Shows like HBO’s “Westworld” and the “Blade Runner” films depict a dystopian future where humankind and machine have merged, blurring the line between people and robots. As a cardiologist, I find myself face to face with both the promise and the peril of such a marriage — a reality for me and my patients rather than a distant hypothetical.

Tens of thousands of Americans today have mechanical pumps keeping them alive , offering the first serious glimpse of what the union of human and machine will look like. Left ventricular assist devices (LVADs) are sutured right into the hearts of patients with severe heart failure, mechanizing them to keep blood circulating throughout the body. While they don’t quite turn into cyborgs, most patients with LVADs don’t have a pulse, and if you put a stethoscope to their chest, instead of hearing the galloping of their heart, you would hear the hum of the pump.

As we move into the post-evolutionary phase of our species, for this union to be a boon to humankind rather than the bane of our existence, we need to ensure that ethical discourse and regulatory oversight keep up.

We have sought to restore our bodies with things like artificial hips to replace arthritic joints or contact lenses to sharpen blurry vision, but never before have we given a home inside our body to technology that fundamentally changes the human experience. LVADs are pushing bodies into places unforeseen: They can survive even if their hearts stop beating, something previously unimaginable. The devices are also teaching us what happens when blood flows continuously through the body rather than in pulses with every beat of the heart.