Fighting Illness From 'The Edge Of Medicine' What if you could diagnose cancer just by smelling it? Dr. William Hanson explains the 'Diag-Nose' — an electronic nose that can do just that — plus other medical technologies that he says will change our lives.
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Fighting Illness From 'The Edge Of Medicine'

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Fighting Illness From 'The Edge Of Medicine'

Fighting Illness From 'The Edge Of Medicine'

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This is Fresh Air. I'm Terry Gross. Surgery has changed dramatically since the days when it took two doctors to hold down the patient and a third to wield the saw. That point is made in a new book about new and developing medical technologies by my guest, Dr. William Hanson. He says the hospitals of the future will be patient-centered facilities employing electronics, robotic attendants, smart computer software, and personalized treatments precisely tailored to each patient, such as gene and stem-cell therapy.

Dr. Hanson is a professor of anesthesiology and critical care at the University of Pennsylvania and an associate faculty member in the Department of Computer Science at Princeton. He holds patents on diagnostic and therapeutic medical technologies, and has helped pioneer new technologies in intensive-care medicine.

Dr. William Hanson, welcome to Fresh Air. Let's start with something really interesting that your lab is working with, and this is an electronic nose to identify diseases. Tell us something about how this works.

Dr. WILLIAM HANSON (Professor of Anesthesiology and Critical Care, University of Pennsylvania; Associate Faculty Member, Department of Computer Science, Princeton): Well, an electronic nose is a sort of a general description for a category of different types of medical devices that use different kinds of sensors, and some of the sensors change color when they sense something like an alcohol or different chemical on the breath. Other sensors change their electrical resistance.

But the bottom line is that these sensors can be configured together to objectively characterize a sense that we don't really have a good measure for, or haven't in the past, which is the sense of smell. So, as you may know, going back into the dawn of time with Hippocrates and some of the very earliest physicians, they used their senses of taste and smell to diagnose disease. So Hippocrates, for example, would taste the urine of a patient.


(Soundbite of laughter)

Dr. HANSON: And if it was sweet, he would diagnose diabetes. And however appalling that sounds, that was a common way of using the tools that he had available to make a diagnosis. The other senses that he used were those of his touch, his fingers, and that of smell. And there are a whole list of descriptions of different disease breath smells. So one is fetor hepaticus. And fetor is the Latin word for smell, and hepaticus is the Latin word for liver, and there's a characteristic musty smell on the patients - the breath of patients who have liver disease.

GROSS: What other diseases have a distinctive odor?

Dr. HANSON: Well, there are a whole list of different diseases. There's a urinary smell, a smell of urine on the breath of patients with kidney disease, not surprisingly, because the toxins that would ordinarily be excreted through the urine accumulate in the body, and you breathe them out through your lungs.

There are a whole bunch of childhood diseases that have very characteristic smells either in the breath or in the urine, and these are diseases of impaired metabolism of different chemicals. And one of the smells of diabetes on the breath is one that we characterize as the smell of Juicy Fruit gum, which is ketoacidosis, which is, when the sugar gets too high, this chemical that can be volatilized, which is that, you know, you smell alcohol in somebody's breath. These are molecules that will go into the air readily as opposed to molecules that prefer to stay in the bloodstream. And you breathe them out, and they are a way of getting at whether or not this patient has a certain disease.

GROSS: Now, can you smell these things when you're diagnosing a patient?

Dr. HANSON: Yeah. You know, in fact, if you're a physician in a first encounter with a patient, there are any number of different breath smells that you can pick up when you examine them, say, in the emergency room or in your office. I work some of the time as an intensive-care specialist, and I can go into a patient's room and distinguish the smells of certain bacteria or, in some cases, funguses.

And if you talk to a very experienced microbiologist, when they open a plate, an agar plate, with bacteria or whatever growing on it, just like a wine specialist, they can smell that plate potentially even with a blindfold on and say, this is Staph aureus, or this is Strep pneumonia.

GROSS: I'm assuming that, just as my cat can smell things that I can't, that your electronic nose can smell things that you can't. So what kinds of diseases can the electronic nose pick up on that the human nose can't?

