Most medical diagnostic and testing equipment involves some type of enclosure, cart, or cabinet that serves as a user workstation or protects sensitive electronics, controls, and hardware. Although not as sophisticated as the actual diagnostic device itself, these enclosures are nevertheless critical to the use and overall service life of the finished product.

Highly automated manufacturing capabilities such as painting, welding, and laser cutting are ideal for production-level quantities.

However, there is often more to forming these types of enclosures than meets the eye. The ability to create component parts with tight tolerances ensures that individual components fit and work to the design intent. Selecting the correct finish for the application is another important factor.

Even the precise placement of electronics and hardware requires careful consideration. The cabinet or cart must allow for easy use and movement by the operator, and its design must take into account any other ergonomic considerations. A good design also provides ease of maintenance and repair, as well as accommodations for future upgrades.

To accomplish this, medical device manufacturers may turn to contract sheet metal fabricators for the enclosure, which enables them to concentrate on the core device or diagnostic technology. For production-level quantities, this often means utilizing contract manufacturers with highly automated capabilities.

In addition to speeding production, this approach provides a significant benefit when producing medical enclosures: increased precision of the component parts, often at a lower cost. Some sheet metal fabricators even provide full assembly, packaging, and direct-to-customer shipping of the enclosure with all of its other component parts. This article looks at the path of a cardiac platform cart through the manufacturing process.

Soteria Cardiac Platform

Soteria Medical, a medical device company based in Miama, FL, employed the automated processes of a contract manufacturer to improve the production and precision of the cart for the Soteria Cardiac Platform, a noninvasive medical procedure designed to detect atherosclerosis at the earliest possible stages.

Atherosclerosis, or hardening of the arteries, is responsible for more than half of all deaths in the developed world, including the United States. The disease silently blocks blood flow, and pieces of plaque can break off and clog the arteries.

“Over a million deaths in the U.S. annually are due to atherosclerosis,” says Dr. Jeffrey Raines, CEO of Soteria Medical. “We developed the first device that quickly, accurately, and noninvasively measures arterial buildup so it can be addressed at earlier stages to change the trajectory of the disease. “The company, which will present as one of the 10 most innovative small businesses in the U.S. at the Small Business Administration 2018 Client Showcase on Capitol Hill, developed a 15-minute test, called the Soterogram. The test uses pressure cuffs on the patient’s arm, calf, and thigh to measure volume changes in the arteries in order to measure compliance of the artery wall. According to the company, because the Soterogram focuses on the disease state of the arterial wall, it is not “blinded to disease not producing abnormal hemodynamics such as flow, velocity, and pressure abnormalities.”

Careful Creation of the Cart

With a general concept of the proposed cabinet’s specifications, the contract manufacturer was able to create CAD drawings from Soteria’s input, which also included feedback from focus groups including doctors, nurses, and engineers.

To create a cardiac platform on a custom cart that would be suitable for hospitals, clinics, and doctors’ offices, the company required design and development assistance. The platform would include additional modules for registration, evaluation of lower extremity peripheral artery disease, and other testing and functions as well. The cart must be easy for the nurse or technician to maneuver because access is needed to the back of the display to connect the pneumatic lines to the cuffs as well as to the front of the display for entering patient information via a keyboard and conducting the tests.

After a previous medical cart did not meet all of its requirements, the company turned to Precision Metal Industries (PMI), a Pompano Beach, FL-based sheet metal and precision machining contract manufacturer that has fabricated tens of thousands of custom enclosures for the medical industry.

Soteria approached PMI with a verbal project description but very few specifics regarding the desired look and feel of the cart. PMI was tasked with creating the best possible design, developing a plan for full manufacturing, and delivering a high-quality final product. When PMI met with Soteria’s team, Soteria provided only a general concept of the proposed cabinet’s specifications, which needed to contain an array of specialized medical equipment, including the pneumoelectric package that generates the Soterogram measurements, the Hewlett-Packard system for processing the platforms’s four modules, various sizes of blood pressure cuffs, a keyboard, and a CPU monitor.

Precision Metal Industries (PMI) employed a variety of automated manufacturing capabilities to fabricate a custom cart capable of housing and protecting the sensitive equipment for Soteria Medical.

With these requirements, the contract manufacturer was able to create CAD drawings from Soteria’s input, which also included feedback from focus groups including doctors, nurses, and engineers.

