Every one of the PCARDIO wearable biosignal sensors runs on one modular recorder platform — sampled on a single clock, written to a single file. The recorder carries configurable 24-bit biopotential channels, set up as ECG or as EMG, together with an on-board bioimpedance channel for respiration, 9-DOF motion, and any combination of the expansion sensors on the digital interface. This page lists every modality, what it measures, what can be derived from it, and which recorder it ships in.
On this page
- What the recorder does — record, stream, compute, report
- Core wearable biosignal sensors — ECG, EMG, BioZ, 9-DOF motion
- Expansion sensors — ICG, GSR, temperature, pressure, sound, heart sounds, PPG, strain
- In development — core body temperature, multispectral light
- Each modality in detail
- What synchronisation makes possible — PEP, LVET, PTT, stroke volume
- Platform specifications
- Custom sensor integration
- Frequently asked questions
What the recorder does
Four functions, all on the device itself, with no cloud dependency. They apply to every configuration of wearable biosignal sensors described below.
Record. Continuous logging to 8 GB or 16 GB of onboard memory, for multi-day recordings without connectivity. Data is downloaded afterwards over the docking station at more than 20 MB/s, or wirelessly.
Live stream. Real-time streaming over BLE 5.2 or Zigbee to a mobile device, headset, tablet, PC or mission dashboard — with latency low enough for biofeedback and VR applications.
Compute. Embedded feature extraction runs on the recorder, turning raw signal into derived parameters and event flags at the edge. This keeps real-time alerting possible where there is no connectivity, and reduces the data volume that has to leave the device.
Report. The recorder can generate summaries and reports on-device from a completed recording, rather than requiring the full raw file to be processed elsewhere first. Setup, download and live view run through the PCARDIO software application or your own code via the open API.
Raw high-resolution data remains available in all cases. On-device computation is an addition to the raw signal, never a replacement for it.
Core wearable biosignal sensors
On the recorder board. All channels are sampled synchronously and written to one file, with no post-hoc alignment required.
| Modality | Sample rate | Resolution | Channels |
|---|---|---|---|
| ECG (biopotential) | 250 / 500 / 1000 sps | 24-bit, right-leg drive | 1-lead, 6-lead, or 8 channels for 12-lead |
| EMG (biopotential) | 250 / 500 / 1000 sps | 24-bit, right-leg drive | 1–2 |
| BioZ — respiration | 250 / 500 / 1000 sps | 24-bit | 1 |
| Accelerometer | 25–800 Hz, in multiples of 2 | 16-bit | 3-axis |
| Gyroscope | 25–800 Hz, in multiples of 2 | 16-bit | 3-axis |
| Magnetometer | 50 / 100 Hz | 16-bit | 3-axis |
ECG and EMG share the same biopotential front end. A channel is configured as one or the other — the same 24-bit input with right-leg drive, differing in electrode placement, filtering and sample rate. A given recorder is set up for cardiac work or for muscle work, not both simultaneously. If your application needs both at once, that is a multi-device or custom configuration and we should talk it through.
Lead on/off detection runs continuously on the biopotential and bioimpedance channels, and an event marker button is available on every recorder. The on-board BioZ channel measures respiration; impedance cardiography and thoracic fluid content use the external BIS BioZ sensor described below.
Expansion sensors
The expansion wearable biosignal sensors attach over the recorder’s digital expansion interface rather than being built into the core board, which is why they are configured per project rather than sold as fixed options. Sample rate and resolution are set to suit the application — tell us what you need to measure and we will specify it. Each sensor below links to its own detail page.
| Sensor | Measures | Typically used for |
|---|---|---|
| BIS BioZ sensor — ICG | Multi-frequency thoracic bioimpedance | Stroke volume, cardiac output, PEP, LVET, thoracic fluid content |
| EDA / GSR | Skin conductance | Stress, arousal, cognitive load, emotional response |
| Skin temperature | Surface temperature at one or more body sites | Thermal strain, circadian rhythm, peripheral perfusion |
| Ambient temperature | Environmental temperature | Heat-stress context for physiological data |
| Barometric pressure | Absolute air pressure | Altitude, cabin and dive pressure, ascent and descent rate |
| Sound exposure | Ambient sound pressure level | Noise dose, hearing-risk assessment, occupational exposure |
| Heart and lung sounds | Acoustic auscultation of the chest | Murmurs, wheeze and crackle detection, S1/S2 timing |
| PPG / SpO₂ | Pulse waveform and oxygen saturation | Perfusion, SpO₂, pulse transit time |
| Heart rate | Beat detection from ECG or PPG | Continuous HR and HRV trending |
| Universal strain | Mechanical deformation | Respiratory effort, segment and joint movement |
In development
Core body temperature. Non-invasive core temperature estimation, currently in development. Skin and ambient temperature are available today and are frequently used as an interim measure for thermal strain work.
Multispectral light. Multi-wavelength optical sensing, currently in development, extending the single-wavelength PPG approach toward richer tissue and perfusion measurement.
