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The Challenge in Medical Device Integration

Healthcare IT professionals face a persistent challenge: troubleshooting and monitoring communication between medical devices and Laboratory Information Systems (LIS). When a lab analyzer stops reporting results, or a blood gas analyzer’s data doesn’t reach the LIS, finding the root cause can be frustrating and time-consuming.

Clinicians depend on these systems. A breakdown in device-to-LIS communication can halt laboratory workflows, delay patient results, and impact clinical decisions. Yet the tools available for diagnosing these connection issues have traditionally required deep technical expertise—packet analysis software like Wireshark, command-line utilities, or custom scripts written specifically for each integration scenario.

What if there was a simpler way?

Meet HL7-Capture

HL7-Capture is a specialized desktop application designed specifically for medical device integration specialists, laboratory IT staff, and healthcare system administrators who need to monitor, capture, and analyze HL7 protocol communication in real time.

Built as a modern Electron application with an intuitive React-based interface, HL7-Capture bridges the gap between raw network traffic and meaningful insights about device-to-LIS communication flows. It strips away the complexity of packet analysis and focuses on what matters: HL7 protocol events, message content, and communication health.

The Origin Story

HL7-Capture was born from a real-world challenge at MediSureOnline. Like many small laboratory clinics, we had medical devices that came pre-configured with supplier-provided LIS systems. But we needed to extend those device results to our own home-grown Laboratory Information System—without disrupting the existing device-to-LIS connections and without expensive vendor integration services.

The solution: intercept and analyze the HL7 communication in real time, understand the exact message format and protocol flow, and use that knowledge to route data to our custom system. HL7-Capture made this possible, and we realized other healthcare IT professionals faced the same challenge. We’re sharing it with the community.

What is HL7?

HL7 (Health Level 7) is the international standard for exchanging clinical and administrative data between healthcare information systems. Medical devices—lab analyzers, blood gas machines, ultrasound systems, vital sign monitors—communicate via HL7 using a special protocol called MLLP (Minimal Lower Layer Protocol).

MLLP frames HL7 messages with special control characters:

  • 0x05 – Start of transmission (device initiates)
  • 0x06 – Acknowledgment (PC confirms receipt)
  • 0x02…0x03 / CR LF – HL7 message data
  • 0x04 – End of transmission

When these messages don’t flow correctly, communication breaks down. HL7-Capture automatically detects these markers and organizes captured traffic into meaningful sessions, so you can understand what’s actually happening.

Key Features

Real-Time TCP Packet Capture

Monitor live network traffic on any selected interface. HL7-Capture uses industry-standard dumpcap (from Wireshark) as its capture backend, ensuring reliable, low-overhead packet collection without requiring administrative expertise.

Automatic HL7 Protocol Detection

Forget about manually parsing packet dumps. HL7-Capture automatically:

  • Detects HL7 protocol markers (0x05, 0x06, 0x04)
  • Groups related transmissions into logical sessions
  • Extracts message content and metadata
  • Displays direction (outbound vs. inbound) based on source IP configuration

Session Organization

Every communication flow—from device initiation through acknowledgment to message delivery and termination—is captured as a coherent session. You can:

  • View all sessions in a scrollable list
  • Filter by submission status (pending, acknowledged, failed)
  • Search and review individual message content
  • Inspect packet-level details (source IP, destination, protocol, timestamp)

Message Viewer with Hex Display

The detailed message viewer shows:

  • Decoded HL7 content – human-readable segments and fields
  • Hex representation – raw binary data for deep inspection
  • Element breakdown – individual HL7 message elements with their values
  • Metadata – source/destination IPs, timestamps, direction

Customizable Configuration

  • HL7 Marker Customization – Change marker bytes if using non-standard configurations
  • IP-Based Direction Detection – Configure source IP to distinguish inbound from outbound traffic
  • Submission Tracking – Track which sessions have been acknowledged, retried, or failed
  • Session Retention Policies – Auto-cleanup based on age or count

Advanced Features

  • Keyboard Navigation – Navigate captured sessions efficiently without a mouse
  • Auto-Scroll – Keep the most recent sessions in view during active capture
  • Submission Management – Retry failed submissions, ignore sessions, or delete unwanted data
  • Persistence – Sessions are saved locally for later review
  • Background Workers – Cleanup and submission workers run silently to maintain system health

Why HL7-Capture?

Designed for Healthcare IT

Unlike generic packet analyzers, HL7-Capture speaks the language of medical device integration. Every feature is built around the specific needs of professionals managing HL7 communications.

Low Barrier to Entry

No command-line tools, no Wireshark expertise required. If you can click buttons and read a list, you can use HL7-Capture. The interface is designed to be intuitive while remaining powerful.

Accurate Troubleshooting

Quickly answer critical questions:

  • Is the device transmitting at all?
  • Is the LIS acknowledging receipt?
  • Are there transmission errors?
  • When did the last successful communication occur?
  • What is the actual message content?

