Optical Sensor Assembly in Catheter-Based Medical Devices Protecting the Sensor Inside a Heart Pump

This patent describes how to mount and protect a light-based sensor inside a catheter-mounted blood pump, using a cured silicone filling that shields the sensor without fouling the optics. It comes from Abiomed, Inc., an American maker of heart support devices.

The Problem

Tiny blood pumps that are threaded into the heart on a catheter can take over some of the work of a failing heart. To run safely they need sensors, including optical sensors that read signals through light, mounted right in the device. Placing a delicate optical sensor inside a device that sits in flowing blood is difficult: the sensor must be sealed against blood and moisture, held firmly in place, and yet the light path must stay clear, because any stray material over the optical window ruins the reading. Potting compounds used to protect electronics can overflow and coat the very surfaces that must remain transparent. The challenge is to protect and fix the sensor while keeping its optical window clean and its housing reliable.

What This Invention Does

The invention is an optical sensor assembly for a blood pump. A visor is affixed to the pump housing, and a support jacket contacts the inner surface of the visor and defines a cavity that holds the optical sensor. A silicone composition is introduced into the cavity, where it cures and protects the sensor. The support jacket does double duty: it locates the sensor and, importantly, it prevents the silicone from overflowing and contaminating the visor, so the optical window stays clear. The silicone itself is engineered as a mix of a silicone component and a plasticiser, with the ratio between them chosen to tune properties such as rigidity, tackiness, adhesion strength, viscosity, shelf life, and curing behaviour. That lets the assembly balance a firm, protective set against the flow and handling needs of manufacturing, giving a sensor that is both well protected and optically clear.

Key Features

• Sensor cavity. A support jacket against the visor defines a cavity that houses the optical sensor.
• Overflow control. The support jacket stops the silicone from overflowing and contaminating the visor’s optical surface.
• Cured silicone protection. A silicone composition is introduced into the cavity and cures to protect the sensor.
• Tunable silicone. A silicone-to-plasticiser ratio is chosen to set rigidity, tackiness, adhesion, viscosity, and curing.
• Catheter-scale design. The assembly is built to fit inside a catheter-mounted blood pump.

Who Is Behind It

The applicant is Abiomed, Inc., a Massachusetts-based company known for the Impella family of catheter-based heart pumps, now part of Johnson & Johnson MedTech. The named inventors include Tao Zhang, Zhenghong Tao, and Soumen Das. This filing is a divisional application from an earlier related Australian application.

Why It Matters

Circulatory support devices are used in some of the most critical moments in cardiac care, and their sensors have to work flawlessly inside the body. A robust way to protect an optical sensor while keeping its light path clear improves the reliability of these devices at the scale of manufacturing, where consistency matters as much as the design itself. Protecting the assembly in Australia supports the availability of advanced ventricular assist technology in its hospitals.

Related Concepts

• Impella – the catheter-based heart pump family this sensor supports.
• Catheter – the delivery route for the pump and its sensor.
• Photodetector – the type of optical sensor being protected.
• Ventricular assist device – the broader class of mechanical heart support.
• Silicone – the protective material tuned for the sensor cavity.

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AU 2026202022 was published in the Australian Official Journal of Patents on 2 April 2026 and is open for public inspection. Patent applications represent inventions that are sought to be protected and do not necessarily reflect commercially available products.