Semiconductor vendors are constantly on the lookout for the market dislocations that will provide the opportunity for product innovation and subsequent sales and revenue growth. Market dislocations tend to be anticipated and debated long before they come to fruition — echoing the old adage that invention is 10 percent innovation and 90 percent perspiration. Today, the healthcare industry is on the cusp of a market dislocation that promises to change the way healthcare is administered.

The pressures to reduce medical costs are driving the need for devices that provide healthcare in the home. These devices provide 24/7 real-time monitoring of:

  • Vital signs (outpatient ECG monitoring, temperature, blood pressure, etc.);
  • Physical well being (fall prevention and detection, weight, and calorie control); and
  • Cognitive behavior (to aid in diagnosis of the onset of a medical condition)

Fig. 1 – Today’s home healthcare devices include those that monitor vital signs along with products that calculate the distance walked and calories consumed during a day.
This is just a very short list of home-based devices, but it gives an idea of how out-of-hospital patient monitoring can help reduce healthcare costs and improve personal health. Reducing the time a patient stays in the hospital for “observation” by transitioning to effective remote “observation” will inevitably reduce costs. Employing these devices to aid in the area of preventative healthcare will also make a significant contribution.

These motivations are driving companies — both traditional manufacturers of healthcare equipment as well as those not familiar with this market — to focus attention on developing devices for this emerging space. However, as with most market dislocations, there are a number of challenges that need to be addressed before a ubiquitous out-of-hospital patient care program can be fully realized. Geoffrey Moore’s bestselling book, Crossing the Chasm, aptly describes the situation in which the healthcare industry will soon find itself.

Moore suggests that the diffusion of innovation is precipitated by the use of that innovative technology by early adopters. Therefore, it is of vital importance that there is a strong acceptance of out-of-hospital medical devices in the early stages of their introduction. Currently, home monitoring and diagnostic devices (Fig. 1) are successful at monitoring vital signs (such as blood pressure and temperature) and testing for glucose levels, but have still not created the paradigm shift in healthcare that is necessary to take us across the chasm.

How Do We “Cross the Chasm”?

Notwithstanding all the other factors that will influence change in the future of healthcare (government programs, insurance, economic climate, regulatory rules, etc.) the product challenges for companies targeting this market are quite significant. These include trying to develop products that are:

  • Able to provide the level of patient monitoring that will have the desired effect (outlined above) and prove to be useful to the patient and the healthcare system;
  • Low enough in power that they operate for long periods without needing to be charged;
  • Low enough in price for mass adoption;
  • Able to communicate with remote servers;
  • Ergonomically acceptable to be part of our everyday lives; and
  • Designed to be error-free even for untrained users

This is no easy task, especially since the business models behind these products are still being defined. Ultimately, those driving this change in paradigm should not lose sight of the problem by becoming obsessed with one or two of the elements listed above. For example, fixating on “low cost” while neglecting “effective monitoring” runs the risk that the product never moves past the gadget category. Of course, there is no question that product affordability is vitally important, but it should never compromise the fundamental reason why out-of-hospital monitoring devices are needed. Credible solutions that address the critical need for patient monitoring outside of the clinical environment are one of the key factors that will enable the healthcare industry to evolve. Achieving the ultimate goal requires acknowledging the key role technology plays in securing the support of not only the early adopters but also the early majority that will take healthcare across the chasm.

For out-of-hospital monitoring to become part of everyday life, an effective return on investment (ROI) must be achieved — that is, there must be assurance that a tangible benefit is gained from being monitored. In the clinical environment, ROI is pretty evident. Being monitored while in the hospital is accepted as a matter of course and gives patients peace of mind throughout the duration of their stay. People tend to take for granted that hospital monitoring equipment is of high quality, comprehensive, and expensive. As such, should it not also be expected that out-of-hospital monitoring devices need to carry the same level of expectation? Once again, advanced technology is the key to achieving this.

Fig. 2 – Analog Devices’ high-accuracy ADAS1000 ECG AFE includes pacemaker pulse detection and respiration measurement for battery and line-powered ECG applications.
Of course, effective out-of-hospital monitors exist today. Holter monitors, for instance, are commonly used to record, for a relatively short period of time, a patient’s ECG (electrocardiogram) for off-line analysis by a cardiologist. Future out-of-hospital healthcare devices will likely call for real-time monitoring (with the potential for performing some local diagnostics).

