Introduction to Imaging‑Based Volume Calibration
Accurate pressure–volume analysis hinges on reliable volume signals, and CD Leycom’s BiV Conduct NT software offers a straightforward method for calibrating catheter‑derived volumes using imaging‑derived end‑diastolic (EDV) and end‑systolic (ESV) volumes. By anchoring the catheter’s relative volume measurements to absolute values from echocardiography, MRI, or CT, clinicians can monitor percent changes in ventricular performance with confidence. Although the absolute accuracy of this technique depends on the quality of the imaging modality, the high‑fidelity nature of CD Leycom’s catheter ensures that relative shifts from a chosen baseline remain exceptionally precise.
When and Why to Use Imaging Calibration
Imaging‑based calibration is ideally suited for scenarios where serial hemodynamic comparisons—rather than standalone absolute volumes—are paramount. For instance, in interventional procedures assessing the impact of device deployment or pharmacologic challenges, clinicians seek to quantify percent changes from an arbitrary baseline. Because the catheter provides continuous, high‑resolution PV loops, tying its baseline to a one‑time imaging‑derived calibration allows every subsequent loop to reflect true percentage deviations.
Prerequisites for Real‑Time Calibration
Volume calibrations can be performed during live procedures, provided you’ve already recorded and saved at least one PV loop data file in real time. The calibration workflow assumes that you’re operating in Live Data mode and that your initial recording represents the baseline state for subsequent comparisons. If you entered imaging values during study setup—an option available in the New Study dialog—you’ll benefit from an automated prompt immediately after your first save. Otherwise, you can enter calibration mode manually once the first recording is saved.
Leveraging Pre‑Inputted Imaging Values
During study setup (as detailed in video #1), the software allows you to supply EDV and ESV values if they’re known in advance. If you did so, BiV Conduct NT recognizes these entries as soon as you save your first recording. When prompted—“Would you like to calibrate the total volume?”—select “Yes” if this file represents your baseline. The software then transitions you directly into the Volume Calibration interface, preloaded with your dataset number, baseline recording, and imaging values. Quickly check mark your baseline recording and select “Apply” to complete the calibration and seamlessly align catheter volumes to your imaging‑derived metrics.
Responding to the Automatic Calibration Prompt
The calibration prompt appears after each recording until you either apply it or disable further reminders. If the first recording isn’t your true baseline—perhaps you performed a test acquisition—click “No”. The prompt will then reappear pause until you save what you intend as the baseline recording, ensuring you don’t inadvertently calibrate to a non‑representative file. This safeguard preserves the integrity of your calibration.
Manual Entry When Imaging Values Are Not Pre‑Inputted
If you didn’t enter EDV and ESV during study setup, the calibration prompt won’t trigger automatically. Instead, after recording and saving your baseline file, navigate to the Volume Calibration interface (Action -> Volume Calibration Mode). Upon entering this interface, you’ll see Dataset 1—your baseline recording should be listed here if saved in Dataset 1. Checkmark it, then enter the imaging‑derived EDV and ESV values manually in the provided fields. Clicking “Apply” initiates the same calibration routine as the automated path, ensuring consistent volume alignment regardless of when values are entered.
Verifying Calibration in Live Data Mode
Once you apply the calibration—whether automatically or manually—BiV Conduct NT confirms success with an on‑screen notification. Return to Live Data mode and press F9 (or use the rescale button) to repopulate tracings. You’ll notice the volume signal change from red to blue (the default calibrated color), the PV loop outline adopt a matching blue hue, and the hemodynamic indices transition from red to white. These color shifts provide immediate visual confirmation that your volume axis now reflects true imaging‑based units.
Color‑Coded Signals and Calibration Persistence
The calibrated color scheme persists across all subsequent recordings within the same dataset. You only need to apply the imaging values once per catheter deployment; every new file saved under Dataset 1 automatically inherits the established calibration. This continuity allows uninterrupted data capture, even during complex interventions.
Managing Multiple Catheter Deployments and Datasets
In procedures requiring catheter removal and re‑delivery—such as transcatheter aortic valve replacement (TAVR)—each re‑deployment demands its own calibrated dataset. For instance, save pre‑TAVR loops as Dataset 1 and, after valve implantation, save post‑TAVR recordings as Dataset 2. Since catheter re-delivery may change volumetric measurements separate from true, physiological responses, Dataset 2 will require a new calibration using post‑deployment EDV and ESV values. This compartmentalization preserves calibration accuracy across procedural phases, ensuring that each dataset’s volume corresponds precisely to its imaging context.
Conclusion: Streamlining Volume Calibration
Imaging‑based volume calibration in BiV Conduct NT bridges catheter‑derived hemodynamics and absolute ventricular volumes, offering a robust platform for monitoring relative functional changes. By understanding when to input imaging values, how to respond to calibration prompts, and how to manage datasets across multiple deployments, clinicians can achieve rapid, reliable calibration in real time. The intuitive color‑coded cues and persistent calibrations within datasets streamline workflow, leaving more room to focus on patient care and data interpretation. Armed with this knowledge, you’re ready to implement imaging‑based calibration confidently—turning raw PV loops into clinically meaningful insights.