Heart Rate (Lilach Cary & Erango Kelbisow & Audrey Benson)

Author(s)

Audrey Benson, Moorpark High School

Erango Kelbisow, Middle College High School

Lilach Cary, Albert Einstein Academy

Sensor / Probe

The heart rate monitor allows you to measure your heart rate by placing your finger over the camera feature on an iPhone and measuring the beats per minute. The monitor detects a color change in your finger tip each time your heart beats to show your heart rate. It also charts your heartbeat the way that a pulse oximeter used in a hospital does.

Sample Investigation

Investigation: What is the effect of exercise on cardiac output of individuals.

Students measure their heart rate using the probe under the following conditions: sitting at rest, lying down, after exercising, 3 minutes after exercising (recovery). From here students measure their cardiac output, which is the measure of volume of blood that is being pumped out by the heart. This is measured by the following equation:

Cardiac Volume = stroke volume x heart rate (assume average stroke volume is 70mL/beat)

Independent variable: Position/activity of individual

Dependent variable: Heart rate (in BMP)

Constant: student being measure, finger used to measure, about of pressure placed on heart rate monitor with your finger

Control: resting heart rate

Second Investigation: What is the effect of exercise on cellular respiration?

Students blow into a test tube which contains water and BTB, both at resting and after a few minutes of exercise. They will record the time it takes for the water to change color (indicating a change in pH, and thus more CO2 production).The students will then measure their breathing rate and heart rate while resting and after exercise.

Lab Activity

Sample Data & Analysis and Interpretation

resting lying down exercising recovery

Resting cardiac volume = 70mL/beat x 73 bpm = 5,110mL/m

Lying down cardiac volume = 70mL/beat x 68 bpm = 4,760mL/m

Exercising cardiac volume = 70mL/beat x 125 bpm = 8,750mL/m

Recovery cardiac volume = 70mL/beat x 83 bpm = 5,810mL/m

Interpretation: During exercise, your heart increases in bpm in order to provide more oxygen to the cells in your body to help with cellular respiration.

7 Days Heart Rate Data - Resting at home

Student Data Example from Exercise vs Cellular Respiration Lab

Photos

Movies