Designed for environments where removal is a risk, not a choice

Most health wristbands are built on a quiet assumption: the wearer wants to wear it. The B5515G starts from the opposite premise. It is designed for settings where the wearer may be confused, resistant, or actively attempting removal — forensic psychiatric units, correctional facilities, dementia wards, and supervised rehabilitation programs.

Every design decision flows from that reality.

The strap: cut detection with FPC technology

The B5515G uses a one‑piece TPU strap with an embedded multi‑layer FPC (Flexible Printed Circuit) sensor running its entire length. The strap is integrated into the body through a secondary injection molding process — there is no pin, no lug, no removable joint. If the strap is cut, torn, or broken at any point, the circuit breaks and the wristband immediately transmits an alarm to the platform. The strap is rated for 70 kg of tensile force. It is not coming off without tools and intent.

The lock: magnetic electronic clasp

The clasp uses a magnetic electronic lock. It cannot be opened by the wearer. If the lock is tampered with or forced, the event is reported to the platform. Removal is an authorized action, not a wearer decision.

IP68 waterproofing: built for 24/7 wear

A wristband that cannot be removed stays on in the shower, in the bath, in the rain. The one‑piece housing — body and strap integrated, no seams, no screws — achieves an IP68 rating that survives continuous immersion, not just splashes. This is not a feature for marketing. It is a requirement for 24/7 supervision in hygiene‑intensive environments.

What happens when removal is detected

The B5515G reports four distinct tamper events to the cloud platform and the supervisor app:

1. Lock opened — magnetic clasp disengaged

2. Strap cut or broken — FPC circuit continuity lost

3. Wristband removed from skin — optical heart rate sensor loses contact, accelerometer detects pattern change

4. Device not worn — prolonged off‑wrist state triggers low‑power mode and a status alert

Each event carries a timestamp and the device's last known location. For a corrections officer or a ward nurse, this means the difference between discovering an absence during a scheduled check and knowing about it the moment it happens.

Two form factors: one security level

The Lite version eliminates the display and physical button entirely. The wearer cannot interact with the device. It is purely a monitoring endpoint. This is particularly relevant for forensic settings where a screen might be broken and used as a weapon, or where any user interface creates an unnecessary point of conflict.

Health monitoring: what it tracks, what it doesn't pretend to do

The B5515G carries a Goodix GH3011 sensor module with the following capabilities:

• Dynamic heart rate (PPG green light + PID, continuous)

• Blood oxygen / SpO2 (PPG reflective, red + infrared)

• Body temperature (±0.2°C accuracy)

• Blood pressure (HR‑derived estimate — see note below)

• HRV / RRI (for stress, mood, fatigue analytics via third‑party platform)

• Step counting (daily reset at midnight, periodic reporting)

• Sleep monitoring (deep, light, awake states)

Positioning: outdoor, indoor, and the UWB option

For the 4G Cat.1 models: Outdoor positioning uses GPS + BDS (BeiDou) with WiFi and cellular LBS as fallbacks. Indoor positioning uses BLE beacon scanning — with beacons at 6‑8 meter spacing, accuracy reaches 1‑3 meters. With an AoA (Angle of Arrival) Bluetooth gateway, sub‑meter accuracy is achievable.

For the UWB model (B5515GU): The device integrates an MK8000 UWB SoC supporting CH5 and CH9 (CH2 optional). UWB delivers 10‑30 cm accuracy indoors. The B5515GU is compatible with two deployment architectures:

1. Native UWB ecosystem — works directly with the G908GU sound/light alarm for proximity alerts, or UB01 UWB beacons for zone positioning without gateway wiring.

2. Third‑party UWB systems — the MK8000 SDK is open. Customers can develop their own UWB air protocol and integrate with third‑party UWB anchors. The MK8000 communicates with the main MCU via serial UART.

This open architecture matters for large institutional deployments — prisons, secure hospitals — where the customer may already have a preferred UWB infrastructure vendor.

Battery and charging: built for continuous operation

The 760mAh cell is substantially larger than the 160mAh in the B2315 series. This is intentional: a wristband that cannot be removed by the wearer must be charged on the wrist, or during a supervised removal window. The larger battery reduces the frequency of supervised charging sessions.

Model specification comparison

Full technical specifications

Optional accessories

• Alternate straps: red silicone, RFID tag strap, velcro strap (multiple colors), metal anti‑removal strap, silicone anti‑removal strap

• UWB beacons: UB01 (10‑year battery life, no wiring, ±5cm accuracy)

• Proximity alarm: G908GU sound/light alarm (UWB <0.5m or BLE 3‑5m proximity detection)

• Bluetooth beacons: OV02, OV03

• Charger: 5V/1A power adapter

Deployment scenarios

Forensic psychiatry & correctional facilities

Continuous location monitoring with tamper alerts. The B5515Lite eliminates the screen entirely, removing any potential for the device to be weaponized or used as a self‑harm tool. Geofencing restricts movement between wards. UWB proximity detection (with G908GU) triggers alarms if a high‑risk individual approaches a restricted area or another specific individual.

Dementia & elderly secure care

Unlike standard wristbands that patients can remove and misplace, the B5515G requires authorized removal. The watch reports location, health trends, and sleep patterns. If a patient wanders toward an exit during the night, geofence breach fires before they reach the door.

High‑risk industrial zones

Chemical plants, mines, and construction sites where workers must wear PPE at all times. The anti‑removal design ensures compliance. UWB models provide sub‑50cm proximity alerts between personnel and heavy machinery.

*For volume pricing, sample requests, or to discuss a deployment‑specific security configuration, contact our solution engineering team. We can provide the full certification package, strap tensile test data, and the MK8000 UWB SDK documentation upon request. If your deployment requires a private LoRaWAN network or on‑premise data hosting, ask us about the B5515L variant.*