System For Monitoring Animals In Motion

Abstract

A system for monitoring animals such as horses in motion, such as during swimming exercise, wherein suction cup attached electrodes on the animal are connected by leads to one or more heart action-measuring instruments such as an electrocardiograph and a pulse rate meter, the suction cup, electrodes and all junctures being of similar metal to prevent electrolytic interference with the electrocardiograph-actuating impulses. The suction cups are connected to a powered vacuum source.

Parent Case Text

This is a continuation of our earlier application Ser. No. 781,038 filed Dec. 4, 1968 for System for Monitoring Animals in Motion, and now abandoned, said earlier application having been a division of our copending application Ser. No. 683,719, filed Nov. 16, 1967 for Monitored and Controlled Conditioning and Exercise Method for Animals.

Description

BACKGROUND AND SUMMARY OF INVENTION

The invention relates to an electrical system whereby the instantaneous condition of animals in motion may be continually monitored. For example, it will be disclosed as applied to a system for operatively connecting an electrocardiograph and a heart rate meter to a swimming horse. Special suction cup electrodes are employed.

While electrocardiograms are well known, they are universally taken with the patient or animal in a state of complete inaction, because experience has shown that motion normally induces undesired electrical signals from other than heart muscles. Also suction cups per se for attaching electrocardiograph leads are known. To applicant's knowledge however, it has never been possible to take an electrocardiograph of an animal in violent motion, and this is a major object of the present invention.

It is another object of the invention to provide a novel electrocardiograph and like instrument lead system wherein metal suction cups to be attached to an animal in exercise such as swimming are connected to the instrument by leads of similar metal to reduce electrolytic side effects.

A related object of the invention is to include a powerful source of vacuum in the system for holding the electrodes immovable on the animal.

A further object of the invention is to provide a novel suction cup-type electrode. Further and more detailed objects will appear in the specification and claims.

The invention is useful in the selection and controlled conditioning of animals, particularly race horses although its basic aspects may be applied to humans.

Prior to the invention it has always been common practice to condition and train horses for racing using traditional methods which vary widely between individual trainers but in all of which the horses are exercised by actual running and their condition ascertained only by visual observation and/or by feeling chest and leg muscles. Experience has shown that horses undergoing such training are likely to accidentally physically injure their legs in one way or another during running, usually because of early fatigue due to poor or inadequate conditioning. Furthermore, there is no way to accurately discover during such training whether the horse is being exercised excessively or in such manner as to cause internal damage.

As a result of these haphazard training methods, many capable horses suffer premature injury and never reach the track, and many of those who do reach the track are so overtrained as not to be in optimum condition at the time.

The invention enables for the first time an optimum substantially injury-free conditioning exercise program wherein the animal's heart action is continually monitored to prevent excesses, and such is a very important object.

The invention enables controlled cyclic conditioning exercise of the animal monitored to prevent overtraining, this comprising vigorously exercising the animal during periods of high heart beat near but under safe values determined by test on the particular animal, such periods being spaced by nonexercising recovery intervals during which the heart beat is allowed to drop to a safe value for resuming the exercise, all the while continually monitoring the animal's heart action to determine the length of these periods and intervals.

The invention will be explained in detail with regard to race horse training which is its preferred application.

An important step is the proper selection of a colt. It is preferable to select colts at the age of 6 months. It is known that a horse's heart size changes between birth and the age of 18 months more than at any other time. For this reason, it is important that concentrated exercise occurs from weaning (6 months) to age two. However the invention may be applied to horses of any racing age. For purposes of simplicity the term horse includes colts.

Two major factors in selection are conformation and size of the heart as determined by observation of an electrocardiogram and measurement of the width of the QRS complex. The QRS width is the time an electrical impulse takes to travel through the muscle mass of the ventricles and this width is directly proportional to the muscle mass of the heart ventricles and therefore it is a measure of heart size. This QRS width would be final determination as to whether or not the colt is selected or rejected, because normally only horses with defect-free large heart size may become efficient winning race horses.