In-hospital vital signs patient monitors generally support one or more of the following: ECG, SPO2 (blood oxygen), blood pressure, respiration, and temperature. While this is not an exhaustive list, it covers the most common vital signs monitored. For in-hospital instrumentation, the likelihood is that within the instrument itself, each of these monitors will be based upon a distinct module that outwardly connects to a discrete sensor or set of sensors on the patient. The ECG will connect to a number of torso electrodes, SPO2 to a finger clip, respiration may use chest electrodes, and temperature and blood pressure will be measured periodically with a thermometer and cuff respectively.

To migrate this level of patient monitoring to devices that exist in the out-of-hospital environment, the bio-medical engineer needs to address certain issues, including but not limited to:

  • Adapting to different environmental conditions: For instance, for long-term monitoring, “wet” ECG electrodes are impractical, so dry electrodes are employed. Dry electrodes introduce additional issues relating to signal integrity.
  • Accurate measurement: Common mode noise, for example, can significantly impair accurate measurement.
  • Multi-sensor connectivity: Monitoring ECG, SPO2, and temperature requires multiple sensors and, in some cases, new innovative techniques for reliable measurements.
  • Multi-parameter system design: Combining the monitoring of multiple vital signs.
  • Real-time processing of measured vital signs: Acting upon events for real-time diagnosis.
  • Power management: Maintaining low power.
  • Remote Monitoring/Communication: Wide variety of wireless and wired communication protocols.
  • Patient mobility: Essential for rapid rehabilitation.
  • Ease of use: Minimal hospital administration.
  • Acceptable industrial design: Devices should be socially acceptable.
  • Reliability: Remote monitoring requires that devices are connected and functioning correctly.
  • Low Cost: An inevitable requirement. Some devices will need only a few of the elements of listed above, while others will be impacted by all of them.

Engineering a Solution

So, how can engineers address these challenges? By doing the following:

  • Adapting to the environment and real-time processing of measured vital signs

Development of innovative signal post-processing techniques with, for instance, algorithms that will help to overcome noise artifacts caused by patient movement or loss of signal integrity due to poor connectivity of the electrode. To enable local/remote real-time diagnostics, noise artifacts such as baseline wander should be addressed locally.

  • Accurate measurement, multi-parameter system design, patient mobility, reliability, and power management

Integration of analog and digital signal processing elements gives rise to innovative designs that help to reduce system area, noise, power, and cost. Also, by reducing the number of system components, reliability is improved along with the non-tangible costs of inventory management.

  • Multi-sensor connectivity

This presents a real challenge since many of the vital signs that must be monitored are geographically remote from each other in the human body (i.e., ECG on the chest, SPO2 on the forehead or finger, and temperature in the ear or under the arm). Wireless sensors that communicate over body area networks will help eliminate the alternative wired network. Innovative garments that have integrated electrodes and sensors are also addressing this challenge.

  • Remote monitoring/communication

There are new innovations in wireless technology that will insure effective remote communication. Bluetooth Low Energy, WiFi, and Zigbee are just a few of the protocols already in place.

Some of the first steps involve system integration and miniaturization. This has occurred over the years in all manner of consumer products, such as the cell phone, now that healthcare has lost its immunity (excuse the pun) to such requirements.

To address the issues associated with power consumption, mobility, and industrial design, ground-up re-engineering of the electronic circuits in the medical instrumentation is required. As previously mentioned, there are many areas that need to be addressed, but the most critical focus is to maintain measurement integrity of the vital signs being monitored while reducing system power, size, and cost.

The ADAS1000 ECG analog front end (AFE) subsystem (Fig. 2) from Analog Devices is an example of how part of this challenge is being addressed. With the ADAS1000, what used to require up to 50 active components and numerous discrete components to achieve can now be realized in a single chip. The ADAS1000 AFE subsystem integrates the following circuits and functions: 5 ECG acquisition channels; Right Leg Drive; ECG Cable Shield Drive; Pacemaker Pulse Detection (on-chip algorithm); Respiration Measurement (Thoracic Impedance); Voltage Reference and Power Management; System Calibration; and Digital Filters.

Devices such as the ADAS1000 AFE subsystem provide a clear line of sight as to how technology innovation can enable efficient and effective remote patient monitoring and help healthcare cross the ever-widening chasm. The end objective is to instill confidence on the part of the patient and the physician that the technology will help the patient in a manner that is just as accurate as in-hospital technology. An upcoming generation of ICs, combined with new equipment designs, will help meet that objective.

This article was written by Tony Zarola, strategic marketing manager for Analog Devices Healthcare Group, Norwood, MA. For more information, Click Here 


Medical Design Briefs Magazine

This article first appeared in the June, 2011 issue of Medical Design Briefs Magazine.

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