Chapter 268: Threshold and Boundary

Zhao Qiming did not answer right away. He turned slightly, picked up a fountain pen from the table, spun the cap half a turn between his fingers, then set it down gently. The light from the screen fell across the line of his jaw, revealing his habitual caution.

"Lin Chen," he began, speaking a little more slowly than before, "the logic behind the 'out-of-hospital rental' and 'auxiliary early warning' you just described works. But capital looks at replicability. If every device requires someone to manually remove an SD card to retrieve data, your iteration cycle will be stretched to a quarterly rhythm. The window for medical AI is not measured in years. It is measured in months. How do you plan to solve the data backflow problem?"

Lin Chen's fingers hovered over the touchpad. Under the table, his left foot had gone completely numb. He could only adjust his posture and shift his weight half an inch to the right. He brought up an architecture diagram and dragged it onto the shared screen.

"In two steps." His voice was steady. "Step one: pure offline mode. The device is responsible only for collection and warnings. Data is encrypted and stored on a local TF card. Each week, we send a technician to copy it on-site, or family members use the out-of-hospital mini program to schedule mailing. This step does not touch the cloud, avoiding compliance risks under the Personal Information Protection Law and rules governing cross-border medical data. Step two: after the model has run through three thousand real-world cases and we push the false-positive rate below 0.4%, we apply to the NMPA for a Class II medical device registration change, add a local differential privacy module, and enable desensitized incremental synchronization. We are not trying to be connected on day one. We are trying to be usable on day one."

The meeting room was quiet for several seconds. Lawyer Zhang pushed up his glasses and took notes quickly in his notebook. Consultant Li nodded slightly but said nothing.

Zhao Qiming looked at the architecture diagram. His gaze paused for a moment on the phrases "differential privacy" and "incremental synchronization."

"Compliance costs will eat your gross profit for the first three years," he said.

"That is why the hardware pricing has to cover amortized R&D." Lin Chen answered immediately. "Three thousand yuan is the ex-factory price. With the rental deposit, insurance, and operations and maintenance included, annual cost per user is around twelve thousand. We earn hardware margin and maintenance service fees. We do not monetize data. It is a slower path, but it can survive."

As soon as he finished, the phone beside the pillow lit up. There was no sound, only a vibration. Lin Chen glanced over from the corner of his eye: [INFO] Local monitoring. Confidence: 0.71. Feature: EMG interference / motion artifact.

His breathing did not change. 0.71 was in the gray zone. The model had mistaken the noise from the electrode pad rubbing when Xiaoman turned over for low-frequency discharge. He quickly switched out of the meeting window, opened the terminal, and entered one command: --motion-filter on --threshold-adjust 0.05. Enter. The script reloaded the baseline. Three seconds later, a log line appeared: [INFO] Artifact filter active. Confidence dropped to 0.32.

He switched back to the meeting interface. The whole process took less than ten seconds. Zhao Qiming seemed to notice the shift in his gaze, but did not ask.

"Legal will draft the disclaimer clauses," Lawyer Zhang finally said, his voice dry. "They must be explicit: the device provides reference signals only, does not replace clinical diagnosis, and does not guarantee intervention outcomes. Before users sign the informed consent form, they must complete at least two offline training sessions. If a delay is caused by family members failing to follow medical advice or by device power loss, liability must be cleanly separated."

"Agreed," Lin Chen said. "I have already asked Su Man to organize the agreement templates. The first clause is a bolded disclaimer. What we are selling is an observation tool, not a safe."

Zhao Qiming leaned back in his chair and folded his hands. He looked at Lin Chen for a long time, as if assessing some invisible toughness.

"I do not invest in stories," he said at last. "I invest in discipline. You just changed parameters during the meeting without panicking, without explaining, and without crashing the system. That tells me you know where the boundaries are. The most frightening thing in medical hardware is not immature technology. It is a founder bringing the laboratory's tolerance for error into clinical use."

He paused, and his tone turned cold.

"I can put in two million as a seed round. Paid in three tranches. The first tranche is five hundred thousand, wired within seven business days after the agreement is signed. But it comes with three performance-bet conditions. First: within ninety days, deploy fifty devices in two prefecture-level community hospitals, with real-user retention no lower than 85%. Second: push the false-positive rate below 0.4%, and the false-negative rate must not exceed 0.1% under any circumstances. Third: complete acceptance of the Class II medical device filing. If you fail, subsequent funds are frozen, and the intellectual property will be held by the fund. Do you accept?"

Lin Chen looked at the time in the lower right corner of the screen. 3:21 p.m. The meeting had lasted twenty-three minutes. Two million. A ninety-day life-or-death line. His mind quickly ran through cash flow, the hardware prototyping cycle, and the difficulty of connecting with hospital channels. There was no way back, but it was not a dead end either.

"I accept," he said. "But one clause must be added: if deployment is delayed because of hospital equipment access procedures or ethics review, the performance-bet period is extended accordingly. I will not take the blame for force majeure."

The corner of Zhao Qiming's mouth moved almost imperceptibly.

"Fine. Have Su Man connect with my FA. Send the TS over before close of business today."

The screen went dark. The meeting ended.

Lin Chen leaned back in his chair and let out a long breath. The shirt on his back was soaked through, cold against his skin. He lowered his head and looked at his left foot. The toes were still completely without sensation. Supporting himself on the edge of the table, he stood and slowly moved to the ward next door.

Xiaoman was sleeping deeply. The monitor waveform was stable, its beeps regular. On the bedside table sat half a glass of warm water, now gone cold. Lin Chen sat down on the folding chair and opened the local log. The 0.71 false-positive record was clearly visible, its timestamp accurate to the millisecond. He enlarged the raw waveform and compared it with the electrode contact impedance curve. It was indeed a motion artifact. The model's filtering of high-frequency EMG signals was still not thorough enough. He created a new line in the development document: V1.2 iteration: add adaptive impedance monitoring, dynamically adjust filtering window.

His phone vibrated. Su Man's message popped up: Zhao's TS has been sent to your email. The terms are hard, but signable. Also, the hardware factory replied. Lead time for the custom motherboard is six weeks. The power module voltage fluctuates by 0.8% below 15°C, creating a risk of power drop. They recommend switching to imported cells, but cost will increase by four hundred.

Lin Chen stared at the screen. Six weeks. A 0.8% power-drop rate. In the laboratory, it was only a parameter; in the ward, it meant an interrupted warning, perhaps missing a ninety-second golden intervention window. He turned off the phone and walked to the window. The early autumn wind passed through the half-open pane, carrying the disinfectant smell unique to hospital corridors. Downstairs, another layer of ginkgo leaves had fallen.

He returned to the desk and created a new Excel spreadsheet. In the header row he wrote: Power redundancy plan / cost accounting / alternate suppliers. The cursor blinked in an empty cell. He picked up a pen and sketched a parallel circuit on scratch paper. Four hundred yuan in added cost, a six-week lead time, a 0.8% risk. Every number had real weight.

He dialed a number. A long waiting tone came through the receiver. After three rings, the other side picked up.

"Hello, is this the equipment department at Provincial Medical? This is Lin Chen. About the offline monitoring terminal for the community hospital pilot, I would like to apply for the green channel as a 'research auxiliary device'... Yes, it does not need a Class III certificate, only a Class II filing. I will send the materials tonight. Please help arrange a preliminary review."

He hung up. He straightened again, pressing his weight onto his right leg. Code and spreadsheets intertwined on the screen like a net slowly tightening around him. He knew the ninety-day countdown had only truly begun at this second. Outside the window, the sky was darkening inch by inch.