Medical Endoscope Camera Assembly and Working Channels

Imaging sensors are smaller than they have ever been. As a result, the medical device market strives to minimize our impact on the patient while at the same time improving their care.

Regardless of size, the give and take between form and function remains consistent.

Medical device engineers continue to ask themselves:

• What functionality are we willing to concede to achieve certain size and form factors?
• What are the functionality requirements that are a must and how do these requirements dictate size and form factors?

As you begin to design and develop a device that incorporates an imaging sensor and a working channel assembly, there are a few questions you’ll want to pose to your project management team to achieve an answer about your specific product.

In this blog, we’ll pose a few questions to get the discussion started and help you progress along the path of designing, developing, and producing devices that improve the quality of one’s life.

Determining the Miniature CMOS Camera and Assembly Size

Camera Image Quality Tradeoffs

ATL partners with Omnivision, their product line of medical-specific sensors ranges from 1080p digital sensors to 200 x 200 analog micro CMOS camera module sensors. As expected, the 1080P sensor in similar volumes to the 200 x 200 analog micro CMOS camera module sensor carries with it a higher per-piece price.

An example of Omnivision’s efforts to support the market with various product offerings, is they have two versions of their 400 x 400 sensor, one that is ~1mm x 1mm and another that is ~.65mm x .65mm. Achieving the same image quality in two different form factors carries the same situation. The smaller device carries with it a higher per-piece price than the larger version.

The tradeoff questions: Can your device and the associated medical procedure utilize a larger form factor camera assembly in conjunction with your desired working channel size? Or does your procedure and desired working channel size require the smaller form factor camera assembly while still requiring the 400 x 400 image quality?

Ask these questions:

• What image quality do we need?
• How does that impact cost and working channel size?

Medical Device Camera Cost Tradeoffs

Everything small is bigger.

Let’s start by considering the components required to support a camera assembly that is designed around an imaging sensor that is .65 x .65 millimeters in size.

ATL utilizes our patented CHIP-ON-TIP® perpendicular attachment method as a starting point when we assemble a camera assembly. This method has the imaging sensor positioned perpendicularly on a PCBA.

As a result, the PCBA is smaller, the wiring to support the CHIP-ON-TIP® assembly is smaller, the LED(s) to drive the light becomes smaller, and the handling and assembly of all these items become a bigger challenge and as a result increase the costs associated with such a device.

Ask these questions:

• Do we need the smaller assembly, or can we utilize a larger assembly?
• How does this decision impact the working channel?

Medical Imaging Camera Lighting Tradeoffs

In our blog post, Medical Endoscope Camera Light Source Options we discuss methods for lighting a medical device.

Based on the device, shaft length, and construction you could utilize a fiber to drive light to the distal end of the device.

If you chose LED as your method of illumination, and based on your procedure, you could choose from 1 to as many LEDs as appropriately fit into your predetermined space.

Ask the question:

• How much light does our medical procedure require?

There are a myriad of other questions that could be asked about sensors and their impact on cost, form, and functionality. For now, we’ll stop here and shift our thought considerations to the working channel questions.

Determining the Endoscope Working Channel Size

Is Our Working Channel Endoscope Intended for a Stagnant or Articulating Channel?

Before you proceed, determine if your device will have a stagnant or articulating section.

After you work through the questions below, remember to do the math and generate the calculations to ensure your working channel will support your use case when articulated.

Ask the question:

• What is the size requirement for the working channel when the device is posed at 90°, 180°, or 270°? (Based on your product requirement)

Which products and devices will we need to send through the endoscope working channel?

Start by listing all the products and devices that will need to be sent through your device, including retrieval devices, balloon-based devices, and other procedural devices.

In another column consider listing how often each is used. Designing around a product or device that “might” be used could add size and cost to your overall assembly.

Ask these questions:

• Have we captured all possible devices?
• Which should we truly design around?

What are the Sizes of Those Medical Procedure Products and Devices?

Create a column to capture the sizes of each product or device. Once you know the largest device you need to send through your endoscope working channel, you can establish a product size variance and then finalize your working channel size.

Ask the question:

• How much space do we have between the Outer Dimension of the working channel and the Inner Dimension of the outer shaft? (The difference between the two is the space available for the camera assembly).

Determining The Best Way to Move Forward with Your Endoscopic Medical Device

At this point I hope you are on the way to being able to validate why you are considering the working channel size you are suggesting, the imaging sensor you desire, and how the two components, when married together, will achieve your desired outcome.

There are off-the-shelf camera assemblies, such as PREVOYANCE® that enable medical device engineers to start at square two by removing the challenge of having to develop a camera assembly.

These types of off-the-shelf assemblies are a good way to conceptualize your vision in physical form quickly to achieve your desired outcome.

By recognizing the procedural requirements and limitations you’ll be able to initiate specification discussions and identify your direction.

Knowing the product offerings and their associated limitations will put you in a better position to succeed.