Sentia Patch One · Skin temperature · Hydration · Activity
Sentia Patch One · Square patch · 2.5 mm profile
Sentia Patch One is a square adhesive sensor patch with strongly rounded corners and a 2.5 mm profile that measures skin temperature, hydration and activity for up to 14 days without a phone. It has no cellular radio and no GPS. Its measurements ride passing phones on the Find My network, or a LoRaWAN gateway kilometres away, into Sentia Cloud.
2.5 mm
Profile
14 days
Wear time
IP67
Water resistance
Measurements that find their own way home.
Sentia Patch One is not a medical device.
The patch
Matte warm white cover with strongly rounded square corners, the SENTIA wordmark and one LED line.
A cushioning layer beneath the top cover.
Carries sensing and processing electronics and the Bluetooth Low Energy and LoRaWAN radios.
Attaches the patch to the skin for up to 14 days of wear.
Protects the adhesive before application.
Thermistor array, reported in °C. Sampled every few minutes and summarised into each digest.
Bioimpedance electrodes, reported as a hydration index from 0 to 100. Sampled every few minutes and summarised into each digest.
Three axis accelerometer, steps equivalent and posture class. Sampled every few minutes and summarised into each digest.
Microfluidic channel, reported in µL/min. Sampled every few minutes and summarised into each digest.
A square adhesive patch with rounded corners worn on the upper arm for up to 14 days. Everything it needs is inside: sensors, two radios, and a printed battery sized for the whole wear.
2.5 mm
Profile
14 days
Wear time
3.1 g
Weight
IP67
Water resistance
2 radios
BLE 5.0 · LoRaWAN
How it works
The patch never looks for a network. It speaks quietly, on a schedule, and lets the networks that already surround us do the carrying.
Every few minutes the patch samples skin temperature, hydration, movement, posture and sweat, and builds one small encrypted measurement digest.
In the city it broadcasts the digest inside rotating Bluetooth Low Energy advertisements, following the Find My network accessory pattern. Out of coverage it sends a fuller LoRaWAN frame instead.
A passing iPhone, iPad or Mac forwards the opaque digest it cannot read. A LoRaWAN gateway forwards the frame to its network server. Neither learns anything about the wearer.
Sentia Cloud retrieves and decrypts the payloads addressed to it, decodes both formats with one codec, stores the time series and evaluates the alert rules.
The wearer, or a care circle they choose, sees the result in the dashboard, through the API, or by asking an assistant through the Sentia MCP Server.
Identifiers rotate with every broadcast window, so a digest cannot be followed across a day. Relay devices see ciphertext and contribute their own location context, never the patch contents. The patch carries no GPS receiver. Only Sentia Cloud holds the keys that link a digest to a wearer and decode it. Battery logic is equally plain: Bluetooth Low Energy first, LoRaWAN only when no relay has carried a digest for a while, and high value alerts, a fall impact for example, escalate at once.
Live demo
A simulated patch, running in your browser with the same packet codec as the server. Choose where the wearer is, and watch each reading take its path.
Waiting for the first packet
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·
Skin temperature
·
Hydration index
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Activity
·
Battery
Dashboard
The product interface. Three patches from the demonstration fleet, served live by the same API an assistant would use.
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Skin temperature
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Hydration index
·
Activity
·
Battery
·
Last sync
·
Arrived via
| Wearer | Patch | Site | Battery | Last sync | Via |
|---|
For assistants
Sentia ships an MCP server, so an AI assistant can answer plain questions about a patch: how did hydration trend today, which patches are low on battery, what just arrived and how. It speaks JSON-RPC 2.0 and reads the same data as this page.
List every Sentia Patch One in the fleet with battery, wear day, last sync path and current skin temperature and hydration index.
Full status for one patch: current skin temperature in °C, hydration index 0 to 100, activity, battery percent, wear time and last sync.
Time series for one patch: skin temperature, hydration index, activity, sweat rate and network path per reading.
