(202 days)
The general purpose of the proposed device is identical to the predicate device: "to perform the measurements needed for electromyography (EMG), nerve conduction velocity (NCV, F wave, and H reflex), and evoked potentials (brainstem, visual, and somatosensory), and repetitive nerve stimulation." The purpose of the proposed device is to allow compatibility with high-impedance electrodes. The proposed device allows electrode inputs to be made closer to the source of the signal for reduced signal noise during procedures requiring high-impedance electrodes.
The proposed device consists of the existing two-channel preamplifier and a buffered electrode input box with extension cable. These components provide electrode inputs that are closer to the source of the signal during electromyographic (EMG) testing. The intent of this design is to reduce signal noise during procedures requiring high-impedance electrodes. The proposed device is for use with the Cadwell Sierra (K924723) and 6200A (K931428) EMG instruments.
All device components are reusable and supplied non-sterile. The extension cable with electrode input box is compatible with EtO sterilization guidelines for procedures requiring a sterile field. The input box is available with separate active and reference input connectors or a single phono jack connector.
The attached extension cable connects the input box to the preamplifier by way of a cable adapter. The existing preamplifier will be fitted with three pin DIN connectors to accept the cable adapter.
The extension cable with buffered electrode input box allows electrode inputs to be made closer to the source of the signal for reduced signal noise during procedures requiring high-impedance electrodes. The electrode input box is available with separate active (labeled .) and reference connectors or a single phono jack connector to accommodate recording electrodes with these connector types.
The input box is enclosed in a white polyethylene foam sheath. The sheath houses a circuit board consisting of a buffer circuit, two electrostatic discharge (ESD) networks (one on each side of the buffer circuit), and a separate circuit designed to limit fault currents.
The circuit board is attached to a polyvinyl chloride extension cable terminated in an eight-pin DIN connector. The input box and extension cable are connected to the preamplifier by way of a polvyinyl chloride cable adapter terminated in a three-pin DIN connector. The adapter cable does not qualify as a class II device.
This document describes a modification to an existing Electromyography (EMG) and Evoked Potential (EP) equipment. The modification involves adding a buffered input box with an extension cable to allow electrode inputs closer to the signal source, aiming to reduce signal noise during procedures requiring high-impedance electrodes. The existing preamplifier is also modified to accommodate this new component.
Here's an analysis of the acceptance criteria and study that proves the device meets them:
1. Table of Acceptance Criteria and Reported Device Performance
The document doesn't explicitly list "acceptance criteria" in a separate section, but rather presents a comparison of technical specifications between the existing and proposed devices, along with results from specific engineering and clinical tests. We can infer the acceptance criteria from these comparisons and test descriptions.
| Criteria | Acceptance Criteria (Inferred) | Reported Device Performance (Proposed Device) |
|---|---|---|
| Safety: | ||
| IEC 601-1 / UL 544 Compliance | Device must comply with IEC 601-1 (Type BF) and UL 544. | Designed to comply with requirements of UL 544. Classification: isolated patient connections IEC 601-1: Type BF. |
| ESD withstand | Input impedance > 10 Mohms after 8-kV ESD strikes. | Results of engineering tests 1 and 2 indicate that the input impedance is greater than 10 Mohms when the active and reference connectors are subjected to ten strikes of 8-kV ESD each. |
| Gain Preservation | Gain should not be affected by passing signal through the device. | The results from test 3 show that the gain is not affected by passing the signal through the proposed device. |
| Patient Auxiliary Current | Patient auxiliary current must be well below IEC 601-1 limits. | The results from test 4 show that the patient auxiliary current is well below the regulatory limits set forth by IEC 601-1 for BF connections. |
| Noise Reduction | Measured peak-to-peak noise must be less than the allowed value. | The results from test 5 show that the measured value of peak-to-peak noise is less than the allowed valued. (Specific allowed value not stated, but implied to be met). |
| Clinical Performance: | ||
| Nerve Conduction Waveform Preservation | No distortion of waveform and no significant effect on onset time, peak time, or amplitude. | Clinical results from test 6 show that the proposed device does not distort the morphology of the nerve conduction waveform, nor does it significantly affect the onset time, peak time, or amplitude when compared to the signal that does not pass through the proposed device. |
| EMG Waveform Preservation | No distortion of EMG waveform. | Additional clinical results in test 7 indicate that the proposed device does not distort the morphology of the EMG waveform when compared to the signal that does not pass through the proposed device. |
| Electrical Specifications (Identical to predicate) | CMRR > 100 dB, Input Impedance > 1,000 Mohms (common mode), Noise 2 micro V peak to peak (10 Hz to 10 kHz), etc. | All electrical specifications (Isolation mode rejection, Common mode rejection, Sensitivities, Noise, Input impedance, Notch filter, Low-cut filters, High-cut filters) are reported as identical to the predicate device, indicating they meet the established performance benchmarks. |
2. Sample Size Used for the Test Set and Data Provenance
The document does not explicitly state the sample size for the test set used in the engineering or clinical tests (tests 1-7).
The data provenance is also not specified (e.g., country of origin, retrospective or prospective). It only mentions "clinical results from test 6" and "additional clinical results in test 7."
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The document does not specify the number of experts used or their qualifications for establishing ground truth in the clinical tests. The clinical tests compare the device's output to signals that do not pass through the proposed device.
4. Adjudication Method for the Test Set
The document does not describe any adjudication method (e.g., 2+1, 3+1) for the test set. The clinical results seem to be based on a direct comparison of waveforms.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, an MRMC comparative effectiveness study was not done. The document describes engineering and clinical tests focused on verifying the device's signal integrity and safety, not on comparing human reader performance with and without AI assistance. The device itself is a hardware modification (buffered input box) for an EMG/EP system, not an AI-assisted diagnostic tool.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
The concept of "standalone performance" typically applies to diagnostic algorithms. Since this device is a hardware component for an existing EMG/EP instrument, a standalone algorithm performance study is not applicable. The tests performed assess the hardware's impact on signal quality and electrical safety.
7. The Type of Ground Truth Used
For the engineering tests (ESD, Gain, Patient Auxiliary Current, Noise), the "ground truth" is based on established engineering standards and regulatory limits (e.g., IEC 601-1, UL 544, and internal specifications for gain, noise, and impedance).
For the clinical tests (Nerve Conduction and EMG Waveform Preservation), the ground truth is established by comparison to signals that do not pass through the proposed device. This implies an internal control where the same physiological event is recorded with and without the new component, and their waveform characteristics are compared. This method relies on the existing, well-understood properties of normal nerve conduction and EMG waveforms.
8. The Sample Size for the Training Set
The device is a hardware modification, not a machine learning algorithm that requires a training set. Therefore, there is no training set in the context of this submission.
9. How the Ground Truth for the Training Set Was Established
As there is no training set for this hardware device, this question is not applicable.
§ 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).