4/23/2007 -- Infrared Scientist GREG MATIS appears with Cardiac Surgery Appliance maker RAY BERTOLERO. SEGMENT 2 of 5
RAY BERTOLERO is the Vice President of ESTECH Cardiac Surgery Specialists of San Ramon, California. Estech makes dozens of products used daily by surgeons around the world. Take a listen as he tells us about their EXCITING new BREAKTHRU CURES for Stage 3 heart failure and Atrial Fibrilation!!! http://www.estech.com/
Wayne B. Norris: Hi. We’re back with Business and Technology on AM 1290, the Santa Barbara News Press radio station. I’m your host, Wayne B. Norris and we’ve been talking to Greg Matis. He’s a senior scientist for Santa Barbara Infrared. I think I gave him a promotion last time and promoted him to vice president by accident, there but you know what? Maybe his boss ought to be listening. Maybe that’s about right.
Just before we start again, I’d also like to mention that Santa Barbara’s own Money Camp is putting on a four-day financial literacy summit. They’re a nonprofit, and they teach children as well as teachers in Train the Trainer sessions about financial literacy. It’s gonna be at the Holiday Inn April 25-28. That’s this Wednesday through Saturday. It starts each day at 8:30.
This nonprofit is featured in the current edition of Newsweek, where they describe it as “one of the very few financial education companies in the United States who are teaching our children financial knowledge and skills to set them up for success.” And as a former chief financial officer of a publicly traded corporation and an accountant by training, I can sure tell you that financial illiteracy abounds in this country. These guys are out doing the right thing, and they’re out going where the need is greatest.
If you have any questions, or if you want to register for the summit, you can call them at 800‑928‑1932. We’re here in the 805 area code. You can call them at 957‑1024 or you’ll be able to link to their site from this show’s Web site after this evening’s update.
Now, Greg, I was asking you about being able to find skunks in my back yard. They’re living, breathing animals. They’ve got a little coat on them so I’m sure the coat isn’t quite as warm as their warm little bodies. How cheaply can I find a skunk in the dark?
Greg Matis: There’s a couple of solutions you might want to look at and this would be for cameras. There’s a number of very competitive uncooled solutions, and why I say that is is that most sensors, in order to get very high gain response and very low noise, they typically are cooled and they use a mechanical, or what’s called a “cryocooler,” to actually make these detectors very highly sensitive.
So if you wanted to do this in a very inexpensive manner, there’s a number of what are called bolometer cameras that are becoming available in reasonable formats, typically in the 320 by 240 pixel size, and these allow you, for a cost of probably about $1,000.00, maybe $2,000.00, to be able to actually have an infrared camera that’s responsive in the long wave infrared, but now this would be – we mentioned the midwave is about 3 to 5 micros.
This is basically an atmospheric band in the 8 to 12 micron band and these have a very – essentially, these are what are called thermal sensors. They’re not so much a photo detector, but they do respond to temperature, and what they do at that point is, they basically respond with current, and therefore allow you to then measure on a pixel-by-pixel basis where this skunk is and to form an image of him.
Wayne B. Norris: Wow. That’s still pretty expensive to find a skunk. I might just – I might keep my dog in at night during skunk season but –
Greg Matis: That’s right.
Wayne B. Norris: Now you said this – ’cause a bolometer, that’s basically just a little resistor in a Wheatstone bridge, right?
Greg Matis: That is correctly, actually two little bolometers, and basically the differential between them creates the current in the Wheatstone bridge, and that’s how they work.
Wayne B. Norris: Wow! And I’m sure that most of our listeners, certainly on this show, are familiar with the Wheatstone bridge, and probably most of them are familiar with bolometers, but I had always thought that bolometers were, well, kind of old hat, passé; certainly never expected them to see way out there at 8 to 11 microns. That’s – those aren’t very powerful photons.
Greg Matis: That’s correct, and in most cases a bolometer, because it is – because they get a thermal detector, as opposed to a photo or photon detecting type of a sensor, they need a lot of integration time. They need a lot of signal collection, so there’s a lot of tricks in order to provide adequate number of essentially photons to absorb on the bolometer surface in order to then create basically what’s called a change of resistance, or these materials have basically a thermal coefficient of resistance change, so as temperature changes, the resistance changes in that Wheatstone bridge and then essentially you sense current and then measure the object.
Wayne B. Norris: Okay, well, now, these little cryocoolers, these are the little Sterling engines that used to make all of our images pretty foggy and jumbly and staticky when we were in the Common Module days at SBRC. I’ll bet they’re better than that now, right?