If either is on the critical path for your programme, contact us — development timelines can often be aligned with a customer project.
Each modality in detail
ECG — 1 to 12 lead
Electrical activity of the heart, sampled at 250, 500 or 1000 sps with 24-bit resolution and right-leg drive. Configurations run from a single channel to eight channels carrying a full 12-lead derivation, with a 6-lead option in between. Lead on/off detection runs continuously, so electrode loss is visible in the recording rather than discovered after the study.
Derived: heart rate, RR intervals, heart rate variability in the time and frequency domains, arrhythmia and ectopic beat detection, ST-segment analysis.
Available in: HP201 1-lead, HP202 6-lead, HP208 12-lead. See also the wearable heart rate monitor.
EMG — surface electromyography
Surface muscle activity on one or two channels, sampled at up to 1000 sps at 24-bit with right-leg drive, using the same biopotential front end as the ECG in an EMG configuration. Data can be streamed live over BLE 5.2 or Zigbee with latency low enough for real-time biofeedback and VR applications, or logged to onboard memory for later download.
Derived: muscle activation timing and amplitude, median-frequency fatigue indices, co-contraction ratios, and gait phase when combined with the IMU.
Available in: HP212 wireless EMG system.
Bioimpedance — on-board BioZ and the external BIS sensor
Bioimpedance appears at two levels in the platform, and the distinction matters when you are specifying a configuration.
On-board BioZ — respiration. The recorder itself carries a bioimpedance channel, sampled at 250, 500 or 1000 sps with 24-bit resolution across the ECG electrode set. Because it shares electrodes with the ECG it adds no body-worn hardware and no extra preparation time. It gives respiration rate, relative tidal volume, breathing pattern and apnoea events — and respiratory sinus arrhythmia when read together with the ECG.
External BIS BioZ sensor — ICG and fluid content. Haemodynamic measurement uses a separate multi-frequency bioimpedance spectroscopy sensor, added over the digital expansion interface with a tetrapolar electrode configuration. This is what resolves the impedance change driven by each cardiac ejection. Synchronised with the ECG on the same hardware clock, it gives left ventricular ejection time, pre-ejection period, systolic time ratio, and beat-to-beat stroke volume and cardiac output — haemodynamics without a cuff or a catheter. Raw ΔZ and dZ/dt are available alongside the derived parameters.
The same BIS sensor measures thoracic fluid content, tracking fluid accumulation in the thorax as a trend parameter relevant to heart failure monitoring. Full detail on the wearable impedance cardiography sensor page.
In short: respiration comes from the recorder, ICG and fluid content come from the external BIS sensor. Both can run in the same configuration, synchronised in one file.
Motion — 9-DOF IMU
Three-axis accelerometer and gyroscope at 25 to 800 Hz in multiples of two, and a three-axis magnetometer at 50 or 100 Hz, all at 16-bit resolution. Motion is present on every recorder in the platform and time-synchronised with the physiological channels in the same file — which is what makes motion-artefact rejection possible rather than approximate.
Derived: posture and orientation, activity classification, step count and cadence, energy expenditure, fall and impact detection, and motion-artefact rejection for the biopotential and bioimpedance channels.
Available in: every configuration, plus the HP215 Motion Pro as a standalone motion logger.
EDA / GSR
Galvanic skin response measures changes in skin conductivity driven by sweat gland activity, which tracks sympathetic arousal. Used for stress research, cognitive load assessment and emotional response measurement — and, combined with heart rate variability from the same device, it gives two independent views of autonomic state.
More detail: wearable GSR sensor. See also T-sense wearable stress monitoring.
Temperature — skin and ambient
One or more skin temperature sensors can be placed at different body sites, including integration directly into the electrode patch. An ambient sensor records environmental temperature alongside, so physiological response can be read against the conditions that produced it. Core body temperature is in development.
More detail: wearable temperature sensor.
Barometric pressure
Absolute air pressure, giving altitude and rate of ascent or descent. Relevant for aircrew and pilot monitoring, high-altitude and mountain operations, cabin pressure context and diving applications — and useful as a correction input wherever altitude affects the interpretation of cardiorespiratory data.
Sound exposure
Ambient sound pressure level, logged continuously alongside the physiological channels. Used for occupational noise-dose and hearing-risk assessment, and for correlating acoustic events with physiological response in defence, industrial and emergency-service environments.
Heart and lung sounds
Acoustic auscultation of the chest, recorded in synchrony with the ECG. Because the electrical and acoustic signals share a clock, heart sound timing can be referenced directly to the QRS complex — which is what makes S1 and S2 interval measurement reliable. Lung sounds support wheeze and crackle detection for respiratory work.
More detail: wearable heart sound sensor, and our note on MEMS microphones for heart sound analysis.
PPG and SpO₂
Photoplethysmography gives the peripheral pulse waveform, from which oxygen saturation and pulse-derived heart rate are obtained. Combined with the ECG from the same device it yields pulse transit time — the basis for cuffless blood pressure estimation in research contexts.
