Sensor Integration

Ward integrates with BLE wristbands for proximity verification, elopement detection, and real-time patient list ordering.

Sensor Types

Sensor Hub

The sensor hub is an on-premise gateway running a headless daemon that:

• Processes wristband data for proximity and elopement alerts
• Monitors wristband health (battery, connectivity)
• Reports fleet telemetry (CPU, memory, disk, BLE radio status) to Ward's cloud
• Communicates securely with Ward's cloud over HTTPS

Each unit needs at least one hub.

Patient Wristbands

BLE wristbands worn by patients:

• Enable proximity verification for observations
• Enable elopement detection via fixed BLE receivers
• Provide real-time distance for patient list ordering

Assign one wristband per patient.

Fixed BLE Receivers

BLE gateways that detect wristband signals and forward to the hub via HTTP. Receivers are added from Management → Devices → Receivers → Add Receiver from within the unit they belong to.

Each receiver can serve one or more roles depending on its configuration on the receiver detail screen:

• Boundary receivers — placed at facility entrances, stairwells, and egress points. Turn on the Boundary Receiver toggle. Any confined patient detected most strongly by a boundary receiver triggers an elopement alert regardless of their geofence level.
• Unit receivers — placed in common areas, hallways, or nurses' stations. No room number needed. Catches patients who wander into another unit.
• Room receivers — placed at or in patient rooms. Set the Room on the receiver detail screen (with autocomplete from existing room numbers). Required for room-level geofences.

Hardware Setup

Installing the Hub

1. Connect hub to facility network (ethernet recommended, WiFi supported)
2. Power on the hub
3. Wait for the hub to boot (~60 seconds) — the status LED turns red (unprovisioned)
4. The hub advertises itself on the local network

Adding the Hub

1. Open the Ward app on a device connected to the same network as the hub
2. Navigate to Management → Devices → Add Hub
3. The app discovers unprovisioned hubs on the local network
4. Tap the discovered hub and select a unit assignment
5. The app adds the hub and configures it automatically
6. Hub confirms connection — status LED turns green

Adding Wristbands

1. In Management → Devices, tap Add Wristband
2. On mobile, nearby unregistered wristbands are detected automatically and listed by signal strength — tap one to select it
3. Or enter the MAC address manually
4. Optionally assign to a patient immediately

Wristbands can also be assigned to patients later from the patient detail screen.

Adding BLE Receivers

1. Mount the receiver at the boundary point (unit exit, stairwell, facility exit, or room doorway)
2. Power and network connect the receiver
3. In Management → Devices, add the receiver
4. Set boundary type (unit exit, stairwell, facility exit, or room doorway)
5. If room doorway: select the room this receiver monitors
6. Associate with the hub

Position Mapping (Optional)

Hubs and receivers can optionally have their physical positions recorded to enable trilateration — a more accurate method of calculating distances using multiple reference points. Proximity verification works without this, but trilateration can improve accuracy in challenging RF environments.

Setting Device Positions

1. Navigate to Management → Devices
2. Tap on a hub or receiver to open its detail screen
3. Enter the X and Y coordinates in meters from your unit's origin point
4. Tap Save Position

Choose a consistent origin point for your unit (e.g., a corner of the nurses' station) and measure all device positions relative to that point using a tape measure.

Trilateration

When 3 or more devices have positions mapped, the system uses trilateration to calculate more accurate distances:

• The app combines direct BLE readings with position data from multiple anchors
• Each anchor's signal strength provides a distance estimate
• Geometric calculation determines the most likely position
• Results in improved accuracy compared to single-device measurement

The device list shows a badge indicating trilateration status:

• "3 mapped — trilateration active": Enough devices for trilateration
• "2 mapped — need 1 more": Add positions to more devices to enable trilateration

Without 3+ mapped devices, the system falls back to single-device distance estimation.

Proximity Verification

With a wristband assigned to a patient, the staff handheld:

1. Scans for nearby BLE wristbands
2. Calculates distance from signal strength (enhanced by trilateration when available)
3. Auto-verifies proximity when within configured threshold
4. Records distance with the observation

Staff see "Proximity Verified" with distance when documenting if the wristband is detected.

Patient List Ordering

The patient list sorts by proximity — nearest patients appear first. This updates in real-time as staff move through the facility. Patients without wristbands appear below detected patients.

