Read about the latest news on ECG / EKG Machines

It is a common misconception that the EKG machine “measures” the patient’s heartbeat. It does not. It detects and records the electrical activity of the nerves of the heart. It is of note that these nerve bundles do not contract themselves. Rather, they set the tone of the contractions and guide the action of the heart. This makes the electrical action of the heart very diagnostic and has made the EKG the essential tool that it is today.

Initially, the EKG machine picks up the signal from the sino-atrial or SA node. This translates into the P wave of the EKG. It goes from the right atrium to the left, causing that part of the heart muscle to contract.

It is notable that the SA node is connected to its counterpart in the ventricles by only one path, and once the signal is in the atrio-ventricular node two important things happen. There is a delay before the AV node sends the signal on to the next part of the heart. This allows the atria to completely empty. Simultaneous contractions would cause either incomplete filling or back flow from the ventricle to the atrium. This delay is seen in the PR segment of the EKG.

The other thing that occurs in the AV node is the further propagation of the signal. This propagation goes into nerve structure called the purkinje fibers. They stimulate the entirety of the ventricles and are seen on an EKG in the QRS section.

The last part of the EKG is called the T wave. This is the part of the cycle that allows the electrical system of the ventricles to repolarize, starting the process over again. The diagnostic value of the EKG is not just in the shape of these waves, but in the length of the sections. Changes in the QRS section can be directly related to changes in the purkinje fibers, which are located in the lower part of the heart, for example.

It is a fact that changes in these electrical impulses are directly parallel to the changes in the heart muscle itself. Sampling the heart itself is not only impractical but could be dangerous in the middle of a cardiac episode, so EKG machines remain an essential diagnostic tool.

For the layman, an EKG is a series of repeated blips. Interpretation is limited to many beeps = good. No beeps = bad. Fortunately, the clinician can glean a great deal more information from those series of beeps and lines on a chart.

One of the breakthroughs of Einthoven (whom we discussed earlier for his Nobel prize win for EKG machine technology) is that he assigned the letters P, Q, R, S and T to the various deflections of the EKG tracing. It is the T wave, the last part of the cycle, that has great diagnostic value. And according to a new study released in the February 24, 2009 online edition of the Journal of the American College of Cardiology (J Am Coll Cardiol, 2009; 53:774-778,) changes in the T wave may have even greater predictive value in the future. This study is receiving a lot of coverage because with heart disease a major cause of death in the U.S., there is always a need for a better way to diagnose the problem.

First a bit of background: the T wave represents the re-polarization of the ventricles, the part of the heart that sends the blood into the lungs (right ventricle) or out to the body (left ventricle). This re-polarization is vital so that the heart can “reset” and get ready for the wave of stimulation to begin again for the next heartbeat.

What is very important is a T wave phenomenon called the T wave alternans or TWA. This is a periodic variation from beat to beat in the amplitude of the T wave. If too many TWAs are detected, the patient is at greater risk for developing a potentially lethal cardiac arrhythmia and sudden death. Patients with increased TWAs become good candidates for pacemakers.

The study referenced above, led by Dr. Rachel Lampert, MD, FACC, showed that when an anger inducing stimulus was presented to test subjects, they exhibited TWAs. This parallels the induction of TWAs by exercise in other studies. Her team also showed an 11 fold increase in the need to implant pacemakers in patients who showed anger-induced TWAs.

While this could ultimately lead to a new way to predict future arrhythmias in patients, Dr. Lampert had only 62 subjects in this study. She cautions that the study data should be considered preliminary and should only be used to generate hypotheses. Still it will be interesting to see if this adds a new dimension to the diagnostic utility of the ubiquitous EKG machine.

Did you ever notice that there seem to be almost two EKGs? There is the constant beeping that becomes an eerie whine when the patient heart stops beating. And then there is the report format that can be charted, argued over, and with dramatic pause, becomes the exciting conclusion of the latest medical drama.

Both of these are based on real medical science. As the signals come in from the leads on a patient, they pass through filters as the signals are processed. A low frequency filter is set at the low end of the hertz scale. Hertz is the number of waves a signal has. While this scale can measure sound waves, here is used for measurement of electric waves. Alternatively, the high frequency filter is set at the high end of the scale.

To further complicate a simple discussion of the subject, the low frequency filter is called the high pass filter; this means that only signals above a certain setting are allowed to pass on through to the computer. The high frequency filter is called the low pass filter; this means that only signals below a certain setting are allowed to pass on through to the computer. For the purpose of this article, they will be called low frequency and high frequency filters.

How these filters are set determines the two most common settings of an EKG machine. The monitor mode has the low frequency filter set at either 0.5 hertz or 1 hertz. The high frequency filter is set at 40 hertz. These settings not only decrease the detail of the parts of the heart beat, but also decrease the extraneous noise that comes across the electric leads and the circuits within the machine itself. For a cycle of continuous monitoring, this is more than acceptable.

