---
title: SRPhotoplethysmogramSample
framework: sensorkit
role: symbol
role_heading: Class
path: sensorkit/srphotoplethysmogramsample
---

# SRPhotoplethysmogramSample

The sample photoplethysmogram (PPG) sensor data.

## Declaration

```swift
class SRPhotoplethysmogramSample
```

## Overview

Overview The PPG sensor provides an array of these objects as its sample type. Apple Watch uses LED lights, paired with light-sensitive photodiodes (PD), to track the heartbeat-induced pulsations. Different Apple Watch models can have different numbers of LEDs and PDs. For more information, see SRPhotoplethysmogramOpticalSample. For more details, see: Monitor your heart rate with Apple Watch Using Apple Watch for Arrhythmia Detection How to use the Blood Oxygen app on Apple Watch Blood Oxygen app on Apple Watch

## Topics

### Accessing PPG data

- [startDate](sensorkit/srphotoplethysmogramsample/startdate.md)
- [nanosecondsSinceStart](sensorkit/srphotoplethysmogramsample/nanosecondssincestart.md)
- [usage](sensorkit/srphotoplethysmogramsample/usage-swift.property.md)
- [SRPhotoplethysmogramSample.Usage](sensorkit/srphotoplethysmogramsample/usage-swift.struct.md)
- [opticalSamples](sensorkit/srphotoplethysmogramsample/opticalsamples.md)
- [SRPhotoplethysmogramOpticalSample](sensorkit/srphotoplethysmogramopticalsample.md)
- [accelerometerSamples](sensorkit/srphotoplethysmogramsample/accelerometersamples.md)
- [SRPhotoplethysmogramAccelerometerSample](sensorkit/srphotoplethysmogramaccelerometersample.md)
- [temperature](sensorkit/srphotoplethysmogramsample/temperature.md)

## Relationships

### Inherits From

- [NSObject](objectivec/nsobject-swift.class.md)

### Conforms To

- [CVarArg](swift/cvararg.md)
- [CustomDebugStringConvertible](swift/customdebugstringconvertible.md)
- [CustomStringConvertible](swift/customstringconvertible.md)
- [Equatable](swift/equatable.md)
- [Hashable](swift/hashable.md)
- [NSCoding](foundation/nscoding.md)
- [NSCopying](foundation/nscopying.md)
- [NSObjectProtocol](objectivec/nsobjectprotocol.md)
- [NSSecureCoding](foundation/nssecurecoding.md)
- [Sendable](swift/sendable.md)
- [SendableMetatype](swift/sendablemetatype.md)