Dialysis Machine - An Overview
A dialysis machine is a medical device used to perform dialysis, a process that replicates the kidney’s function of filtering and purifying the blood in individuals with renal failure. Dialysis machines are essential for patients with chronic kidney disease or acute kidney injury, providing a critical life-support function. The two main types of dialysis are hemodialysis and peritoneal dialysis, but this explanation focuses on the hemodialysis machine.
Components and Functions of a Hemodialysis Machine
- Blood Pump:
- This component draws the patient’s blood from the vascular access site and sends it through the dialysis circuit.
- Dialyzer (Artificial Kidney):
- The dialyzer contains a semi-permeable membrane that separates the blood from the dialysate. Waste products and excess fluids pass through the membrane into the dialysate, which is then discarded.
- Dialysate Delivery System:
- Temperature Control: Maintains the dialysate at body temperature to avoid patient discomfort and complications.
- Conductivity Monitoring: Ensures the correct concentration of electrolytes in the dialysate.
- Flow Rate Control: Regulates the rate at which blood and dialysate flow through the system.
- Ultrafiltration Control (in high permeability systems):
- Manages the removal of excess fluids from the patient’s blood by controlling the pressure gradient across the dialyzer membrane.
- Safety Monitors and Alarms:
- Pressure Monitors: Ensure the pressures within the blood and dialysate circuits are within safe limits.
- Air Detectors: Prevent air bubbles from entering the patient’s bloodstream.
- Leak Detectors: Detect any blood leaks in the dialyzer.
- Conductivity and Temperature Alarms: Alert if the dialysate’s conductivity or temperature is outside the safe range.
- Heparin Pump:
- Administers anticoagulants to prevent blood clotting during the procedure.
- Computer Interface:
- Provides a user interface for healthcare providers to set parameters, monitor the treatment, and adjust as needed.
- Patient Monitoring Systems (in advanced systems):
- Continuously track vital signs such as blood pressure, heart rate, hematocrit, urea levels, and oxygen saturation.
How Hemodialysis Machine / Dialysis Machine Works
- Blood Access:
- Blood is accessed through a fistula, graft, or central venous catheter.
- Blood Circulation:
- The blood pump draws blood from the patient’s access site and pumps it through the dialyzer.
- Dialysis Process:
- Inside the dialyzer, blood flows past one side of the semi-permeable membrane, while dialysate flows past the other side. Waste products and excess electrolytes pass from the blood into the dialysate due to diffusion and osmosis.
- Fluid Removal:
- Ultrafiltration removes excess fluid by applying a pressure gradient across the dialyzer membrane, drawing fluid out of the blood into the dialysate.
- Clean Blood Return:
- The cleaned and filtered blood is returned to the patient’s body.
Hemodialysis delivery systems
Medical devices regulated by the FDA, hemodialysis delivery systems are described and classified under specific sections of the Code of Federal Regulations (CFR). Two distinct types of hemodialysis delivery systems are outlined under 21 CFR §§ 876.5820 and 876.5860, each with unique characteristics and requirements.
Conventional Hemodialysis Delivery System (21 CFR §876.5820)
A conventional hemodialysis delivery system is defined as a system that:
- Monitors and Controls: This system includes mechanisms that monitor and control various parameters essential for dialysis, such as temperature, conductivity, flow rate, and pressure of the dialysate.
- Dialysate Circulation: It circulates dialysate through the dialysate compartment of the dialyzer.
- Dialysate Concentrate: The system comprises the dialysate concentrate, which can be in liquid or powder form.
- Alarms: It includes alarms designed to indicate abnormal dialysate conditions, ensuring patient safety.
High Permeability Hemodialysis Delivery System (21 CFR §876.5860)
A high permeability hemodialysis delivery system encompasses more advanced and comprehensive features compared to the conventional system:
- Ultrafiltration Controller: This system includes an ultrafiltration controller to manage fluid removal accurately.
- Monitoring and Control Mechanisms: It monitors and/or controls a wider range of parameters, including:
- System temperature
- Dialysate conductivity
- Fluid flow rates (blood, dialysate, effluent)
- Pressure and fluid balance.
- Proportioning of the dialysate
- Additional Components: The system includes various integrated components such as pumps (e.g., heparin pumps), air foam detectors (bubble detectors), and computer interfaces.
- Patient Treatment Parameters: It monitors patient treatment parameters, such as blood pressure, hematocrit, urea levels, and oxygen saturation.
- Alarms and Safety Features: Comprehensive alarm systems are included to alert people to any abnormal conditions.
Documents required for Dialysis Machine 510k
In both Traditional and Abbreviated 510(k) submissions, the FDA advises including the listed section headings in the recommended sequence. Although certain sections may not apply to your device, maintaining the specified order of headings is suggested by the FDA to facilitate expedited reviews.