On the other hand, the diagnostic mode has the low frequency filter set even lower (0.05 hertz,) allowing more detail to be recorded, especially in the ST segment of the heart stimulatory cycle. The high frequency filter is set at 40, or 100 or even higher to catch greater variations in the signals of the heart across the range of the signals.

This means that the monitoring mode display is more filtered than the diagnostic mode. A higher level of interference is the price to be paid for the greater detail. Remember, an EKG is a tool. It is the interpretation of the results that is key to the value of the test.

In 1924, the Nobel Prize in medicine was given to Willem Einthoven for his work on the EKG machine. But he, as many in science, built on the works of those who came before him. Einthoven won the award in 1924, but the Nobel committee did its usual speedy job and saluted work done in 1901. Einthoven’s innovation was built on the movement of a thread of crystal stretched between two electromagnets. This gave new sensitivity to the test, making it much more useful as a diagnostic tool.

Einthoven technology was built on a device called a Lippmann capillary electrometer. It had a column of mercury suspended beneath a strong acid solution. Electrodes were then attached to the mercury end and the acid end of the column. The column of mercury would move in direct relation to the amount of electricity passing through the mercury/acid column.

This detector had been in existence since the 1850’s, but it had little use in medicine, and was a curiosity at best. The very first real time EKG was done by August Waller. In 1887, Dr. Waller took an Lippmann capillary electrometer, and combined it with a new technology: photographic film. He passed a beam of light across the column of mercury in the Lippmann capillary electrometer. The light then hit a moving photographic plate. When the tiny electrical charges made the mercury column move up and down, it alternatively blocked and exposing a track on the moving plate. Thus the first recognizable EKG tracing was produced when this machine was attached to a patient.

Dr. Waller is rightly credited with the first EKG machine, but as late as 1911, he saw little practical use for it. It was the innovation of Dr. Einthoven that made the machine sensitive enough to be diagnostic. And it is Dr. Einthoven that took the new technology farther, defining the data his machine produced with terms that are still in use today.

As the medical sciences advance beyond anyone’s imagination, everybody is keen to know about their health parameters. Almost all companies need a detailed health examination done before recruiting candidates. Yes, health is wealth and nothing can be compared to the happiness that health gives us. It is therefore absolutely necessary that doctors advise apt and necessary investigations to the patients on regular basis especially after they cross forty years of age.

Among the different medical equipment available, EKG machines and ultrasound machines are seen to conquer the medical equipment market. These two equipment are absolutely necessary to investigate different aspects in an individual. Therefore, it is the duty of hospital administrators and doctors to keep both these equipment in condition. If something goes wrong, they have to get it corrected immediately. Otherwise patients suffer and in some cases even emergency diagnosis can be left out, which is not good At all.

This is the reason why many hospitals these days have more than one machine and like to purchase either new or reconditioned machines as per their convenience. Many online shops are helpful in this regard. It is always better to opt for online purchase because you get far more varieties to see and compare. Also if you are tight on your budget, you can opt for reconditioned portable ultrasound machines and used medical equipment that are available at much more affordable rates than those in virtual shops.

Basically these online shoppers need not invest in the place and interiors of their shops. They share their savings with you and give you good discounts on almost all medical equipment purchases. You just have to be keen on the required features in your machines and on services offered by the provider such as the training and online support.

Once you land on a good deal, these machines will certainly take the first place of hierarchy in your hospital putting into consideration the durability of good purchases that will not also deceive you during emergency diagnoses.

An electrocardiogram is one of the basic diagnostic tools for cardiologists and general physicians. It is the machine used for one of the routinely performed investigations in almost all hospitals, and physicians well know how desperate they become when the EKG machine doesn’t work properly. Yes, the ECG taken can be one of the most valuable tools to diagnose impending heart attacks, tachycardia, arrhythmia’s, etc. After an initial study is gained on the patients’ health through ECG or EKG, the physician then advises further tests or investigations.

It is no wonder then that EKG machines have to be in great shape at all times. Many physicians therefore like to purchase EKG machines only from reputable companies so that they can be assured of the durability, they also seek to take advantage of the many attractive sales offers and good after sales service options. Let’s see some of the top-selling EKG machines:

1) Cardioline Inc: this is one of the oldest manufacturers of medical equipment and the brand is no doubt trustworthy. Along with EKG machines, Cardioline Inc also manufactures stress testing systems, defibrillators, holter monitoring systems, and related accessories.

2) Burdick: This is also one of the oldest companies supplying EKG machines to many US hospitals. The brand has set definite standards for building EKG machines and related medical equipment. Many other cardio-pulmonary diagnostic test tools are designed by the company.

3) Philips Medical Systems: being one of the strong competitors in medical equipment manufacturing, Philips offers wide range of options. Philips is synonymous with fast, efficient, and accurate diagnostic tools. The standard and best medical equipment have been manufactured by Philips. Their product range includes: Xray machines, ultrasound machines, CT scan machines, monitoring equipment, radiation oncology systems, resuscitation products, and EKG machines.

