(117 days)
The Levita Magnetic Surgical System is designed to grasp and retract the body and the fundus of the gallbladder in laparoscopic cholecystectomy procedures, the liver in bariatric procedures, and the prostatic tissue in prostatectomy procedures to facilitate access and visualization of the surgical site. The in patients with a BMI range of 20-60 kg/m2.
The Levita Magnetic Surgical System is composed of two hand-held instruments, the Magnetic Grasper and external Magnetic Controller. The Magnetic Grasper (sterile, single use), comprised of a distal detachable Grasper Tip attached to a Shaft with handle, is actuated via its pistol-grip handle with two distinct scissor-type motions to open and close the detachable Grasper Tip jaws. Once the Magnetic Grasper is inserted through a compatible The Magnetic Controller (non-sterile, reusable) is a single unit with handles that is held external to the body and emits a magnetic field that attracts the Grasper Tip. Once the Grasper Tip is attached to the desired tissue and detached from the Shaft, the Magnetic Controller is placed external to the body to magnetically attract the Grasper Tip to manipulate the target tissue. Adjusting the distance between the Magnetic Controller and the Grasper Tip will modulate the magnetic attraction used for tissue retraction/mobilization. If desired, the user can connect the Magnetic Controller to a commercially available surgical support arm that is compatible with its arm mount.
Here's a summary of the acceptance criteria and study details for the Levita Magnetic Surgical System, based on the provided document:
1. Table of Acceptance Criteria and Reported Device Performance:
| Acceptance Criteria (Special Controls - §21 CFR 878.4815) | Reported Device Performance |
|---|---|
| (1) In vivo performance data must demonstrate that the device performs as intended under anticipated conditions of use. Testing must demonstrate the ability of the device to grasp, hold, retract, mobilize or manipulate soft tissue and organs. | Effectiveness: The Magnetic Surgical System (MSS) was able to adequately retract the prostate to achieve an effective exposure of target tissue. It was not necessary to replace the MSS with another instrument to retract the prostate during the procedure. |
| Safety: No cases of severe or serious adverse events and no device-related adverse events were reported. Eleven (11) adverse events occurred, all resolved with no clinical sequelae and were categorized as not related to the subject device. | |
| Procedure Times: Mean overall procedure time was 3 hours 23 minutes. | |
| (2) Non-clinical performance data must demonstrate that the system performs as intended under anticipated conditions of use. The following performance characteristics must be tested: (a) Magnetic field strength testing characterization to identify the distances from the magnet that are safe for patients and users with ferromagnetic implants, devices or objects. (b) Ability of the internal surgical instrument(s) to be coupled, de-coupled, and recoupled with the external magnet over the external magnet use life. | No new testing was required. The modifications did not change magnetic field strength or coupling. Previously conducted nonclinical performance testing for the predicate device applied. |
| (3) The patient-contacting components of the device must be demonstrated to be biocompatible. | No new testing was required. The modifications did not change any aspect of the device. Previously conducted biocompatibility testing for the predicate device applied. |
| (4) Performance data must demonstrate the sterility of the device components that are patient-contacting. | No new testing was required. The modifications did not change any aspect of the device. Previously conducted sterility testing for the predicate device applied. |
| (5) Methods and instructions for reprocessing reusable components must be validated. | No new testing was required. The modifications did not change any aspect of the device. Previously conducted testing validating reprocessing methods for the predicate device applied. |
| (6) Performance data must support shelf life by demonstrating continued sterility of the device or the sterile components and device functionality over the labeled shelf life. | No new testing was required. The modifications did not change any aspect of the device. Previously conducted testing validating shelf life for the predicate device applied. |
| (7) Training must be developed and validated by human factors testing and analysis to ensure users can follow the instructions for use to allow safe use of the device. | A training program was developed, and a usability study was completed to validate it. |
| (8) Labeling must include: (a) Magnetic field safezones. (b) Instructions for proper device use. (c) A screening checklist to ensure that all patients and operating staff are screened from bringing ferromagnetic implants, devices or objects near the external magnet. (d) Reprocessing instructions for any reusable components. (e) Shelf life. (f) Use life. | The labeling complies with these special controls. |
2. Sample Size Used for the Test Set and Data Provenance:
- Sample Size (Test Set): 30 subjects
- Data Provenance:
- Country of Origin: Santiago, Chile (Fundacion Arturo Lopez Perez)
- Retrospective or Prospective: Prospective clinical study
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications:
- Number of Experts: 5 investigators (surgeons)
- Qualifications: The document identifies them as "surgeons" and "investigators" participating in a clinical study for prostatectomy procedures. Specific experience levels (e.g., years of experience or specialization) are not detailed in this document.
