Pressure for Oxygen Therapy

Welcome to All Sensors “Put the Pressure on Us” blog. This blog brings out pressure sensor aspects in a variety of applications inspired by headlines, consumer and industry requirements, market research, government activities, and you.

Pressure for Oxygen Therapy

Patients short of breath may need an oxygen concentrator to provide sufficient oxygen to make their breathing easier. Underlying health issues that could require the extra oxygen or oxygen therapy include asthma, lung cancer, chronic obstructive pulmonary disease (COPD), the flu and, most recently, COVID-19. Without requiring oxygen stored in tanks or containers, oxygen concentrators provide a continuous supply of oxygen that comes from the surrounding air.

Modern oxygen concentrators delivering about five to 10 liters of the gas per minute, typically at about 93% purity, are designed for either stationary (home) or portable usage. While a home oxygen concentrator may weigh less than 20 pounds, many portable oxygen concentrator models weigh less than 5 pounds.

Oxygen Concentrator

The oxygen concentrator uses a pump to compress the oxygen, filters or sieves to separate out nitrogen and other impurities, and pressure reducers to provide low pressure oxygen for patients to breath. With varying pressures and flow rates, different pressure sensors can be used at various points in the system. Any of the sensors for portable units need to be both small and light weight making microelectromechanical systems (MEMS) sensors ideal for these applications.

The low differential pressure measurements for flow are typically only a few kPA. Essentially, any of All Sensors DLHR, DLVR, ELVR, ELV and MLV series products that have respiratory pressure ranges will work for O2 concentrators in these ultra-low pressure applications.

All Sensors E1NJ Package

Do you have a pressure sensing question? Let us know and we’ll address it in an upcoming blog.
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Protecting MEMS Pressure Sensors with Parylene

Welcome to All Sensors “Put the Pressure on Us” blog. This blog brings out pressure sensor aspects in a variety of applications inspired by headlines, consumer and industry requirements, market research, government activities, and you.

Protecting MEMS Pressure Sensors with Parylene

Microelectromechanical systems (MEMS) pressure sensors provide accurate measurements for many applications. However, the top side of the piezoresistive MEMS pressure sensor die that has the sensing elements and potentially other circuitry cannot survive exposure to many common items that need to have their pressure measured — including water. To isolate the top surface of the pressure sensor die and other exposed circuitry, parylene is often used as a protective coating. Applied by a vapor deposition polymerization process, the parylene allows pressure to be transmitted to the top side of the pressure sensor to make measurements without damaging or impacting the reliability of the circuitry. The conformal, thin-film coating provides a moisture, chemical and dielectric barrier to protect the sensor’s critical circuitry in medical, automotive and other applications.

In fact, parylene extends the applications that a specific sensor design can address and is part of the packaging expertise that a sensor company may provide. Parylene coating can be found on a wide variety of All Sensors’ products. Specifically, parylene coating is available in all miniature digital product families such as the miniature digital DLVR, DLHR and DLLR Series as well as the millivolt output MLV series and the miniature digital and analog ELVR series.

All Sensors' E1BD Package

 

A protective parylene coating is an option for moisture/harsh media protection in the DLVR, DLHR and DLLR Series E1BD package.

Comments/Questions?
Do you have a pressure sensing question? Let us know and we’ll address it in an upcoming blog.
Email us at [email protected]