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The Medi-Dx 7000 is a diagnostic device for the quantitative detection of sensory neurological impairments. The population of subjects for whom this device may be used for diagnostic purposes would include any individual capable of communicating their perception of cutaneous sensation.

The Medi-Dx 7000 diagnostic examination may be conducted as part of a routine neurological examination or as a screening procedure for the detection of peripheral neuropathy which may be caused by various pathological conditions or exposures to toxic substances.

The Medi-Dx 7000 is a Current Perception Threshold (CPT) device for the examination of peripheral neuropathies. It generates a sinusoidal electrical currents in the 5 Hz, 250 Hz and 2000 Hz frequencies from 0 mA to 9.99 mA.

The Medi-Dx 7000 weighs approximately 15 lbs. and is housed within a 12" x 6" x 11" heavy duty plastic case with metal face and rear panels. The rear panel has an access door for installation and replacement of (8) standard (6) Volt Alkaline Batteries. The Face panel has an 'ON/OFF' switch, a 'Battery Test' switch (also functioning as an automatic calibration switch), and three (3) switches, one for each of the frequencies; 5 Hz, 250 Hz and 2000 Hz respectively. The intensity control is immediately below an LCD which reads mA output. Two ports are available on the from panel for connection with electrodes (which are not provided with the unit and are ordered by the user from suppliers mentioned in the owners manual).

Here's an analysis of the provided text regarding the Medi-Dx 7000, focusing on acceptance criteria and the supporting study, based on your requested categories.

It's important to note that the provided text is a 510(k) summary (or a letter related to an older 510(k) submission), which typically focuses on demonstrating substantial equivalence to a predicate device rather than detailing extensive clinical trials for new device performance. As such, many of your requested points regarding a clinical study or performance metrics won't be fully addressed, as the submission appears to rely heavily on the equivalence of technical specifications.

Acceptance Criteria and Study for Medi-Dx 7000

Based on the provided 510(k) summary, formal acceptance criteria and a structured study to prove the device meets these criteria in the way a modern AI/software device would be evaluated are not presented. The submission primarily establishes substantial equivalence to a predicate device (Neurometer by Neurotron) based on technical similarities and safety improvements, implying that if the predicate device is safe and effective, the Medi-Dx 7000, being "essentially the same" in function and reliability, also is.

Here's an attempt to populate the table and answer your questions based on the available information:

1. Table of Acceptance Criteria and Reported Device Performance

Note: The document does not explicitly state acceptance criteria in terms of performance metrics (sensitivity, specificity, accuracy, etc.) for diagnosing neurological impairments. Instead, the "acceptance" is implicitly tied to its functional equivalence and safety compared to the predicate device.

• Minimum/maximum output (0.0 mA to 9.99 mA)
• Current characteristic (sinusoidal waveform)
• Frequencies (5 Hz, 250 Hz, 2000 Hz) |
  | Safety - Absence of RFI | The Medi-Dx 7000 "produces no RFI" due to four independent clocks for frequency production, unlike the predicate device (which uses one crystal-controlled clock and produces RFI). |
  | Safety - Output Isolation | The Medi-Dx 7000 has "isolated output via the transformer," whereas the equivalent device "depends on non-failure of the charger and selector switch to prevent 110v AC leakage." |
  | Safety - Case Material | The Medi-Dx 7000 case is "largely non-conducting plastic," providing a safety advantage over the equivalent device's "all metal case." |
  | Safety - Electrical Field Build-up (No-load conditions) | "No-load conditions will not build up an electrical field at the electrodes, because the output is dampened." It is unknown if the predicate device has this feature. |
  | Safety - Power Supply Disconnect | The Medi-Dx 7000 has a "safety interlock which disconnects the power supply if the case is opened." (Not mentioned for predicate) |
  | Safety - Low Battery Warning | The Medi-Dx 7000 "WARNING" light flashes if power drops below that needed to supply max output. (Predicate device has a "steady on" warning for low batteries and a flashing warning for waveform clipping at intensity increase, or flashing at zero for low battery). |
  | Operational Control | The Medi-Dx 7000 is "fully manually controlled." (Predicate has manual and auto-test modes). The manufacturer contends manual control avoids "over-stimulation." |
  | Accuracy/Calibration | Both devices "manufacturers 'burn in the devices for 168 hours and testing insures accuracy/calibration." |
  | Indications for Use (same as predicate) | "Quantitative detection of sensory neurological impairments" in individuals capable of communicating cutaneous sensation, as part of routine neurological examination or screening for peripheral neuropathy. |

2. Sample Size Used for the Test Set and Data Provenance

• Test Set Sample Size: Not applicable/Not mentioned. There is no mention of a formal "test set" of patients or data used to evaluate the device's performance in diagnosing neurological impairments. The submission relies on technical comparisons to a predicate device.
• Data Provenance: Not applicable.

3. Number of Experts Used to Establish Ground Truth for the Test Set and Their Qualifications

• Number of Experts: The document mentions that the manufacturer "has consulted with" neurologists and other medical experts regarding the auto-test mode and its potential to alter thresholds. Several of these physicians "have compared the devices clinically and have agreed to share their opinions if contacted." However, this is not presented as a formal consensus-building process for establishing ground truth on a test set.
• Qualifications of Experts: "Neurologists and other medical experts." No specific experience levels are provided.

4. Adjudication Method for the Test Set

• Adjudication Method: Not applicable/Not mentioned. There was no formal test set requiring adjudication.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

• MRMC Study: No. The document does not describe an MRMC study comparing human readers with and without AI assistance (as this is an older, non-AI device). The "clinical comparison" by a "several physicians" mentioned is not formal enough to be considered an MRMC study.
• Effect Size: Not applicable.

6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study

• Standalone Study: The Medi-Dx 7000 is a hardware device; it does not contain a complex algorithm or AI that would require a "standalone" performance study in the modern sense. Its function is to generate electrical currents and measure perception thresholds, which directly involve human interaction. The performance of the device itself in terms of output accuracy and stability is "insured" by manufacturing tests (burn-in and calibration).

7. Type of Ground Truth Used

• Type of Ground Truth: The concept of "ground truth" for diagnostic performance (e.g., against pathology or clinical outcomes) is not discussed for the Medi-Dx 7000's diagnostic capabilities. The submission implies that the functionality of the device (generating currents at specific frequencies and intensities) is equivalent to the predicate, and therefore its utility in detecting sensory neurological impairments is assumed to be similar to the established utility of the predicate device. The only "truth" mentioned is the opinion of "neurologists and other medical experts" regarding the theoretical advantage of manual testing over auto-test mode to avoid receptor fatigue.

8. Sample Size for the Training Set

• Training Set Sample Size: Not applicable/Not mentioned. This is a hardware device, not an AI/ML algorithm that requires a training set.

9. How the Ground Truth for the Training Set Was Established

• Ground Truth for Training Set: Not applicable.

Summary of the Document's Approach:

The 510(k) submission for the Medi-Dx 7000 primarily focuses on demonstrating "substantial equivalence" to a legally marketed predicate device (Neurometer). This means the manufacturer largely argues that because their device is similar in intended use and technological characteristics to a device already deemed safe and effective by the FDA, it should also be considered safe and effective. The emphasis is on showing that any differences are either minor or lead to improved safety (e.g., RFI reduction, better isolation, non-conducting case). There is no detailed clinical study with performance metrics for diagnosis presented, as is common for many Class I and II devices seeking substantial equivalence where the technology is well-understood.

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