Chapter 282: Boundary Line

The cursor blinked steadily in the blank document. Lin Chen typed the first title: The Clinical Mapping Relationship Between EEG Feature Extraction and Manual Review. No rhetoric, only definitions. He had to translate the logic tree in the code into a decision path doctors could understand. His left foot rested on the spare computer case, the chill of the metal casing climbing up from his ankle; in the numbness, a sharp stab of pain occasionally darted through. He adjusted his posture, shifted his weight entirely onto his right leg, and bent his knee slightly to ease the pressure on his lumbar spine.

Su Man was checking the cloud server bills at the workstation next to his. Her keystrokes were soft, like rain tapping on a tin shed. Lin Chen opened the V3.0 runtime logs and exported the processing records for waveform 0317 one by one: feature-extraction thresholds, band-pass filter parameters, manual review markers, two-person signature timestamps. The data was scattered across different CSVs and PDFs. He had to stitch it into a complete chain of evidence. Medical procurement did not care how fast the code ran; it cared whether every step could be traced. He created a new Excel spreadsheet and set the headers as: sample ID, original waveform frequency band, algorithm preliminary confidence, reviewing physician employee number, correction basis, final label. Then he filled it in, row by row.

By entry 412, his eyes began to ache. He got up and went to the pantry to make coffee. The instant powder had clumped. When hot water poured over it, a dark brown film of oil floated up. He carried the paper cup back and, on the way, raised the air-conditioner temperature by two degrees. The server room was held at a constant twenty-two degrees Celsius, but if he sat too long without moving, his joints stiffened. He lowered his head and glanced at his left foot. The shoelace had come loose, and the top of his foot was slightly swollen. He rummaged through a drawer for a roll of elastic bandage and wrapped it into place with practiced ease. His movements were gentle and uninterrupted. It was an old problem. Ever since the day he had rattled down from the county seat on the slow train, it had never fully healed. He was used to treating it as a parameter that required periodic maintenance, not as a source of emotion.

Su Man handed him a printed competitor-parameter sheet. “Zhinao Technology turned its explainability module into a plug-in. They claim it’s plug-and-play. But underneath, it’s still a black box. They just added a visual heat map.”

Lin Chen took the sheet and scanned it. “No matter how flashy the interface is, if the underlying decision logic isn’t transparent, clinicians won’t dare use it. Doctors aren’t afraid of the machine being wrong. They’re afraid of not knowing where it went wrong. A heat map can only tell someone, ‘this part matters.’ It can’t tell them why it matters.”

He set the sheet aside and kept typing.

At three in the afternoon, the first draft of the white paper was complete. Its structure was dry: background, methods, validation data, limitations, allocation of responsibility. Lin Chen sent the document to Su Man and Zhao Qiming’s due-diligence team. Zhao Qiming replied quickly: “The structure works. But it lacks an endorsement signature from a chief physician at a top-tier hospital. Fifteen percent of the weighting. The review experts want to see clinical recognition. Can you get an evaluation opinion from the neurology director at City First Hospital?”

Lin Chen stared at the screen. The neurology director at City First Hospital was surnamed Zhou, famous for being exacting. He usually did not even take calls from pharmaceutical representatives. They had only done data-cleaning outsourcing there before; they had never dealt with him directly.

He picked up his phone and found Old Zhao’s number. The call connected.

“Old Zhao, can you get Director Zhou’s schedule for neurology at City First Hospital?”

The other end went silent for a few seconds. In the background came the hum of a printer working. “Mr. Lin, Director Zhou has expert outpatient clinic on Wednesday morning and ward rounds on Thursday afternoon. If you want to see him, you’ll have to bring something with you. He doesn’t care for empty talk.”

“What should I bring?”

“Something that can help him work less overtime.” Old Zhao paused. “That review node of yours—if it can cut thirty percent off his daily reading time, he’ll naturally take a look.”

Lin Chen wrote down the time. “Understood.”

After hanging up, Lin Chen began preparing demonstration materials. Not slides—raw data comparison charts. He selected ten typical cases, marked the differences between the algorithm’s preliminary judgment and manual review in red, and attached time-consumption statistics beside them. Zhinao Technology’s fully automatic process averaged 2.5 minutes. Their process took 4.1 minutes. It cost an extra 1.6 minutes, but the missed-diagnosis rate fell from 0.12 percent to 0.03 percent. He turned the data into line charts and scatter plots, printed them, and bound them into a booklet. On the cover, he wrote only one line: Comparison of Clinical EEG Analysis Efficiency and Safety (De-identified Samples).

At eight in the evening, only the two of them remained in the office. Lin Chen’s left foot had swollen so badly that it no longer fit into his original leather shoe. He changed into a pair of loose old sneakers and tied the laces very loosely. Su Man handed him the printed materials.

“Thursday at two in the afternoon, after Director Zhou finishes ward rounds. I’ll go with you.”

Lin Chen shook his head. “You keep an eye on the bid-system upload node. The document format can’t be off by a single character. I’ll go alone.”

Su Man looked at him and did not try to persuade him again. She knew Lin Chen’s temper. Once he had decided something, ten oxen could not pull him back. She only placed a packet of stomach medicine on the corner of his desk. “Don’t drink coffee on an empty stomach. If Thursday doesn’t work out, we still have Plan B.”

Lin Chen put the materials into a canvas bag and zipped it shut. As he reached the doorway, his phone vibrated. It was a text message from the Municipal Health Commission procurement office: “Dear supplier, the on-site demonstration session for the City First Hospital Phase II medical equipment procurement project has been moved up to 9:00 a.m. next Monday. Please arrive on time with the system core module and clinical validation report. Late arrival will be regarded as withdrawal.”

Lin Chen stopped walking.

Next Monday. Two days earlier than originally scheduled.

He looked back at the blinking server indicators in the machine room, then lowered his eyes to the phone screen. The shoulder strap of the canvas bag pressed heavily into his collarbone. He turned off the screen and pushed the door open into the corridor. Wind poured in from the stairwell, carrying the chill of early autumn. When his left foot landed on the step, the pain was clear and steady.

He knew there was not much time left.