCS all require accurate and continuous pressure measurement to ensure optimal performance, patient safety, and therapeutic effectiveness. For IABP, accurate pressure data synchronizes balloon inflation and deflation with the cardiac cycle, enhancing coronary perfusion and reducing cardiac workload.
In VADs, pressure monitoring ensures effective blood flow, prevents complications like suction events or thrombosis, and allows for precise adjustments to match the patient’s hemodynamic needs. Similarly, tMCS devices depend on real-time pressure insights to stabilize critically ill patients, prevent issues like excessive afterload or vascular injury, and adapt support to individual conditions. Across all three techniques, continuous pressure measurement is vital for detecting complications, optimizing device function, and improving patient outcomes.
Limitations with Conventional Fluid-Filled Pressure Sensors
During cardiac therapies, pressure is typically measured either at the pump unit or at an external patient monitor using fluidic transduction through the catheter and interconnecting hydraulic tubing. For accurate readings, the pressure must be zeroed to atmospheric pressure and referenced to subtract the hydrostatic pressure contribution of the fluid due to different levels between the catheter end tip and the external measuring unit.
One major disadvantage of this measurement method is related to the dynamic response of fluidic transduction: any factor that affects impulse transmission, such as compressible bubbles in the line or movement of the tubing, can distort the waveform traveling through the fluid-filled system. The tubing may also distend as the pulsating waveform travels through it, dissipating energy. As a result, long lengths of tubing may fail to accurately reproduce the blood pressure signal, especially if the tubing diameter is reduced.
Read more: Why can external transducers introduce unreliable and inaccurate pressure measurements?
Solution: Miniature Fiber Optic Pressure Sensors
Miniature fiber optic pressure sensors based on micro-optical mechanical systems (MOMS) address the limitations associated with fluidic pressure transduction currently used to trigger cardiac therapy.
The small size of the MOMS (∅ 550 or 260 μm) allows the sensor to be positioned directly at the tip of the intra-aortic catheter, where pressure monitoring is most critical. With exceptional performance in resolution and frequency fidelity, this absolute pressure sensor can accurately detect small and fast pressure variations, such as the dicrotic notch in the intra-aortic pressure waveform, which is used as a trigger point in IABP therapy.
Additionally, the fiber optic sensor is inherently immune to electromagnetic fields and noise perturbations. The patented white-light cross-correlation technology in the signal conditioner further ensures immunity to fiber optic bending and enhances tolerance to optical losses. As a result, this solution is highly suited for in situ pressure monitoring in various medical applications.
Enhanced Medical Device Control with Fiber Optic Pressure Sensors
In short, the miniature size of fiber optics allows pressure sensors to be placed directly at critical points, enabling highly accurate and continuous measurements of blood flow and pressure gradients that remain unaffected by surrounding conditions, such as compressible bubbles in the line or tubing movement—common challenges with conventional fluid-filled pressure sensors.
These unique advantages of fiber optic technology ensure reliable pressure measurements and continuous feedback, which are essential for the safe and effective operation of medical devices used in MACEs. This reliability empowers doctors to navigate complex, high-risk interventions confidently, fostering safer procedures, more informed decision-making, and, ultimately, better outcomes for patients facing life-threatening conditions.
Discover Resonetics’ FOP-MIV miniature fiber optic pressure sensors, which were developed to meet the specific needs of cardiovascular applications, such as IABP and VADs.