Search Results

The Primary Relief is a percutaneous electrical nerve stimulator (PENS) system indicated for up to 3 days for symptomatic relief of post-operative pain following cesarean section delivery or up to 3 days adjunctive symptomatic relief of post-operative pain following cardiac surgery.

The Primary Relief is designed to aid in the reduction of post-operative pain by the method of cranial electrical stimulation at the auricular stimulation points. The Primary Relief is a wearable, battery-operated device that is designed to administer periodical low level electrical pulses to the ear over three days / 72 hours from the time of activation of the device. The electrical pulse from the device will be delivered to the branches of cranial nerves on the ear through a set of wire assembly and stimulation needles. Three zinc air batteries with 1.4 V each provide the required stimulation energy for 72 hours. There stimulation electrode and one ground electrode which constitute of a needle and lead/ wire with the snap-fit ring. The stimulation needles are inserted at three specific points, which have the ability to stimulate the cranial nerves. The ground electrode is inserted at one specific point (constant in all treatments) which forms the functional earthing to the device. This constant current source guarantees equivalent stimulation energy regardless of the individual impedance of the stimulation pattern consists of rectangular pulses with differing inter-pulse intervals. A 3-pin connector is provided, which is used to check the output voltage of the device once it is activated and before applying to the patient with any one of the voltage measuring devices available in the market with the appropriate regulatory compliance.

Here's a breakdown of the acceptance criteria and study information for the Primary Relief device, based on the provided FDA 510(k) summary:

Description of Acceptance Criteria and Proving Study

The acceptance criteria for the Primary Relief device appear to be primarily focused on demonstrating its effectiveness in reducing post-operative pain, specifically after cardiac surgery, to support its expanded indications for use. The study aimed to show a statistically significant reduction in pain scores compared to a sham device.

1. Table of Acceptance Criteria and Reported Device Performance

2. Sample size used for the test set and the data provenance

• Sample Size: 60 subjects (29 in the intervention group and 31 in the control/sham group).
• Data Provenance: Single center, prospective study. The country of origin is not explicitly stated, but the submitter's address is in San Mateo, California, USA, and the FDA is a US regulatory body, suggesting the study likely took place in the US or was conducted under US regulatory standards.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts

The ground truth for pain was established through Numeric Rating Scale (NRS) scores reported by the patients themselves. This is a patient-reported outcome measure and does not involve expert adjudication in the traditional sense for image interpretation or diagnosis. The study notes that the primary and secondary endpoints were measured using "validated and widely used tools."

4. Adjudication method for the test set

There was no external adjudication method (like 2+1 or 3+1) described for the pain scores, as these are direct patient-reported outcomes via NRS. The study itself was a double-blinded prospective study, meaning neither the subjects nor the study staff administering the treatment (and presumably collecting pain scores) knew whether the patient received the active or sham device. This blinding helps maintain the integrity of the data collection for patient-reported outcomes.

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

• No, an MRMC study was not done. This study is for a medical device (Transcutaneous Electrical Nerve Stimulator for Pain Relief), not an AI-powered diagnostic tool requiring human reader interpretation of images. Therefore, the concept of "human readers improve with AI vs without AI assistance" is not applicable here.

6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done

• Yes, in spirit, a standalone performance was assessed. The device (Primary Relief) delivers electrical stimulation for pain relief. Its performance is directly measured by its effect on patient pain scores. While a human applies the device, the device itself functions autonomously for 72 hours, delivering stimulation. The clinical study evaluated its direct effect (standalone effect) on pain scores compared to a sham device.

7. The type of ground truth used

The ground truth for the primary efficacy endpoint (pain intensity) was patient-reported outcomes using the Numeric Rating Scale (NRS). For secondary efficacy endpoints, the summary mentions "five measures intended to assess the pulmonary function," which would also be objective physiological measurements or patient-reported outcomes, but the specific ground truth establishment method for these is not detailed in the summary.

8. The sample size for the training set

The document does not explicitly mention a separate "training set" in the context of the clinical study for the expanded indication. The 60 subjects were part of the test set or the clinical validation study for this specific 510(k) submission. For medical devices like this, there isn't typically a "training set" in the machine learning sense for the device's functionality. The "training" for the device's design and parameters would have occurred during its development and prior predicate clearance (K213188).

9. How the ground truth for the training set was established

As there's no explicitly defined "training set" for an AI model in this context, the question regarding its ground truth establishment is not directly applicable. If we consider the development of the device itself (including its electrical parameters), the ground truth would have been established through preclinical studies, engineering specifications, and previous clinical trials that led to the predicate device's clearance (K213188), demonstrating its general safety and effectiveness for a similar indication (post-operative pain following cesarean section delivery).

Ask a specific question about this device