Pictured: SpectraWAVE
SpectraWAVE is developing a medical imaging platform that provides high resolution plaque structure and content in coronary blood vessels.
The imaging data aids cardiologists during stent optimization and in their assessment of the patient’s risk for future adverse events.
By combining two state-of-the-art technologies, SpectraWAVE’s system is designed to help interventional cardiologists optimize PCI and improve their patient outcomes.
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The coronary is like a mesh of narrow arteries that supply heart tissue with oxygenated blood. Without blood, tissue loses oxygen and cells die.
Coronary artery disease (CAD), the buildup of plaque in the wall of the coronary arteries that supply blood to the heart, causes nine million deaths worldwide each year.
Sometimes heart disease may be “silent” and not diagnosed until a person experiences signs or symptoms of a heart attack, heart failure, or an arrhythmia.
Dangerous lipid rich plaque can build up in the vessel and rupture, causing a clot. A heart attack can occur when a blood clot blocks flow to the muscle.
Cardiologists perform interventions and may recommend medication therapy, diet, exercise, change of lifestyle.
Coronary artery disease causes nine million deaths worldwide each year
A heart attack occurs when the flow of blood to the heart is severely reduced or blocked.
The blockage is usually due to a buildup of fat, cholesterol and other substances in the heart (coronary) arteries.
The fatty, cholesterol-containing deposits are called plaques. The process of plaque buildup is called atherosclerosis.
Cardiologists perform interventions and may recommend medication therapy, diet, exercise, change of lifestyle.
A percutaneous coronary intervention is a minimally invasive procedure to open blocked coronary arteries. Also known as coronary angioplasty with stenting or angioplasty for short.
Four million X-ray guided PCIs are performed per year to battle heart disease.
Intravascular imaging is utilized during PCI and similar procedures using imaging catheters.
A PCI procedure uses a small balloon to reopen a blocked artery to increase blood flow to the heart tissue.
Usually, an interventional cardiologist then places a small, permanent tube (stent) to keep the artery open long term. The stent usually contains medication that releases directly into your artery (drug-eluting stent) to reduce the risk of re-narrowing within the stent.
Patients can undergo stent placement to relieve symptoms, but one in five patients can experience a major adverse event within two years.
A cardiac catheterization lab, also known as a "cath lab,” is a specialized area in the hospital where doctors perform minimally invasive tests and advanced cardiac procedures to diagnose and treat cardiovascular disease.
Diagnostic cardiac catheterization is recommended whenever it is clinically important to define the presence or severity of a suspected cardiac lesion that cannot be evaluated adequately by noninvasive techniques.
The information obtained is crucial to optimize the selection of mechanical or medical therapy.
There are a variety of state-of-the-art medical imaging tools used in interventional cardiology today.
Some of them use technologies similar to X-ray in order to see through the body. Others use narrow catheters with sensors in the tip that allow doctors to see inside a patient's blood vessels.
Intravascular echocardiography is a medical imaging methodology using a specially designed catheter with a miniaturized ultrasound probe attached to the distal end of the catheter. The proximal end of the catheter is attached to computerized ultrasound equipment. It allows the application of ultrasound technology to see from inside blood vessels out through the surrounding blood column, visualizing the inner wall of blood vessels.
The arteries of the heart (the coronary arteries) are the most frequent imaging target for IVUS. IVUS is used in the coronary arteries to determine the amount of atheromatous plaque built up at any particular point in the epicardial coronary artery.
Collapse detailsNear-infrared spectroscopy (NIRS) is a spectroscopic method that uses the near-infrared region of the electromagnetic spectrum. Typical applications include medical and physiological diagnostics and research including blood sugar and lipid rich plaques.
Near-infrared spectroscopy is based on molecular overtone and combination vibrations. Instrumentation for near-IR (NIR) spectroscopy is similar to instruments for the UV-visible and mid-IR ranges. There is a source, a detector, and a dispersive element (such as a prism, or, more commonly, a diffraction grating) to allow the intensity at different wavelengths to be recorded.
