«DeviceMed» has published a success story about Microdul’s miniaturized electronic module for a highly innovative neuromodulation system designed to reduce epileptic seizures.
Click here for the online version of the article: Mit Pulsen gegen Epilepsie
Click here for the PDF of the print edition: Mit Pulsen gegen Epilepsie
In addition, the article was published online on the industry magazines All About Industries (english) as well as Aktuelle Technik (german).
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EASEE—Epicranial Application of Stimulation Electrodes for Epilepsy—is an innovative neuromodulation system designed to reduce epileptic seizures. It treats the human brain using the FCS therapy method (Focal Cortex Stimulation) and significantly improves the well-being of those affected. A compact and highly complex PCBA (Printed Circuit Board Assembly) by Microdul ensures the reliable operation of this minimally invasive system.
Around 3 to 4 percent of the global population will develop epilepsy at some point in their lives. The condition is chronic and can be well controlled with medication in up to 70 percent of those affected. However, seizure-suppressing drugs are not effective enough for everyone. If seizures continue despite careful treatment, this is referred to as “drug-resistant epilepsy.” Around 70 percent of these patients suffer from focal epilepsy – in their cases, the PRECISIS treatment method may be a therapeutic option.
EASEE stimulates the focus in the cortex with electrical pulses through the skull without the patient feeling anything. The system consists of an electrode mat, a so-called Laplace electrode, which is placed under the scalp through a minimally invasive procedure—leaving the skull intact—and a flat electronic module that is placed on the chest muscle. The placement is customized for each patient, and the two units are connected subcutaneously with a stretchable cable.
The hermetically sealed pulse generator contains the electronic module and the battery. PRECISIS brought Zurich-based Microdul on board for the development and manufacture of the microelectronics. The company has many years of experience in medtech and has implemented high-quality PCBAs in more than 15 class 3 active implantable medical devices (AIMDs) that are successfully on the market – and make everyday life easier for well over half a million people.
One of Microdul's specialties is supporting start-ups that want to bring a high-quality device or implant to market on a limited budget. Young companies such as PRECISIS benefit from a partnership that lasts throughout the entire product life cycle, from prototype development and qualification to industrialization and series production in accordance with ISO 13485. This means that expertise and experience are incorporated into product development at an early stage, which prevents errors and helps to speed up market entry.
The challenge of EASEE lies in the flexible parameterization and precise control of electronic stimulation so that it is directed exactly to the right areas of the brain and activates or inhibits specific nerve cells as needed. Control is based on AI-based learning models that can be individually tailored to the patient's situation.
In addition to subgaleal implantation, the system is also unique in another respect: it uses two different stimulation paradigms. First, “DC-like stimulation” (DLS) is applied for 20 minutes per day to reduce the hyperexcitability of the epileptic network and thus reduce the seizure frequency in the long term (“long-term depression at the epileptic focus”). Secondly, high-frequency stimulation (HFS) is used every two minutes during the time when DLS is not being applied. This aims to suppress acute seizures. Both paradigms can be individually adjusted in terms of stimulation parameters.
The hardware core of EASEE is the densely populated PCBA, co-developed by Microdul, which takes up minimal space despite its complex layout and functions with absolute reliability. The PCB design contains many different SMD components, small and large ball grid arrays (BGAs), and a bare die (chip-on-board) installed in a very small space. The latter is connected by wire bonds and covered with a glob top for mechanical protection. An underfill is applied to a BGA for heat dissipation and stability.
The higher the component density, the more demanding the SMD assembly, BGA mounting, and bare die packaging. The qualification therefore covers all process steps from assembly and wire bonding to the application of the glob top cover, laser marking, and separation.
During the creation of the PCBA layout, risks, manufacturability, and sources of potential defects leading to off-spec units are identified in close cooperation with the customer (design for manufacturing). To ensure that PRECISIS delivers only modules of the required quality, the PCBAs are subjected to X-ray inspection, automatic optical inspection, and visual inspection (under a microscope). In addition, the bond connections in each production batch are tested destructively. The production tests are followed by a burn-in (accelerated lifetime test) to detect early failures. Before and after this stress test, the entire circuit is measured electronically.
To ensure consistently high quality, comprehensive statistical process control (SPC) is applied. From design development to production and quality testing, all processes are fully traceable, as required by ISO13485.
Thanks to the miniaturization of electronic circuits, medtech manufacturers can design smaller and more complex AIMDs. This in turn benefits patients: the smaller the medical device, the easier and safer the procedure.
Following CE approval of EASEE in 2022, Precisis has set its sights on entering the US market as its next major goal and recently received the green light from the US Food and Drug Administration (FDA) to start the necessary clinical trial.