An electrocardiogram for a particular horse is studied, not only for acquainting the veterinarian with the size of the heart, but also for examination of the T-wave position and amplitude. When a horse is completely out of condition for racing, the T-wave on the electrocardiogram is positive in location and high in amplitude, on a unipolar base apical lead, at rest. As the horse becomes conditioned the T-wave becomes negative in polarity and greater in amplitude in the negative direction. This is an important determination as to whether or not the horse is fit from an electrocardiogram standpoint.

The horse begins active conditioning with the swimming exercise cycle program. The horse is preferably exercised in the following manner. He is placed on an elevator platform above a body of water and restrained from appreciable movement front, rear and laterally, care being taken not to physically restrain in any way the legs or any muscles used in swimming. A heart condition meter in the form of an electrocardiograph and a heart rate meter are connected to his body by means of special suction devices as will appear. His heart action is continually monitored during the entire program. He is lowered into the water until he is forced to swim and so remains until his heart is observed to attain a steady rate of approximately 200--225 beats per minute depending on the horse's normal. Instantly, at that point, the horse is raised out of the water far enough so that he may breathe as freely as possible and stop swimming. This is preferably done by raising the platform until he can stand on it. He is raised to such height that the lung cavity is completely out of the water so that there is no hydrostatic pressure against the lungs when he is in a state of oxygen debit induced by the exertion. The recovery interval now starts. The heart rate meter and electrocardiogram are watched until his reducing heart rate reaches a point on the electrocardiograph where the T-P base line becomes discernible and the T-wave shape indicates the start of reversal. The heart rate at this point may be within the neighborhood of 100--140 beats per minute depending on the individual. Either meter may be used to determine this period. When the individual's heart rate reaches the low range the recovery interval is over and he immediately is returned to the water by lowering the platform so that he is again forced to swim until his heart rate arrives at approximately 200--225 again. In practice, the length of this recovery interval is carefully noted, as recovery rate is a barometer of the horse's condition. The whole sequence is repeated cyclically to the end of the exercise.

With this particular manner of conditioning horses, a horse may always be maintained in condition from the time he is 6 months of age until he is through with his racing career, for all practical purposes. It does not damage the horse to be kept in constant condition as long as it needs to be kept in condition and can run. It is actually easier for a horse to be kept in condition rather than to let it down at the end of each racing schedule but the main advantage is heavy exercise can be maintained without damage to the horse's legs.

One of the major advantages in swimming a horse for exercise is that a high heart rate can be obtained and safely maintained, and by the invention the horse can be continually monitored so as to obtain recovery rates at rest intervals and the use of this as a barometer of the animal's change in condition. Heart action monitoring as is obtained in the invention is moreover not possible in a running horse. The better the condition the more rapidly the animal returns to normal. A horse that is trained at a high heart rate level at periodic intervals will develop more capillaries in the muscular tissue and more venous capillaries for the return of carbon dioxide and lactic acid during exercise, thereby making a more efficient machine which will operate at greater capabilities, more efficiently, for longer periods.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagrammatic view showing the monitored interval swimming exercise program wherein the invention is used;

FIG. 2 is a diagrammatic view showing preferred placement of the measuring instrument leads on a horse undergoing the interval swimming exercise program of FIG. 1;

FIG. 3 is a specimen section of an electrocardiograph taken on a horse at rest;

FIG. 4 is a specimen section of an electrocardiograph taken during an actual exercise period of a vigorously swimming horse; and

FIG. 5 shows a preferred suction cup structure used for attaching electrocardiograph and heart rate meter leads to the horse during the exercise program.

PREFERRED EMBODIMENTS

The invention is used for the controlled exercise of a selected animal.

Applicants have found that the optimum manner of controllably exercising an animal such as a horse for racing is swimming. This is mainly because swimming utilizes essentially all of the major muscles used in running, and swimming takes place in an environment wherein the horse is least subject to injury.

Swimming moreover is an exercise which causes a relatively great increase in cardiac output to supply needed oxygen to the muscles. Several factors other than the exercise itself, namely, increased heat loss, respiratory stimulation, and pressure of the water, are responsible for the greater cardiac response in this type of exercise. A large heart will be capable of handling most increased venous return caused by vigorous exercise without appreciable increase in heart rate, and therefore by increasing the rate of beat of such a heart during violent exercise such as strong swimming it maintains a constant high output adequate to handle the corresponding increased venous return, and so increase the total circulation with more blood being delivered to the capillaries to supply oxygen to the muscles for sustained effort.

