BAKER, B

KOUWENHOVEN, WB

STARZL, TE

English

PubMed

D-Scholarship@Pitt

C A LOW Cost Treadmill for Experimental Animals' iV. B. GOL-WESHOVES, T. E. ST.4RZL AXD B. BAKER. From Ilre Deparr~~rents (!I Engineering and Surgery, Tire Jolms Hopkinr L'nivnsily. Balrimore, .Maryland MONG PHYSIOLOGISTS in recent years, there strap iron a t  each side of the mid-point. Mounted " A has been a growing interest in the adap- in these side pieces are seven spaced rollers which tive mechanisms of the normal or altered furnish support for the weight of the animal. The , erperimental animal to conditions of exertional rollen are made of 2" diameter pieces of pipe on stress. Such studies depend upon accurate assess- )" diameter shafts. .All pulley hnd roller shafts turn in ball bearings. ! ment and reduplication of exercise conditions in For running surface, a i n  continuous leather tly same or different animals. The treadmill, in 4 belt was employed, I I feet In length and 11 i n  wide. '' which the parameters of travel rate, incline angle. Before the pulleM and roUen were mounted the and time can be controlled, has cmne to be a stand- belt was placed in position around them, the ad method of exercise measurement. unit then assembled. T o  control belt tension two Because used for in- adjustable idler rollers, of the same type as the j t i g a t i o n  are to accommodate human other were on the under surface of I e j e c t s  as well, these instruments are usually the belt-mounted on four additional ),, 2,, '- ' *? e ~ n s i v e .  and the 'patlal Or financial s i d e  from permitting adjustment of I means of a small research unit. In the course of a ~ r k  in this laboratory a simple, inexpensive, small &admill has been developed for use with dogs or L9,,-6,,+ ; other small animals. This treadmill has a con- . , tinuously variable speed range of .8 to 7 mph, and mdi ly  accommodates dogs weighing from 5 to i 25 kg. I t  has been used with satisfaction for many hmdreds of hours, and because of the instru- ment's utility it was thought that it might be of d u e  to present the construction in some detail. r ,  THE FRAME DOG TREADMU The principal dimensions of the frame are FIG. I. Construction details of animal treadmill. shown in fie. I .  .\ I 1 "-wooden olank. ;' long and - - - I 14" wide, forms the base of the treadmill. To it are ' attached the motor and vertical supports of the m e .  The supports consist of 14" pieces of fC x 2" strap iron, one a t  each corner, each of ahi~h is reinforced by a 45' angle brace which runs , t@ the base. .4t the driving end these braces are W e  of in x I "  strap iron, and a t  the other end m i s t  of 3"  eve to eve turnbuckles which are for publication June 14, 19j4. FIG. 2. Treadmill showing chain drive and cage 'Aided by a grant from the Public Health Service. (chain guard removed). belt tension, the idler rollers elevate the belt sufliciently to allow room for the drive motor. THE DRIVE The drive motor is mounted on the base, beneath the running belt, figure I. Because this laboratory is supplied with 60 cycle AC current, the simpler and cheaper variable speed direct current motor could not be used. Instead, a )-horse power, 1750 rpm, 60 cycle AC motor with a variable speed Master Speedranger drive was chosen. Speed is adjusted with a small calibrated hand wheel mounted on top of the drive housing. The drive shaft of the motor is attached to the shaft of the 8-inch pulley by means of a chain and sprocket connection, which is covered with a guard. I n  practice, this power source has given the full speed range with no demonstrable loss of torque? THE CAGE .\ light cage was mounted upon the frame, 36" in height, 14" wide and 54" long. This was con- structed of an angle iron () x f x &") skeleton, covered with chicken wire, figure 2. A door was installed a t  one end, located a t  the animal's rear while running. To prevent the animal's feet from sliding off the side of the belt, triangular strips of wood. 4" in height and I "  wide a t  the base, were placed along the sides of the cage in close proximity to the belt surface. The treadmill has been used with 5-25 kg dogs for approximately 350 hours with no mechanical difficulties. \\'ith patience, almost any dog can be taught to run contentedly. The most effective train~ng method is to run the animal for short periods on consecutive days, starting a t  m i n k m  and s l o ~ l y  increasing to maximum speed. After the training period, the exercise tolerance in any given animal is usually reproducible on different , days within 15 minutes. Sormal dogs, running a\ 7 mph on this treadmill, usually have an exerciv 1 tolerance, defined as time ior collapse, of about hours, although this varied widely from animal d to animal. Below 5 mph, most normal dogs can run almost inde6niteIy. If it is desirable to increase work load, the wooden base can be given varying degrees of incline, since the treadmill is a unit structure. THE COST 4 Components and labor were as follows: Belt. .  . . . . . . . . . . . . . . . . . . . . . . . .  $ 47-00 j Motor and Master Speedranger (Master Electric Co., Dayton, Ohio).. . . . . . . . . . . . . . .  $ 3 0 5 . ~  Chain and sprocket. . . . . . . . . . .  S 26.00 Ball bearings.. $ 13.00 I . . . . . . . . . . . . . . . . .  Pulleys, strap iron and miscellaneous. $ 40.00 Labor. $200.00 'I . . . . . . . . . . . . . . . . . . . . . . .  Total . .  . . . . . . . . . . . . . . .  $631.00 - I Details have been given for the construction of I a cheap, simple, small treadmill, designed for ex- ercising dogs or other small animals. This device I has a continuously variable speed range of .8 to 7 mph. Total cost \\-as $631 .oo. i i 1 4 

A low cost treadmill for experimental animals

Kouwenhoven, WB

Starzl, TE

Baker, B

Name not available

W. B. Kouwenhoven

T. E. Starzl

B. Baker

Crossref

Journal of Applied Physiology

<i>A Low Cost Treadmill for Experimental Animals</i>

http://d-scholarship.pitt.edu/3394/1/31735062123058.pdf

A low cost treadmill for experimental animals

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