Heart failure home-monitoring via web-enabled bathroom scales
One evening suddenly started to realize I
was having trouble breathing, but it got worse and worse to where I couldn’t even go from
the chair I was sitting in to the bathroom without – I mean, I had to go so slow, and
then I would just collapse and I could hardly get back up.
There are almost 6 million Americans living with heart failure today, and heart failure
is the condition in which the heart isn’t really failing, it’s just not pumping blood
as efficiently as it should, and sometimes that means it’s not meeting the demands of
the body. So, on of the main functions of the heart is to propel blood forward, taking
blood from the lungs, sending it on towards the body. So, if it’s not doing that well
enough you start to have fluid back up into the lungs and that fluid gives people symptoms.
They get really short of breath, especially when they lie down. And if the fluid is backing
up into the rest of the body it can cause swelling in the legs and weight gain. The
goal for patients who have heart failure is to keep them feeling well, keep their heart
functioning well, and keep them at home and out of the hospital. So, primary care doctors
and cardiologists who manage patients with heart failure use an array of medications
to make this possible. Unfortunately, the only tools that we have right now to see how
well the medications are working and how well the patient’s heart is doing, or asking the
patients about their symptoms and asking them to weigh themselves everyday so they can see
if they start to put on fluid weight. I weigh myself daily, I take my blood pressure
daily, and those things are just so if there are big changes, big increases, for example,
in my weight that’s a very likely indication that I’m retaining water and fluid, and that’s
an indication that my heart isn’t functioning the way it should be.
Unfortunately, sometimes these signs come too late and by the time a patient notices
symptoms or has started to put on weight they are already past the point where an additional
dose of medication is gonna help and they end up coming into the hospital. But there
has to be a better way, because if you think about it physiologically, the heart function
has already started to decline well in advance of these symptoms developing. So, there’s
this pre-symptomatic window when the heart function has decreased but fluid hasn’t backed
up enough to the point where the patient’s feeling any symptoms.
We wanted to create a device that could monitor patients during this pre-symptomatic window,
hopefully detecting a decline in heart function before the patients feel any symptoms. It
turns out that every time your heart beats, your weight actually changes just a little
bit. This weight change can be detected by modifying an ordinary bathroom scale. Over
the last few years at Stanford we’ve recorded data from this modified bathroom scale on
many subjects, mainly athletes and healthy volunteers, and have shown that this slight
weight change that occurs with every heartbeat is actually proportional to cardiac output,
or the amount of blood that your heart is pumping with every beat. To use the device,
you simply stand on a bathroom scale like you normally would. Some bathroom scales have
handlebars for measuring body fat. We’ve repurposed these to measure the electrocardiogram, but
this is an optional measurement. After standing on the scale, the scale collects the data
and sends it over Bluetooth to a Cloud server where it can be viewed simply by opening a
web browser. : If I had some way to know on a regular basis,
I mean, daily would be wonderful, wonderful, but on a regular basis how my heart was doing
would be a tremendous relief. So, based on the success of the preliminary
data collected with this device, we’re now designing a clinical trial using heart failure
patients. We’ll be enrolling them as they come into the hospital with a heart failure
exacerbation and tracking as their heart function improves over the course of their stay, and
then sending the device home with them to continue monitoring their heart function remotely
once they’re back in their home. After this Phase 1 trial, we’ll then have enough data
to justify a large clinical trial to see if our device can actually make an improvement
in heart failure care. I’m Mozziyar Etemadi. I’m a fourth year M.B.P.C.
student here at U.C.S.F. I’ve always been an engineer at heart. I’ve been working on
this project as an electrical engineering student for the past five years and I’m just
so excited now, as a medical student, to see this technology finally make it to the clinic.
This is, in fact, what I really hope to do with the rest of my career is create innovations
at the interface between medicine and engineering and see them through to clinical practice.