In conditioning a horse as shown in FIG. 1, the animal is placed on a platform 11 elevated above a confined body of water indicated at 12 and restrained from lateral, forward and rearward movements of the platform. This restraint is applied to the upper part of the body as by straps well above the legs, or by connecting the tail to a stable bar behind the horse, so that there is no mechanical interference with normal leg movement or shoulder and upper rear leg muscles or respiratory action during swimming.

FIG. 1 diagrammatically illustrates the cycle of swimming exercise under the invention. Position a in FIG. 1 indicates the start of the exercise period. This position may be above water level to enter the horse directly onto the platform.

The platform, with the animal thereon, is lowered gradually into or in the water until at the position indicated at 11' submersion is such that the animal must swim to remain afloat. Swimming tends to propel the animal forwardly, but this movement is prevented by the front restraint so that effectively the animal remains longitudinally substantially in the same place while the legs move through the water.

While the animal is swimming its heart is closely monitored. The effort of swimming will cause the heart rate to rise, in proportion to the energy being exerted, and a sustained high heart rate above a certain safe value, which value will be indicated for that animal by the foregoing physiological analyses and electrocardiograms, will result in harmful fatigue rather than beneficial conditioning.

The heart action is constantly measured during the exercise cycle by a special combination of novel body attached electrodes shown at 13 and 14 and an electrical instrument 15 capable of detecting and measurably indicating the very small generated voltages incident to heart action, in the neighborhood of 1 to 3 millivolts, such as an electrocardiograph which may be also serve as a heart rate meter. Alternatively a separate heart rate meter may be connected to the leads as part of instrument 15. As will be described, the electrodes are special suction cups attached as by lines 16, 17 to an external source of vacuum 18.

It is absolutely essential that there be no extraneous electrical signals to vary or mask the potentials generated by heart muscle action which operate the electrocardiograph. Therefore the electrodes 13 and 14 are preferably attached to the horse's body at the illustrated points in FIG. 2 where adjacent muscular activity is minimum notably near the top of the front shoulder and at the underside of the body near the front leg. It is further essential that the electrodes make good unvarying contact with the horse's body, and that is the function of the external vacuum which in exercises to date indicate that a vacuum of about 25 inches of mercury is satisfactory to anchor the electrodes to the body so as to prevent any static generating movement thereof relative to the body even when the horse is swimming vigorously.

As shown in FIG. 5 each vacuum line 16 (or 17) is a vinyl or like nonconducting plastic tube 21 fitted upon a stainless steel collar 22 welded airtight into an aperture in a shallow noncollapsible stainless steel cup 23. The end of a stainless steel wire 24 is welded at 25 to collar 22, and the wires 24 emerge from the tubes 21 in an insulating sheath 20 for connection to meter assembly 15, so that the wires 24 are electrically insulated from each other between their respective electrodes and the meter assembly. Preferably the tubes 21 of lines 16 and 17 are joined to a single tube 26 leading to vacuum source 18, so that the vacuum is connected to simultaneously act on the electrodes.

The importance of the external suction lies in its ability to exert sufficient force to properly anchor electrodes 13 and 14. Suction bulbs have been proposed for electrodes in human electrocardiography, but such would not be adequate for attachment to vigorously exercising horses. We know of no instance where electrocardiographs have been taken of vigorously exercising humans during exercise, so that the problems solved by this phase of the invention have never been presented or recognized.

In actual practice it was discovered that the presence of chlorine and like substances in the water containing the swimming horse resulted in sufficient electrolytic action at electrodes containing junctures of dissimilar metals to produce misleading signals in the meter leads. Hence care is taken in the invention to eliminate this difficulty, and a current solution is to use the same metal along the entire conductive path between the horse's body and the meter 15. In practice the suction cups 23 and collars 22 are formed of 316 stainless steel about 0.035 inch thick, and wires 24 are 316 stainless steel. Welding is done with a 316 stainless steel welding rod. Therefore the conductive metal composition is uniform along its entire length, and no electrolytic effects are present.

