Is it possible to stop receiving BPM after a while?

Hello everyone! I'm doing a school project and i need your help with the code. I'm using Pulse Sensor in my project to measure heartbeat (BPM- beats per minute) and i'm using the examples code from its website: https://pulsesensor.com/. I did change the code a little bit for my purpose.
My idea is that, i want a sensor to measure BPM for about 10 seconds and stop getting the values, and then i'll get all that BPM numbers as a array, and find the most frequent values in array and display it to LCD beacuse i want to get the stable BPM. This is the first time i'm doing this so i dont know what to do next. This is my code:

/*  Getting_BPM_to_Monitor prints the BPM to the Serial Monitor, using the least lines of code and PulseSensor Library.
 *  Tutorial Webpage: https://pulsesensor.com/pages/getting-advanced
 *
--------Use This Sketch To------------------------------------------
1) Displays user's live and changing BPM, Beats Per Minute, in Arduino's native Serial Monitor.
2) Print: "♥  A HeartBeat Happened !" when a beat is detected, live.
2) Learn about using a PulseSensor Library "Object".
4) Blinks LED on PIN 13 with user's Heartbeat.
--------------------------------------------------------------------*/

#define USE_ARDUINO_INTERRUPTS true    // Set-up low-level interrupts for most acurate BPM math.
#include <PulseSensorPlayground.h>     // Includes the PulseSensorPlayground Library.   
#include <LiquidCrystal.h>
//  Variables
const int PulseWire = 0;       // PulseSensor PURPLE WIRE connected to ANALOG PIN 0
const int LED13 = 13;          // The on-board Arduino LED, close to PIN 13.
int Threshold = 550;           // Determine which Signal to "count as a beat" and which to ignore.
                               // Use the "Gettting Started Project" to fine-tune Threshold Value beyond default setting.
                               // Otherwise leave the default "550" value. 

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
PulseSensorPlayground pulseSensor;  // Creates an instance of the PulseSensorPlayground object called "pulseSensor"
String choice;
void setup() {   
  
  Serial.begin(9600);          // For Serial Monitor
  // Configure the PulseSensor object, by assigning our variables to it. 
  pulseSensor.analogInput(PulseWire);   
  pulseSensor.blinkOnPulse(LED13);       //auto-magically blink Arduino's LED with heartbeat.
  pulseSensor.setThreshold(Threshold);   
  pulseSensor.setSerial(Serial);
  // Double-check the "pulseSensor" object was created and "began" seeing a signal. 
   if (pulseSensor.begin()) {
    lcd.setCursor(0,0);
    lcd.println("Loading...      ");  //LCD Starting Display  
    delay (3000);
    lcd.clear();
  }
}


void loop() {

 int myBPM = pulseSensor.getBeatsPerMinute();  // Calls function on our pulseSensor object that returns BPM as an "int".
 int Count=0;                                             // "myBPM" hold this BPM value now. 
 String StrBPM = "BPM: ";
 String Space = "          ";
 pulseSensor.outputSample(); 
if (pulseSensor.sawStartOfBeat()) {            // Constantly test to see if "a beat happened". 
  pulseSensor.outputBeat();
 //Serial.print("BPM:");                        // Print phrase "BPM: " 
 //Serial.println(myBPM);                  // Print the value inside of myBPM. 
 String StrPrint=StrBPM+myBPM+Space;
 lcd.setCursor(0,0);
 lcd.print(StrPrint);
}
  delay(20);                    // considered best practice in a simple sketch. 100


}

Anyone please help me! I really appreciate it!

Then measure for 10 seconds and stop:

bool measuring = false;
unsigned long startMeasuring;

void loop() {
  if (measuring == false) {

    // Start measuring.
    measuring = true;
    startMeasuring = millis();
  }

  if (millis() - startMeasuring < 10000) {
    measureBPM();
  }
  else {
    processBPM();

    // To do another measurement, trigger the first if block again:
    measuring = false;

  }
}

wvmarle:
Then measure for 10 seconds and stop:

bool measuring = false;

unsigned long startMeasuring;

void loop() {
 if (measuring == false) {

// Start measuring.
   measuring = true;
   startMeasuring = millis();
 }

if (millis() - startMeasuring < 10000) {
   measureBPM();
 }
 else {
   processBPM();

// To do another measurement, trigger the first if block again:
   measuring = false;

}
}

I'll try it and tell you soon

It works perfectly! Thank you very much!

Glad it works.

Hope you also understand what's going on, as it showcases two basic techniques that come back time and again: millis() based non-blocking timing, and a very basic finite state machine having just two states: measuring and not measuring.