The idea of Professor Alexander Kölpin from the Hamburg University of Technology is impressively simple: If you can use radar to locate ships, calculate flight altitudes and flash speeders on the autobahn, then this contactless technology can certainly also be used in medicine: Wireless sensors have great potential to make medical examinations more convenient, safer and more efficient, “says Köplin.
The idea of using radar to locate buried people through their breathing and heartbeat is not entirely new, but Kölpin and his research team are the first in Europe to develop radar systems for medical use and already have clinical patient tests.
At the Institute for High Frequency Technology, the team has developed highly sensitive sensor systems for the medical monitoring of patients. With the new radar technology, both heartbeat and breathing can be continuously and contact-free analyzed.
Determine body values wirelessly
With the classic EKG, the heartbeat is determined using electrodes and cables that connect the patient to the measuring devices. With radar technology, on the other hand, monitoring is non-contact and from a distance.
A small box measures the heartbeat and breathing – unlike this test – contactlessly under the bed.
The radar sensor developed by Kölpin can record heart and respiratory values through clothing, duvets and even mattresses and transmit them to the monitoring devices. “Our sensors emit electromagnetic waves that are reflected by the body. In the implementation it works something like this: The blood expelled by the heart runs along the vessels in the form of a pulse wave, which appears as a vibration on the body surface. We can do this with the help of the sensors measure and determine many medical aspects of the cardiovascular system from them. “
Highly sensitive measurement of the pulse rate
The inconspicuous little box hangs under the bed. When the heart pumps blood through the veins, the surface of the skin rises minimally, so we can also measure the pulse rate with our bare fingers, for example on the wrist.
With the help of sensors, both breathing and heartbeat can be measured.
The new radar device can analyze this minimal elevation of the skin surface by measuring the distance. The sensors are so precise that the heart rate, the cardiac load and the pulse wave speed, with which one can determine a hardening of the arteries and thus the risk of stroke, can be measured exactly.
If the heart is no longer beating regularly or there are rhythm disturbances, the new device sounds the alarm. In this way, life-saving measures can be initiated much earlier.
Identify epilepsy in newborns
For the time being, the research project focuses on the medical observation of premature and newborn babies. “Our main focus is on epileptic seizures. It is believed that undetected epilepsy is responsible for up to 20 percent of all sudden infant deaths. The problem with this is that these seizures are often undiagnosed in young children because they are not yet showing motor cramps. ”
In contrast to the ECG, the small patients can be observed without contact
Thanks to the contactless measurement with the sensors, the children are monitored continuously and without restrictions. A seizure can thus be noticed and treated early enough.
Can also be used with COVID-19 patients
It makes sense to use the technology in the current corona pandemic, says Kölpin. “In connection with the cardiovascular and respiratory activity measured by us, the temperature can be determined without contact and thus important parameters for assessing the state of health in connection with a possible corona infection can be checked,” says Kölpin.
Infected people can be examined without contact, which also reduces the risk of infection for medical staff.
Even death can be predicted four days
So far, the newly developed heart radar has only been used in the Palliative Care Unit at the Erlangen Women’s Clinic. Anyone lying here is terminally ill and will soon die. When the time comes, the new heart radar can determine about four days before death. In this way, patients and relatives know when the time has come to say goodbye to each other.
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The heart – a beating marvel
Marvel of nature
The heart is a marvel of nature: the fist-shaped hollow muscle contracts around seventy times a minute and pumps up to 10,000 liters through the body every day. And that for a lifetime. When necessary – when jogging, for example – the heart transports five times as much blood through the body.
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The heart – a beating marvel
Double work
Our heart actually consists of two pumps. Because there is not just one blood circulation, but two. The right ventricle pumps blood to the lungs, where it is refueled with oxygen. At the same time, the left ventricle transports the same amount of blood into the body’s circulation. Not easy. Because there is much higher pressure in the body’s circulation than in the pulmonary circulation.
