US1811168A - Barometer for use in connection with diagnostic work - Google Patents

Description

D. R. BARR.

June 23, 1 931.

BAROMETER FOR USE IN CONNECTION WITH DIAGNOSTIC WORK Filed April 25, 1928 INVENTOR ATTORNEY Patented June 23, 1931 UNITED STATES DANIEL B. BARR, OF GRAND RAPIDS, OHIO,

PATENT OFFICE ASS IGNOR TO TAYLOR INSTRUMENT COM- PANIES, OF ROCHESTER, NEW YORK, A CORPORATION OF YORK BABOMETER ron USE IN connnc'rron wi'rn DIAGNOSTIC worn:

Application filed April 25,

'5 is necessary to reduce volumes of air at an observed pressure and an observed temperature to the corresponding volumes at standard conditions, usually C. (temp), 760 mm. (pressure) and 80% aqueous vapor saturation.

It is common practice to provide tables for facilitating the reduction of observed values of volumes at observed conditions of pressure and temperature to standard conditions.

The resent invention has for its object to simplii y not only the use of the table, butalso the observations to be made.

Another object is a barometer which aside from its usual pressure scale contains indicia and mechanism for translating the pressure indicated together with other values observed into terms of standard conditions.

For a full explanation of the invention, reference is made to the drawings, wherein:

Fi 1 is a face view of a barometer embodyin t e invention;

Tig. 2 is an enlarged view of a part thereof and Fig. 3 is a similar view, on a smaller scale, of another form of the invention.

The barometer mechanism may be of any well known construction enclosed in the casing 1 and including a pointer 2 co-operating with a scale 5 graduated to indicate atmospheric pressure.

For the purpose of the invention, in agreement with the medical practice in this respect, the pressure is indicated in millimeters of mercury.

The pressure is marked along the periphery of the dial 3, as indicated by the numbers 640, 645, 650 and 655 780.

Inradial alignment with each number is a column of figures. concentrically with the arbor of the instrument, but independently of it, preferably on the glass cover, is mounted a hand 4, which may be turned by means of a knurled nut 4a or the like to any desired position on the dial. On the hand 4 are marked in superposition numbers consecu- 1928." Serial No. 272,686.

tively varying from about 1537. Thereare as many numbers on this hand as there are figuresin each of the radial rows in'alignment with the pressure indications. In the particular instance, there are twelve numbers on the hand-and twelve numbers in each radial row on the dial.

The numbers in-the radial columns on the dial signify numbers of calories per liter 'of oxygen. One liter. of oxygen at 0? C. and 760 mm. pressure is assumed, when inhaled, to

have a calorific value of 4.85 cal. -The physician calculates the volume of oxygen inhaled per hour and he must 'multiply'this volume, expressed in liters, by a factor corresponding to thefactor 4.85. This factor, however, is ordinarily smaller than 485 since the barometric pressure at altitudes higher than" sea level is usually lower than 760 mm. and thet'emperature is usually higher'th'an ;0. The numbers in the radial columns on the dial represent the calorificvalues of 1,.liter of oxygen at different temperatures and different barometric'pressures. Each number represents thecalorific value a liter of oxygen at" a definite temperature and a definite barometric pressure would have at 0 C. and 760 mm. pressure. The definite temperature referred tois that number on the hand 4, which lies on the same circle asthe number in question and the definite pressure is the pressure indication on the scale radially outwardly fr'om'the'column containing the number in question." Each number represents the calorific value of 1 liter of oxygen'measured at a known temperature and known pressure, when'reduced to standard conditions; 7

The'operation and significance ofthe arrangement are as follows:

Thephysician'or otheroperator moves the hand 4 into alignment with the pointer 2' or rather into juxtapositionof the radial row nearest to the pointer and notes the-nuinber in lateral alignment with a selected one ofthe numbers on the hand 4. 1 These numbers denote temperatures 'of respiratory contents in a spirometer chamber which does not form a part of this invention. The operator, at the time of operating the hand 4, consults the thermometer usually attached to the spirometer and then makes the reading on the dial 3, as mentioned. Assume that the temperature is 19 and the pointer stands at 699 as indicated in Fig. 2. The hand 4 is moved to the position indicated so that the numbers on the hand are. directly adjacent to the numbers in the radial row in alignment With the pressure indication 700. The number 43.08 is the number adjacent to the number 19 on the hand 4 and thisnumber 1.08 is the number sought.

In the particular instance, the calorific equivalent of one liter of oxygen at 19 (3., 700 min. pressure and anyrelative humidity combined with factors for reduction of vol nine to 0 C. 111111., 760 mm. pressure and aqueous vapor saturation.

Itis understood that the figures of the radial roWs represent, in general, correction factors including the reduction of the volume ofoxygen at any observed pressure and temperature to the volume corresponding to standard conditions of pressure and. temperature.

The handd is preferably of transparent material such as celluloid to facilitate visual juxtaposition of the numbers on the hand and the numbers on the dial.

In Fig. 3, the dial is the same as in Fig. 1, but in placeof the hand 4, a disk 6 is mounted for pivotalmovement. The disk 6 is provided With a slit 7 on one or both sides of which are marked the numbers 15-37.

I claim:

1. In a barometric device, the combination with a pointer, of a dial for the pointer having along its periphery a set of barometric pressure indications corresponding to different positions of the pointer and having inwardly of each of said pressure indications a radial group of diagnostic indicia, a member pivotally mounted concentrically With the pointer and the dial and bearing temperature indicia in radial alignment for correlation with the said diagnostic indica, and means for moving the said member and the dial relatively to one another.

2. In a barometric device, the combination with a pointer, of a dial for the pointer hav ing along its periphery a set of barometric pressure indications corresponding to different positions of the pointer and having inwardly of each pressure indication a radial group of diagnostic indicia, a hand pivotally mounted concentrically with the pointer and the dial and bearing temperature indicia in radial alignment for correlation with the said diagnoistic indicia, and means for moving the hand about its pivot.

In testimonywhereof I afiix my signature.

DANIEL R. BARR.

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