Open alerts across the fleet, or for one patch: fever trend, dehydration risk, fall impact and patch detached.
How readings reached Sentia Cloud in the last 24 hours: counts by path (Find My network and LoRaWAN), by relay type, and the last sync per path.
Encode one patch’s current reading as a real wire payload: a 16 byte BLE digest for the Find My network path, or a 19 byte LoRaWAN frame as hex. Returns the payload, its size and the decoded reading.
{
"mcpServers": {
"sentia": {
"url": "https://sentia.info-693.workers.dev/mcp"
}
}
}
An assistant asks the server to demonstrate the whisper for Marina Soler's patch. Request:
{
"jsonrpc": "2.0",
"id": 2,
"method": "tools/call",
"params": {
"name": "simulate_uplink",
"arguments": {
"patch_id": "patch-01",
"path": "findmy"
}
}
}
Response, trimmed to the essentials:
{
"jsonrpc": "2.0",
"id": 2,
"result": {
"content": [
{
"type": "text",
"text": "{\"patchId\":\"patch-01\",\"path\":\"findmy\",\"network\":\"Find My network\",\"payloadEncoding\":\"base64\",\"payload\":\"UwFYDkVpAABHQDqBCcgBzg==\",\"payloadBytes\":16,\"decoded\":{\"temperatureC\":36.72,\"hydration\":69,\"activitySteps\":105,\"flags\":{\"impact\":false,\"detached\":false,\"lowBattery\":false,\"alert\":false},\"battery\":71,\"counter\":14912,\"timestamp\":1793210940,\"hydrationIndex\":69,\"batteryPercent\":71}}"
}
]
}
}
Specifications
| Profile | 2.5 mm |
|---|---|
| Layers | Top cover, comfort foam, sensing and processing board, adhesive layer, release liner |
| Weight | 3.1 g |
| Wear time | Up to 14 days, single use |
| Battery | Battery, sized for the full wear period |
| Radios | Bluetooth Low Energy 5.0 and LoRaWAN Class A |
| Water resistance | IP67 |
| Find My network payload | 16 byte encrypted digest |
| LoRaWAN payload | 19 byte frame, SF9, 125 kHz |
| Sensors | Thermistor array, bioimpedance electrodes, three axis accelerometer, microfluidic sweat channel |
| Positioning | None on the patch. No GPS receiver. Relay devices contribute location context. |
Questions
When no phone is near, Sentia Patch One switches to its LoRaWAN radio and sends a fuller 19 byte frame to any public or private gateway within a few kilometres. The gateway forwards it to a network server, which passes it to Sentia Cloud. No pairing, no hub, and no cellular subscription is involved.
Sentia Patch One broadcasts a short encrypted digest over Bluetooth Low Energy every few minutes, following the accessory pattern used by the Find My network. Apple devices passing nearby relay the digest to Apple, and Sentia Cloud retrieves and decrypts the payloads addressed to it. The patch itself carries no GPS receiver.
Sentia Patch One measures skin temperature with a thermistor array, hydration with bioimpedance electrodes, and movement and posture with a three axis accelerometer. A microfluidic channel estimates sweat rate. Measurements are wellness indicators, sampled every few minutes and summarised into digests, not continuous clinical grade streams.
The battery is sized for the full 14 day wear period. Bluetooth Low Energy does most of the work because a relay broadcast costs very little energy. The patch listens for relay patterns and only spends LoRaWAN transmissions, which cost more, when no phone has carried a digest for a while.
Almost nothing. A relaying phone receives an opaque encrypted digest under a rotating identifier and forwards it without being able to read it. The phone contributes its own location context to the network, never the patch contents. Only Sentia Cloud holds the keys that link a digest to a wearer and decode it.
No. Sentia Patch One is a wellness and monitoring concept product. It does not diagnose, treat or prevent any condition, and its readings are not a substitute for medical advice or clinical instruments. If a reading worries you, talk to a qualified clinician. Sentia is not sold or certified as a medical device.