Chapter 284: Offline Terminal and Sliding Window

The progress bar in the terminal was stuck at 98 percent, and the hum of the fan seemed amplified in the empty office. Lin Chen stared at the screen without moving. His left foot was propped on a low stool; the swelling around his ankle had spread into his calf, stretching the skin taut and shiny. When he pressed it, the flesh rebounded slowly. Under his fingertips he could feel hard knots beneath the skin. The pain was dull, like a rusty nail wedged between bones—not sharp, but dragging downward without end. He pulled his hand back, picked up the cold instant-noodle cup on the desk, and drank the last of the broth. Salty, astringent, with grease congealed along the wall of the bowl, but it was enough to press down the emptiness in his stomach.

The compile finished. No errors. Lin Chen hit Enter, and the local parser began loading the real data packet Director Zhou had sent. The binary stream was read byte by byte, and the sampling rate missing from the header was inferred from hidden fields. The first frame of waveform popped onto the screen: severe baseline drift, mixed with high-frequency EMG noise and mains interference. He opened the sliding-window adaptive filtering module and fine-tuned the parameters. The waveform gradually smoothed, and spike-and-slow-wave complexes emerged from the chaotic background. Su Man sat across from him, the light of her monitor reflected on her face. She said nothing, only pushed over a printed stack of dependency lists. “The local environment is packaged. PyTorch CPU build, with all cloud-sync hooks removed. Memory footprint is down under four gigabytes.”

Lin Chen nodded. He opened the terminal and ran the full dataset. The progress bar climbed slowly. Eight thousand records, mixed with electrode dropouts, truncated signals, and unlabeled sleep segments. The script did not crash. Log files generated line by line, and the cleaned CSVs were exported in timestamp order. He checked the final rows. Missed-detection flags: zero. But the memory curve showed a tiny spike after the six-thousandth record. Not a crash—a warning. Garbage collection had not kept up, and the ring buffer was accumulating redundant data during high-frequency noise segments.

He closed the terminal and rubbed the bridge of his nose. Three thirty in the morning. The office air conditioner had already shut down, and the coolness of early autumn crept up his trouser legs. He could not pull another all-nighter. His injured foot would not allow it. Neither would his brain. He stood, putting weight on his right foot while his left barely touched the floor, and slowly walked to the window. He pushed half of it open. Night wind poured in, carrying the dusty smell from the city’s edge and the tire noise of the distant overpass. He took a deep breath, turned, and walked back to his workstation. “Su Man, tomorrow at ten in the morning, we’ll run the stress test on real hardware. Use that old ThinkPad and simulate the clinical site’s hardware conditions.” Su Man looked up at him. “That machine only has eight gigs of RAM. The full run may lag.” “Then let it lag.” Lin Chen sat back down. “Clinical equipment won’t give you top-end specs. We need to know where the bottleneck is, and then route around it.”

On Saturday morning, the office blinds were half lowered. Sunlight was cut into thin strips across the desktop. Lin Chen connected the old laptop to power and unplugged the network cable. Su Man copied in the packaged local image. Two engineers stood beside them, watching the monitoring panel. Lin Chen pressed Run. The fan spun up at once. At 30 percent progress, memory usage broke past 7.5 gigabytes. The waveform rendering began dropping frames, and the mouse pointer left a smear behind it. Lin Chen did not stop. His fingers moved rapidly over the keyboard. He brought up the memory analyzer and traced the issue to the sliding-window cache module. The problem was not the algorithm; it was redundant data structures. He changed the fixed-length ring buffer into a dynamic linked list, released repeatedly loaded intermediate variables, and manually triggered a lightweight collection after each window shift. Code committed. Recompiled.

Second run. The memory curve fell steadily, with the peak held at 6.2 gigabytes. Waveform rendering became smooth again. Logs exported normally. Lin Chen watched the screen until the last record finished parsing. The terminal printed “Done.” He leaned back in the chair and let out a long breath. His left foot had gone numb; he reached down and squeezed his calf, the muscle stiff as a plank. Su Man handed him a cup of warm water. “It runs through. But there’s a problem.” She pointed at the end of the log. “Sample 412. The electrode-dropout marker was misclassified as high-frequency noise. The algorithm filtered it out, but under the clinical standard, this kind of dropout has to be marked for manual review.”

Lin Chen straightened. He pulled up the raw waveform for sample 412. She was right: in the frequency domain, the characteristics of electrode dropout overlapped heavily with EMG interference. The existing filter logic would cut them both away. He thought for a moment, then added a pre-check node to the parser: if signal amplitude dropped sharply for three consecutive seconds and was accompanied by baseline zeroing, mark it directly as “suspected dropout,” skip the filtering pipeline, and output it separately to the review queue. The change was less than twenty lines. He ran the full dataset again. The log updated; sample 412 was correctly captured.

At eight that night, half the office lights had gone dark. Lin Chen wrote the final offline-terminal image to a USB drive and backed it up to a portable hard disk. He checked every dependency package, debugging script, and printed operation manual. His canvas bag sat by his foot, zipper half open. His phone lit up. Zhao Qiming had sent a message: “Municipal First Hospital’s IT department just sent a notice. The demo room will have a temporary power outage for maintenance on Monday. Backup power can only support two laptops and one monitor. The network will be completely down. Bring enough batteries.” Lin Chen read it and replied: “Received.” He turned off the phone, plugged the USB drive into the computer, and ran one last integrity check. The progress bar completed. He pulled out the drive and slipped it into an inner pocket. Rising, he set down his right foot first, then slowly brought his left along. The pain was still there, but his center of gravity had steadied. At the door, he looked back once at the silent servers in the machine room. Tomorrow morning at seven, he would have to arrive at the hospital two hours early. The voice-activated lights in the corridor came on with his footsteps, then went dark behind him. The night was still long, but the road was already laid beneath his feet.