Healthcare Systems Applications
Control and Integration of Medical Devices and Systems
Healthcare is in transition. Advanced device connectivity will change medical practice, lower costs, and improve patient outcomes. RTI Connext DDS is a software communications platform that leads the way in providing quality care and improving the safety and efficiency of healthcare.
Healthcare applications fall into three broad categories: connected medical devices, imaging and treatment machines, and surgical systems. Fast, reliable networking is changing all three.
Connected Medical Devices for Patient Safety
Thirty years ago, health care technologists realized a simple truth: monitoring patients improves outcomes. That epiphany spawned dozens of devices that populate today's hospital rooms: pulse oximeters, multi-parameter monitors, ECG monitors, Holter monitors and more. Over the ensuing years, technology and intelligent algorithms improved many other medical devices, from infusion pumps (IV drug delivery) to ventilators. Healthcare is much better today because of these advances.
However, hospital error is still a leading cause of preventable death. Thousands of errors occur in hospitals every day. Many of these errors are caused by false alarms, slow responses, and inaccurate treatment delivery.
Today, a new technology disruption is spreading through patient care: intelligent distributed medical systems. By networking devices, alarms can become smart, only sounding when multiple devices indicate errant physiological parameters. By connecting measurements to treatment, smart drug delivery systems can react to patient conditions much faster and more reliably than busy hospital staff. By tracking patients around the hospital and connecting them to cloud resources, efficiency of care can be dramatically improved. The advent of true Internet of Things networking in healthcare will save costs and lives.
The Integrated Clinical Environment (ICE)
Researchers and device developers are making quick progress on medical device connectivity. The Integrated Clinical Environment (ASTM F2761) standard is one key effort in building connected systems. ICE combines standards. It takes data definitions and nomenclature from the IEEE 11073 (x73) standard for health informatics. It specifies communication via the Data Distribution Service (DDS) standard. ICE then defines control, data logging and supervisory functionality to create a connected, intelligent substrate for smart clinical connected systems.
Modern hospitals use hundreds of types of devices for patient care and monitoring. These systems must work in a large hospital environment. Integrating whole hospitals with thousands of devices presents scalability, performance and data discovery challenges.
To prove a design was viable for a large customer, RTI simulated a hospital with 90 patients and 270 devices. The simulation sent realistic dataflows between hundreds of these applications. RTI Services developed a matrix (Excel spreadsheet) to configure Prototyper to send the mix of data types and rates expected from real devices. RTI developed an automated test harness to deploy applications across the lab's test computers and collect the results. RTI's test harness collected dataflow rates and loading across this topology. RTI Connext DDS handled realistic scale, performance and discovery.
Since it is important to communicate real-time waveforms and video, the potential network-wide dataflow is large. DDS filtering, and RTI's ability to propagate those filters to the sender, eliminates wasted bandwidth. Since 62 percent of hospital patients move every day, the system tested transitions between network locations.
When deployed, the new system will ease patient tracking. It will coordinate devices in each room, and connect rooms into integrated whole hospital. Information will flow easily and securely to cloud-based EHR databases. The hospital of the future will become an intelligent, distributed machine in the Industrial Internet of Things.
Emergency Medical Systems
Firemen and emergency medical technicians (EMT) need to carry portable diagnosis and treatment systems into hazardous situations. Once on board, ambulance systems need to care for patients during transport to the hospital
The software architecture for emergency medical systems integrates several patient-facing devices on portable devices and inside vehicles. It also connects these systems to cloud assets such as Electronic Health Records and to hospitals so they can prepare for patient arrival. It supports both Class III certified medical devices on the patient side and secure, encrypted communications for any data leaving the vehicle. This connectivity improves response and efficiency and eases the load on harried emergency personnel. The information sharing with doctors and hospitals improves patient care before the patient even arrives.
The world's largest emergency medical equipment manufacturer is using Connext DDS software architecture to take advantage of the Internet of Things. Now, with RTI, emergency medicine is entering the Industrial Internet of Things.
Medical Imaging and Treatment Systems
Major medical systems consist of many parts that must be coordinated. They may include 50 or more processors that work together to control motion, generate and form radiation, collect images, and synchronize operation with patient waveforms. Precise, reliable control of complex dataflows form the core infrastructure required. Imaging systems generate massive data. Bandwidth control and efficient transport is critical.
Connext DDS excels at large machine integration. It handles complex interactions between distributed components and can deliver data fast enough to accurately synchronize the parts of the machine. It can also handle the extreme dataflows.
RTI middleware is ideal for, and used in, many such applications, including CT scanners, MRI imagers, X-ray systems, ultrasound probes and radiation treatment systems.
Computed Tomography Scanner
A modern CT scanner is a marvel. It generates X-rays by firing high-energy electrons at a spinning tungsten disk. Beam formers direct the X-brays through the patient to collimating receivers. The entire system spins on a gantry 360 degrees around the patient fast enough to freeze motion. The controller must get all the parts ready and fire them at the right time to coordinate with the patient's heartbeat. Then, it sends the megabytes of raw data to a processor to back-project a 3D image.