Thus, if you are interested in brand new models of EKG machines or any other medical equipment, you should opt for good companies to give you the best deals. If you are tight on budget, look out for re-modeled second-hand machines that are well maintained.

Today we almost take EKG machines for granted. Place a few leads on the body, flip a few switches, and out pops red graph paper with a series of black squiggly tracings that can show us what is happening with the heart. But this essential piece of medical technology has existed as we know it for less than a century. In 1924, “…for discovery of the mechanism of the electrocardiogram,” Dutch scientist Willem Einthoven received the Nobel prize in Physiology or Medicine.

We know that electrical impulses cause the heart muscle to contract in a wave of chain reactions, pumping blood to the lungs and the rest of the body. Those electrical impulses originate in cells known as pacemaker cells. The amount of electricity produced is very small, measured in millivolts. One of the challenges Einthoven faced was measuring electricity in this small amount, and from the outside of the body. As the electric wave travels through bone and the tissues of the body, it grows weaker.

Early experiments using frogs were able to measure the electrical activity of the heart only by placing the measuring equipment directly on the heart. Obviously, researchers did not want to have to go inside the human body to conduct such measurements. Einthoven used a string galvanometer to improve the sensitivity of the EKG, mostly to avoid complex mathematical calculations. He published his first detailed description of his instrument in 1909. His original research is still the fundamental basis of electrocardiography and we still use his terminology today. And although the string galvanometer has been supplanted by EKG machines using amplification techniques, EKGs using the string galvanometer remained the standard of references even to recent times.

Born in 1860 in Semarang, Einthoven was the son of an army medical doctor, and entered the University of Utrecth in Holland in 1878 hoping to follow in his father’s footsteps. In 1908 his interests turned toward electrocardiology.

In his Nobel speech, Einthoven wrote, “A new chapter has been opened in the study of heart diseases, not by the work of a single investigator, but by that of many talented men, who have not been influenced in their work by political boundaries and, distributed over the whole surface of the earth, have devoted their powers to an ideal purpose, the advance of knowledge by which, finally, suffering mankind is helped.”

When you next use an EKG machine, think for a moment of Einthoven, and the scientists who made this amazing piece of technology possible.

Because heart disease is so prevalent, an EKG machine is an essential piece of equipment for the medical practitioner. The EKG, or electrocardiogram, machine measures the electrical activity of the heart. Electrical impulses cause the heart muscles to contract, which causes the heart to beat. Pacemakers supply the electrical impulses when your body cannot do it for you naturally.

If you need to choose an EKG machine, here are some features you should evaluate.

What kind of paper does the machine use? The classic EKG result is a printed strip, but some machines use standard 8.5” x 11” pieces of paper. Standard paper may be less expensive and is easier to store in a patient’s chart.

Can you enter demographic data? Some EKG machines have keyboards that allow you to enter the patient’s name on the report. While that gives a more professional result and makes it easier to make sure the report gets and stays with the right chart, it takes time to key in that personal information. If you may need your machine for emergency use, make sure you can bypass entering that personal data.

Does the machine have a screen so you can see the results before they’re printed? If not, you’ll have to print results to verify that all leads are properly placed. Ideally your screen will show all leads on the screen at once, and give real time results.

What kind of computer integration does the EKG machine provide? Ideally you want to be able to download results into any system you already own including electronic medical records. A machine that only works with proprietary software may not communicate as well, and may be more expensive. You also want to be able to evaluate your EKG findings in concert with other diagnostic tests such as stress testing and Holter monitoring.

If you are running a hospital, you know how essential well-conditioned EKG machine is. Whether used in an emergency to diagnose a serious heart problem, or used as a regular investigation tool, the importance of EKG machines cannot be overstated. Moreover, many physicians today like to purchase more than one EKG machine for their hospital to make it easier to use them for different purposes. No wonder the medical equipment market is studded with a wide variety of EKG machines to suit your needs.

Today mostphysicians opt for portable and FAA approved models of EKG machines. These machines are easy to handle in different situations and are very reliable. Cart-mounted EKG machines are also popular.

Numerous online shops offer huge discounts too on new or used models. Be cautious and avoid hasty deals, lest you fall prey to costly yet featureless equipment.

 In an EKG machine, you should consider:

• Paper width and the length of the strip the machine prints
• Availability of a keyboard for entering patient demographics
• Ability to connect to your computer
• Availability of screen
• Ability to connect to electronic medical records
• Integration with other diagnostic features including holter monitoring, stress test, vital monitoring, spirometry, etc.

When you purchase online, your service provider should offer you training as well as instructional material for your newly purchased machine. Ensure that the manufacturer will handle the warranty and any service problems. Many manufacturers offer good discounts if you purchase a previously used machine. Many will also give guaranteed conditioning and maintenance of the machines if you request it.

Burdick, Schiller, GE Marquette, Phillips, Nihon, and Bionet are some of the popular brands of EKG machines in the market today. Do a careful comparative study regarding the features and price ranges of these machines. After a thorough analysis and consulting with the manufacturer, you can purchase these life-saving machines for your hospital and feel confident in your choice.