HP Prime: Fick Cardiac Output (The Blog Turns Six!)

HP Prime:  Fick Cardiac Output  (The Blog Turns Six!)

A Special Note

Happy sixth birthday to my mathematics blog!   And a big reason why blog has turned six on April 11, 2017 is because of all of you readers!  Words can’t explain how appreciated I am. 

Thank you!  Cheers to everyone!

Fun fact:  The most popular blog entry is my TI-36X Pro review (my fourth blog entry, 4/27/2011).  Link:  http://edspi31415.blogspot.com/2011/04/ti-36-pro-review.html

Now let’s get to today’s subject. 

Fick Cardiac Output Equations

The program FICK will calculate:

* CO: Cardiac Output (L/min)

* SV: Stroke Volume (ml)

* CI:  Cardiac Index (L/(min/m^2))

* SI:  Stroke Index (ml/m^2)

Given the following inputs:

* C_a:  Arterial blood oxygen (O₂) content percentage

* C_vO₂:  Venous blood oxygen (O₂) content percentage

* VO₂:  Oxygen compulsion (in ml per pure oxygen gas per minute, STPD)

* HR:  Heart Rate in beats per minute (BPM)

* Height in cm

* Weight in kg

STPD: Standard Temperature Pressure Density

Conversion factors:  1 in = 2.54 cm, 12 in = 1 ft, 1 lb = 0.45359237 kg

Formulas: 

CO = VO₂ / (10 * (C_a - C_vO₂))

SV = CO * 1000/HR

CI = CO/BSA

SI = SV/BSA

BSA:  body surface area, measured in cm^3.  There are several formulas, but the Fick program uses the simple approximation formula:

BSA = √(weight * height)/60

HP Prime Program FICK

EXPORT FICK()

BEGIN

// Fick Cardiac Output

// HP 65, 1972

// EWS 2017-04-10

// inputs

LOCAL ca,cv,vo,hr,h,w;

INPUT({ca,cv,vo,hr,h,w},

"Fick Cardiac Output",

{"Ca O_2:","C_v O_2:","VO_2:","HR:",

"Height:","Weight:"},

{"Arterial blood (%)",

"Venous blood (%)",

"O_2 compulsion (ml/min)",

"Heart Rate (BPM)",

"Height (cm)",

"Weight (kg)"});

// calculation

LOCAL co:=vo/(10*(ca-cv));

LOCAL sv:=co*1000/hr;

// simple BSA

LOCAL bsa:=√(w*h)/60;

LOCAL ci:=co/bsa;

LOCAL si:=sv/bsa;

// output

PRINT();

PRINT("Cardiac Output (l/min)");

PRINT(co);

PRINT("Stroke Volume (ml)");

PRINT(sv);

PRINT("Cardiac Index (L/(min/m^2))");

PRINT(ci);

PRINT("Stroke Index (ml/m^2)");

PRINT(si);

END;

Example:

Inputs:

* C_a:  19%

* C_vO₂:  15%

* VO₂:  250 ml/min

* HR:  64

* Height: 5 ft 11 in, 180.34 cm

* Weight 196 lb, 88.90410452 kg

Results:

* CO: 6.25 L/min

* SV: 97.65625 ml

* CI:  2.96158586825 L/(min/m^2)

* SI:  46.2747791914 ml/m^2

Source:

Hewlett Packard.  HP-67/97 User’s Library Solutions: Cardiac Corvallis, OR 1976  pg. 20

Here’s to many more years!

Eddie

This blog is property of Edward Shore, 2017.