Designing a compact, efficient and high-performance multi-parameter patient monitor

Continuously measuring patient vital signs such as heart rate, respiratory rate and blood oxygen saturation (SpO2) is critical to providing effective care, and the ability to measure these signs simultaneously makes multi-parameter patient monitors increasingly important.

Electronic patient monitors use non-invasive sensors attached to the patient to collect and display physiological data. One of the main challenges for multi-parameter patient monitors 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 through many wires, and the monitors cannot be moved, which limits the widespread use of multi-parameter patient monitors in mobile care and home care environments. This has created a market demand for compact multi-parameter patient monitors that can be wirelessly connected to patients and transmit data to mobile phones, tablets or computers wirelessly or wired.

Texas Instruments' (TI) "Multi-parameter Patient Vital Signs Monitor Front-End Reference Design" is small, low-cost, and low-power, integrating the necessary front-end components for collecting 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 ICs. This design can be combined with the software-configurable pacemaker detection module reference design to support pacemaker pulse detection, and three 0.1 degree Celsius accurate temperature sensors (TMP117) can be connected to measure skin temperature. To measure ECG, this design uses standard wet ECG electrodes, and a transmitting finger cuff sensor can also be used to measure SpO2. The acquired raw data is transmitted by the on-board MSP432P401 microcontroller through an isolated universal asynchronous receiver-transmitter (UART) interface at 460.8 Kbps to the backend/processor or PC. A standard USB port or USB-charged lithium-ion battery can provide power for this design.

Multi-parameter Front-end Subsystem for Vital Signs Patient Monitor Reference Design

The graphical user interface (GUI) displays the acquired waveforms at 5-second moving intervals, while performing basic filtering to remove noise, such as common-mode interference caused by power and lighting, etc. The following figure shows the ECG measurement results, respiration and SpO2 on the PC, as well as the heart rate and respiration rate (breaths per minute), SpO2 percentage and temperature values ​​per minute.

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

The following figure shows data from an ECG, photoplethysmography (PPG), pacemaker, heart rate, and temperature sensor measured on a computer. When a pacemaker pulse is detected, the pacemaker will indicate the presence of a pacemaker pulse, as shown by the top line in the figure.

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

View TI's multi-parameter patient vital signs monitor front-end reference design

This reference design facilitates your evaluation of devices that work together. It comes with a design guide, schematics, layout, and bill of materials to help you quickly evaluate and accelerate product development. This reference design also facilitates real-time acquisition of vital sign parameters. Click here to go directly>>>

(Article source: TI E2E Community Author: Kevin Chen1)