Dialysis Mode — The Complete Pre-Treatment Workflow.
When Dialysis Mode is confirmed from the main boot banner, the machine initiates a strict 8 to 12-minute pre-treatment test profile. The top of the TFT display outputs real-time step sequences with LLC and LLP status codes.
The Three Phases: Phase 1: Chronological T1 Test Blueprint → Phase 2: Transition Milestone ("Connect Dialyzer") → Phase 3: Post-Connection Troubleshooting Protocol
Image Placeholder: TFT Display — T1 Test Progress with LLC/LLP Codes
Insert photo: Screen showing T1 test progress bar with LLC 11xxx, 12xxx, 13xxx, 14xxx step codes.
Mutual electronic verification of RAM, ROM checksums, and NVRAM calibration profiles. High-power 24V supply lines are held inactive via open safety relays.
The system's primary hydraulic isolation phase. Solenoid valves V41, V24, and V25 slam shut to trap fluid. The Fresh Dialysate Pump (FPE) drives pressure up to +400 mmHg (LLC 12100). The Used Dialysate Pump (FPA) reverses flow to drag vacuum down to -400 mmHg (LLC 12200).
The machine targets the exact stroke metrics of the UFP piston pump. The balancing chambers remain locked at net-zero. The UFP is commanded to pulse a fixed volume (e.g., 50 strokes). The LLC tracks resulting pressure shifts to confirm <1% tolerance.
Wakes up the extracorporeal blood line modules. The Supervisor Air Detector (S.A.D.) runs an acoustic pulse optimization check. The Optical Blood Leak Detector (BLD) dims its internal LED. Venous (PVD) and arterial (PDA) pressure pods are queried to ensure 0 mmHg atmospheric zero.
Once all internal software blocks hit 100% completion, the machine outputs an audible tone, freezes the background pumps, and flashes the central instruction banner:
The Post-Connection Volumetric Priming Phase (~2 to 3 minutes):
The operator physically hooks the blue inlet hand to the bottom of the dialyzer and the red outlet hand to the top.
Pressing the Enter/Confirm Key breaks the internal bypass loop (Valve 26 closes; Valves 27 and 28 open). Fresh dialysate floods the dialyzer compartment.
The machine evaluates the immediate stability of the CD_TOTAL (Conductivity) and temperature matrix.
It forces the blood pump to spin at a maintenance priming speed (100–150 mL/min) to completely de-air the filter rows.
Image Placeholder: "Connect Dialyzer Couplings" Banner Screen
Insert photo: TFT screen showing "Connect Dialyzer Couplings" instruction banner after T1 completion.
The table below maps the common mechanical and electronic failures that trigger immediately after the dialyzer is coupled and the fluid lines open:
| Error Presentation & Code | Pathophysiological Mechanism | Diagnostic Step & Target Metrics | Biomedical Management |
|---|---|---|---|
| LLC Error 12100 / 12200 (DFS Test Failure) |
Microscopic air leaking past the blue/red coupling hand interfaces. | Spray leak detection solution on the dialyzer port connectors; observe for frothing. | Extract the coupling handles. Replace the internal flattened black EPDM O-rings. |
| "Conductivity Low/High" (CD_TOTAL Error) |
Fluid cross-contamination or chemical ratio drift due to a slipping concentrate pump. | Compare CD_BIC vs. CD_TOTAL values in TSM Mode. Cross-check with an external master reference meter. | Execute an immediate Hot Citric Acid Decalcification loop. If slippage remains, rebuild the ceramic pump piston heads. |
| "Blood Leak Alarm" (False Optical Trip) |
Micro-air bubbles streaming through the line due to a loose upstream connector, scattering the light beam. | Read raw BLD phototransistor voltage in TSM Menu 1.05. Verify it spikes > 4.0V DC on pure fluid. | Run an intensive Sodium Hypochlorite (Bleach) flush to scrub organic protein biofilms off the optical lens windows. |
| "TMP Instability" (Transmembrane Pressure Error) |
An air pocket trapped inside the dialyzer dialysate compartment, causing fluid cavitation. | Visually confirm that dialysate is entering the bottom port and blood is moving down the core straws. | Physically invert the dialyzer assembly (turn it upside down) during the prime phase to force out trapped air pockets. |
Image Placeholder: Post-Connection Troubleshooting — Error Screens
Insert photo sequence: LLC 12100 error, Conductivity Low/High alarm, Blood Leak Alarm, TMP Instability screen.
Post-connection errors are protective mechanisms. The machine is detecting a condition that could harm the patient. Never attempt to bypass or override these alarms — always resolve the root cause before continuing.