How brushless motors help enhance atherectomy procedures

Nicole Monaco, global marketing manager, Portescape, outlines the company’s role in partnering with a medical device OEM to assist in atherectomy procedures.

The atherectomy procedure is one of the most effective ways to remove arterial plaque and improve a patient’s blood flow. When a medical device OEM was searching for an alternative motor manufacturer for their atherectomy device, it was important that their new motion partner could optimize performance within the same form factor. With experience in providing motor solutions for handheld medical devices, Portescape was able to develop a customized solution while improving on the OEM’s original requirements.

At least 2.6 million people in the UK have narrowing of the arteries around the heart, which can lead to heart attack, angina, or both, while the American Heart Association estimates that more than 16 million Americans suffer from coronary artery disease, which is considered the number one killer for men and women in the US. A build-up of fatty material in the arteries can narrow them in a condition called atherosclerosis. Medical professionals say that the risk of suffering from this condition is increased due to aging, high cholesterol and blood pressure, smoking and inherited susceptibility.

A healthy lifestyle is recommended to reduce the onset of atherosclerosis. However, in more severe cases, which may lead to narrowing or blockage of the arteries, which may lead to impaired blood flow to various organs and tissues, the patient may need to undergo an atherectomy procedure. In this medical procedure, a thin tube is inserted into the affected artery through an incision in the skin. At the tip of the tube is a grinder, and through a combination of centrifugal force and sanding, fatty material, known as arterial calcification or plaque, is removed, or modified, within the artery. This procedure may also be combined with the insertion of a stent, which props up and supports the artery, either biodegrades over time, or remains within the patient.

high-speed operation

The critical speed for the atherectomy equipment is the solution that drives the grinder. As a result of combined operational and commercial considerations, a large medical equipment manufacturer needed to replace its originally specified motor. Portescape’s expertise in designing motion solutions for handheld medical devices enabled rapid development of the drop-in solution.

To meet the form factor and functionality requirements of the existing motor, the Portescape design team engaged with medical device OEMs. High motor speed was critical for grinding optimization, so Portescape engineers specified a two-pole design in brushless DC (BLDC) format. The friction-free operation of the brushless motor, along with the improved control provided by electronic commutation, enabled it to achieve greater speeds. With this in mind, the Portescape engineering team specified the Ultra EC16ECS brushless DC motor design, capable of meeting the high speed target at the required torque. The Ultra EC design also increases torque density and helps provide smooth control critical to the precise requirements of an arterial procedure.

Given the compact size required for a hand-held device, the thermal efficiency of the motor was an additional factor to consider. The OEM specified a lower motor operating temperature because surgeons needed to hold the instruments during the procedure. The slotless BLDC motor’s frictionless operation is enhanced by the Ultra EC 16ECS’s low iron loss at high speeds, which is achieved due to the motor’s proprietary U coil technology. This efficient design allowed the PorteScape to meet high-speed requirements while ensuring low operating temperatures, even within a compact package.

fast optimization

To ensure fast and seamless integration without the need for OEM redesign, Portescape’s engineering team was able to optimize the motor and provide exact replacements in the connections, as well as the form factor. As a result of the new partnership, the medical device OEM has increased performance and improved heat management of its atherectomy devices while maintaining the same compact dimensions and reduced weight. These improvements have helped increase the availability of life-saving technology in new markets.