“Continuous measurement of patient vital signs such as heart rate, respiratory rate, and oxygen saturation (SpO2) is critical to providing effective care, and the ability to measure these signs simultaneously makes multiparameter patient monitors increasingly important.

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Continuous measurement of patient vital signs such as heart rate, respiratory rate, and oxygen saturation (SpO2) is critical to providing effective care, and the ability to measure these signs simultaneously makes multiparameter patient monitors increasingly important.

Electronic patient monitors use non-invasive sensors attached to the patient to collect and Display physiological data. For multiparameter patient monitors, one of the main challenges is to achieve small size and low power consumption while maintaining high performance.

Today, patients lying in hospital beds are connected to bulky and expensive multi-parameter patient monitors with many wires, and the monitors cannot be moved, which limits the widespread use of multi-parameter patient monitors in mobile care and home care settings . This has created a need for compact multi-parameter patient monitors that connect wirelessly to the patient and transmit data wirelessly or wired to a cell phone, tablet or computer.

Texas Instruments’ “Multiparameter Patient Vital Signs Monitor Front-End Reference Design” is small, low-cost, low-power, and integrates the necessary front-end components to collect vital signs data.

This design can acquire parameters such as electrocardiogram (ECG), SpO2, heart rate, and respiratory rate through the AFE4403 and ADS1292R biosensing front-end integrated circuits. This design can be combined with the software-configurable pacemaker detection module reference design to support onset pulse detection and can connect 3 accurate 0.1°C temperature sensors (TMP117) to measure skin temperature. For ECG measurement, this design uses standard wet ECG electrodes, but also uses a transmission fingertip sensor to measure SpO2. The raw data collected is transmitted by the on-board MSP432P401 microcontroller to the back-end/processor or PC via an isolated Universal Asynchronous Receiver Receiver (UART) interface at 460.8 Kbps. A standard USB port or a USB-charged Li-Ion battery can power this design.

Figure 1 shows the reference design block diagram.

Figure 1: Multiparameter Front-End Subsystem for Vital Signs Patient Monitor Reference Design

The graphical user interface (GUI) displays the acquired waveforms in 5-second moving intervals, while basic filtering removes noise, such as common-mode interference caused by power supplies and lighting. Figure 2 shows ECG measurements on the PC, respiration and SpO2, as well as heart rate and respiration per minute (breaths per minute), SpO2 percentage and temperature values.

Figure 2: Graphical user interface showing ECG, PPG, respiration, heart rate and skin temperature

Figure 3 shows data from ECG, photoplethysmography (PPG), pacemaker, heart rate, and temperature sensors measured on a computer. When a start pulse is detected, the pacemaker will indicate the presence of a start pulse, as shown by the top line in Figure 3.

Figure 3: Graphical user interface showing ECG, PPG, pacemaker, heart rate and skin temperature

in conclusion

This reference design allows you to evaluate devices that work together. It comes with design guidelines, schematics, layouts, and bills of materials to help you quickly evaluate and accelerate product development. This reference design also facilitates real-time acquisition of vital signs parameters.

What are your biggest challenges in patient monitoring applications? Please tell us your opinion.