Human body surface area

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Human body surface area
Ex dubois.png
author Leif Roschier

Theory and background

Calculated body surface area (BSA) of human body is according to Ref. [1] [2]

[math]{BSA}=(71.84 \times {weight \mbox{ (kg)}}^{0.425} \times {height \mbox{ (cm)}}^{0.725})\ / \ 10000[/math]

Construction of the nomograph

A nomograph is illustrated at [3] that guided the construction of the nomograph. A type 1 was chosen and dual scales were put by using type 8 singular blocks.

Equation was written as

[math]-\log(\frac{BSA}{0.007184})+\log(w^{0.425})+\log(h^{0.725})=0 [/math]


for type 1 block.

References

  1. http://en.wikipedia.org/wiki/Body_surface_area
  2. Du Bois & Du Bois, Arch Intern Med 1916;17:863:
  3. http://www.projectrho.com/nomogram/compound.html

Generated nomograph

Body surface area
Ex dubois.png
Generated portable document file (pdf): File:Ex dubois.pdf

Source code

"""
    ex_dubois.py
 
    Body Surface Area (BSA) according to
    Du Bois & Du Bois, Arch Intern Med 1916;17:863:
 
    Body Surface Area = 0.007184* (Weight(kg)**0.425)*(Height(cm)**0.725)
 
    Copyright (C) 2007-2009  Leif Roschier
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
"""
from pynomo.nomographer import *
 
# BSA (m2)
BSA_params={
        'u_min':0.6,
        'u_max':3.0,
        'function':lambda u:-log(u/0.007184),
        'title':r'BSA (m$^2$)',
        'tick_levels':3,
        'tick_side':'left',
        'tick_text_levels':2,
        'scale_type':'linear smart',
                }
 
weight_params={
        'tag':'mass',
        'u_min':15.0,
        'u_max':200.0,
        'function':lambda u:log(u**0.425),
        'title':r'm (kg)',
        'tick_levels':3,
        'tick_text_levels':2,
        'scale_type':'linear smart',
        'title_x_shift':0.8,
                }
 
height_params={
        'tag':'height',
        'u_min':75.0,
        'u_max':220.0,
        'function':lambda u:log(u**0.725),
        'title':r'h (cm)',
        'tick_levels':4,
        'tick_text_levels':4,
        'tick_side':'left',
        'title_x_shift':-0.8,
        'scale_type':'linear smart',
                }
 
block_1_params={
             'block_type':'type_1',
             'width':10.0,
             'height':10.0,
             'f2_params':BSA_params,
             'f1_params':weight_params,
             'f3_params':height_params,
             'isopleth_values':[[85,'x',183]]}
 
weight_params_lbs={
        'tag':'mass',
        'u_min':15.0*2.2,
        'u_max':200.0*2.2,
        'function':lambda u:log(u**0.425),
        'title':r'm (lbs)',
        'tick_levels':4,
        'align_func':lambda u:u/2.2,
        'tick_text_levels':4,
        'tick_side':'left',
        'scale_type':'linear smart',
        'title_x_shift':-0.8,
                }
 
block_2_params={
                 'block_type':'type_8',
                 'f_params':weight_params_lbs,
                 'isopleth_values':[['x']]
                 }
 
height_params_inch={
        'tag':'height',
        'u_min':75.0/2.54,
        'u_max':220.0/2.54,
        'function':lambda u:log(u**0.725),
        'title':r'h (inch)',
        'tick_levels':4,
        'align_func':lambda u:u*2.54,
        'tick_text_levels':4,
        'tick_side':'right',
        'scale_type':'linear smart',
        'title_x_shift':0.8,
                }
 
block_3_params={
                 'block_type':'type_8',
                 'f_params':height_params_inch,
                 'isopleth_values':[['x']]
                 }
 
 
main_params={
              'filename':'ex_dubois.pdf',
              'paper_height':20.0,
              'paper_width':15.0,
              'block_params':[block_1_params,block_2_params,block_3_params],
              'transformations':[('rotate',0.01),('polygon',),('scale paper',)],
              'title_str':r'Du Bois \& Du Bois:  $BSA = 0.007184 m^{0.425} h^{0.725}$'
              }
Nomographer(main_params)