On wider screens (landscape tablets and desktop), the patient list is always visible as a sidebar alongside every screen, so proximity-sorted patients are accessible from the dashboard, alerts, shift view, or any other screen.

Elopement Detection

For patients with elopement risk and a configured geofence:

1. Assign a wristband to the patient
2. Configure geofence level (unit, floor, or campus — room level available when room doorway receivers are installed)
3. Fixed BLE receivers detect the wristband at boundaries
4. Hub evaluates whether detection constitutes a violation
5. Alert triggers after confirmation

Geofencing

Patients can be confined to a zone by setting their Geofence Level on the patient edit screen:

Level	Violation trigger
None	Geofencing is disabled for this patient.
Room	The patient is detected strongest by a receiver in a different room, a different unit, or at a boundary.
Unit	The patient is detected strongest by a receiver in a different unit or at a boundary.
Facility	The patient is detected strongest by a boundary receiver. Movement between units inside the facility is allowed.

A violation requires three consecutive scan windows (default 2 s each, ≥6 dB margin vs. the runner-up receiver) where the winning receiver is out of zone. Alerts re-arm when the patient returns to an authorized zone.

Setup requirements:

• Patient must have a wristband assigned. The patient edit screen warns when a geofence level is set but no wristband is assigned.
• For Room level, a BLE receiver must be installed in the patient's room. The edit screen warns when the selected room has no matching receiver.
• For Facility level, at least one receiver must have Boundary Receiver enabled.

Configuration change propagation

Geofence-related configuration is cached on the hub and refreshed every 5 minutes. Changes to any of the following take up to 5 minutes to take effect on active detection:

• Patient geofence level
• Patient wristband assignment
• Patient room or unit reassignment
• Receiver room assignment
• Adding or removing a receiver
• Toggling a receiver's boundary flag

This is by design — the hub avoids chattering with the cloud for every change and tolerates brief cloud outages. Plan deployment changes with the 5-minute window in mind; for time-critical changes (a patient who just became an elopement risk, for instance), expect up to 5 minutes before detection reflects the new configuration.

Wristband Health

The hub continuously monitors all registered wristbands:

• Battery: Warning at 20%, critical at 10%
• Connectivity: Alert if not seen for >1 hour

Health indicators appear on patient cards and in the device management screen.

Device Management

Viewing Device Status

Navigate to Management → Devices to see:

• All registered devices (hubs, wristbands, receivers, staff handhelds)
• Online/offline status
• Battery level (wristbands)
• Last seen timestamp
• Hub software version and health metrics
• Position mapping status for trilateration

Hub Fleet Management

The device management screen provides fleet-level visibility for hubs:

• Status: Online/offline, software version, uptime
• Health: CPU, memory, disk usage, CPU temperature, BLE radio status

Device Health Alerts

Ward alerts when devices have issues:

• Wristband battery low or critical
• Wristband or hub offline
• Hub degraded (high CPU, low disk)

Hub Status LED

The hub has an LED that indicates its current state:

Pattern	Meaning
Solid green	Connected to Ward's cloud
Solid red	Unprovisioned — needs to be registered
Alternating green/red blink	Provisioned but can't reach cloud
Red blink	Error

Troubleshooting

Hub offline:

• Check the status LED (see table above)
• Check power connection
• Verify network connectivity
• If on the same network, use Local Diagnostics:
  • Open the hub's detail screen in Management → Devices
  • Enter the hub's hostname (e.g. ward-hub-1.local) or IP address
  • View real-time CPU, memory, BLE radio status, uptime, and wristband count
• Restart the hub if needed

Wristband not detecting:

• Check battery level
• Verify wristband is assigned to patient
• Ensure staff handheld has Bluetooth enabled

Proximity not verifying:

• Confirm patient has a wristband assigned
• Check that staff handheld BLE scanning is active
• Move closer to patient — RSSI accuracy improves at shorter range
• Run RSSI calibration in unit settings if distances seem inaccurate

Distance readings seem wrong:

• Run RSSI calibration (Management → Facility → Edit Unit → Calibrate)
• Ensure calibration was done in the same environment where you're testing
• Optionally, map device positions for trilateration (3+ devices needed)

Enterprise RTLS Integration

For facilities with existing Real-Time Location Systems, Ward can integrate with your current infrastructure through custom integration projects.

Contact your Ward representative to discuss RTLS integration requirements.