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The Extracorporeal Shock Wave Lithotripter, model: U200, is intended to fragment urinary stones in the kidney (renal pelvis and renal calyces) and ureter (upper, middle, and lower ureter).

The Extracorporeal Shock Wave Lithotripter, U200, is intended to treat urinary tract stones using ESWL. The Extracorporeal Shock Wave Lithotripter generates high-energy shock waves using a shock wave generator that is focused to produce a highly concentrated stress area at the focal point. These pressure pulses are focused on a specific point in the body where the Urinary calculi are located using assisted movement and manual localization through B-ultrasound. The pressure generated by the shock wave causes the human urinary tract stones to produce physical effects to achieve the therapeutic purpose of crushing stones.

The Extracorporeal Shock Wave Lithotripter, U200, is composed of main unit, control console, patient table, electrical cabinet, power supply unit, and computer.

Control platform is integrated control of electric cabinet, main engine and treatment bed.

Electrical cabinet is used to provide power control of the whole machine, and shock wave source function control.

Main Unit contains the L-shape arm and the support matrix of the impact wave source, and realize the movement of L-shape arm up and down, rotation and oscillation of the impact wave source inside and outside.

Power box is power supply of the whole machine, power supply input voltage 120 V, 60 Hz, 3000VA.

Treatment bed is used for patient support and treatment position, and provides three-dimensional movement to allow easy positioning of the stone in the shock wave focus for lithotripsy and urological procedures.

PC(OptiPlex 7000 Tower) is used for installation of Extracorporeal Shock Wave Lithotripter Computer Control System, and to realize the Movement Control Support Function and the calibration of shock wave target, and image handling.

Principle of operation:

The extracorporeal shock wave lithotripter generates pressure pulses using an electromagnetic shock wave generator, with water serving as the transmission medium. These high energy shock waves with peak acoustic pressure up to 35MPa are focused on a specific point using a lens. In addition, the lithotripter often incorporates an ultrasound-based assisted movement system which locates and aligns the shock wave focus with the urinary tract stone. The shock waves create a stress effect on the stone. After several hundred to around two thousand discharges, the stones are fragmented into smaller pieces which can be excreted from the body.

This document is a 510(k) clearance letter for an Extracorporeal Shock Wave Lithotripter (U200). It describes the device, its intended use, and the studies conducted to demonstrate its safety and effectiveness.

Here's an analysis of the acceptance criteria and the study that proves the device meets them, based on the provided text:

Acceptance Criteria and Reported Device Performance

The acceptance criteria are not explicitly stated as quantitative thresholds for the clinical study's primary effectiveness endpoint. Instead, the clinical study aims to demonstrate that the device has a "safety and effectiveness profile that is similar to the predicate device." The reported device performance is presented as successful outcomes in various subgroups. The key performance metrics are "effective rate" for stone fragmentation.

• FAS (Full Analysis Set): 79.2%
• PPS (Per-Protocol Set): 86.4% |
  | Localization Accuracy: Auxiliary positioning target error, number of auxiliary positioning operations, and total time of auxiliary positioning operations should demonstrate relative speed, accuracy, and convenience. | Localization Performance:
• Auxiliary positioning target error: within 3mm
• Number of auxiliary positioning operations: within 3 times
• Total time of auxiliary positioning operations: within 15min
  (Stated as "relatively fast, accurate, and convenient, and the system ergonomics performance is good.") |
  | Safety: Device should be safe with no device malfunctions reported in the clinical investigations. | Safety: "The incidence of device malfunction does not happen in these clinical investigations." "patients treated by the Extracorporeal Shock Wave Lithotripter (model: U200) are safe." |
  | Subgroup Effectiveness (Inferred, as results are presented): Demonstrate effectiveness across different stone sizes, locations, and densities. | Stone Size:
• Stones 5-10mm (FAS): 92.9% effective rate
• Stones 10-15mm (FAS): 60.0% effective rate
• Stones 5-10mm (PPS): 100% effective rate
• Stones 10-15mm (PPS): 66.7% effective rate |
  | | Stone Location:
• Kidney stones (FAS): 80.0% effective rate (Renal calyx: 75.0%, Renal pelvis: 100%)
• Ureteral stones (FAS): 78.6% effective rate (Upper ureteral: 70.0%, Middle ureteral: 100%, Lower ureteral: 100%)
• Kidney stones (PPS): 80.0% effective rate (Renal calyx: 75.0%, Renal pelvis: 100%)
• Ureteral stones (PPS): 91.7% effective rate (Upper ureteral: 87.5%, Middle ureteral: 100%, Lower ureteral: 100%) |
  | | Stone Density:
• Density 1000HU (FAS): 81.8% effective rate
• Density 1000HU (PPS): 81.8% effective rate |

