An Anthropometric Analysis of Seated and Standing People
4.5 Applications to Other Areas of Health and Disease
110 A. Nucara et al.
111 4 An Anthropometric Analysis of Seated and Standing People
(i.e., less than 0.15 m/s). A lamp with a color temperature of 3,000 K is positioned in this environment whose intensity of the emitted radiation at the distance of 1 m, q ir,1m , is equal to 150 W/m 2 . The lamp, a high intensity heat source, is placed in front of the subject at a distance varying from 1 to 4 m; this may be the case for a patient about to undergo surgery (see, e.g., Fig. 4.15 ).
The positions of the human body and the lamp enable us to adopt the view factor values for standing people and, consequently, the pertinent equation for the radiative human body thermal balance.
In order to evaluate the total thermal radiation leaving the body for unit of body area, (4.35) is used, dividing (4.7) by the naked body surface area:
= σ r⎡⎣
(
cl+) (
4− r+)
4⎤⎦− αir p ir b273 273
R f t t f q
A e (4.35)
In (4.34) , the clothed surface temperature, t cl , may be obtained by means of a balance of the dry component of the energy exchanged between the external surface of the body and the environment (Fanger 1970 ) . Emissivity, e , and the effective radiating area factor, f r , have been assumed equal to 0.97 and 0.696, respectively; the projected area factor, f p , has been set at the value of 0.35 (valid for a standing subject with altitude and azimuth angles of 0°); and the relative absorptance of skin, a ir , has been assumed to be equal to 0.8, with reference to Fig. 4.16 .
Fig. 4.15 Sketch of subject about to undergo surgery. The case for a patient about to undergo surgery may be considered as a naked resting subject, lying on his back, placed in a moderate thermal uniform environment, with a lamp placed in front of him
0.6 0.7 0.8 0.9 1.0
0 1000 2000 3000 4000 5000 6000
Relative absorptance
Color temperature (K) Fig. 4.16 Relative absorp-
tance of skin at various color temperatures (ASHRAE 1989 ) . The relative absorp- tance of skin depends on the color temperature of the emitting source
112 A. Nucara et al.
Moreover, the dependence of the radiant fl ow on the distance of the lamp has been evaluated by the following equation:
ir( ) qir,12m
q d = d (4.36)
Finally, the behavior of the radiative heat fl ow leaving the body of the irradiated subject is reported in Fig. 4.17 , as a function of the distance between the subject and the lamp.
In Fig. 4.17 , the total radiative heat fl ow by the subject toward the environment is assumed as positive, while the total radiative heat fl ow reaching the human body from the environment is assumed as negative. When the lamp is near the subject, the total radiative heat fl ow is a gain; when the lamp is further away, this radiative heat fl ow is considered dispersion.
These considerations defi nitely confi rm the crucial importance of the knowledge of human body radiative parameters (particularly, the projected and the effective radiating area factor) in order to evaluate radiative heat fl ows and the thermal sensation of a subject. Similar considerations can be made for clothed persons by taking into account the importance of other human body radiative parameters, which the clothing area factor will markedly increase.
Summary Points
The thermal sensation of a subject in a confi ned environment is related to the need of the human
•
body to arrive at a homeothermic state at body core level.
In order to evaluate the thermal condition of a subject in a confi ned environment, a suitable set of
•
radiation data referring to the human body anthropometry is required.
The main parameters facilitating the evaluation of the convective and radiative exchanges between
•
the human body and the environment are:
The body surface area;
◦
The clothing area factors;
◦
The effective radiation area factor;
◦
The projected area factors.
◦
Fig. 4.17 Total thermal radiation as a function of the distance between the body and the high intensity heat source. The fi gure shows as, when a lamp is near to the subject, the total radiative heat fl ow is a gain, whereas, when a lamp is further away, the radiative heat fl ow is a dispersion
113 4 An Anthropometric Analysis of Seated and Standing People
A detailed description of the practical methods and techniques for determining the relevant human
•
body anthropometry parameters has been described by pointing out the main features and the ease or otherwise of their suitable application.
The results of a new study concerning the determination of the differences of peoples of various
•
gender and nationalities on the radiation anthropometric parameters has been outlined.
References
Alfano G, d’Ambrosio FR, Riccio G. La valutazione delle condizioni termoigrometriche negli ambienti di lavoro:
comfort e sicurezza.Napoli (in Italian): CUEN; 1997.
ASHRAE. ASHRAE handbook – HVAC applications. Atlanta: American Society of Heating, Refrigerating and Air Conditioning Engineers; 1989.
Boyd E. The growth of the surface area of the human body. Minneapolis: University of Minnesota Press; 1935.
Calvino F, Nucara A, Pietrafesa M, Rizzo G, Scaccianoce G. In: Proceedings of CLIMA 2000 – 7° REHVA World Congress, Naples; 2001.
Calvino F, La Gennusa M, Nucara A, Rizzo G, Scaccianoce G. Occup Ergon. 2005;5:173–85.
Calvino F, Scaccianoce G, Simone A. In: Proceedings of 6° Congresso Nazionale CIRIAF, Perugia (in Italian);
2006.
Calvino F, La Gennusa M, Rizzo G, Scaccianoce G. Appl Ergon. 2009;40:239–50.
DuBois D, DuBois EF. Arch Int Med. 1916;17:863–71, Chicago.
Fanger PO. Thermal comfort. Copenhagen: Danish Technical Press. 1970.