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The heart – a beating marvel
Bumm, Bumm
Each half of the heart consists of an atrium and a heart chamber. The blood can only flow in one direction, as heart valves (green) that work like check valves are located between the atria and the chambers and between the chambers and the adjoining vessels.
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The heart – a beating marvel
Real muscle work
The heart is just a muscle – but a very special one. It is similar to those on the arm and leg, because it can contract just as quickly and powerfully. But he is particularly persistent and does not tire. In addition, all heart muscle cells are coupled to one another so that the entire heart muscle always contracts at the same time.
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The heart – a beating marvel
Natural pacemaker
Try using willpower to keep your heart beating! This does not work because the heart is not controlled by nerves, but has its own clock generator: Special muscle cells in the sinus node regularly generate a small current that spreads over the whole heart at lightning speed and makes it contract. If the sinus node is defective, the AV node takes over.
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The heart – a beating marvel
Out of step
If the heart gets out of rhythm, for example with ventricular fibrillation, it no longer relaxes, but remains constantly tense. Then the organ can no longer pump blood. A shock generator, the defibrillator, interrupts the life-threatening constant excitation in the heart so that the natural clock can take over again. Even a layperson can use the device.
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The heart – a beating marvel
Rescuer
If a patient’s heart beats too slowly, an artificial pacemaker can help. The device generates electrical impulses and transmits them to the heart muscle. Doctors first implanted a pacemaker in 1958. A modern cardiac pacemaker lasts between five and twelve years, with an average of eight years.
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The heart – a beating marvel
With an open heart
In order to be able to operate on the heart, doctors have to stop it briefly and shut down the circulation – actually a death sentence. But in the 1950s, scientists solved the dilemma: They developed the heart-lung machine. The device takes over the function of the heart and lungs for a short time, enriches the blood with oxygen and pumps it through the body.
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The heart – a beating marvel
Through the groin into the heart
Modern medicine allows the heart to be examined or operated on without cutting open the patient’s chest. To do this, the doctor inserts a heart catheter – a thin plastic tube, so to speak – through the groin, the crook of the elbow or the wrist and pushes the tube over veins or arteries to the heart. The patient is only anesthetized locally beforehand.
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The heart – a beating marvel
Foldable heart valve
If one of the heart valves is broken or worn out, a new one is needed. Doctors use either organic pig replacements or mechanical metal heart valves. There are now also artificial heart valves that can be folded up (see photo) and can therefore be inserted using a catheter in a minimally invasive manner. Open heart surgery is then no longer necessary.
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The heart – a beating marvel
Clogged vessels
The coronary vessels supply the heart muscle with blood, i.e. nutrients and oxygen. If one of these vessels clogs, the tissue no longer supplied with blood dies – heart attack! The cardiac surgeon bridges the narrowed area with a bypass (green in the picture). To do this, he takes a vein from the patient that is no longer needed or a vascular prosthesis made of plastic.
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The heart – a beating marvel
Metal lifeguards
If a coronary artery is narrowed, the doctor can insert a catheter into the blood vessel and expand the constriction with a balloon. To prevent the vessel from contracting again afterwards, it is held open with a stent: These are fine metal sleeves that support the blood vessel wall from the inside. The tubes can also be coated with medication.
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The heart – a beating marvel
When your own heart doesn’t want anymore
The first heart transplant was performed by cardiac surgeons in 1967. A sensation back then. In the meantime, the operation is no longer uncommon: every year, doctors transplant several thousand donor hearts from deceased people worldwide. The recipients, however, have to take medication for a lifetime that prevents their own body from rejecting the foreign organ.
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The heart – a beating marvel
Life on credit
Donor hearts are rare. If your own heart is no longer working properly, for example in the event of an insufficiency, it can be supported with an artificial heart. Your own, sick heart stays in the body, supported by an implanted pump. The drive and energy supply for the pump are outside the body.
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The heart – a beating marvel
An artificial heart
The researchers dream is an artificial heart, which completely replaces the patient’s sick heart. It should be able to be inserted into the body without connecting hoses to the outside world and be maintenance-free for many years. There are already prototypes.
Author: Brigitte Osterath