Dr. HANSON: Well, let me just actually start with the cat thing because that's a very interesting side story. There is a whole school of thought that animals, dogs in particular, who have very good smell sensations, can actually smell diseases in their owners.

So there are dogs that are known as seizure dogs. And these dogs, using perhaps smell cues or perhaps other cues that we're not able to recognize, can anticipate when a patient, their owner, is about to have a seizure and can warn them. So, before the patient even knows that they're to have a seizure, the dog can be trained to give some signal that they should sit down or get in a position of safety and perhaps call for help.

But to return to the question that you asked about what kind of diseases, we've used the electronic noses that we work with - and we worked with several different technologies - in analyzing the breath of patients in the intensive-care unit who might be developing pneumonia, which is a big problem in intensive-care patients. We've also worked in analyzing the breath of patients with sinusitis, which is a big problem for a large number of people who have other acute or chronic infections of their sinuses.

And we can distinguish between different bacteria, and we hope to be able, at some point, to determine whether a patient has a disease, whether it's responding to treatment, perhaps. In some cases, we've been able to show that certain organisms that are resistant to antibiotics are growing as opposed to organisms that are not resistant to antibiotics. So these are big problems in medicine, and this device is a way of sort of objectifying this sense that we usually have a great deal of difficulty describing.

GROSS: What can the electronic nose diagnose that you'd have difficulty diagnosing otherwise?

Dr. HANSON: Well, I don't want to say that this technology is mature at this point. This is something that we're working with from a research standpoint. But to give you an example of the kind of problem we face in the intensive-care unit, we have patients who are on respirators, and they may develop something like a fever. And then the question is, do they have an infection in the lungs, do they have an infection elsewhere, and how do we distinguish between the two of them?

And the way that we historically have done that is by getting an x-ray and looking for a shadow on the x-ray. The problem with shadows on the x-ray is that you can have a shadow from an infection or just from a little bit of lung collapse or some other process. So that doesn't say this is pneumonia.

Another thing that we do is we take a sample of the secretions in the patient's lung, and we take them off for a lab assay on a bacterial plate. The problem with that is, that takes two days to grow. So we have this interval of two days in which we either do or don't prescribe antibiotics. If they're prescribed unnecessarily, as you well know, we have a potential for resistance, and you don't always know what antibiotic to start. And then we have other indicators. So, if we had something that were able to say to us at the point that that fever occurs, there is a high likelihood that this is a bacterial infection, that takes us way down the road.

GROSS: One of the largest and maybe most impressive and most promising technologies that you write about in your book is proton-beam therapy. Tell us a little bit about what that is.

Dr. HANSON: Well, one of the early physicists recognized that protons had a special characteristic, that they could be trained, in effect, to drop or release their energy at a very localized place in space given the right set of characteristics. And this same physicist recognized that that property was a way in which to have energy released that would kill tumors or cancers in a very localized fashion, so that you could train a beam of protons to enter the human body and not release any of their damaging radiation until they were inside of a tumor.

So, let me compare that to traditional radiation, which we are much more familiar with, where beams of radiation are trained on a tumor, but the radiation is released all the way along the path. So there's damage to the skin over the tumor. There is damage to the organs between the skin and the tumor, and you try to concentrate the damage in the tumor, but there is damage to all the tissue surrounding the tumor.

As you may be aware, one of the elements of the Hippocratic Oath is that a physician is primarily directed not to do harm to their patient, and the Latin term for that is primum non nocere. We do damage to patients all the time with our medications, with radiation and the like.

GROSS: Oh yeah.

Dr. HANSON: And it's a recognized risk-benefit ratio, in effect, that you take the risk of damaging normal tissue in order to kill the malignant tissue. The proton beam approach is so precise that we can train a beam of protons on a tumor millimeters in size or even a millimeter in size that may be located in somebody's eyeball, kill that tumor, and leave sight intact. That is not a possibility with traditional radiation.

GROSS: That sounds really amazing. How close are we to actually integrating that technological medicine into everyday practice?

Dr. HANSON: Well, we're doing it. I mean, proton-beam therapy is a therapy that's been in existence for a while now. We're getting better at it, and the devices are getting more precise, and the targeting is getting better because we can now use things like a CAT scan or an MRI to very precisely localize the tumor, which then allows us to very precisely train the beam of protons.

