MedMath is a medical calculator for the Palm Computing Platform. MedMath is designed for rapid calculation of common equations used in adult internal medicine. MedMath is capable of calculating complex quantities (e.g. Dubois formula for Body Surface Area) without resorting to external libraries such as MathLib. For certain quantities, alternate units can easily be selected.

MedMath is largely self-explanatory. On startup, a list of formulas is displayed. Different categories of formulas may be viewed using the pop-up trigger at the upper right corner of the screen. Tapping the menu silkscreen button reveals options for selecting United States (US) units vs. Système Internationale (SI) units, and for clearing the Last Used list of equations.

After a formula from the list is selected, the calculation form appears. Simply fill in the numeric fields using Graffiti or the onscreen numeric keypad. The up and down arrow buttons on the keypad move the cursor from field to field; a field may also be selected by tapping directly on it. The units for some quantities may be displayed within selection boxes; tapping on these boxes brings up a pop-up menu of other units that may be used instead. Note that the formula at the top of the calculation form is always shown using US units.

Special buttons:

C (Clear): clears the field under the cursor.
Backspace: deletes the digit to the left of the cursor.
Reset All: clears the form and re-loads default values, if any.
Calculate: calculates the desired quantity; all numeric fields must be filled. Please note that range-checking is not provided, except to prevent division by zero. If you enter physiologically unreasonable values, dont be surprised to see physiologically unreasonable answers. Be careful with the units!
Info: displays a screen giving background information about the formula being used. Most of the formulas are documented with references.
Menu: returns to the formula list.
Formulas currently supported by MedMath:

A-a O2 Gradient
Absolute Neutrophil Count
Anion Gap (Serum)
Anion Gap (Urine)
Basal Energy Expenditure
Body Mass Index
Body Surface Area (Dubois)
Cardiac Output (Fick)
Corrected QT (QTc)
Corrected Serum Calcium
Corrected Serum Phenytoin
Corrected Serum Sodium
Creatinine Clearance (Cockcroft-Gault)
Creatinine Clearance (measured)
Fractional Excretion of Sodium
Glomerular Filtration Rate (MDRD)
Henderson-Hasselbalch Equation
Hepatitis Discriminant Function
Ideal Body Weight
Kt/V (Daugirdas)
LDL
Likelihood Ratios
Mean Arterial Pressure
MELD (Mayo Endstage Liver Disease) Score
Number Needed to Treat
Osmolality (Serum)
Osmotic Gap (Stool)
Peak flow, predicted (Nunn-Gregg)
Posttest Probability (Sensitivity/Specificity)
Posttest Probability (Likelihood Ratios)
Reticulocyte Index
Transtubular Potassium Gradient
Water Deficit
Winters Formula

Prominent features of MedMath include:

Formulas sorted by category
Consistent, straightforward user interface
Onscreen numeric keypad with backspace button
Global selection of US or SI units
Onscreen individual unit selection from pop-up menus
Information screens providing tips on equation usage and references
Program keeps track of the last 10 equations used
Editable Favorites category
No external programs or libraries required
State of the program is saved on exit
Runs on all Palm platforms, including Palm OS 1.0, without external libraries