(447 days)
Nihon Kohden Sen-4100 Electric Stimulator is used for the intraoperative diagnosis of acute dysfunction in corticospinal tract axonal conduction brought about by mechanical trauma (traction, shearing, laceration, or compression) or vascular insufficiency.
The SEN-4100A is the stimulator to output electrostimulation pulses. It conducts the constant voltage stimulation that is necessary for MEP (Motor Evoked Potential) measurement, from an electrophysiological viewpoint, diagnosing and analyzing the neuromuscular action potential for a patient provided with anesthesia care in an operating room.
The provided text describes the Nihon Kohden SEN-4100 Electric Stimulator, a device used for intraoperative diagnosis of acute dysfunction in corticospinal tract axonal conduction. However, the document does not contain specific acceptance criteria or details of a study that quantifies device performance in terms of metrics like sensitivity, specificity, accuracy, or other performance characteristics.
Instead, the submission focuses on demonstrating substantial equivalence to a predicate device (Digitimer D185 Multipulse Cortical Stimulator) based on technological characteristics and compliance with electrical safety and performance standards.
Here's an attempt to answer the questions based on the available information, noting where data is absent:
1. Table of acceptance criteria and the reported device performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Not explicitly defined in terms of specific performance metrics (e.g., accuracy, sensitivity, specificity, or quantitative output precision). | The device's operation, software, and hardware were confirmed to be in accordance with design specifications through design validation. |
| Compliance with electrical safety and performance standards (e.g., IEC 60601-1, IEC 60601-1-2). | The device was subjected to electromagnetic, environmental, safety, and performance testing procedures, which "verified the proper operation of the device." Specific results of these tests (e.g., measured electromagnetic emissions/immunity levels, environmental withstand limits, actual safety parameter readings) are not detailed within this summary. |
| Substantial Equivalence to predicate device (Digitimer D185 Multipulse Cortical Stimulator, K020400). | Nihon Kohden believes the SEN-4100 is "substantially equivalent" to the predicate, stating it performs the same function (outputting electrostimulation pulses for MEP measurements and neuromuscular action potential analysis) for the same intended use. |
2. Sample size used for the test set and the data provenance
- The document does not mention any clinical "test set" in the context of device performance evaluation (e.g., for diagnostic accuracy). The testing described appears to be engineering validation and verification.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
- Not applicable. The submission focuses on substantial equivalence and engineering testing, not a clinical study involving ground truth establishment by experts for a test set.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
- Not applicable. No clinical test set or adjudication process is described.
5. If a multi-reader multi-case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance
- Not applicable. The device is an electrical stimulator, not an AI or imaging diagnostic aid, and therefore, an MRMC study is not relevant to its stated function or the information provided.
6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done
- Not applicable. This device is an electrical stimulator designed to be used in conjunction with other clinical devices for neurological function (EMG/Stimulator for evoked reaction) and would always involve human operation/interpretation. There is no "algorithm only" performance reported as it's a hardware device.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
- For the engineering validation, the "ground truth" was likely the design specifications and established engineering standards (e.g., IEC standards). For the claim of "proper operation," it implies that the device's output and characteristics (e.g., voltage, pulse shape) met predefined engineering targets. No medical or biological ground truth (like pathology or clinical outcomes) was used for performance assessment in this submission.
8. The sample size for the training set
- Not applicable. The device is not a machine learning or AI algorithm, so there is no concept of a "training set" in the context of its development or submission.
9. How the ground truth for the training set was established
- Not applicable. As there is no training set mentioned, this question is not relevant.
In summary, the K071969 submission for the Nihon Kohden SEN-4100 Electric Stimulator primarily relies on demonstrating compliance with recognized electrical safety and performance standards, and substantial equivalence to a legally marketed predicate device based on technological characteristics and intended use. It does not present a study with specific clinical performance metrics (like accuracy or sensitivity) derived from a test set with established ground truth. The "study" referenced is the design validation and engineering testing (electromagnetic, environmental, safety, and performance testing) which "verified the proper operation of the device" according to design specifications and relevant voluntary industrial standards.
§ 882.1870 Evoked response electrical stimulator.
(a)
Identification. An evoked response electrical stimulator is a device used to apply an electrical stimulus to a patient by means of skin electrodes for the purpose of measuring the evoked response.(b)
Classification. Class II (performance standards).