Signal FAQ

Frequently asked questions about Particle Signal, covering setup, implementation, troubleshooting, and optimization of your real-time clinical alerting system.

Getting Started

What is Particle Signal?

Particle Signal is a real-time clinical alerting system that monitors national health information networks (HINs) and Health Information Exchanges (HIEs) for critical patient care events. It delivers focused, actionable alerts to your systems via webhooks when significant clinical events occur for your subscribed patients.

What types of alerts does Signal provide?

Signal offers four main types of alerts:

• Transition Alerts - Admissions, discharges, and transfers
• New Encounter Alerts - New clinical documentation and encounters
• Discharge Summary Alerts - Post-hospitalization discharge summaries
• Referral Alerts - New referral documents and notifications

How do I get started with Signal?

Follow our Setting Up Signal guide, which covers:

1. Configuring your webhook endpoint
2. Subscribing patients to Signal
3. Testing your integration
4. Production deployment

Do I need to have patients registered with Particle first?

Yes, patients must be registered in your Particle system via the Patients API before they can be subscribed to Signal alerts.

Technical Implementation

How are Signal alerts delivered?

Signal delivers alerts via HTTP POST requests to your configured webhook endpoint. Alerts are sent in real-time as events are detected in the healthcare network.

What does a Signal alert look like?

All Signal alerts follow a consistent JSON structure:

{
  "signal_id": "unique-alert-id",
  "signal_type": "transition_alert|new_encounter_alert|discharge_summary|referral",
  "particle_patient_id": "patient-identifier",
  "timestamp": "2024-01-15T10:30:00Z",
  "data": {
    // Alert-specific information
  }
}

What webhook requirements must I meet?

Your webhook endpoint must:

• Accept POST requests with JSON payloads
• Respond with a 200 HTTP status code within 30 seconds
• Use HTTPS protocol (HTTP is not supported)
• Handle authentication using provided credentials
• Implement proper error handling and logging

How do I authenticate webhook requests?

Webhook authentication is configured during setup through the Management API or with your Particle Health representative. Authentication methods include API keys, bearer tokens, or custom headers.

Can I subscribe patients in batches?

Yes, use the batch subscription endpoint:

POST /api/v1/patients/subscriptions

This allows you to subscribe multiple patients to Signal in a single API call.

Alert Management

How quickly are alerts delivered?

Signal alerts are delivered in near real-time, typically within minutes of event detection in the healthcare network. Actual delivery time depends on network conditions and webhook response performance.

What happens if my webhook is down?

Signal implements automatic retry logic with exponential backoff:

• Initial retry: 30 seconds
• Second retry: 2 minutes
• Third retry: 10 minutes
• Final retry: 1 hour

After all retries fail, the alert is marked as undeliverable.

Can I receive duplicate alerts?

Yes, duplicate alerts can occur due to network conditions or multiple data sources reporting the same event. Implement idempotency handling in your webhook processing using the unique signal_id field.

Data & Coverage

Which healthcare networks does Signal monitor?

Signal monitors major national health information networks including:

• Carequality
• CommonWell Health Alliance
• eHealth Exchange
• State and regional Health Information Exchanges (HIEs)

What clinical events trigger alerts?

Depending on which alerts your patients are subscribed to, Events that trigger alerts can include:

• Hospital admissions, discharges, and transfers
• Outpatient visits and specialist consultations
• New clinical documentation (progress notes, visit summaries)
• Discharge summary document availability
• Referral document creation

How comprehensive is the coverage?

Signal monitors networks that connect to approximately 90% of U.S. EHRs, including 90%+ of active CMS hospitals. This provides broad coverage across healthcare organizations. However, coverage varies by region and healthcare system participation in health information networks.

What if a patient receives care at a facility not connected to these networks?

Signal can only alert on events from facilities connected to monitored health information networks. Care at non-connected facilities will not generate alerts.

Are ADT feeds included in the Signal offering?

Signal delivers Admit, Discharge, and Transfer alerts through Particle’s national network connections, so there’s no need for ADT feeds to power this solution.

If you also want access to ADT messages, we offer a separate ADT feed option. Reach out to your Particle Health representative to learn more.

Troubleshooting

Why am I not receiving alerts for subscribed patients?

Common causes include:

• Webhook endpoint not accessible or returning non-200 responses
• Patient not active in connected healthcare networks
• Incorrect subscription configuration
• Authentication issues with webhook requests

How can I test my Signal integration?

1. Subscribe a test patient with known recent healthcare activity
2. Monitor your webhook endpoint for incoming alerts
3. Verify alert processing and workflow triggers
4. Test error handling scenarios

How do I troubleshoot webhook authentication errors?

Verify:

• Authentication credentials are correctly configured
• API keys or tokens haven't expired
• Authentication headers match expected format
• HTTPS certificate is valid and trusted

ADTs

What is the format of the ADT message?

ADT messages are delivered as Base64-encoded JSON containing the raw HL7 V2 message. Messages are encoded in Base64 to ensure HL7 V2 standard encoding characters (| & ^ ~) are transmitted without corruption.

Do you support ADT messages in FHIR or FLAT?

At this time ADT messages are not available in the FHIR or FLAT formats. However, we are exploring offering this feature in the future, if there's sufficient demand.

What ADT event types are available?

The following ADT events are supported:

Note:

Update Patient (A08): Applies to the preceding event. When patient information is updated, such as insurance, that update should link to the previous admission or discharge event.

Register Patient (A04): Creates a presented event for ED presentations. This means for an A04 message with a patient class of emergency, the event will be mapped to CREATE_PRESENTED in the EVN.4. Additionally, Registration events do not precede an admit event unless the patient is returning to the ED.

Optimization & Best Practices

How can I optimize alert processing performance?

• Respond to webhook requests immediately with 200 status
• Process alerts asynchronously after acknowledging receipt
• Implement proper logging and monitoring
• Use batch processing for high-volume scenarios

What's the best way to handle high alert volumes?

• Implement queue-based processing for alert handling
• Use load balancing for webhook endpoints
• Set up monitoring and alerting for processing backlogs
• Consider alert prioritization based on clinical significance

How should I integrate Signal with existing workflows?

• Map alert types to appropriate care management workflows
• Use alert data to trigger automated tasks (appointments, outreach)
• Integrate with care registries and population health tools
• Build reporting to track alert-driven outcomes

Can I customize alert content or timing?

Alert content is standardized, but you can:

• Configure webhook routing based on alert characteristics
• Implement custom processing logic for different alert types
• Set up internal prioritization based on patient risk factors

Support & Advanced Features

Where can I get help with Signal implementation?

• Contact your Particle Health representative for technical support.
• Review our documentation for implementation guidance

How do I request new Signal features or alert types?

We welcome feedback and feature requests. Contact your Particle Health representative to discuss new capabilities that would benefit your use case.

Additional Resources

• Setting Up Signal - Complete setup guide
• Transition Alerts - Critical care transitions
• New Encounter Alerts - Clinical encounter monitoring
• Subscriptions API - Patient subscription management

Still have questions? Contact your Particle Health representative for personalized assistance with your Signal implementation.