Soteria granted PMI full license to create a design that would employ its any necessary manufacturing capabilities to fabricate a custom cart capable of housing and protecting the sensitive equipment.

After completing detailed plans, PMI utilized sheet metal forming and machining, as well as welding and automated laser cutting, to manufacture the cabinet. Special care was taken to not only create the most accurate and functional cabinet possible, but also to provide an aesthetically pleasing product with a smooth, durable finish.

According to Raines, Soteria once had its own facility for manufacturing and assembly but chose to outsource this part of the product to improve the quality of the cart and the efficiency of the manufacturing process. He selected, PMI in part because it is ISO 9001:2008 certified and utilizes a sophisticated quality management system.

“Having a clear quality assurance program is vital to us and the FDA and must be present in order to sell, lease, or place this type of medical device,” says Raines.

Toward this end, Raines acknowledges that automation can do much to reduce human error and improve quality. As such, working with a contract manufacturer that can automate the manufacturing processes such as laser cutting and machining to make medical enclosures can be an effective strategy.

PMI uses tools such as this CNC press brake for creating U bends, V bends, and custom forms from flat metal sheets, as well as for folding.

Custom automated laser cutting is among the most effective processes for cutting plate or sheet metal for fabrication. The technology allows cutting precise, accurate geometric shapes, no matter how irregular or unusual they may be. Once programmed, it requires zero setup time and allows unattended lights-out processing for efficient longer runs on a 24/7 basis, which can expedite production and lower cost.

In the same vein, advanced CNC (computer numerical control) press brakes can help to ensure precision bending and forming, with software minimizing setup and lead times. CNC allows for very close control of positioning, velocity, coordination, feed rates, and other precision aspects of the manufacturing process for a particular part or object.

As an example, PMI follows such an approach, to include very precise, fully automated robotic bending and forming that can also be done in an efficient, lights-out fashion with minimal labor, setup, and lead times. This can involve tools such as CNC press brakes for creating U bends, V bends, and custom forms from flat metal sheets, as well as for folding. With off-line programming software capability, once setup is done, such equipment eliminates human variability and ensures a repeatable, reliable process.

This exploded view shows the various pieces that had to be machined for the medical cart. After completing detailed plans, PMI utilized sheet metal forming and machining, as well as welding and automated laser cutting, to manufacture the cabinet.

Automated robotic welding, with a robotic welder positioned in a specially configured cell, can also perform with extreme consistency, repeatedly producing perfect welds in the most efficient way. The precision of robotic welding makes both the process and final product very neat with little splattering and controlled seams. Such welding minimizes human error, improves reliability, and maximizes yields, which ultimately reduces cost.

Additional finishing and assembly capabilities were also critical to the manufacture of the Soterogram cart. Automated finishing services utilizing spray booths and ovens, for example, were used to apply wet paint or powder coat on parts. The specific finish is designed to withstand the harsh cleansers and disinfectants frequently used in medical settings. According to Raines, the contract manufacturer also carries out additional duties that help to streamline the entire fulfillment process.

“Based on a bill of materials and detailed specifications provided by us, PMI purchases the electronics and accompanying hardware, which includes a pump, exhaust valve, blood pressure monitor, air manifold, piston, linear actuator, and other items,” says Raines.

The contract manufacturer then assembles the components into a working custom cart and even calibrates the system using special software designed by Soteria. By streamlining the manufacturing process and by completing the entire project in its own facility, PMI was able to provide substantial cost savings and a fast lead time for Soteria.

After the design, manufacturing, and delivery processes were completed, PMI received a report that the cabinet provided the functionality required and fulfilled all the requirements the original model had been unable to fulfill — at a lower cost as well.

“It starts out as sheets of metal and when [PMI] is done it comes back as the Soteria Cardiac Platform,” says Raines. “Under our instructions, they also package and ship the carts to expedite delivery.”

“With the automated manufacturing processes of our contract manufacturer, the quality from PMI is better than if we built it in house as the OEM,” says Raines. “When it can be built and assembled better, faster, and cheaper that way, it makes sense to do it.”

Soteria is already reaching out to PMI for other projects involving new medical cabinets that will be used in a variety of medical environments.

This article was written by Gregory S. Wilson, Vice President and General Manager of Precision Metal Industries, Inc., Pompano Beach, FL. For more information, visit here .