(24 days)
The IRMA Blood Analysis System is intended for professional use in those settings where direct measurement of blood such as blood gases (pCO2 and pO2), pH, Na , K , iCa BUN. CI'. and Hct. in whole blood are performed such as the clinical laboratory or the patient bedside.
The pH, pCO2, pO2 measurements, and their associated calculated values are used to assess acid-base status and state of oxygenation. Common causes of acid-base disturbances include: cardiopulmonary disease, metabolic abnormalities, drugs and poisons, and fluid imbalance.
The electrolyte measurements (Na . K . Cl) are used to assess hydrational status, aid in the diagnosis of respiratory and metabolic acid-balance, and prevention of cardiac arrhythmia. Common disease states which utilize these measurements for diagnosis are acid-base disturbances, dehydration, diarrhea, ketoacidosis, alcoholism and other toxicities.
The measurement of ionized calcium is used to assess disease states such as thyroid abnormalities, renal failure or transplant, and to monitor dialysis patients.
The measurement of blood urea nitrogen is used to monitor renal disease, dialysis --patients, and hyperalimentation.
The measurement of hematocrit is used to assess anemia, blood loss such as in an accident or during surgical procedures, and polycythemia.
With the addition of BUN and Cr, the IRMA Blood Analysis System will measure: blood gases (pCO2 and pO2), pH, sodium, potassium, ionized calcium, blood urea nitrogen, chloride, and hematocrit. The sensor arravs of the cartridge will also be packaged in various combinations.
The current IRMA Blood Analysis System comprises a system of an electronic instrument and disposable cartridges (single-use or multi-use) intended for the measurement of blood gases (pCO2 and pO2), pH, potassium, sodium, ionized calcium, and hematocrit in blood.
The new system will measure the above mentioned analytes plus blood urea nitrogen (BUN) and chloride (Cl) in blood on the single-use cartridge. Except for the addition of these two analytes and their associated changes, the system will remain the same as the current system.
The IRMA analyzer can use either battery or AC power. The system's operation utilizes a microprocessor which is controlled by internal electronics and diagnostics. The microprocessor controls the touch screen, analog electronics which collect the digital signals from the sensors and the controls the printer. The printer provides a hard copy of the measured and calculated values.
Samples are introduced via syringe or capillary injections with the IRMA Capillary Collection Device. The minimum sample volumes are 200uL from a syringe injection and 125uL from a Capillary Collection Device injection. Other capillary collection devices which require aspiration are not compatible with the system.
The cartridges utilize microelectrode technology for the measurement of the following blood analytes: pH, pCO2, pO2, sodium, potassium, ionized calcium, blood urea nitrogen, chloride, and hematocrit.
The principles of measurement are similar to traditional electrode methodologies for blood gas and electrolyte measurements. The pH, pCO2, Na*, K*, iCa**, BUN, and Cli utilize ion-selective potentiometric electrodes including a reference electrode. The pO2 electrode is an amperometric Clark electrode. The hematocrit sensor utilizes a conductivity electrode.
Here's a breakdown of the acceptance criteria and study information for the IRMA Blood Analysis System's BUN and Chloride sensors, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
| Analyte | Acceptance Criteria (Implicit) | Reported Device Performance (Correlation to Reference Method) |
|---|---|---|
| Chloride (Cl-) | Not explicitly stated as a numerical threshold, but implied to be "substantially equivalent" to predicate device. | IRMA Cl = 0.9262 * Cl- conc (mM) - 22.43 |
| Correlation Coefficient (r) = 0.9976 | ||
| Sy.x = 4.0 | ||
| Blood Urea Nitrogen (BUN) | Not explicitly stated as a numerical threshold, but implied to be "substantially equivalent" to predicate device. | IRMA BUN = 1.0831 * BUN conc (mg/dL) + 3.7837 |
| Correlation Coefficient (r) = 0.9996 | ||
| Sy.x = 1.5 |
Note: The acceptance criteria are "not explicitly stated" in numerical form within the provided text. They are implied by the statement "indicate substantial equivalence between Cl- and BUN sensors on the IRMA Blood Analysis System and the predicate devices" and the presentation of strong correlation coefficients.
2. Sample Size Used for the Test Set and Data Provenance
- Chloride (Cl-) Test Set Sample Size: n = 99
- BUN Test Set Sample Size: n = 97
- Data Provenance:
- Country of Origin: Not explicitly stated, but the submission is to the US FDA and the company is based in Roseville, MN, USA.
- Retrospective or Prospective: Not explicitly stated, but the description "split sample studies were conducted using whole blood samples measured by both the IRMA system and a reference method" and "heparinized whole blood samples were prepared by spiking with varying concentrations of electrolytes to allow testing throughout the reportable range" suggests a prospective study where samples were prepared and then tested on both systems.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
- Number of Experts: The text states, "Testing was conducted by three laboratory personnel."
- Qualifications of Experts: Not explicitly stated beyond "laboratory personnel." No specific professional certifications (e.g., medical technologist) or years of experience are mentioned. The document notes that the IRMA system was previously cleared for use by non-laboratory personnel, and this submission's data does not include such personnel.
4. Adjudication Method for the Test Set
- Adjudication Method: Not explicitly described. The study appears to rely on direct comparison of the IRMA system's results against a reference method, rather than an adjudication process between multiple readers/interpretations. "The method of least squares was used to determine the best fit line."
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and Effect Size
- MRMC Study Done?: No, an MRMC comparative effectiveness study was not done. This study focuses on the analytical accuracy and precision of a diagnostic device (blood analyzer) compared to reference methods, not on human reader performance with or without AI assistance.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
- Standalone Performance Done?: Yes, the accuracy and precision data presented for Chloride and BUN represent the standalone performance of the IRMA Blood Analysis System's sensors, measuring the analytes in blood and aqueous samples. It's an instrument-based measurement, not an AI or human interpretation task.
7. The Type of Ground Truth Used
- Type of Ground Truth: Reference methods, specifically a Vitros Chemistry System DT6011 (for BUN) and a Buchler Digital Chloridometer (for Chloride) for accuracy studies. For precision, aqueous standards and control materials with known concentrations were used.
8. The Sample Size for the Training Set
- Training Set Sample Size: Not applicable. The IRMA Blood Analysis System is a medical device based on established electrochemical and enzymatic methodologies, not a machine learning or AI model that requires a "training set" in the traditional sense. Its "training" is in its engineering design, calibration, and manufacturing process.
9. How the Ground Truth for the Training Set Was Established
- How Ground Truth for Training Set Was Established: Not applicable, as this is not a machine learning device. The "ground truth" for its operation is inherent in the design and calibration using NIST traceable gases and salt standards, as described in the "Calibration" section.
§ 862.1170 Chloride test system.
(a)
Identification. A chloride test system is a device intended to measure the level of chloride in plasma, serum, sweat, and urine. Chloride measurements are used in the diagnosis and treatment of electrolyte and metabolic disorders such as cystic fibrosis and diabetic acidosis.(b)
Classification. Class II.