Greg Matis: Yeah, they’ve progressed considerably since those days. In fact, they’re the preferred way to provide a very uniform temperature, essentially, to each of these pixel elements, because each of these photo detectors, whether they’re photovoltaic or photoconductive, are extremely sensitive to noise and, of course, as the – especially to like Johnson and shot noise, which are basically driven by thermal conditions, and as the material itself becomes very warm, the noise level overwhelms the signal, and you can’t see anything. So you must cool these materials down considerably. In fact, you cool them down to approximately minus 220 degrees Celsius.
Wayne B. Norris: Well, that’s even colder than liquid nitrogen, isn’t it?
Greg Matis: A little bit, yeah.
Wayne B. Norris: Yeah. That’s what? Minus 193 or something?
Greg Matis: Yes, that’s right.
Wayne B. Norris: Yeah. You know, now – and by the way, didn’t mean to be kicking any trouble on people from SBRC. They were working at the dawn of this stuff, and it was pretty tough. We built a test set for that common module to try to find out what was going on with that microphonic noise from those little Sterling engines, and that was some tough detective work to be able to find out but, you know, I guess those are – are those expensive these days? I wouldn’t think a Sterling engine would be expensive.
Greg Matis: Not that bad, but they do add considerably to the cost. For example, the commercial user, you know, wanted to use these. You’ll find that in handheld camera systems, because of the portability issues and the size, most of these systems will incorporate, if they require cooling, a very small version of this particular type of a cooler, but they do add somewhat to the cost of that particular camera.
Wayne B. Norris: Well, now, right after I left there – oh, maybe three or four years after I left SBRC, and this is going back about 20 years – I was out looking at some infrared cameras for security for a warehouse, and they told me that they had ONE MercCad Telluride pixel, and that it was so fast and it was room temperature, that they were optimizing it by scanning the optics all over it, you know, XY scans. And it was just one pixel that was giving them all the information! I was thinking, boy, that is – if that one pixel goes out, the whole system’s dead, but that’s really saying something for MercCad Telluride. Are they doing that anymore with MercCad Telluride?
Greg Matis: Not the scanning, although in some case some people have still looked at trying to paint scenes, and then basically use basically a small element of MercCad. The idea is that in order to produce a large ray of MercCad, there’s a certain fixed expense, so if you put that expense into something else like a scanner and then use a smaller piece, you can come out ahead in the cost curve, but what you really get into then is the whole coordination of how to do the scan, you know, the interlace thing, the integration times.
It’s becomes kinda – and also the jitter issues which factor into it, how stable is your platform between each pixel you collect, and when you want to actually render a very useful scene, let’s say that scene is 1024 by 1024, for each point you have to integrate in order to fill that whole scene, you actually spent a considerable amount of time, which means you’re not very good at looking at dynamic scenes, where things are actually moving in a live time basis.
Wayne B. Norris: Wow. Yeah, well, I tell you that fixed constant on that MercCad Telluride that was always – I never knew a chemist who didn’t beat their knuckles on the wall every once in a while trying to put those things together. Now I’ve got a question for you. We’re talking about multiband. How about – and this is a problem that’s facing those of us in our game here – how about finding from looking down up above when somebody has shoveled out some dirt recently? Can you see recently disturbed ground? And I bet you know what I’m thinking of.
Greg Matis: Yes, it’s actually a very good point, and you can. A lot of manufacturers that we support with test equipment, such as the SBRCs of the world or the Raytheons of the world, or even some of the other local companies that do have satellite imagery, they look at combining different spectral bands and fusing those in order to provide the scene essentially that you’re looking at with very relevant content and, in this case, when one looks at mineralogy, one looks for reflectance spectrum, such as things that are actually –wavelengths that are bouncing off of the different types of dirt and rock that are present based on this excavation, as well as the thermal signature, because recently moved dirt will have a certain – different temperature as opposed to static dirt or compacted dirt.
So, therefore, if you can fuse different bands, you can see throughout obscurants, such as haze or clouds, in order to actually localize the particular object of interest, and then use the thermal bands essentially to look for very small temperature differentials which may say, “Oh, there’s air circulating below. That must be a tunnel!” Or if it’s a mine or something like a broken water pipe, you can look for temperature differentials localized to that area, and that helps you decide what you want to do regarding either excavation or monitoring the area.
Wayne B. Norris: Wow. Well, you know what? This is a fast medium that we have here on the radio, and we’ve come to the end of this segment, but, my friend, we have to talk and take this offline, because there’s a couple of areas that I’d like to talk to you about maybe that we shouldn’t have on the air. This has been really, really fascinating. I have more fun on this than it ought to be legal to have. The show is Business and Technology and we’ve been here with Greg Matis, who’s a senior scientist for Santa Barbara Infrared. Thank you, Greg. We’ll be back right after this with Ray Bertolero, vice president of Estech Cardiac Surgery Specialists.