- FDA Medical Device User Fee Cover Sheet
- FDA Premarket Review Submission Cover Sheet
- FDA 510(k) Cover Letter
- FDA 510(k) Indications for Use Statement
- FDA 510(k) Summary or FDA 510(k) Statement
- FDA Truthful and Accuracy Statement
- FDA Class III Summary and Certification
- Financial Certification or Disclosure Statement
- Declarations of FDA Conformity and Summary Reports
- FDA 510 (k) Executive Summary
- Medical Device Description
- FDA 510(k) Substantial Equivalence Discussion
- Proposed Labeling
- Sterilization and Shelf Life
- Biocompatibility
- Software
- Electromagnetic Compatibility and Electrical Safety
- Performance Testing-Bench
- Performance Testing-Animal
- Performance Testing-Clinical
FDA Classification for Dialysis Machine
Regulation Number | Product code | Class | Type |
876.5665 | FIP | 2 | Subsystem, Water Purification |
876.5665 | NHV | 2 | System, Water Purification, General Medical Use |
876.5665 | NIH | 2 | Disinfectant, Subsystem, Water Purification |
876.5820 | FIF | 2 | Set, Dialysis, Single Needle with Uni-Directional Pump |
876.5820 | FIJ | 2 | System, Dialysate Delivery, Recirculating, Single Pass |
876.5820 | FIK | 2 | System, Dialysate Delivery, Recirculating |
876.5820 | FIL | 2 | System, Dialysate Delivery, Single Pass |
876.5820 | FKH | 2 | Solution-Test Standard-Conductivity, Dialysis |
876.5820 | FKP | 2 | System, Dialysate Delivery, Single Patient |
876.5820 | FKQ | 2 | System, Dialysate Delivery, Central Multiple Patient |
876.5820 | FKR | 2 | Subsystem, Proportioning |
876.5820 | FLB | 2 |
Meter, Conductivity, Induction, Remote Type |
876.5820 | KPO | 2 | Dialysate Concentrate for Hemodialysis (Liquid or Powder) |
876.5820 | MNV | 2 | Strip, Dialysate Ph Indicator |
876.5820 | NNG | 2 | Set, Dialysis, Single Needle with Uni-Directional Pump, Reprocessed |
876.5820 | NTZ | 2 | Strip, Dialysate, Ph, Bicarbonate, Glucose, Acid, Indicator |
876.5860 | FII | 2 | System, Dialysate Delivery, Sealed |
876.5860 | NII | 2 | Disinfectant, Dialysate Delivery System |
FDA 510k test requirements for Dialysis Machine
Submitting a sequential dialysis machine notification for 510(k) clearance requires the submission of various tests and information to the FDA. Some of the tests that may be required for a sequential dialysis machine include:
Biocompatibility testing
The biocompatibility evaluation for the device was conducted in accordance with the international standard ISO 10993-1 “Biological evaluation of medical devices -Part 1: Evaluation and testing within a risk management process”.
- Chemical characterization
- Toxicological Risk Assessment
- Cytotoxicity
- Sensitization
- Irritation
- Pyrogenicity
- Hemocompatibility
- Systemic toxicity
Electrical safety and electromagnetic compatibility (EMC)
The system complies with the IEC 60601-1 standard for electrical safety and with IEC 60601-1-2 standard for EMC.
Software verification and validation testing
Software verification and validation testing were conducted, and documentation was provided as recommended by FDA’s Guidance for Industry and FDA Staff, “Guidance for the Content of Premarket Submissions for Software Contained in Medical Devices”.
Unit, integration, and system level software verification testing were performed to demonstrate the efficacy of the software and to confirm operation of the machine. The following testing was performed:
- Functional and Performance Verification
- Regression Testing
- Code Reviews
Software verification information within this submission is provided in accordance with the following FDA guidance documents:
- Guidance for the Content of Premarket Submissions for Software Contained in Medical Devices (11 May 2005)
- Guidance for Off-The-Shelf Software Use in Medical Devices (27 September 2019)
- Content of Premarket Submissions for Management of Cybersecurity in Medical Devices (02 October 2014)
Performance Bench Testing
- ISO 23500-3
- chemical and heat disinfection testing
- bacterial count and endotoxins
- Microbial Retention
- Evaluation of Bacteriostatic Additive
- Silver Migration Testing
- Flow Rate Testing
- Analytical testing Per device specifications and applicable sections of USP and EP
- Physical testing of container (bag) Per device specifications
- Container closure integrity testing Per ISO 11607-1
- Temperature excursion testing Per device specifications.
- Stability/Shelf-life testing Per ICH Q1A to support 24-month shelf life.
- Ship testing Per ASTM D4169-22
We recommend you perform the following tests on three or more hemodialysis tubing sets of each model you intended to market:
- pressure leak testing demonstrates that the blood tubing can withstand pressures up to 1.5 times the maximum labeled positive and negative pressures.
- endurance testing of the pump segment at maximum labeled blood flow rates and pressures.
- endurance testing, under both positive and negative pressures, of any injection ports (if
- applicable), using the largest recommended gauge needle identified in the labeling.
- priming volume assessment.
- tensile testing of joints and materials of all tubing segments.
- the ability of pressure transducers to withstand leakage when subjected to pressures up to
- 2 times the maximum labeled pressure, e.g., “strikethrough”
- performance testing of the device’s clamps to demonstrate that they can successfully occlude the blood tubing.
- hemocompatibility (i.e., mechanical hemolysis) for a new or significantly altered.
- hemodialysis tubing design that affects the pattern of blood flow; and
- performance testing to evaluate the ability of the tubing to resist kinking after repeated.
- clamping, particularly in the post-pump tubing segment.
Sterilization and Shelflife
- AAMI/ANSI/ISO 10993-7:2008/(R)2012 Biological Evaluation of Medical Devices – Part 7: Ethylene Oxide Sterilization Residuals
- ANSI/AAMI/ST72:2011/(R)2016 Bacterial Endotoxins – Test Methodologies, Routine Monitoring, and Alternatives to Batch Testing.
Risk Management
The risk analysis of the device should be done according to the device design, materials and others.