OVMed medical image sensor is world's smallest commercial sensor

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OmniVision Technologies, Inc., a leading developer of advanced digital imaging solutions, today announced its new OH0TA OVMed® medical image sensor—with a package size of just 0.55mm x 0.55mm, featuring a 1.0 micron pixel and a 1/31” optical format—smaller than the Guinness World Record held by its predecessor for the “Smallest Commercially Available Image Sensor.” The OH0TA also quadruples the RGB image resolution to 400x400, or 160 K Pixels, at 30 frames per second, while reducing the power consumption by 20% to 20mW. This allows designers to add ultra-compact visualization to single-use and reusable endoscopes, as well as catheters and guidewires, with a small outer diameter of 1-2mm. Alternatively, this sensor’s uniquely small size gives medical device OEMs the flexibility to create a larger-diameter scope with a larger working channel.

The OH0TA’s increased resolution allows higher quality color images to be captured from within the body’s smallest organs, enabling medical devices to reach deeper into the body for procedures such as neuro, ophthalmic, ENT, cardiac, spinal, urology, gynecology and arthroscopy, as well as dental and veterinary diagnosis and surgery. Additionally, the sensor’s lower power consumption reduces “chip on tip” camera heat for greater patient comfort and longer procedure durations, while also reducing noise for crisper images.

“The trend toward minimally invasive procedures continues to grow, due to their greater success rates and shorter patient recovery times. However, for the narrowest areas of the anatomy, particularly in neuro and cardiac surgeries, previous sensors did not have the necessary combination of high resolution and extremely small size,” said Ehsan Ayar, medical product marketing manager at OmniVision. “The OH0TA is the world’s first sensor to offer this combination, enabling significant endoscope improvements, especially in comparison to traditional videoscopes made with optical fibers, which have limited resolution, poor imager quality and high cost.”

The market research and strategy consulting company Yole Développement (Yole) is expecting a 10.4% CAGR from 2020 to 2025, for the CMOS image sensor (CIS) industry. “Advanced node technology in CISs is bringing higher resolution, and innovative stack processes help to optimize the performance as well as the module size,” commented Chenmeijing Liang, technology and market analyst, imaging at Yole. “These state-of-the-art CIS technologies are meeting today’s key endoscopy requirements to support doctors in their diagnostic processes or surgical procedures with higher image quality and better contrast, while increasing patient comfort. They also allow less invasive imaging techniques for neurologic, ENT or pediatric applications without altering image resolution.”

To achieve this increase in resolution, along with a smaller pixel size and optical format, the OH0TA is built on OmniVision’s PureCel® Plus-S stacked die technology. This next-generation pixel technology also provides higher color fidelity and excellent low light sensitivity of 3600 mV/lux-sec, along with a high signal-to-noise ratio of 37.5dB for crisper images. Additionally, PureCel Plus-S enables the OH0TA’s higher full well capacity (FWC), zero blooming and lower power consumption.

Other key features include a 15.5 degree chief ray angle, enabling the use of lenses with high fields of view and short focus distances. It also supports a 4-wire interface, as well as raw analog data output, both of which can transmit via cables as long as 4 meters with minimal signal noise. For backward compatibility and easy adoption, this sensor interfaces with OmniVision’s existing OV426 analog-to-digital-conversion bridge chip. Additionally, it is autoclavable for reusable endoscope sterilization.

Samples of the OH0TA are available now, in OmniVision’s hCSP chip scale package with 100 micron thick cover glass and an anti-reflective coating.

