​【98】When the catheter needs to enter a blood vessel narrower than a hair

【98】When the catheter needs to enter a blood vessel narrower than a hair

This morning, as the video conference from Boston Scientific in the US was just connected, the director of research and development from the other side immediately shared the microscopic image on the screen. It was a close-up of the interior of a metal tube as thin as spider silk. His tone was full of astonishment: "We have tested it seven times, and the inner diameter is indeed 0.19 millimeters. How did you do it? The suppliers from Germany and Japan all said this was the physical limit." After the meeting ended, I walked to the company's honor wall and looked at the patent certificate that had been hung in the center three months ago - that was the 17th invention patent we applied for for this 0.19-millimeter micro catheter coil.

The story began nine months ago. At that time, the world's leading vascular interventional equipment company approached us. They were developing the next-generation neuro-interventional catheter and needed to integrate an electromagnetic positioning coil inside a 0.2-millimeter-diameter catheter. But the solutions provided by the three top suppliers worldwide all failed - the smallest inner diameter could only reach 0.25 millimeters, and the yield was less than 30%. "If you can solve this problem within one year," the Chinese-American chief scientist Dr. Wang wrote in the email, "it will be a revolution in the field of neuro-interventional."

The entire team clearly understood what this meant. The human brain's smallest blood vessels have a diameter of only 0.2 millimeters. To have the catheter carrying the treatment equipment pass through them, there was almost no space left for the coil. Our first challenge was very specific: to reduce the wall thickness of the coil from the conventional 0.05 millimeters to 0.015 millimeters, which was already close to the theoretical limit of metal materials. The more difficult part was that the coil also needed to remain undamaged after being bent 10,000 times with a bending radius of 0.5 millimeters.

The most difficult stage came in the fourth month. The seventh alloy material we tried performed well in the tests, but when we started to produce a sample with an inner diameter of 0.19 millimeters, the stamping molds broke thirteen sets in a row. Old Chen, the mold engineer, suddenly stared at the microscope and said, "We are going in the wrong direction. The conventional stamping process will generate micrometer-level stress concentration, and we must find another way." His proposed solution was extremely bold - using micro electroforming technology, which required building a completely new production line with an investment of over eight million.

I still remember that afternoon when the board voted. When the financial director listed the risk data, the founder said only one sentence: "If we give up breaking through the limit just because of fear of risks, Falcon Eagle would have gone bankrupt ten years ago." During the two months of building the production line, the entire team lived and worked in the factory. What moved me the most was Xiao Li from the quality inspection team. To ensure that the roundness tolerance of each coil was controlled within 0.001 millimeters, he designed an optical detection system and worked in front of the microscope for sixteen hours every day. Finally, his eyes were so red that he needed to use eye drops to continue working.

In the early morning of the eighth month, when the first qualified sample was born, the laboratory was so quiet that one could hear the sound of breathing. When the test data showed that all parameters were met, Dr. Wang called from Boston across the ocean, his voice choked: "My mentor spent his entire life researching cerebrovascular diseases. Before his death, he said the biggest regret was not being able to see the device enter the smallest blood vessels. Today, you have fulfilled his wish."

Now, this 0.19-millimeter coil has begun clinical trials. The surgery video sent last week showed that the catheter successfully reached the terminal of the brain vessels that traditional devices could not reach. Looking at those lives about to be saved on the screen, I suddenly understood: We have broken through not only the technical limit, but also the boundary that life can reach.

Creating miracles of life in a difference of 0.01 millimeters - The Golden Eagle minimally invasive interventional coil reaches the unexplored realm of medicine.