Study Details from the Provided Text:

1. Sample Size Used for the Test Set and Data Provenance:

   • Clinical Test Set Sample Size: 25 subjects enrolled, 22 subjects completed the study. (4 subjects failed screening, 3 dropped out). The study used both a Full Analysis Set (FAS) and a Per-Protocol Set (PPS) for effectiveness calculation, implying some missing data handled by intent-to-treat (FAS) and per-protocol (PPS).
   • Data Provenance: The clinical investigation was a "multicenter, open-label clinical design." The specific countries of origin for the clinical data are not mentioned, but the manufacturer and correspondent are based in China. The retrospective or prospective nature is not explicitly stated, but "clinical investigations" with "subjects screened," "enrolled," and "followed for a period of follow-up" strongly suggest a prospective study design.

2. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of Those Experts:

   • The document does not explicitly state the number of experts or their qualifications used to establish "ground truth" for stone fragmentation. The primary effectiveness endpoint, "effective rate," is defined based on the outcome of the ESWL treatment, likely assessed clinically (e.g., successful fragmentation and clearance/passage of stones). This assessment would typically be done by treating physicians (urologists) or through imaging (e.g., ultrasound, X-ray) reviewed by radiologists, but the document does not specify.

3. Adjudication Method for the Test Set:

   • The document does not describe any specific adjudication method (e.g., 2+1, 3+1 consensus) for assessing the "effective rate" or other clinical outcomes. It suggests that the clinical outcomes were observed and reported as part of the study.

4. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done, and the effect size of how much human readers improve with AI vs. without AI assistance:

   • No. This device is an Extracorporeal Shock Wave Lithotripter, which is a physical medical device for breaking up stones, not an AI-assisted diagnostic or imaging device. Therefore, an MRMC study comparing human readers with and without AI assistance is not applicable and was not performed.

5. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done:

   • Not applicable in the AI sense. The device's primary function is a physical therapy. However, the document does mention "PC(OptiPlex 7000 Tower) is used for installation of Extracorporeal Shock Wave Lithotripter Computer Control System, and to realize the Movement Control Support Function and the calibration of shock wave target, and image handling." It also states "Software Verification and Validation was performed, and it was demonstrated that the software performs as intended." This implies a standalone software performance assessment, but not a standalone diagnostic algorithm performance assessment. The device's "localization/stone targeting system" appears to be an integral part of its operation, not a separate diagnostic algorithm.

6. The Type of Ground Truth Used:

   • For the clinical effectiveness endpoint ("effective rate"), the ground truth is based on clinical outcomes (successful stone fragmentation and presumed clearance) observed in patients after receiving ESWL treatment. This would typically be assessed by follow-up imaging and clinical evaluation.
   • For Localization Accuracy, the ground truth was likely established by physical measurements comparing the "target location" to the "shock wave focus."

7. The Sample Size for the Training Set:

   • The document does not mention a separate training set or its sample size for the clinical study. This is a medical device clearance, not an AI model development project where explicit training sets are typically discussed. If any software component used machine learning, details of its training would be relevant, but those are not provided. The clinical study described appears to be a validation/test set for the entire system's clinical performance.

8. How the Ground Truth for the Training Set Was Established:

   • Since no explicit training set for a machine learning model is mentioned, the method for establishing ground truth for a training set is not applicable based on the provided text.

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