Collapse detailsFluoroscopy is an imaging technique that uses X-rays to obtain real-time moving images of the interior of an object. There are two main sub-category of Fluoroscopy. Larger, typically Floor, Wall or Ceiling mounted device often called Cath Lab. A fluoroscope allows a surgeon to see the internal structure and function of a patient mainly during surgery so that the pumping action of the heart can be watched. This is useful for both diagnosis and therapy and occurs in general radiology, interventional radiology, and image-guided surgery.
Fluoroscopy is similar to radiography and X-ray computed tomography (X-ray CT) in that it generates images using X-rays. The original difference was that radiography fixed still images on film, whereas fluoroscopy provided live moving pictures that were not stored. However, today radiography, CT, and fluoroscopy are all digital imaging modes with image analysis software and data storage and retrieval.
Collapse detailsAngiography or arteriography is a medical imaging technique used to visualize the inside, or lumen, of blood vessels and organs of the body, with particular interest in the arteries, veins, and the heart chambers. Modern angiography is performed by injecting a radio-opaque contrast agent into the blood vessel and imaging using X-ray based techniques such as fluoroscopy.
Depending on the type of angiogram, access to the blood vessels is gained most commonly through the femoral artery, to look at the left side of the heart and at the arterial system; or the jugular or femoral vein, to look at the right side of the heart and at the venous system. Using a system of guide wires and catheters, a type of contrast agent (which shows up by absorbing the X-rays), is added to the blood to make it visible on the X-ray images.
The X-ray images taken may either be still, displayed on an image intensifier or film, or motion images.
Collapsible detailsAn endoscopic technology that uses a catheter to deliver and collect near infrared light– creating cross-sectional images of the artery lumen and wall– helping physicians to understand morphology and plan treatment. It's used as guidance for intervention of coronary arteries, including optimization of stent implantation.
OCT creates images at an improved resolution with respect to intravascular ultrasound and X-ray coronary angiogram.
Collapse detailsPhysicians and other medical professionals utilize imaging devices designed to help optimize performance during procedure and improve their patient outcomes.
Imaging data aids interventional cardiologists during stent optimization and in their assessment of the patient’s risk for future adverse events.
Devices used in medical imaging are considered medical devices by the FDA. Most medical imaging technologies are non-510(k)-exempt Class I and II medical devices, making them eligible for clearance under the 510(k) pathway.
Under this pathway, a next-generation imaging technology may be found substantially equivalent to an existing one. However, the intended use and overall purpose must remain essentially unaltered. The indications for use define the particular conditions or locations to which the device is to be applied.
Any technological differences in comparison to the predicate device must not raise new questions of safety or effectiveness. If a new intended use is sought, or if the technology raises new questions of safety or effectiveness when compared with the predicate, the new device is designated as Class III and requires a premarket approval (PMA) application.
https://www.mddionline.com/
radiological/medical-imaging-basics-fda-regulation
510(k) clearance is authorization from the FDA to market a medium-risk medical device, while PMA (premarket approval) is required for more high-risk and novel products. The PMA process requires a demonstration of safety and effectiveness prior to the granting of marketing approval. PMA submissions typically take longer to secure and require more evidence such as clinical trial data, to prove that a device is safe and effective for its intended users.
Under the 510(k) pathway, new medical devices may be cleared for the U.S. market if they are substantially equivalent to existing, legally marketed Class I and II devices in terms of indications for use and technological characteristics.
These legally marketed devices of which new devices are compared are referred to as predicate devices.
Predicate devices
Descriptions comparing a device to another can be tricky. The difficult balance is that you need your device to be shown to be novel and unique, but not so different that the FDA thinks that your predicate used is not a good example. In this case, multiple multiple predicates are needed for multiple technologies being combined.
Products also needs to be slightly different in order not to infringe on competitors' IP. This is also challenging because you need to demonstrate why all the differences don’t matter. Device developers must demonstrate that equivalence and comparison for 510(k) clearance.
This involves designing tests that can verify equivalence, formally and informally.
The FDA authorized the Safe Medical Device Act of 1990 to expand the scope of current Good Manufacturing Practice to impose more control over the development process of medical devices. The intention was to avoid uncontrolled changes during the design process and afford more predictability to ultimately avoid previously unforeseen problems. With this came Design Controls.
