I just watched a webinar on non-invasive bio-imaging as a way to detect and track disease, which gave me a sense of the way tech progresses in the medical field and makes for a positive counterpoint to my views on medical IoT, at least as envisioned in much of our industry. The webinar, on new approaches to in-vivo imaging was hosted by Science magazine and sponsored by Perkin Elmer (remember those guys?). Presenters were Christopher Contag, Professor in Pediatrics, Radiology and much more at Stanford and Anna Moore, Professor in Radiology and much more at Harvard Medical School. A lot of the focus was around detection and treatment of cancers so I’ll stick to what I learned there, though there was also mention of application to diseases like diabetes.
Cancer is still a very challenging disease, both in detection and therapy. As we live longer and avoid what earlier might have killed us for other reasons, cancer becomes more prominent as a cause of death. Detection is hampered by the fact that current methods find possible tumors at a quite late stage (grown to as many as 1 billion cells), and remedial action such as excision always leaves the possibility of some residual cancer cells around the periphery of the surgery which then go on to metastasize. A sobering fact mentioned in the webinar is that 90% of cancer-related deaths are due to metastasis, not to the original cancer.
For imaging, one goal is to get to much earlier detection, when a tumor has grown to as little as 1000 cells. This gives a better chance of micro-targeting the tumor, not just in where it is but also in cell biology. Some suggested methods for detection are use of photoluminescence (uptake of luminescent compounds in cancerous cells which can then be detected from outside the body), to the use of optical imaging (either from outside or through endoscopy) in short-wave IR (~1.5um) with carbon nanotubes. Imaging helps not only in detection but also in tracking progress in response to therapies. Wearables could also help here in counting tumor cells circulating through the vascular system which can contribute to metastasis.
Another practical and possibly near term advance in imaging is in use of complementary imaging techniques to confirm diagnoses. A known problem with mammography is the rate of false positives, leading in some cases to unnecessary surgery, since X-rays cannot easily distinguish between tumors and fibrous tissue. One method that has been shown to be very complementary is optical imaging of hemoglobin concentration in the breast, combined with X-ray data. Fibrous tissue showing as a potential tumor in an X-ray does not show in the optical view and can be ruled out as cancerous (because blood concentrates around a growing tumor but not around fibrous tissue).
Finally, remember that point about surgery leaving a residue of cancerous cells too small for the surgeon to detect? Surgical tools for excision could be supported by cancer-detecting microscopes with resolution down to 1um, helping surgeons be much more accurate in eliminating margins of tumors around the main excision. Advanced laser-based surgical tools could micro-target these margins, based on this microscopy.
So where does this leave semiconductor and system design? First, any development would need to be in partnership with experts in the field, like GE or Perkin Elmer. Given that, suppport for imaging at specialized wavelengths, new and more portable methods for tomography combining X-ray or other sources and light images, wearables counting circulating tumor cells, creative combinations of microscopy and laser surgery – these are all possibilities and, once proven, many of these will be fairly high demand solutions. Where successful, these will certainly have more lasting value than counting how many times you stood up today.
The literature in this domain that I have found is heavily medical, but if you’re willing to try, there are a few references HERE, HERE and HERE.
