Emerging Applications in Medical Care Using GaN Technology
6月 28, 2016
Image resolution is critical to MRI scanners
The contribution that gallium nitride semiconductor technology is making in medical applications can be measured not only in dollars saved, but also more importantly in its contribution to the speed of intervention, diagnostic accuracy and patient comfort. Because of its superior performance and small size, GaN components (FETs and ICs) are enabling end applications such as wireless power charging, higher resolution diagnostics, and precision surgical robotics. These applications are improving ways health care is being provided.
Being untethered to the power cord not only makes life easier for patients and health workers, but also increases safety and allows health care to be administered faster and more efficiently. Imagine medical teams never having to plug in a power cart while rushing to save a life in an emergency room or having to worry about the tangle of wires that can interfere with the delivery of IV fluids.
From a patient’s point of view, think about eliminating the need to have infection-prone wires extending from the body to recharge the batteries for a heart pump. In the world of diagnostic procedures, just think about the impact of significantly increasing the resolution of scanning equipment such as sonograms and MRI, or the ability to swallow miniaturized X-Ray machine imbedded in a pill to perform a colonoscopy. And, for intricate, delicate surgeries, robots using GaN components have precision positioning capability.
These improvements to the world of medical care are being enabled by gallium nitride technology. Let’s take a closer look.
At The Hospital – Untethered Emergency Carts, Unplugged Bedside Monitoring Instruments, And Untethered Patients
Medical emergency room environment with critical equipment
We are all familiar with the chaotic environment in which emergency medical personnel navigate at life-saving speed and can thus appreciate the advantage of having the equipment readily available without the need to “find power outlets.”
Even at a patient’s bedside, not having power cords will be welcomed – for ease of moving instruments, avoiding accidental unplugging of critical equipment, reducing the risk of electrical shock, and reducing the potential to breed bacteria. The emerging availability of wireless power charging is making wireless medical carts and powered bedside stands a reality.
The advancement of wireless power charging is an electronics industry-wide movement. Industry leaders including Hewlett Packard, Texas Instruments, Samsung, and Witricity have established a consortium (AirFuel™ Alliance) for wirelessly charging consumer and computing equipment. This same technology is applicable to hospital environments, which is using frequencies at both 6.78 and 13.56 MHz, speeds at which MOSFET cannot obtain efficiently. In addition to the convenience, wireless power increases safety for the health professions who otherwise have to dodge or step over by the “cable clutter” in the patient environment.
On The Patient – Heart Pumps, Prosthetics, Muscle and Nerve Stimulators, and Electric Wheelchair Recharging
In addition to untethering the instrument carts in the emergency room, having wireless power available enables patients to be more comfortable while bedridden and increases their freedom of movement when ambulatory.
On-patient wireless power applications
In a similar way, if a patient is bound to an electric wheelchair, the need to recharge batteries can be accomplished with a “drive over” mat that will charge the battery without the need to plug in. As with electric vehicles in general, electric wheelchairs can recharge simply by rolling over a wirelessly-coupled mat. This vehicle recharging technology is in operation today with drive-over chargers for electric cars and buses.
There are also numerous direct patient high-impact applications for wireless power transfer enabled by GaN technology currently under development and in clinical trials. These applications involve heart monitors and nerve stimulators that do not require that wires – wires that are prone to infection – protrude from the body in order to “plug in” for power. Wireless charging is not only more convenient, it is safer for the patient since protruding wires are potential sources of infection. Promising work in this application is being undertaken at Stanford where engineers have invented a safe way to transfer energy to medical chips in the body, wirelessly.
Diagnostics – MRI, Colonoscopy
Amplifier with eGaN FETs from EPC applied to a conventional MRI RF coil
Resolution is a critical attribute for all medical scanning devices, such as sonograms, CAT scans, and MRI imaging. Imaging equipment manufacturers are very excited about using eGaN FETs and ICs to increase the speed and precision with which an instrument can conduct scanning measurements. In the case of MRI systems, eGaN FETs are used in the transmit functions, which require extremely high RF power for both the power supply and power amplifier being constrained by heat. The extremely small size and high efficiency of eGaN FETs and ICs allow the transmit function to be placed closer to the patient allowing effective higher power capability for faster imaging. This faster imaging can be taken as either more image slices in the same time for higher resolution, or shorter scan time for more efficient equipment usage.
The receive coils are placed in direct contact with the patient and are limited by heat. Replacing silicon-based components with eGaN FETs to detune these coils for the transmit phase and tune them for the receive phase yields a drastic reduction in power dissipation, allowing a higher density receive matrix. This provides more information in the same space for higher resolution images. Thus, medical professionals will have more accurate images and a patient’s care will benefit with improved diagnosis.
Perhaps the most innovative medical application enabled by the extremely small size of the eGaN FETs is the “colonoscopy pill.” This pill contains a miniature X-ray machine that, after ingestion (no pre-purging needed!), creates a 3-D image of the intestinal track as it passes through the patient’s digestive system.
Non-invasive "colonoscopy pill" from Check Cap
The scanned images are transmitted wirelessly to a receiving unit placed on the patient. Once the pill has passed through the patient’s system, physicians can analyze the digital information stored on the receiving unit. Imagine, no more discomforting overnight preparation for the traditional colonoscopy! This “pill” and procedure is the result of EPC’s customer Check Cap, and is currently undergoing European agency trials and is on track for final evaluation by 2016.
Summary: GaN Technology For Medical Applications
The world of semiconductors is undergoing a technological disruption with the emergence of GaN technology. Numerous medical applications are taking advantage of the high performance eGaN FETs and ICs are bringing into play – applications improving the quality of medical care include:
- Untethering the all-important “medical cart” containing emergency instruments to make movement of the cart less of a contributor to bacterial infestations, as well as faster and easier to address patients.
- Removing the necessity to have infection-prone “wires” protruding from a patient’s body because they are needed to power heart pumps, or nerve stimulators.
- Increasing the resolution of body scanning devices, such as MRI equipment, giving more accurate information about the condition of patients at a lower cost.
- Introducing new diagnostic procedures, such as the “colonoscopy pill,” giving doctors more precise critical information, while making more comfortable for patients.
- Enabling higher resolution for robots medical used in surgical applications
GaN technology is contributing to significant improvements in medical care – and this is only the beginning!