At present, the commonly used fetal monitors on the market are based on the principle of ultrasound Doppler and fetal cardiac current changes, with fetal heart rate recorder and uterine contraction recorder as the main structures, and can describe fetal heart activity patterns. As a non-invasive measurement prenatal monitoring system, its use shows the maternal abdominal contractions and fetal heart rate through waveforms and graphs, and can record the data on a strip chart recorder. This data can aid in the assessment of the health of the fetus before delivery (stress response test). The monitored data can be recorded on the strip chart recorder continuously or intermittently according to the operator’s request. Logged information includes graphical trend data and monitor hardware and software status information, time and date, patient ID, changes to operating settings, patient and clinician event flags.
And now a new detector for fetal heart rate and fetal movement powered by Nordic’s nRF52833 Bluetooth LE SoC, which uses passive sonar technology to record fetal heart rate rather than traditional ultrasound The Doppler method, which uses audio sensors to detect any vibrations on the wearer’s skin, simply places the product on the skin of a pregnant woman’s abdomen.
The powerful 64 MHz, 32-bit Arm Cortex M4 processor with floating point unit (FPU) inside the NRF52833 SoC device amplifies the signal and filters the data. It filters the data using algorithms that reduce background noise and track signal changes over time, while transmitting the data results to the user’s smartphone, where fetal movement and fetal heart curves are analyzed against years of reference data to help identify signs of intrauterine distress, such as hypoxia. Users can also send data to online doctors for more interpretation analysis.
The ultra-low-power nRF52833 multi-protocol SoC features a radio with Bluetooth 5.1 direction finding and can operate over an extended temperature range of -40°C to 105°C. It supports Bluetooth 5.1, Bluetooth mesh, 802.15.4, Thread, Zigbee and proprietary 2.4 GHz protocols.
The nRF52833 is the fifth product in the industry-leading nRF52 family of SoCs, built around a 64 MHz Arm Cortex-M4 with a floating point unit (FPU), and features 512 KB of Flash and 128 KB of RAM memory for more high-value applications. With an extended temperature range up to 105°C, ample storage space, and dynamic multi-protocol support, the nRF52833 is an ideal device for a variety of commercial and industrial applications, including professional lighting and asset tracking.
The nRF52833 features a 1:4 RAM-to-Flash ratio and +8 dBm output power, making it ideal for advanced wearables or smart home applications requiring robust coverage.
The nRF52833 includes a range of analog and digital interfaces such as NFC-A, ADC, full-speed 12Mbps USB 2.0, high-speed 32MHz SPI, UART/SPI/TWI, PW-M, I2S, and PDM, and has a 1.7V to 5.5V supply voltage range, The device can be powered from a rechargeable battery or USB. It features a two-stage LDO regulator and DC-DC converter, combined with an automatic power management system, to help achieve low power consumption even in more advanced applications.
nRF52833 comes with nRF5 SDK, nRF5 SDK for mesh and nRF5 SDK for Thread and Zigbee support. These SDKs provide all the necessary samples, software libraries and drivers as a starting point for Bluetooth Low Energy, Bluetooth mesh, -Thread or Zigbee design development.
The nRF52833 supports the Bluetooth 5.1 certified stack using Nordic Semiconductor’s S113 or S140 SoftDe-vice. The S140 is a full-featured Bluetooth 5 stack and supports high-throughput, Bluetooth long-range operation with 2Mbps transfer rate, and uses Channel Selection Algorithm #2 (CSA#2) for improved coexistence.