Design Controls are like a formalized structure of development steps and conduct for development of medical devices. You determine which goals needs to be achieved in order for a design to be validated, then you act on ways which will reach those goals, documenting each step. The point is to keep focused, clear and concise, avoid errors and unnecessary features or waste. This involves planning in the early stages then fleshing out the details step-by-step until you have a device deserving of a clearance.
A general purpose of design controls is also to ensure that a plan is in place for the design, development and manufacturing of a product. This includes layers of required documentation that show the FDA exactly how you have provided for the safety and efficacy of your new device.
The purpose of the subsystem controlling the design process is to assure that devices meet user needs, intended uses, and specified requirements.
The process breaks down into five sections which get outlined in a design matrix and documentation.
First we're understanding user needs as requirements, then identifying those requirements as inputs, developing design solutions as outputs, verifying that those design outputs meet the inputs, then validating the solutions. After a prototype is developed the process is also controlling design changes, reviewing design results, transferring the design to production, and compiling a design history file help assure that resulting designs will meet user needs, intended uses and requirements.
Every step is ultimately supported by documentation in the Design History File and every document and component in the DMR must be well controlled.
A design history file (DHF) is a collection of records that describe the design history of a finished medical device. The DHF may include records such as design inputs and outputs, engineering change orders, and design review documentation. The FDA specifies requires each manufacturer to establish and maintain a DHF for each type of device which contain docs necessary to demonstrate the design was developed in accordance with the design plan and the requirements.
Design for manufacturability (DFM) is the practice of designing products in a way that makes the manufacturing process more efficient. The end goal is to produce high-quality products at a lower cost. A well-executed DFM process begins early on in the design phase and continues throughout the entire product lifecycle. It should involve a cross-functional team from engineering, quality, purchasing, and manufacturing as well as external supply chain partners. Getting input from all key stakeholders helps mitigate production issues, improve quality, and reduce the cost of goods sold (COGS).
Five fundamental principles underpin DFM, all of which must be carefully taken into account during the design phase:
User-centered design is a framework of process (not restricted to interfaces or technologies) in which usability goals, user characteristics, environment, tasks and workflow of a product, service or process are given extensive attention at each stage of the design process.
These tests are conducted with/without actual users during each stage of the process from requirements, pre-production models and post production, completing a circle of proof back to and ensuring that "development proceeds with the user as the center of focus.
Cardiologists are doctors who have extra education and training in preventing, diagnosing and treating heart conditions. They are experts on the heart muscle itself and the arteries and veins that carry blood.
Interventional cardiologists use non-surgical procedures to repair damaged or weakened arteries, veins, and other parts of the heart.
A surgical technician usually assists in the operating room before, during, and after an operation, such as setting up the operating room equipment and instruments.
Also known as a scrub tech and an essential member of the surgical team, and they work under the supervision of a registered nurse (RN) or surgeon. Their primary responsibility is to help prepare the patient and operating room prior to surgery, maintain sterile conditions during the procedure, and assist other team members throughout the process.
A scrub nurse, also called a perioperative or operating room (OR) nurse, plays a key role in providing safe and effective medical care by serving as an assistant to the surgeon during operations.
A scrub nurse usually takes part in an operation by directly handling the instruments necessary for surgery.
In addition to these responsibilities, operating room nurses may handle specimens taken during surgery and apply dressings or sutures, among other duties.
We submitted the prototype to a usability study and sought feedback from cardiologists who work with OCT and IVUS systems.
User interviews are guided interviews where a researcher asks existing or potential users questions to gain an understanding of their preferences, thoughts and feelings.
User interviews can be used to examine the user experience and usability of a product or service, as well as flesh out demographic or ethnographic data for input into user personas.
An important consideration is how to integrate usability tests into the software development life cycle.
Summative usability tests:
Formative usability tests:
Testing throughout helps identify usability issues that would create significant schedule problems if discovered downstream.
