Applying Evolutionary Thinking To Point-Of-Care Diagnostic Design

By Wayne Maddever, ChroMedX Corp.

Developments in computer science, biology, and communications are starting to push testing out of the lab and back to the point of care (POC). At the macro-level, this is truly a revolution in treating the sick and injured. Rather than carting the patient to an emergency room or hospital bed for a series of tests that will take hours to produce results, we will be able to get the same information on the spot, in real time.

“POC test devices have contributed significantly to the growth of the overall diagnostics market over the past 10 years. POC testing appears to be headed for an even bigger role in diagnosis and monitoring patient care,” states Research and Markets’ report The World Market for Point of Care (POC) Diagnostics. “New technologies are allowing POC devices to produce quantitative lab-quality test results that can be transferred automatically to an information system, a remote caregiver service for consultation, or an electronic medical record.”

A revolution indeed, but when it comes to designing a single POC device, revolutionary thinking is not as useful as evolutionary design. Incremental changes, and not paradigm shifts, are the norm

Case Study: Handheld Blood Analyzer

For the last several years, ChroMedx has been working to commercialize patent-protected technology in the medical diagnostics and research field. We have emphasized in vitro diagnostics (IVD) and point-of-care testing (POCT).

Currently, we are developing a handheld blood analyzer that we call the HemoPalm. It integrates full CO-oximetry, measured through spectroscopy (the only method for CO-oximetry), with analysis of blood gases and electrolytes. It is intended to replicate the kind of CO-oximetry and blood gas analysis traditionally performed using bench-top analyzers that are large, expensive, and usually located in central laboratories. The idea for the device came from our CSO, a clinical biochemist, who saw a need for POC testing of co-oximetry, blood gases, and electrolytes.

Strategically, with this device, we are trying to bring many of the benefits of bench-top testing to a handheld device while leaving behind as many of bench-top's drawbacks as possible. We must, by the nature of this process, make some choices and accept some trade-offs. Getting the balance right is the key to having a chance at breaking into the handheld market.

However, the entire process requires us to begin with tests that already are standards of care, and then migrate those tests to handheld devices. We are not trying to invent an entirely new battery of tests. We are endeavoring to take what exists and make it mobile and field durable, while still generating accurate readings.

The parallel I like to draw is with the self-driving car that Google, Tesla, and others are trying to build. A car that can drive itself would revolutionize transportation. A successful model will require a lot of work on navigation software and some development of sensor hardware before we even consider marketing it. These are large jobs, to be sure, but the basic design of the car itself doesn't change. The engine, the transmission, the brake system — all of that remains the same.

Point-of-care testing is much the same. We are improving on the bench-top tests, but we are not reinventing them or even trying to replace them outright.

One of the biggest issues that we had in designing the HemoPalm was creating a product that didn't rely on an arterial blood sample, the way labs do. Taking such a sample is a painful process, because the arteries lie deep below the skin and the needle needs to penetrate a lot of tissue to access them. As one physician we work with has said, “That's no fun for the patient and it’s no fun for me.” That is coming from a highly trained medical professional. It's certainly not the kind of thing you want a person with minimal training to do.

It is impractical to take that kind of sample in the field. So, we had to find a way around it. Although the HemoPalm can accept a conventional syringe sample, it can use as an alternative a blood sample collected directly into the cartridge from a finger prick or, in the case of neonatals, a heel prick, which makes the technology applicable in the markets outside of a clinical setting. Moreover, the pin-prick sample has the potential to change medical practice by replacing the arterial syringe sample. This sample method opens the field of use to include first responders, military, emerging economies, and disaster relief — all areas where central labs simply are not available.

The trick was to extract the same blood gas data from a finger-prick sample that you get from an arterial-blood sample. The data are there, so it was obvious that the solution lay in writing the software capable of extracting that data from a much smaller sample, and in making sure the device’s hardware was sensitive enough to detect it.

Like a lot of small medical device companies, we have to keep an eye on our expenses, and that dictated how we addressed these challenges. We could not afford to build the research and design infrastructure possessed by some of the big firms. Instead, we assembled a team of consultants with very specific objectives. The result is a device capable of taking of the sample in a manner that is both simpler and less painful than alternatives, which improves the situation for physicians and patients.

Lessons Learned From Designing A POC Device

Our design team learned a few things throughout this process that will make it easier for ChroMedx and other device developers to create viable POC testing products in the future:

• Perhaps most important, POC testing devices are improvements on existing tests; rarely, if ever, do they offer brand new medical tests.
• The challenges of miniaturization, mobility, and shock/waterproofing can actually offer you marketing advantages. Our resolution of the arterial-blood challenge provided a less painful way to do the test. Not only does it allow the use of the device in field settings, but by using finger prick sample, it can expedite patient care and reduce costs in clinical settings, such as hospital emergency departments.
• Your development budget will dictate how you structure the design team and its objectives. We couldn't afford to hire full-time staff to undertake the tasks we needed accomplished. A team of consultants with very specific objectives provided deep expertise without internal overheads.

The HemoPalm is still in the prototype development stage and has yet to be approved by the FDA. Its path to market will depend on proving that we can achieve results within the margin of error considered acceptable for hospital labs. To be accepted by the market, however, we need to demonstrate that we can carry most of the hospital lab’s advantages to the point of care.

About The Author

Wayne Maddever is director, president, and CEO of ChroMedX Corp. He received his B.A.Sc./M.A.Sc/Ph.D. in metallurgical and materials science engineering from the University of Toronto. He began his career with the Gas Products Division of Union Carbide (now Praxair) in both the U.S. and Canada, where he held positions in R&D, product management, and sales management.  He has considerable experience in the plastic molding industry, having led several companies in the industry. He is familiar with precision equipment manufacture, having served as GM of Sanden Machine, a printing press manufacturer, and as COO of CFN Precision, a precision machining company producing parts for aircraft and scientific instruments. Maddever also operated Ontario’s third-largest home oxygen therapy and medical supply company as GM-Canada for MG Industries, a German industrial gases company.

Since 2000, he has specialized in management of technically based private and publicly held companies, particularly in early stage or turnaround situations. Maddever holds several patents, is the author of numerous technical papers in several different fields, and has contributed to a textbook on degradable plastics.