But these sorts of technologies are entering medicine at a pace that - I don't think most of us recognize that therapies like proton-beam therapy or technologies like robotic surgery or computerized artificial-intelligence applications, these technologies are diffusing into medicine at a rate and a pace that I think most of us are unaware of, and are going to drive us to places that, without some thought, could be very good or could be very problematic.

GROSS: So, what kinds of tumors is the proton-beam therapy best suited for?

Dr. HANSON: Well, that's a bit of a debate, and the tumor that most people think is most suited for treatment with proton-beam therapy is prostate cancer.

GROSS: Because?

Dr. HANSON: Because the prostate is a wallet-sized organ that lies between some other critical structures. Included in that are those of urination, defecation, and sexuality. So one of the big concerns that people have with the variety of different current treatments for prostate cancer is, will I be able to have sex? Will I be able to be continent and not urinate in my underwear? Will I be able to have fecal continence? These are very meaningful questions, and people struggle with the different treatment alternatives based in large part on the answers to those questions and how they prioritize these things.

GROSS: But with proton-beam therapy, you go directly to the tumor, and the other tissue isn't going to be affected. So...

Dr. HANSON: It's a very precise way...

GROSS: It's much less risky.

Dr. HANSON: Yes, it's a very precise way of treating that cancer with minimal to negligible damage to the surrounding important tissues.

GROSS: If you're just joining us, my guest is Dr. William Hanson. And he has written a new book called "The Edge of Medicine: The Technology that Will Change Our Lives." He's a professor of anesthesiology and critical care at the University of Pennsylvania. Let's take a short break here, and then we'll talk some more. This is Fresh Air.

(Soundbite of music)

GROSS: My guest is Dr. William Hanson. He's written a new book called "The Edge of Medicine: The Technology That Will Change Our Lives." He's a professor of anesthesiology and critical care at the University of Pennsylvania. Part of your work is telemedicine. As part of your work, you monitor intensive-care patients from an office through video and audio technology, and you do this through, I think, three different hospitals.

Dr. HANSON: Actually, at this point, four hospitals, and our facility is one example. Other places are monitoring patients at a much larger number of hospitals from a central core.

GROSS: Would you describe the setup where you monitor the patients from and what it is you can see and hear that's going on in their rooms?

Dr. HANSON: Yes. The core, which is sort of the hub of this wheel of links, is basically a large room in which we have several critical-care nurses and a critical-care doctor. And each of them are sitting at separate computer consoles with a large number of computer screens. And they have in front them a microphone, and there's a camera that's trained on them.

And what they're able to do is, by looking at the information on the patients that are covered - and in our case, we cover 80 patients; other places cover even more - is to efficiently scan through the patients, continuously looking for emerging trouble spots. So, as I sit there at night, I may have a list of 15 of the most critically ill patients out of that group of 80.

So, I'm looking at them continuously. I'm looking at their labs as they come in. I'm looking at their vital signs. I have the ability to look in any room at any time with a camera that I can very precisely look at what's going on in that room and interact with the providers who are physically at the bedside. And I have smart software that is trolling through all of the information coming in from of all of these bedsides looking for emerging problems.

So, for example, I might get an alarm that says that Mrs. Jones in bed seven has a blood pressure that's going up and a heart rate that's going up, which would direct me then look into her room and see if for example, she's agitated because she's being moved or washed or something, or if there's something else going on that's more medically problematic. So I'm able from that central location, working with very skilled partners in my nursing staff, to cover a large number of patients very efficiently, and it's particularly useful, we found, in other units where the expertise isn't typically there at the bedside. So, you know a community hospital that might not have intensive clear specialist during the day would benefit from this. In our place, we have critically ill patients coming in throughout the night and the day from helicopters, from emergency wards, occasionally from somebody's car when they drop them off at the emergency room. And they arrive in the intensive care unit, and they are sick on arrival. We have skilled physicians at the bedside, but I am an expert in intensive care, and can provide additional help to them as needed or direct their care.

GROSS: Give us an example of something you were able to catch monitoring on your high-tech video and audio from a remote location that you think would've gone unnoticed if there wasn't that kind of telemedicine in practice.

