Maybe one day in the future, people will be able to forget the uncertainty of batteries for their pacemakers. Researchers at the University of Michigan have found a way to power cardiac pacemakers from heartbeat vibrations.
The device gathers energy from the vibrations and transforms it to electricity. The electrical signals are then transmitted to the heart to keep it beating in a healthy rhythm and to power an implanted defibrillator or pacemaker.
Currently, the only way to replace batteries, which last five to 10 years, is through surgery.
Writing in the current edition of Applied Physics Letters, Amin Karami, a research follow in Michigan’s department of aerospace engineering, said the idea is to “use ambient vibrations that are typically wasted and convert them to electrical energy. If you put your hand on top of your heart, you can feel these vibrations all over your torso.”
Although the researchers have not yet built a prototype, they have created detailed blueprints and conducted simulations showing that the idea would work. According to the researchers, heartbeat vibrations would essentially be caught by a thin (hundredth-of-an-inch) slice of a special “piezoelectric” ceramic material. In response to being caught, the vibrations would briefly expand. Mechanical stress causes piezoelectric materials to expand, which creates an electrical voltage.
According to Karami, these mini-medical devices could produce 10 microwatts of power, about eight times the amount needed to operate a pacemaker. The researchers highlight that the device always produces more energy than the pacemaker needs, and performs well below and above the normal heart rate range.
This may come as no surprise but a new study has shown that expectant parents would rather have everything possible done to prolong a pregnancy or “save the baby” via interventions, such as caesarean sections.
A study published in the March issue of the American Journal of Obstetrics and Gynecology, said those patient preferences are a major factor in directing obstetric decision-making and counselling for periviable deliveries: early preterm birth between 22 and 26 weeks gestation.
Researchers at University of Pennsylvania found that nearly 50 per cent of periviable babies do not survive, and half of those who do survive suffer moderate to severe neurologic disability. Neonatal outcomes can be influenced by how these cases are obstetrically managed.
Earlier studies revealed that neonates’ chances of survival increased by 3.7 times by obstetricians’ willingness to perform a caesarean section at 24 weeks, although chance of survival with serious morbidity increased two-fold.
In this latest study, 21 obstetricians were asked to describe their usual approach to managing periviable delivery; personal, patient and institutional factors that influence their decision-making; and their approach to counseling patients, and what challenges they encounter in doing so.
The researchers discovered that, even though obstetricians were confined by institutional norms, perspectives on patient autonomy, patient preference and clinical presentation strongly influence their decision making and counselling for periviable deliveries.
Participants of the study reported a significant amount of variation in practice. Furthermore, the researchers found that there were no formal policies to dictate practice standards for periviable care in the majority of institutions.
While most participants said their “first consideration was balancing maternal and child well-being, and the need to weight the questionable benefits of caesarean delivery for neonatal survival against the known risks of maternal morbidity, many described a ‘do everything default,’ wherein interventions to prolong the pregnancy were universally pursued unless patients actively opted out,” wrote lead researcher Brownsyne Tucker Edmonds.
Obstetricians’ approach to decision-making and counselling was strongly influenced by how they perceived patient autonomy. Some participants believed it was their job to provide information instead of direction. Other participants made recommendations to guide care, stating that patients are often unable to make decision regarding their care due to the complexity and emotionality of the situation.
There is no difference in the risk of developing heart disease between living kidney donors and the healthy general population, a new study suggests.
The study published on bmj.com says there is a strong association between an increased risk of heart disease and reduced kidney function in the general population. Because kidney donors lose half of their kidney mass, it’s important for doctors to determine whether this risk extends to them.
Previous investigations indicated no increase in risk, but a consensus has not yet been achieved. So Canadian, American and Australian researchers conducted a study to see whether kidney donors have an increased risk of developing heart disease.
The study compared 2,028 individuals in Ontario who donated a kidney between 1992 and 2009, with 20,280 healthy non-donors.
Even though kidney donors had reduced kidney function, results from the study showed that donors had a lower risk of death or first major cardiovascular event (2.8 per 1,000 person years), than non-donors (4.1 per 1,000 person years).
As well, no considerable difference was found between donors and non-donors in the risk of major cardiovascular events (1.7 compared with 2 events per 1,000 person years).
