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Pulse Oximeter

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Block Diagram - Pulse Oximeter
PSoC programmable analog & digital resources integrate everything shown in light blue below. Click on the colored blocks to view or sample the recommended PSoC Components.


The flexibility of PSoC allows you to customize each colored block, or PSoC Component, to meet your design requirements through the easy-to-use PSoC Creator Software IDE.  These Components are available as pre-built, pre-characterized IP elements in PSoC Creator.

Design Considerations

A Pulse Oximeter is a non-invasive device for measuring the percentage of arterial blood (or hemoglobin) that is saturated with oxygen. This device can also measure heart rate. Pulse Oximeters are used in medical, sports training and home appliance applications. Knowing the percentage of hemoglobin that is saturated with oxygen is important to provide anesthesia, to determine the effectiveness of a patient's respiratory system, as well as help to diagnose various illnesses.

The principle of operation of a Pulse Oximeter is based on measuring the absorption of red and infrared light that passes through a patient's finger or ear lobe by utilizing light sensors. Hemoglobin that transports oxygen (oxy-hemoglobin) absorbs infrared wavelength (800-940 nm) of light and hemoglobin that does not transport oxygen (deoxy-hemoglobin), absorbs visible RED wavelength (600-700 nm) of light. Backgrounds such as fluid, tissue and bone are factored out of the measurement by monitoring the steady state of absorption from bone, tissue, venous blood and arterial blood. LEDs are used as the light source and are sequentially pulsed at a fast rate. During a heartbeat, blood volume increases and this AC component of the photodetector's current is used to calculate the absorption of oxy- and deoxy-hemoglobin.

PSoC enables a scalable one chip pulse oximeter solution that flexibly integrates all the basic and advance requirements of a pulse oximeter. PSoC can also enable more advanced features for innovating Pulse Oximeters including USB, Graphics Display, and CapSense buttons. Finally, PSoC can also integrate numerous vital sign functions such as Blood Pressure Monitor, IR Thermometer, and Pulse Oximeter into a single chip solution.

Application Notes

AN52927 - PSoC® 3 and PSoC 5LP - Segment LCD Direct Drive

AN57821 - PSoC® 3, PSoC 4, and PSoC 5LP Mixed-Signal Circuit Board Layout Considerations
AN57821 introduces basic PCB layout practices to achieve 12- to 20-bit performance for the PSoC® 3, PSoC 4, and PSoC 5LP families of devices. The design practices covered in this application note are good rules to use in any mixed-signal design for any accuracy.

AN58304 - PSoC® 3 and PSoC 5LP – Pin Selection for Analog Designs

AN58827 - PSoC® 3 and PSoC 5LP Internal Analog Routing Considerations
AN58827 discusses how internal trace and switch resistance can affect the performance of a design and how these issues can be avoided by understanding a few basic details about the PSoC® 3 and PSoC 5LP internal analog architecture.

AN60305 - Using PSoC® 3 and PSoC 5LP IDACs to build a better VDAC
This application note describes how to configure the PSoC® 3 and PSoC 5LP IDACs as a flexible analog source. It presents different approaches for using the IDACs in applications, and discusses the advantages and disadvantages of the topologies presented.

AN60590 - PSoC® 3, PSoC 4, and PSoC 5LP – Temperature Measurement with a Diode
AN60590 explains diode-based temperature measurement using PSoC® 3, PSoC 4, and PSoC 5LP.

Training On-Demand

PSoC 3 and PSoC 5 101: Introduction to the Architecture and Design Flow

PSoC 3 and PSoC 5 102: Introduction to System Resources

PSoC 3 and PSoC 5 103: Introduction to Digital Peripherals

PSoC 3 and PSoC 5 104: Introduction to Analog Peripherals
This module introduces the analog peripherals of PSoC 3 and PSoC 5 devices that can be implemented using PSoC Creator.

PSoC 3 and PSoC 5 106: Introduction to CapSense Touch Sensing
This module introduces the CapSense touch sensing peripheral of PSoC 3 and PSoC 5 devices that can be implemented using PSoC Creator.

PSoC 3 and PSoC 5 201: Analog Peripherals
This module builds on the previous analog modules (PSoC 3 / PSoC 5: 104) and goes into the details of the analog peripherals of the PSoC 3 and PSoC 5 devices which can be implemented using PSoC Creator.



Software and Drivers

PSoC Creator
PSoC Creator is a state-of-the-art software development IDE combined with a revolutionary graphical design editor to form a uniquely powerful hardware/software co-design environment.

PSoC Designer
PSoC Designer is the revolutionary Integrated Design Environment (IDE) that you can use to customize PSoC to meet your specific application requirements. PSoC Designer software accelerates system bring-up and time-to-market.

Spec No: None; Sunset Owner: YMT; Secondary Owner: GHR; Sunset Date: 06/15/20