Dr. HANSON: I can tell you a very specific sort of compelling example that was related to me by my colleague that was covering one night. He got an alarm from a room that somebody's heart rate was decreasing, and that their blood oxygen level is decreasing. So he was prompted to go look in this room. And when he put the camera on, he saw a nurse working at the bedside with a tray full of instruments and two physicians who were attempting to put a intravenous catheter in the patient. And the patient was not on a respirator. And as he sat there, he saw that the heart rate was indeed down and the oxygen saturation was down. The alarms in the room were not on. And as he looked around he sort of had this suspicion that something wasn't quite right, and he looked at the patient, and recognized that the patient was not breathing. So what had happened was that the physicians and the nurses were occupied, there were sort of head down on this problem of getting this difficult line in place. And their attention - even though they were at the bedside, and even there were a very good doctors and nurses - had strayed from the patient, and the patient was getting into trouble, big trouble, and would very likely have had a cardiac arrest or respiratory arrest in front of them. He was able to say, Stop, put the breaks on. Let's take care of the patient first and go back to your problem.

GROSS: You said that a lot of doctors described that doctor in the room monitoring through telemedicine, what's going on in the ICU, as the doc in the box.

Dr. HANSON: Yeah.

GROSS: And how does it feel to be the doc in the box? Do you wish when you were doing that, that you were in the hospital having more, you know, direct physical contact with the patients?

Dr. HANSON: Yes. I practice on both sides of the camera so I practice at the bedside. And I think the very first night that I took this responsibility as - with this new system covering patients, I had a sort of an interesting experience, which was that I was called to a room where a cardiac arrest was underway. So the team was in there, and they were doing CPR, they were putting a breathing tube in, all the stuff you would see on television show for cardiac arrest. And one of the things that's critical in a cardiac arrest is being able to get drugs into the patients, so you have to have an intravenous catheter. The other thing is when measuring blood pressure. And the folks that were in the room were residents who were not skilled at doing this, and they were having trouble. And I knew from my remote location that, were I there at the bedside I could do this, and sort of facilitate this process. And it was very frustrating trying to guide this thing with my voice and not being able to use my hands. That's one aspect of this.

The other aspect is a very real one. If you see a patient and the patient is having pain or they're anxious or they're crying out for help in effect, I'm pretty confident that being at the bedside I can be more reassuring than acting as some voice from the sky, which in some patient's cases - patients who are agitated don't really get it. It's even more confusing and disorienting. So there are trade-offs.

GROSS: Dr. William Hanson will be back in the second half of the show. His new book is called "The Edge of Medicine: The Technology That Will Change our Lives." I'm Terry Gross, and this is Fresh Air.

(Soundbite of music)

GROSS: This is Fresh Air, I'm Terry Gross back with Dr. William Hanson, author of "The Edge of Medicine: The Technology That Will Change Our Lives." He's a professor of anesthesiology and critical care at the University of Pennsylvania, and an associate professor in Princeton's Department of Computer Science. He holds patents on diagnostic and therapeutic medical technologies, and has helped pioneer new technologies in intensive care telemedicine.

You write about robotic surgery in your book. I've never witnessed anything like that, and I can't visualize how this would work. So maybe you could describe a procedure that's done robotically.

Dr. HANSON: Patients who smoke commonly develop or are susceptible to cancers of the throat and the larynx. So these are cancers that involve the back of the throat, and they're hidden from view oftentimes. And the way they become apparent is the patients develop hoarseness or something alone those lines, and then the physician looks with a scope and sees this malignancy, and then elects to operate. The way that that operation would have been done five years ago at our institution would have involved an incision that would basically cut the jaw in half and spread the right side of the face off to the side, sort of opening up that area so that the surgeon can get in there with his or her instruments and hands.

Robotics - and let me describe a robotic setup very quickly. There is a set of tools attached to sort of the operating limb of the robot, which is parked at the bedside. So the robot has, let's say, two or different arms, and each arm has a hand - I'm using the word hand loosely here - that might have a pair of pickups or might have a scalpel or might have a scope or some complex of those things. And each of those things are programmed very specifically, have specific capabilities. That whole arm containing those instruments is attached by wires to a console, which may be several feet away from the bedside.