A user story is a simple description of a feature told from the perspective of the person who desires the new capability. They typically follow a simple template:
As a < type of user >, I want < some goal > so that < some outcome >
Historically user stories were kept informal, written on cards or sticky notes and arranged to facilitate planning and discussion. Their impermanence made it easy replace them with new stories as more was learned about the product being developed.
User stories are designed to strongly shift the focus from writing about features to discussing them.
Procedures
Task analysis
Medical staff are constantly trying to improve contact-to-catheterization timing.
Learning from people who work in this industry using similar devices and seeing them use the software interfaces throughout predicate research helps to point out expectations from the user.
This also sheds a bit of light on the features that are overlooked or underused.
Human factors/usability engineering focuses on the interactions between people and devices.
To understand the user-device system, it's important to understand the ways that people:
Human factors/usability engineering is used to design the user-device interface. The user interface includes all components with which users interact while preparing the device for use (e.g., unpacking, set up, calibration), using the device, or performing maintenance (e.g., cleaning, replacing a battery, making repairs).
https://www.iso.org/
standard/52075.html
ISO 9241-210:2010 provides requirements and recommendations for human-centered design principles and activities throughout the life cycle of computer-based interactive systems. It is intended to be used by those managing design processes, and is concerned with ways in which both hardware and software components of interactive systems can enhance human–system interaction.
The FDA requires user interface specs for medical devices but a robust specification establishes design specs, which inform the experience users ultimately have with your product and overall brand. The user interface is the connection between humans and the developed machine.
The commercial success of a medical device is largely dependent on a positive user experience.
(https://en.wikipedia.org/wiki/IEC_62366)
In IEC standard 62366-1, they state:
The user interface is the means by which the user and the medical device interact. User interface includes all the elements of the medical device with which the user interacts including the physical aspects of the medical device as well as visual, auditory, tactile displays and is not limited to a software interface.
It’s important to call out, as the IEC does above, that user interface and digital interface are not synonymous.
Touchscreen devices have invaded all aspects of our lives. As a result, the term ‘user interface’ has become generic and mostly associated with digital user interfaces — like smartphone touchscreens. However, the medical device industry and the applicable standards it adheres to refer to these digital user interfaces as graphical user interfaces — or GUI for short.
The term GUI might seem outdated or even clunky to contemporary designers. Still, in the healthcare industry often adopts the IEC and FDA terminology to avoid miscommunication, confusion, and conflation.
A user interface encompasses all the ways a user and a device interact. IEC 62366-1 defines a user interface specification as:
A collection of specifications that comprehensively and prospectively describe the user interface of a medical device.
The first step is to gather and document the interface requirements before generating the user interface specification. As defined in IEC 62366-2, user interface requirements ensure your user interface ascribes to good usability engineering principles and meets needs identified by user research. Both the United States (21 CFR part 820.30) and the international community (ISO 13485) mandate these requirements.
Product design process: the set of strategic and tactical activities, from idea generation to commercialization, used to create a product design. In a systematic approach, product designers conceptualize and evaluate ideas, turning them into tangible inventions and products. The product designer's role is to combine art, science, and technology to create new products that people can use.
At some point, designs need to advance from concepts to working prototypes, or prototypes to functional software.
Software teams have their own way of approaching their tasks in developing a product.
The waterfall model is a breakdown of project activities into linear sequential phases, meaning they are passed down onto each other, where each phase depends on the deliverables of the previous one and corresponds to a specialization of tasks.
The approach is typical for certain areas of engineering design. In software development, it tends to be among the less iterative and flexible approaches, as progress flows in largely one direction ("downwards" like a waterfall) through the phases of conception, initiation, analysis, design, construction, testing, deployment and maintenance.
In software development, agile practices include requirements discovery and solutions improvement through the collaborative effort of self-organizing and cross-functional teams with their end users, adaptive planning, evolutionary development, early delivery, continual improvement, and flexible responses to changes in requirements, capacity, and understanding of the problems to be solved.
Working in two-week sprints, feedback is addressed between design phases. New deliverables or adjustments to exhisting designs, including flow diagrams, component requirements, documentation, wireframes, visual designs or prototype applications.
