2M has buildup over the last decade extensive knowhow and expertise on bed sensor monitoring solutions for a wide variation of applications.
Sensors for contactless bed monitoring
Most of our experience is in the selection of the right sensor for placement on top, below or fully integrated into the mattress. Sensors that work reliable under all conditions independent of the person or bed characteristics.
Algorithms for reliable feature extraction
The accuracy and robustness of bed sensors is to a large extend made in the quality of the algorithms used. Over the years we have build up a lot of expertise on what works and what not. This enables us to create new solutions, that work reliably, with short development times.
Application areas
At 2M we mostly focus our bed sensor development efforts on medical, sport and (home) rehabilitation applications in which accuracy, sensitivity and specificity is important. We provide both streaming and event based solutions. These last two parameters are especially important when the bed sensor signals are used to alarm or warn third parties. False alarms should be avoided at all times. The same technologies can also be used for consumer applications.
Starting point for new OEM product developments
BedSensor placed under the mattress
Minimize disturbance for the patient also over long measurement times.
Use in medical and professional home applications
Robust durable and cleanable design.
Physiological signals
In/Out bed detection. Movement / motion. Breathing rate. Heart rate.
Customization 4 new applications
Customization of product design, algorithms / feature extraction, wireless or wired interfacing in other systems.
Extensive experience with bed sensor related algorithm development.
Clinical research network for testing and validation
Over the years we have build up a diverse network of clinical and research partners to quickly verify and validate new applications against professional polysomnography systems.
Bed sensor Demonstrator for testing new applications
2M can provide the BS100 demonstrator to test and explore new applications. We can deliver one to small series for first investigations, field trials and research studies. This enables quick assessment of our client’s ideas and enables fast creation of proof of concepts, which helps to clarify user requirements and product specifications.
Output
Raw physiological signals or events (on request / application specific)
Physiological signals
- Internal sample frequency – 250 sps
- Bed in/out detection – motion based
- Breathing Rate
- Heart Rate – average of last 10 beats
- Others – on request
Power
Battery or external power adapter.
Connectivity / interfacing
- Bluetooth Low Energy (other on request)
- Wired: USB, UART, SPI, I2C (others on request)
User Interface
- Power on/off button.
- LED indicator – for power on/off Bluetooth connect.
PC demo application
Visualize and store measurement data.
Integration in other platforms and API on request.
High-level system architecture of the demonstrator
Interested to learn more?
Optical fibre based bedsense bed sensor system
From 2016-2018 2M, Kempenhaeghe and TUe focused on creating new monitoring solutions for medical applications around epilepsy, sleep apnea, parkinson and sleep related disorders. Within the first Bedsense project an optical sensor solution was used.
At the moment this system is still available as reference system.
This project was made possible by a contribution from the European Regional Development Fund as part of OP-Zuid. For more information see EFRO.
Components optical fiber based bed sensor solution
The BedSense system exists of the following components:
- BedSense datalogger, functions:
- Store measurements of upto 3 sensors in raw format for later signal analysis
- Live data-feed in Matlab for real-time testing of features (via USB interface)
- 1-3 BedSense contactless bedsensor’s
- Accessories:
- Power supply (5V)
- Micro SD card + adapter card
- External sync: TTL, 3.5mm jack cable
- Remote control: start/stop recordings and check recording status when the BedSense system is placed under a hospital bed.
Technical specifications
- Sensing
- Sensors: 1 to 3 sensors
- Sampling Rate: 100 Hz
- Sampling Rate Drift: 0.021% / ºC
- ADC Resolution: 24 bit (20bit effective)
- External synchronization
- Sync Pulse: K x 0.5 seconds with K=1-144
- Sync Amplitude: 0 volt (off) – 3 volt (on)
- Sync Frequency: 10 minutes (first pulse; K=1 at t=0 sec)
- Sync Interface: 3.5mm mono jack plug
- Power: 5V power adapter and internal battery powered (upto 10 hours)
- Recordings: max 100 files
- Storage: 32Gb micro SD card
Data output
Stored data files can be exported to BDF format with the supplied BDF convertor. BDF is the 24-bits version of the EDF file. BDF files can be viewed with multiple (open source) software packages like EDFBrowser. The BDF file contains 3 data signals per each connected sensor channel XX:
- ChXX: 24 bit sensor data
- ChXX_Syncpulse: Sensor synchronization pulses
- ChXX_Temperature: Sensor temperature (updated every 0.5sec)
So when all 3 sensors were connected, the BDF file holds 9 signals in total.
Results
122 complete night recordings have been made at Kempenhaeghe which are analyzed and used for creation of new algorithms. BedSense is available as a high-end research evaluation prototype for detailed monitoring of people and patients.