So whereas the operating surgeon of five years ago at our institution doing the same procedure would be at the bedside with his or her hands on the patient, that same surgeon is now sitting basically at a console in a chair, like an organist. And he or she has foot controls and has a pair of eyepieces to look into. The eyepieces show the camera's view of the lesion in three-dimensional perspective. The camera lens is heated so that it is defogged, you can focus in and out. And then with his hands, he's operating the instruments that do the surgery, and that may include cutting, sewing, all the things that a surgeon would do ordinarily. But the beauty of this is that he's able to effectively operate around corners so that that very disfiguring surgery of five years ago is no longer necessary.

GROSS: But why isn't it necessary? I don't understand operating around corners.

Dr. HANSON: Well, the robotic instruments are kind of like - you've probably seen though the tools the plumbers used to retrieve things from pipes where they have sort of a curved...

GROSS: Like a snake?

Dr. HANSON: A snake, yeah. So basically, a lot of robotic tools allow and operator to work at one end of the snake with his fingers. But the snake can snake around corners.

GROSS: Kind of like a colonoscopy.

Dr. HANSON: Exactly. Yeah. So a colonoscopy involves a scope, and you can put tools to this scope to biopsy - this is a much more sort of sophisticated extension of that. Although, you know, interestingly the current day robots will be superceded by robots that deploy from within the human body like a colonoscope. So you can drive your colonoscope into the stomach and then deploy these robotic tools which will operate from inside the body. And there will never be an incision.

GROSS: Wow. You're point out in your book that one of things that the robot can't do, or that the doctor can't do through the robot, is feel how elastic the tissue is and when the tissue might be at its kind of final stretching point and break. So what are some of the things that the human hands of the surgeon can sensorialy do that the robotic instruments can't do yet?

Dr. HANSON: The human hand is just a remarkable instrument. You can - you know, you can feel the single hair with a human digit so it's a remarkably sensitive instrument. What the current robotic instruments lack is that ability to feel if something is going to tear apart. There is a technology known as haptics, H-A-P-T-I-C-S which is forced feedback. So it's a way in which surgeons - and in fact, those of us who work with computer mice and other devices will in a very near future be able to feel edges or tissue strength, so, you know, you can imagine that haptic mouse that would allow you to feel as you move over a window on a computer screen, and a haptic robotic instrument can tell you this is going to tear if I pull too hard.

GROSS: All the relatively new high-tech medicine that we have including CAT scans and MRIs which are so commonly used now cost so much money. And the skyrocketing cost of health care is in part because of all the new technologies that we're using. So as you're discussing all these incredible breakthroughs that have already happened or that are on the horizon, I'm also thinking, particularly given where our economy is right now, how do we find the money to keep developing it and then to pay for patients that actually use it?

Dr. HANSON: Yeah, I think technology has the potential to throttle medicine in a way that - the analogy that I use when I think about this is that we're around a water hole. And the water hole is drying up. There is not an infinitely large amount of money that we can spend towards health care, and many of us would argue that the amount we're spending now at this too much and is taking our financial resources away from other important agendas. The technologies of the future will have to intervene or to function in a way that we can prevent these sort of end-stage diseases that are catastrophic, that cost a lot. We have had patients in my intensive care Unit that they've been there for a year, two years, and you can imagine the cost of that.

GROSS: Are the hospitals that you work with suffering a lot because of the economic crisis?

Dr. HANSON: I think what we're seeing now is some impact. Medicine is always been described as a sort of a recession-proof industry. I don't believe that's the case. I think that, you know, with the current combination of increased costs in terms of prescription medications or co-pays or the like being put onto patients and the economic times, we are in fact seeing whether it's true-true and related or not, an impact on the hospital admissions and the like.

GROSS: I want to thank you so much for talking with us.

Dr. HANSON: Thank you, Terry.

GROSS: Dr. William Hanson is the author of the new book, "The Edge of Medicine," he's a professor of anesthesiology and critical care at the University of Pennsylvania. Coming up, the opposite side of medicine, low-tech make it no-tech medicine. We talk with Dr. Jim Withers about practicing street medicine treating the homeless. This is Fresh Air.

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