Platform Flexibility

  • Windows – Full support with Npcap for packet capture
  • macOS – Supported with native libpcap
  • Linux – Works with standard libpcap tools

Technical Foundation

HL7-Capture is built on modern web technologies:

  • Electron – Cross-platform desktop application framework
  • React – Responsive, component-based UI
  • TypeScript – Type-safe JavaScript for reliability
  • Vite – Fast development experience
  • dumpcap – Reliable packet capture from the Wireshark project

The architecture cleanly separates concerns:

  • Main Process – Network capture, HL7 parsing, session management, background workers
  • Preload – Secure IPC bridge between main process and renderer
  • Renderer – React UI for user interaction
  • Persistence Layer – Atomic file-based storage for captured sessions

This modular design ensures HL7-Capture remains fast, responsive, and reliable even during continuous packet capture.

Real-World Use Cases

Use Case 1: Troubleshooting Device Communication Failures

Challenge: Device Not Reporting

A lab tech reports that a new blood gas analyzer isn’t sending results to the LIS. Using HL7-Capture, the integration specialist:

  1. Selects the network interface where the device is connected
  2. Starts capture
  3. Runs the analyzer’s test transmission
  4. Observes that the device sends 0x05 (start) but never receives 0x06 (ack)
  5. Diagnosis: LIS isn’t responding. Network team checks firewall rules.

Time to diagnosis: 5 minutes instead of an hour of Wireshark analysis.

Use Case 2: Diagnosing Intermittent Data Loss and Performance Issues

Challenge: Intermittent Data Loss

Results from an automated analyzer arrive sporadically. The administrator:

  1. Leaves HL7-Capture running in the background
  2. Reviews the session list showing which transmissions succeeded and which failed
  3. Notes a pattern: failures occur at specific times
  4. Checks the detailed retry logs
  5. Diagnosis: Network congestion at shift change causes buffer overflow.

Root cause identified without needing custom logging scripts.

Use Case 3: Validating New Device Integrations

Challenge: Integration Validation

Before deploying a new medical device, the IT team:

  1. Configures HL7-Capture with the expected marker bytes and IP addresses
  2. Runs device simulations and real transmissions
  3. Verifies all messages are captured with correct content
  4. Exports session data for compliance documentation
  5. Result: Confident that the device integration works correctly.

Use Case 4: Extending Device Data to Multiple Systems (The Primary Motivation)

Challenge: Connecting Supplier-Provided Medical Devices to Your Custom LIS

Many small laboratory clinics face this situation: medical devices arrive pre-configured with a supplier-provided LIS. But you need to extend those device results to your own Laboratory Information System—whether it’s a new enterprise LIS, a custom-built system, or an existing EHR.

Traditionally, this required:

  • Expensive vendor integration consulting
  • Custom point-to-point messaging solutions
  • Complex middleware configurations
  • Months of development and testing

Using HL7-Capture, you can now do this independently:

  1. Deploy HL7-Capture on a network tap or mirrored port to observe device-to-LIS communication
  2. Capture all HL7 messages transmitted from the device (non-invasively)
  3. Review the exact message format, field mappings, segment structure, and protocol details
  4. Use captured data to configure the routing/translation layer for your secondary system
  5. Monitor ongoing transmissions in real time to ensure your system receives accurate data
  6. Iterate and refine as needed without vendor involvement
  7. Result: Successfully extend device data to multiple systems without disrupting the device’s original LIS connection.

Impact: This is how HL7-Capture came to be. At MediSureOnline, we needed to connect our laboratory analyzers to our home-grown LIS without waiting for expensive integration services. By understanding the exact HL7 protocol flow, we solved the problem. HL7-Capture democratizes that capability for every healthcare IT team.

Getting Started

Prerequisites

  • Node.js 18 or higher
  • npm package manager
  • Npcap (Windows), libpcap (macOS/Linux)

Installation

git clone https://github.com/glennlugod/hl7-capture.git
cd hl7-capture
npm install
npm run dev

First Steps

  1. Open HL7-Capture
  2. Select a network interface from the dropdown
  3. Configure your HL7 markers (defaults are standard: 0x05, 0x06, 0x04)
  4. Click Start Capture
  5. Initiate a transmission from your medical device
  6. Watch the session appear in the capture list

That’s it. You’re now monitoring HL7 communication.

The Future of Healthcare IT Integration

HL7-Capture represents a shift toward specialized, user-focused tools for healthcare IT. Rather than forcing professionals to learn packet analysis, specialized tools like HL7-Capture embed domain expertise directly into the interface and workflow.

As healthcare IT becomes more complex—with more devices, more integration points, and higher demands for reliability—having the right tools becomes critical. HL7-Capture is built for that future.

Learn More

  • GitHub Repository: glennlugod/hl7-capture
  • Documentation: See the project README for detailed usage, configuration, and troubleshooting
  • Contributing: I welcome contributions from healthcare IT professionals and developers

Conclusion

HL7-Capture makes medical device integration monitoring accessible, intuitive, and effective. Whether you’re troubleshooting a communication failure, validating a new device integration, or maintaining ongoing system health, HL7-Capture gives you the insights you need.

Stop struggling with generic packet analyzers. Start using a tool built for healthcare IT.

Have you used HL7-Capture? Share your experience in the comments or on GitHub Issues. I’d love to hear how you’re using it to improve healthcare IT operations.