OVMed OCHTA camera module

OmniVision has also introduced the OVMed® OCHTA camera module with quadruple the resolution of its predecessor, at 400x400, or 160 KPixels, for clearer images inside the body’s farthest recesses. This module features the CameraCubeChip™ wafer-level technology, enabling it to match the world’s smallest size of its predecessor, at 0.65mm x 0.65mm, for deep anatomical access. This technology also allows for the integration of OmniVision’s new higher-resolution OH0TA image sensor, the size of which is smaller than the Guinness World Record held by its predecessor, along with signal processing and wafer-level optics in a single compact package. With OCHTA camera modules, endoscope, catheter and guidewire OEMs can now develop mass-produced, single-use devices with 1-2mm optical diameters and higher resolution to address the many challenges posed by reusable equipment, including cross-contamination risks and high maintenance costs.

Yole Développement (Yole) continues to predict strong demand in single-use medical endoscopes, with an expected 27% CAGR between 2019 and 2025. Yole also predicts a US$241 million market at the end of that period for CMOS image sensor camera modules. “Reinforced by the COVID-19 pandemic, regulations from health authorities are strongly changing the endoscopy industry landscape,” explained Jérôme Mouly, team lead analyst, sensing and actuating at Yole. “The aim is to avoid cross contamination in high risk imaging procedures that use tiny endoscopes, like bronchoscopies, ureteroscopies or pediatric imaging diagnostics. Key requirements from caregivers include strong miniaturization of cameras, image quality increases as well as high contrast at low power to avoid any heat disturbances during procedures.”

“Previously, medical procedures on the body’s smallest anatomy were performed either blind or with low quality images from fiberscopes, as existing cameras were too big and reusable endoscopes were not cost effective,” said Aaron Chiang, marketing director at OmniVision. “The OCHTA wafer-level camera module maintains the industry’s smallest size while quadrupling the resolution for single-use endoscopes, catheters and guidewires, which reduce the cross-contamination risks and downtime inefficiencies of reusable devices, as well as costs from their repairs, preprocedural testing and sterilization.”

OmniVision remains the only company to offer ultra-small “chip on tip” camera modules with backside illumination (BSI), which provides excellent image quality and better low-light performance to help reduce LED heat and improve sensitivity. BSI also allows the use of superior lens technology over competing front-side illumination cameras in this class, while improving patient comfort and accelerating recovery time. Additionally, with OmniVision’s economical CameraCubeChip wafer-level packaging technology, the OCHTA makes possible the mass production of high-resolution, single-use medical imaging equipment.

This module’s small size enables devices that can reach deep into the body for neuro, ophthalmic, ENT, cardiac, spinal, urology, gynecology and arthroscopy procedures, as well as dental and veterinary diagnosis and surgery. Alternatively, its unique size gives medical device OEMs the flexibility to create a larger-diameter scope with a larger working channel. By integrating the image sensor, signal processor and wafer-level optics in a single compact package, the OCHTA also reduces the complexity of dealing with multiple vendors while increasing supply reliability and speeding development time. Furthermore, unlike traditional cameras, all CameraCubeChip modules are reflowable. This means they can be mounted to a printed circuit board simultaneously with other components using automated surface-mount assembly equipment, which increases quality while reducing assembly costs.

The integrated OH0TA image sensor is built on OmniVision’s PureCel® Plus-S stacked die technology, which enables this module’s increased resolution at 30 frames per second. Additionally, this next-generation pixel technology provides higher color fidelity and excellent low light sensitivity of 3600 mV/lux-sec, along with a high signal-to-noise ratio of 37.5dB for crisper images. It also offers higher full well capacity (FWC), zero blooming and 20% lower power consumption of 20mW for greater patient comfort and longer procedure durations, while reducing noise for crisper images. These images are further improved by the sensor’s new exposure and gain control settings, which allow endoscope designers to fine-tune captures—prior to processing—for the best possible video quality under the lighting conditions of specific procedures.

Other key features include a wide 120 degree field of view and an extended focus range of 3mm to 30mm. This module also supports a 4-wire interface, as well as raw analog data output, both of which can transmit via cables as long as 4 meters with minimal signal noise.

The OCHTA camera module is available now for sampling in the tray format.

Six images at relevant wavelengths to differentiate tumour cells. Credit: CEA-Leti

18 March 2021