Gehan EA, George SL. Cancer Chemother Rep. 1970;54:225–35.
Guibert A, Taylor CL. J Appl Physiol. 1952;5:24–37.
Haycock GB, Schwartz GJ, Wisotsky DH. J Pediatr. 1978;93:62–6.
Horikoshi T, Tsucjikawa T, Kobayashi Y, Miwa E, Kurazumi Y, Hirayama K. ASHRAE Trans. 1990;96:60–6.
Howland J, Dana RT. Am J Dis Child. 1913;VI:33–7.
ISO. ISO 9920: Ergonomics of the thermal environment – Estimation of the thermal insulation and evaporative resis- tance of a clothing ensemble. Geneva: International Standard Organization; 1995.
Key Points of Homeothermic State
The thermal comfort of people in confi ned, thermally moderated environments is considered
•
to be of paramount importance today in order to guarantee optimal working and living condi- tions to the occupants of any given building. The conditions for ensuring indoor comfort involve a relevant consumption of energy, required by HVAC systems in winter (heating) and summer (cooling). Thus, suitably addressing the thermal conditions of buildings could result in a signifi cant primary energy saving.
In order to evaluate the thermal body (thermo-hygrometry) comfort conditions at a design
•
level, specifi c algorithms, which obtain human body thermal balance in a given indoor envi- ronment, are required. This calls for knowledge of various important anthropometric param- eters, particularly in relation to the radiative heat exchange of the human body, which represents one of major factors in the thermal balance of human body.
Algorithms, practical methods and techniques for obtaining such parameters (the body surface
•
area, the clothing area factor, the effective radiating area factor and the project area factors) have been reported in this chapter.
The potential of these parameters to address new areas of health and disease, particularly in
•
hospitals and buildings where people assume predominantly supine postures, has also been analyzed.
114 A. Nucara et al.
ISO. ISO 7726: Ergonomics of the thermal environment – Instruments for measuring physical quantities. Geneva:
International Standard Organization; 1998.
ISO. ISO 7250: Basic human body measurements for technological design. Geneva: International Standard Organization; 1995.
ISO. ISO 13731: Ergonomics of the thermal environment – Vocabulary and symbols. Geneva: International Standard Organization; 2001.
Jones B, Ogawa Y. ASHRAE Trans. 1992;98:189–95.
Lo Curcio FP. Scambi termici tra corpo umano ed ambiente indoor: verifi ca della validità degli algoritmi per il calcolo del fattore di area proiettata. Degree Thesis. Supervisor: Scaccianoce G, University of Palermo (in Italian); 2009.
Meeh K. Zeitschrift für Biologie. 1879;15:425–58 (in German).
Miyazaki Y, Saito M, Seshimo Y. J Hum Living Environ. 1995;2:92–100.
Mosteller RD. The New England J Med. 1987;317:1098.
Ozeki Y, Higuchi S, Saito T, Ohgaki S, Sonda Y. (1992) In: International Symposium on Room Air Convection and Ventilation Effectiveness; 1992. p. 479–489.
Ozeki Y, Sonda Y, Hiramatsu T, Saito T, Ohgaki S. Trans SHASE (The Society of Heating Air-Conditioning and Sanitary Engineers of Japan). 1997;66:1–11 (in Japanese).
Rizzo G, Franzitta G, Cannistraro G. Energy Build. 1991;17:221–30.
Roebuck JA, Kroemer KHE, Thomson WG. Engineering anthropometry methods. New York: Wiley; 1975.
Scheid F. Theory and problems of numerical analysis. Schaum’s Outline Series, New York: McGraw-Hill; 1968.
Tanabe S, Narita C, Ozeki Y, Konishi M. Energy Build. 2000;32:205–15.
Underwood CR, Ward EJ. Ergonomics. 1966;9:155–68.
V.R. Preedy (ed.), Handbook of Anthropometry: Physical Measures 115 of Human Form in Health and Disease, DOI 10.1007/978-1-4419-1788-1_5,
© Springer Science+Business Media, LLC 2012
Abstract The allied health disciplines of prosthetics and orthotics require specialized knowledge of anthropometrics and have consequently developed instrumentation and systems to capture shapes of specific body segments. This instrumentation has found application for digital shape capture and subsequent model modification for intact and residual limbs as well as for the head and torso. Two primary technologies have emerged. Optical scanners are largely non-contact and use combinations of digital cameras, lasers, and lights to capture the surface geometry of a limb. Electromagnetic field-based systems are contact scanners that require the entire surface of the limb segment to be traced using a stylus. The accuracy of both systems has been established versus known measures and conventional hand-tool anthropometrics. Furthermore, the use of systems for routine collection of anthropometrics for all patients has been proposed even in cases when the instrumentation is not used as part of the process of fabrication of a prosthesis or an orthosis. Additional utility is possible with the use of the digital caliper function of magnetic field scanners. In particular, the collection of body segment parameters that is a necessary part of clinical gait analysis is significantly more efficient with the digitizer. An additional practical application of the systems is centralized fabrica- tion of prosthetic and orthotic components. In conclusion, specialized equipment for limb digitization has benefitted the disciplines of prosthetics and orthotics and could have ancillary benefits in other fields as well.
Abbreviations
CAD/CAM Computer aided design/Computer aided manufacturing CNC Computer numerical control
CAPOD Computer aided prosthetic and orthotic design BSP Body segment parameter