Heart Rate and Blood Pressure (Erango Kelbisow & Andrew Salg)
Research Question and Hypothesis
How does heart rate and blood pressure change throughout the day for a whole week? Blood pressure and heart rate should be at their lowest when first waking up in the morning, and the highest at the end of the day after being busy and possibly stressed all day.
Standards
HS-ETS1-3. Evaluate a solution to a complex real-world problem based on prioritized criteria and trade-offs that account for a range of constraints, including cost, safety, reliability, and aesthetics as well as possible social, cultural, and environmental impacts.
HS-LS1-2. Develop and use a model to illustrate the hierarchical organization of interacting systems that provide specific functions within multicellular organisms.
HS-PS4-2. Evaluate questions about the advantages of using a digital transmission and storage of information.
Experimental Design
The design of the experiment is to see the change in heart rate and blood pressure throughout the day over a period of one week. The measurements will be taken around the same time as much possible, unless schedule conflicts arise, then these measurements should be taken as soon as activity is done. The idea is to show how the body adjusts from the time we wake up to the end of the day where a person may feel tired and stressed out.
Independent variable
The independent variable is the time. The time will be measured over several days at the same time of day to have a constant time spread.
Dependent variables
The dependent variable is heart rate and blood pressure. Depending on the time of day these variables may be higher or lower than previous measurements depending on sleep, tasks throughout the day, and mental state, etc.
Series
The series is heart rate and blood pressure changes for one week at various parts of the day, first waking up, then around noon, and then finally around dinner time. The charts will have dates and time listed to help show when each recording took place.
Constants and Controls
The constant will be the position that blood pressure and heart rate is taken (in a sitting down position on chair or couch), no exercise being performed before measurement, and the time of day in which the measurement is taken unless there are scheduling conflicts. There is no real control due to only current measurements being compared to previous measurements around the same time.
Materials
Electronic Blood pressure machine
Way to record data (note pad paper, computer, phone, etc.)
Procedures
To take blood pressure there are several ways.
1. Purchase a machine from a store like Walgreens or Rite Aid. Most stores and Hospitals will sell them in some form. Make sure to make proper measurements on the arm circumfrence of the humerus (bone above the elbow).
2. All this machine requires is for a person to put on the blood pressure cuff turn on the machine. Make sure that the cuff in not tight on the arm as air will be pumped in the cuff. The machine will read zero, and start inflating the cuff, eventually machine will stop pumping air and start to deflate the cuff. Make sure not to move or talk during the process as this can throw the readings off. Also, don't try holding your breath, but take nice deep relaxed breaths.
3. Eventually the cuff will fully deflate and the final reading is shown, record the systolic and diastolic blood pressure in mmHg or millimeters of mercury. Also record the heart rate.
The other option is much more difficult but can be accomplished. Before machines, medical personnel using a stethoscope( used for taking heart rate) and a sphygmomanometer (for blood pressure). Both these instruments will be used to take blood pressure, but a person may want to have another person assist them with taking measurements. It is also highly advised to practice taking measurements before recording any data for the experiment.
1. First is to put the blood pressure cuff on the arm above the elbow. Then taking the sphygmomanometer and placing it on the front center of the arm where your arm bends ( right where the biceps insert into the ulnar).
2. Start to inflate the cuff by twisting the little knob under the pump to lock in air. Continue to pump until it is snug but not too tight.
3. Then slowly begin to let a little air out by twisting the knob. Listen to the sound of the artery opening up and closing to let blood rush to the arm. Record when you first heard it afterwards.
4. Continue to release air until you can no longer heard any sound, record the number on the meter the last time you heard any sound in the artery. These sounds is called the Korotkoff sounds. The first is systolic (when the artery begins to open up again).
5. The last sound is diastolic ( the artery is fully open). You may want to be the person taking the measurements of a family member because taking them of yourself can be a little bit more difficult with only one hand able to use during the process. If you want yours measured be sure that the other person knows what they are doing.
Sample data and graphs
Physiology Lab Activity & data collection Form (added)
Blood Pressure data Collection Form
Longitudinal Study data (Excel Form)
Healthy and Unhealthy Blood Pressure Range Chart
Analysis & Conclusions
The data shows that some days that there was little change in heart rate through out the day, and other days there were large gaps. The only reason that for the larger gaps could be possible to added stress after working all day or some form of physical exertion before measurement and not fully recovered. My conclusion is finding ways to just relax and remembering taking deep breaths during the day help during the day. Also even though not part of the study, sleeping about 8 hours a night could have been a contributing factor in helping maintain a rather consistent range.
Photos & Movies
References