The Changing Pulse of Medical Care
Arrhythmias are transient events. Most arrhythmias – where the heart beats too fast, too slow or with an irregular rhythm – are reasonably harmless. But some can be life threatening. During an arrhythmia episode, the patient’s heart may not be able to pump enough blood to the body. The lack of blood is known to result in brain damage and other organ failures. Arrhythmias can be treated successfully and most patients can hope to lead a normal, anxiety-free life. The difficult part is in monitoring the condition. Traditional ECG monitoring of a cardiac patient may not establish a reliable diagnosis unless the patient experiences an event during the recording. For a reliable diagnosis, the patient must be monitored continuously. Medical researchers have developed a range of ambulatory techniques to address the challenge. These are good techniques that have been around for decades. But are they great? Are they simple? Do they serve the best interests of the patient? So far, the answer has not been a resounding “yes”. If anything, it has been an uncertain “maybe”. Now, the medical device industry is addressing the challenge by creating simple wearable medical devices. Mobile development combined with advances in semiconductor technology are making these devices portable, accurate, reliable and in several instances, cheaper.
The medical device and the semiconductor industries have sensed that health costs in the western world are rising and there is a need for a solution that brings down cost of medical care. Today, with tremendous pressure on medical infrastructure, the average length of stay in hospitals is dropping. For nonfederal short-stay hospitals in the US it has fallen from 6.4 days in 1990 to 4.8 days in 2009-2010 across all ages1. But patients benefit from continuous monitoring of critical signs, even after leaving the hospital, and allow doctors to respond quickly to situations and emergencies. Remotely monitoring the patient helps patients leave potentially-expensive hospitals faster and also improves the quality of step-down care.
There are several advantages of the new range of wearable medical devices that are emerging. They allow medical providers to offer preventive monitoring to the aged, for chronic disease management and general wellness. Remotely monitoring those who may be susceptible to illnesses like cardiac disorder before catastrophe strikes can bring down the need for hospitalization and subsequent medical costs.
Expectedly, the demand for these devices is growing. The market for them is forecasted to hit $20 billion by 20182. A major chunk of the revenues will go to manufacturers of semiconductor components and embedded systems like memory, displays, processors, sensors and connectivity solutions that go into these devices.
Wearable devices that work outside the confines of the hospital without expert medical assistance must fulfill a number of characteristics:
- Usability: The device has to be worn on a continuous basis and must therefore be small and lightweight. The challenge is to compress the device size down.
- Power consumption: The device should have low power consumption, reducing the need for frequent re-charging and disruptions in monitoring.
- Design: The device must be elegant without the need to attach long wires and electrodes from the device to the patient and from the device to the mobile gateway that transmits data (to the remote medical care unit).
- Cost: If a patient is required to purchase the unit, it should cost sub US$200 to be affordable or for the hospital to give it away free as part of medical care.
Devices that fulfill these conditions can expect to become popular. Manufacturers will find that users are able to easily integrate such devices into their daily lives for maximum benefit.
The typical set of parameters that the device must monitor include heart activity, fetal heart rate, skin resistance, skin temperature, refractive index of blood etc. Based on what the device is required to measure and monitor, its components would include:
- Bio sensors: Application specific bio sensors that emit signals indicating measured parameters
- Analog-to-digital converters: Application specific analog front end to digitize the sensor signals. The device may also be equipped with signal conditioning circuitry.