Cycle ergometer

March 12, 1957

2,784,591

B. A. SHOOR

CYCLE ERGOMETER

Filed July 25, 1955

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United States Patent Office _P , _M^2,784,591 , ^v Patented Mar. 12, 1957

2,784,591

CYCLE ERGOMETER Bernard A. Shoor, Los Angeles, Calif.

Application July 25,1955, Serial No. 524,094 6 Claims. (Cl. 73—379)

The present invention relates generally to the field of 15 medicine and more particularly to a novel cycle ergometer.

In the medical treatment of certain disorders it is essential to have an accurate indication of the exact amount of work a patient can perform over a certain period of time. It has been heretofore proposed to 20. measure such work output by means of various types of cycle ergometers. Generally, these devices utilize the principles of a prony brake and they have not provided sufficiently accurate results.........................

It is a major object of the present invention to provide 25 a new and improved form of cycle ergometer.

Another object is to provide a cycle ergometer which affords extremely accurate results over a wide range of operating conditions.

Yet another object is to provide a cycle ergometer 30 which is simple in design and rugged of construction whereby it may afford a long and trouble-free service life.

It is a further object of the invention to provide a cycle ergometer which may be manufactured and maintained at less cost than the majority of the heretofore-proposed 35 devices of this type offering comparable results with respect to accuracy.

A further object is to provide a device of the aforedescribed nature which utilizes common and inexpensive electrical components.

An additional object of the present invention is to provide a cycle ergometer which does not require the services of a highly trained technician for its operation.

It is yet another object of the invention to provide a cycle ergometer which may be operated with the patient disposed in either a sitting or in a prone position.

These and other objects and advantages of the present invention will become apparent from the following detailed description of a prefered embodiment thereof, when taken in conjunction with the appended drawings, wherein:

Figure 1 is a perspective view of a preferred form of cycle ergometer embodying the present invention; and

Figure 2 is an electrical circuit diagram of said cycle ergometer.

Referring to the drawings, the preferred form of cycle ergometer C embodying the present invention is adapted to measure the work output of a patient P shown lying upon a suitable table T. The cycle ergometer C includes a pair of pedals 10 which are engaged by the feet of the patient P in order that he may effect rotation thereof. The pedals 10 extend from either side of the front of a support bar 12 having its front end pivotally connected to a gear box housing 14. The elevation of the pedals 10 may be adjusted to the needs of individual patients by means of a bracket 16. The lower end of the bracket is pivotally affixed to a cross-bar 18 which extends between a pair of frame elements 19. The front end of these frame elements 19 support the sides of the gear box housing 14. Each of the frame elements 19 carry suitable clamps 20 by means of which they may be removably attached to an X-ray table T, or the like, upon which the patient P rests during a work measuring operation. The patient P may determine the rotational speed at which he is pedaling by means of a tachometer 21 mounted upon a stand 22 that is clamped to one side of the table T. 5 A suitable cable 23 interconnects the pedals 10 and the gear box housing 14. Preferably, as shown in Figure 2, a free wheeling clutch 24 is incorporated in the gear box housing 14 so as to prevent inadvertent contact of a rapidly rotating pedal with the patient’s feet or ankles. As also shown in Figure 2, the cycle ergometer C includes an electric motor-generator or dynamotor unit U, the generator portion 26 of which is connected to the pedals 16 through the gear box 12 and a suitable cable 28.

The motor portion 30 of the motor-generator unit U is connected to a suitable source of electric current 32 such as an outlet for domestic alternating current. Preferably, this alternating current will pass through a stepdown transformer 38 and a rectifier 40. The amount of current flowing to the motor 30 and hence its rotational speed may be adjusted by means of several electrical resistances R, Rl, R2, R3, R4 and R5. The amount of work being applied by the patient P to the generator 26 is measured as by. means of a watt meter 44. A load, such as a variable resistance 45, is connected to the generator 26. Conveniently the motor generator unit U, the transformer 38, the rectifier 40, the resistances R, the watt meter 44 and the variable resistance 45 are mounted within a housing 46.

In the operation of the preferred form of cycle ergometer embodying the present invention, the motor 30 is caused to rotate at a desired speed by proper manipulation of the resistances. The patient P is then instructed to pedal at a rate which will cause the generator 26 to rotate at the same speed as the motor. At this time the patient will not be performing any substantial amount of work. The patient is further instructed to maintain the tachometer reading constant.

Next, the operator decreases the electric current input to the motor 30 by means of the resistances. Such decrease is effected in predetermined steps. Each time an additional resistance is introduced the rotational speed of the motor tends to decrease. The added work required to maintain the rotational speed of the motor (and hence the.tachometer reading) constant must be supplied by the 45 patient. The value of such added work may be accurately obtained by means of the watt meter 44. The utilization of the variable resistance 45 permits the loading of the generator 26 to be readily adjusted. In this manner the work load of the generator may be varied so as to provide 50 most accurate results when persons of different strengths are being tested.

With the aforedescribed arrangement, it is possible to carefully chart perimetric curves of the work supplied by the patient under varying load conditions at different 55 constant velocities. Such perimetric curves may be charted with the patient disposed in a sitting position as well as in a prone position. To this end the gear box bracket 14 may be lowered relative to its supporting pedestal 16. The patient P may then sit upon the edge 00 of the table T and engage the pedals 10 with his feet.

While there has been shown and described hereinbefore what is presently considered to be the preferred embodiment of the present invention, it will be apparent that various modifications and changes may be made θ₅ thereto without departing from the spirit of the invention or the scope of the following claims.