Referring to FIG. 5, it will be noted that application of vacuum to tube 21 results in the skin 27 of the horse being pulled into closed conformity with the interior of the cup 23, with the sharp annular edge 26' of the cup indenting (but not cutting) the skin. This provides a good locking attachment which does not change position or become detached when the horse is swimming. We believe that such strong attachment of the electrodes and selection of regions of the horse's body which undergo little movement when the horse is exercising mutually contribute to the clarity with which the heart action signals are received on the electrocardiograph and the heart rate meter during exercise.

A weight-indicating system 28 including a scale dial 29 measures the horse's weight when the platform is free of the water, as shown in FIG. 1.

The measuring system including attachment of electrodes 13 and 14 is placed usually when the horse enters to position a in FIG. 1 and is in normal equilibrium. Then his heart action is measured, and he is lowered to swimming position b during which the electrodes remain attached.

In position b, monitoring of the heart action continues. As soon as the measured heart rate reaches the upper limit range (200--225 beats/minute) the platform is raised toward position 11 until the horse can find footing, is no longer swimming, is standing on the platform as shown at a' in FIG. 1 and is breathing easier as above explained. Now the recovery interval starts and during this interval constant monitoring of the heart action continues and the horse's rate of recovery is noted.

When the lowering heart rate reaches a predetermined range, usually below 140 beats/minute, or when the P-T line becomes discernible on an electrocardiogram, the platform is again lowered as at b' in FIG. 1 until the animal is forced to resume his swimming. The duration of the recovery interval is noted.

The foregoing is repeated several times, the animal being thus violently exercised by swimming for successive periods at high heart beat levels and allowed to partially recover between periods of exercise. Inversion of the T-wave from negative in FIG. 3 to positive in FIG. 4 indicates that the animal is in condition.

During conditioning, the horse is given this swimming exercise cycle on the average of about once a day and he is weighed each day about the same time. As training progresses and the horse becomes conditioned it will be noted that the exercise period in cycle time gradually increases and the recovery interval decreases which is an indication that endurance is increasing. Each exercise period lasts a reasonable time, usually about 3--10 minutes depending on the horse and his current condition. The conditioning period may last up to about 3 to 6 weeks, but this may vary for individuals.

The foregoing described conditioning is safe and humane, and it unexpectedly improves a horse's endurance capabilities. Constant monitoring of the heart action insures that the horse never reaches the fatigue point between recovery intervals. Continual monitoring of recovery is equally important. The quicker the horse's heart rate drops from 200--225 to 100--140 beats per minute during a recovery interval between swimming periods the better the horse's condition. The quicker the horse's heart rate recovers to the equilibrium normal following the exercise of a conditioning cycle, whether the exercise be swimming or running, the better the horse's condition.

Claims

The embodiments of the invention in which we claim an exclusive property or privilege are defined as follows:

1. A measuring system for continually monitoring an animal taking violent exercise comprising a plurality of rigid noncollapsible metal suction cup electrodes for direct attachment to spaced selected areas of the animal's skin for determining potentials arising from heart action, means providing an apertured hollow fitting on each electrode, a flexible tube of electrically insulating material connected between each fitting and adapted to be connected to an external source of vacuum, and a flexible metal electrical conductor attached at one end within each of said electrodes and extending away from the electrode within the associated one of said tubes, whereby each electrode is operable in a hostile, aqueous environment, a heart action meter, and electrically insulated means remote from the electrodes conveying the other ends of all of said conductors from said tubes into operative connection with said heart action meter, and means defining a downwardly projecting sharp annular edge about the lower periphery of each suction cup whereby each suction cup is firmly engaged with the skin of the animal without cutting the skin.

2. In the system defined in claim 1, said conductors suction cup and fittings all being composed of the same metal.

3. In the system defined in claim 2, said metal being stainless steel.

4. In the system defined in claim 1, said meter being an electrocardiograph.

5. In the system defined in claim 4, said meter including a heart rate meter.

6. In the system defined in claim 1, each suction cup having a substantially uninterrupted interior skin contact portion for maximum surface contact of each suction cup with the skin of the animal being monitored.