RTI Connext DDS integrates all these pieces in real time. With precise quality-of-service control, Connext DDS delivers the feedback and event signals fast enough to ensure a quality image. By changing QoS settings, it can handle high-throughput image storage. Direct publish-subscribe data access eases development of an intuitive operator interface. There are about 50 CPUs involved, some on rotating boards, some in offline processing, some running the operator interface. The software combines C, C++, and Java code and runs on several operating systems, from Linux to VxWorks. It connects to predictive maintenance and service devices off site. The Connext DDS software architecture supports today's needs and will evolve to fit tomorrow's demands. Imaging systems are a picture of the Industrial Internet of Things.
Mevion Proton Beam Radiation Therapy (PBRT)
Conventional cancer radiotherapy uses high-energy x-rays. X-rays, unfortunately, affect all tissue along their path, damaging the DNA of both healthy and tumor cells. Thus, traditional radiation therapy has secondary exposure risks including skin cancer, brain damage, and radiation burns.
High-energy proton beams, by contrast, have little interaction with tissue until they reach a critical speed. Then, they deposit nearly all their energy in a very short distance. Thus, proton therapy lets physicians tailor radiation doses to attack tumors while minimizing radiation damage.
Of course, this assumes you can generate a perfectly-controlled beam of protons traveling at 99 percent of the speed of light. That requires a particle accelerator. Before the Mevion device, PBRT systems cost over $100 million and required a building as big as a football field. The Mevion system shrinks that particle accelerator, a superconducting synchro-cyclotron, down to fit in a large room. The cyclotron controls extremely rapidly-changing magnetic fields to accelerate and contain speeding protons.
You must also aim the beam. The Mevion accelerator is small enough to mount on a gantry. By positioning the patient on a motion table, this system can aim proton beams in any direction. It is a complex system, including patient positioning, treatment planning, motion control, beam scattering, field shaping, magnetic control, ion sourcing and dosimetry. RTI software enables the system to safely ramp the magnet up to 12 Tesla and back down, while controlling magnet current to within ~1 ppm. This is nearly MRI-class stability at much higher field strengths in a rapidly-varying magnet. The result? A machine that is accurate enough to zap a retinal blastoma without damaging vision.
The Mevion PBRT system treated its first patient at the Siteman Cancer Center in St Louis in December 2013. Cancer therapy has entered the Industrial Internet of Things.
Today's surgical systems are becoming intelligent distributed machines. Modern surgery can take advantage of new technologies, including tiny embedded video cameras, live imaging navigation systems and online patient status and information.
But don't underestimate the challenge of integrating into an operating room. The requirements for ease of setup, reliability and sterility make systems harder to implement.
Surgical Theatre Integration
Information is critical in surgery. Patient status and waveform displays keep the surgeon and staff aware and informed. Increasingly, multi-channel real-time video feeds also provide valuable information.
Consider a common invasive cardiology operation. The task is to guide a catheter to a blocked cardiac artery, inflate a balloon and insert a stent. Today's catheters are well instrumented with video, pressure sensors and more. A modern fluoroscope and ultrasound imagers provide real-time video navigation assistance. The operation is planned and then directed by 3D CT images showing the surgeon.
All this information must flow to the operating team, to the room control staff and even wirelessly to observers – both local and remote. The inputs must be combined into intuitive displays. Fielded solutions transfer all this information over dedicated wires. Hard-to-sterilize HDMI cables snake through the theatre. Setup is manual and static.
A flexible, fast DataBus design changes the picture. RTI Connext DDS can deliver multiple channels of video from any set of sources to any set of users. Single fibers or wireless links replace hundreds of wires. Automatic discovery eliminates much of the manual configuration, making it easier, and cheaper, to set up equipment and people. Information can flow off site, integrate with devices and update the EHR.
Robotic Surgery at DLR
Robotic surgery has many advantages over conventional procedures. Robots can operate through tiny incisions, perform delicate motions, and enable use of better sensors.
Robots can also enable otherwise impossible operations. For instance, a minimally invasive robotic surgery system being developed at DLR in Germany can operate on a beating heart. Today, heart surgery requires stopping the heart and invasively routing the patient's major blood flow through a heart-lung machine. The DLR system instead uses fast sensing and fast feedback to compensate for the motion of the heart with motion of the robots.
The surgeon, wearing virtual reality goggles, sees a static surface. Through haptic (touch) controls, the surgeon feels a static surface but the fidelity is so good that texture can be felt during an incision. Of course, at the patient, the actual tissue is moving rapidly, and the robots are moving along with it to compensate. The patient does not require open-heart incisions, grafts into major arteries or a heart-lung machine because the blocked coronary arteries are directly treated.
To make this work, the system must close a feedback loop between the sensors, robots, haptic effectors, and virtual reality display. That loop runs at 3kHz – 3000 times a second. Effective control requires latency variation (jitter) to within about 10 percent. Thus, this system requires data delivery, over a network, that is within a 30,000th of a second. RTI Connext DDS delivers. It demonstrates the potential of intelligent machines to benefit mankind in the Industrial Internet of Things.