More detail: wearable PPG sensor.
Universal strain
Measures mechanical deformation, which can be applied to respiratory effort, chest and abdominal expansion, or the movement of a joint or textile segment. Frequently used as a mechanical complement to the bioimpedance respiration signal where both effort and flow matter.
What synchronisation makes possible
Synchronisation is not a convenience feature. Because all the wearable biosignal sensors share one clock and one file, the parameters below become measurable — they are defined by the interval between events in two different signals, and two separate devices with two separate clocks cannot produce them reliably.
| Parameter | Requires | What it gives you |
|---|---|---|
| PEP — pre-ejection period | ECG + BIS BioZ sensor | Sympathetic drive and contractility |
| LVET — left ventricular ejection time | BIS BioZ sensor | Duration of ejection |
| Systolic time ratio | ECG + BIS BioZ sensor | An index of left ventricular performance |
| Stroke volume, cardiac output | ECG + BIS BioZ sensor | Beat-to-beat haemodynamics without a cuff or catheter |
| Thoracic fluid content | BIS BioZ sensor | Fluid accumulation trend |
| PTT — pulse transit time | ECG + PPG | Basis for cuffless blood pressure estimation in research |
| Respiratory sinus arrhythmia | ECG + on-board BioZ respiration | Parasympathetic tone, separated from respiratory confound |
| Motion-corrected HRV | ECG + IMU | HRV with movement artefact identified, not silently averaged away |
| S1/S2 timing | ECG + heart sounds | Acoustic events referenced to electrical depolarisation |
| Gait phase with muscle activation | EMG + IMU | Which muscle fires at which point in the stride |
| Thermal strain index | Skin + ambient temperature + HR | Heat stress read against the conditions producing it |
Pulse transit time as a blood pressure surrogate is a research parameter, not a cleared measurement. The full derivation for each parameter is described in our technical whitepaper, PCARDIO Platform — BioSignals & Derived Features.
Platform specifications
These apply to the wearable biosignal sensors across all configurations. Exact figures per device are on the individual product pages.
| Data access | Raw, unprocessed sensor output — no proprietary formats, no black-box preprocessing |
| On-device processing | Embedded feature extraction, event flagging, and on-recorder summaries and reports |
| Storage | 8 GB or 16 GB onboard |
| Download | Over 20 MB/s via the docking station, or wirelessly |
| Wireless | BLE 5.2 and Zigbee — setup, start/stop, live streaming, time sync |
| Recording duration | 10+ days continuous on the HP201 at 250 sps ECG and respiration with accelerometer at 50 sps; shorter at higher sample rates |
| Ingress protection | IP67 |
| Interfaces | Open device API and SDK, and PC application for Windows 10/11, macOS optional |
| Quality system | Developed within an ISO 13485 QMS; CE certified, EU MDR pathway available for OEM programmes |
Custom sensor integration
The digital expansion interface is open. If the sensor you need is not on this page, that usually means it is not a catalogue item rather than that it cannot be done — we routinely integrate customer-specified wearable biosignal sensors into the platform, including sensors embedded in patches, straps and textiles.
Tell us what you need to measure and in what conditions, and we will tell you whether it fits the existing interface or needs a hardware variant. We offer development, certification support and ISO 13485 production for client-specific medical and non-medical solutions.
Frequently asked questions
Can one recorder measure ECG and EMG at the same time?
No. ECG and EMG use the same 24-bit biopotential front end, so a channel is configured as one or the other. A recorder is set up for cardiac work or for muscle work. Applications needing both simultaneously are handled with more than one device or a custom configuration.
Which wearable biosignal sensors are standard and which are add-ons?
The biopotential channels, the on-board BioZ respiration channel and the 9-DOF IMU are on the recorder board. ICG and thoracic fluid content require the external multi-frequency BIS BioZ sensor. Everything in the expansion table attaches over the digital interface and is configured per project.
Can I get raw data from every sensor?
Yes. Every channel is available as raw, unprocessed, high-resolution data. There is no proprietary format to translate and no algorithm sitting between you and the signal. On-device computed values are provided in addition to the raw signal, not instead of it.
Can the recorder stream live as well as log?
Yes. It can log to onboard memory, stream live over BLE 5.2 or Zigbee, or do both. It can also compute derived values and produce summary reports on the device itself.
Are the wearable biosignal sensors time-synchronised?
Yes — all the wearable biosignal sensors share one clock and one file. This is what makes the cross-modal parameters above measurable, and it cannot be reproduced by combining separate devices.
Can you add a sensor that is not listed here?
In most cases, yes. The digital expansion interface is open and customer-specified sensor integration is a routine part of our development work.
Discuss your sensor configuration
Tell us which parameters your programme needs and we will tell you which configuration delivers them — or what it would take to build one that does. We respond to all international enquiries directly, with no regional distributor in between. You can also request an evaluation kit to test the wearable biosignal sensors on your own data.