4. Adjudication Method for the Test Set:
- The document states that "Investigators reported that adequate retraction was achieved since it was not necessary to replace the MSS with another instrument to retract the prostate during the procedure." and "All eleven events resolved with no clinical sequelae and were categorized as not related to the subject device."
- This suggests that the surgeons themselves were the primary adjudicators of effectiveness and relatedness of adverse events during the procedure. There is no mention of an independent adjudication panel or a numerical adjudication rule (e.g., 2+1, 3+1). The study describes itself as a "single-arm, open label study."
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
- No, a MRMC comparative effectiveness study was not done.
- This was a single-arm study evaluating the device's performance in a new indication (prostatectomy), primarily to demonstrate safety and effectiveness for that specific use extension compared to the predicate device, not to show human reader improvement with AI assistance. The device itself is a surgical instrument, not an AI diagnostic tool.
6. Standalone (Algorithm Only) Performance:
- Not applicable. This device is a surgical instrument, not an algorithm, and thus does not have "standalone" algorithm performance in the typical sense of AI/diagnostic devices. Its performance is intrinsically linked to its use by a human surgeon.
7. Type of Ground Truth Used:
- Expert Consensus/Clinical Observation during Surgery: The "ground truth" for effectiveness was established by the clinical judgment of the participating surgeons during the procedure. Specifically, effectiveness was defined as the "ability to adequately retract the prostate to achieve an effective exposure of the target tissue," and "Adequate retraction was deemed to be achieved if it is not necessary to replace the Levita Magnetic Surgical System with another instrument to retract the prostate during the procedure." Safety was based on the absence of severe or serious adverse events reported by the investigators.
8. Sample Size for the Training Set:
- Not applicable / No specific training set mentioned. This is a medical device, not an AI model, so there isn't a "training set" in the machine learning sense. The device's design and previous versions (predicate devices) would have undergone development and testing, but a distinct "training set" for an algorithm is not relevant here.
9. How the Ground Truth for the Training Set Was Established:
- Not applicable. As a surgical device and not an AI model, the concept of establishing ground truth for a training set does not apply. The development would have involved engineering, material science, and prior clinical experience with similar devices, leading to verification and validation activities. The clinical study described in the document is for validation of its performance in an extended indication, not for training an algorithm.
§ 878.4815 Magnetic surgical instrument system.
(a)
Identification. A magnetic surgical instrument system is a prescription device used in laparoscopic surgical procedures consisting of several components, such as surgical instruments, and a magnetic controller. The magnetic controller is provided separately from the surgical instrument and is used outside the patient. The external magnetic controller is magnetically coupled with the internal surgical instrument(s) at the surgical site to grasp, hold, retract, mobilize, or manipulate soft tissue and organs.(b)
Classification. Class II (special controls). The special controls for this device are:(1) In vivo performance data must demonstrate that the device performs as intended under anticipated conditions of use. Testing must demonstrate the ability of the device to grasp, hold, retract, mobilize, or manipulate soft tissue and organs.
(2) Non-clinical performance data must demonstrate that the system performs as intended under anticipated conditions of use. The following performance characteristics must be tested:
(i) Magnetic field strength testing characterization to identify the distances from the magnet that are safe for patients and users with ferromagnetic implants, devices, or objects.
(ii) Ability of the internal surgical instrument(s) to be coupled, de-coupled, and re-coupled with the external magnet over the external magnet use life.
(3) The patient-contacting components of the device must be demonstrated to be biocompatible.
(4) Performance data must demonstrate the sterility of the device components that are patient-contacting.
(5) Methods and instructions for reprocessing reusable components must be validated.
(6) Performance data must support shelf life by demonstrating continued sterility of the device or the sterile components and device functionality over the labeled shelf life.
(7) Training must be developed and validated by human factors testing and analysis to ensure users can follow the instructions for use to allow safe use of the device.
(8) Labeling must include:
(i) Magnetic field safe zones.
(ii) Instructions for proper device use.
(iii) A screening checklist to ensure that all patients and operating staff are screened from bringing ferromagnetic implants, devices, or objects near the external magnet.
(iv) Reprocessing instructions for any reusable components.
(v) Shelf life.
(vi) Use life.