Sonosite LX and Sonosite PX Ultrasound Systems

• K Number: K251106
• Device Name: Sonosite LX and Sonosite PX Ultrasound Systems
• Manufacturer: Fujifilm Sonosite Inc
• Date Cleared: 2025-08-29 ( 140 days)
• Product Code: IYN , ITX , IYO , QIH
• Regulation Number: 892.1550
• Type: Traditional
• Panel: RA
• Reference & Predicate Devices: K233597

Intended Use

The Sonosite LX and Sonosite PX ultrasound systems are general purpose ultrasound systems intended for use by qualified physicians and healthcare professionals for evaluation by ultrasound imaging or fluid flow analysis of the human body. Specific clinical applications and exam types include:

• Abdominal
• Adult Cephalic
• Neonatal Cephalic
• Cardiac Adult
• Cardiac Pediatric
• Fetal - OB/GYN
• Musculo-skeletal (Conventional)
• Musculo-skeletal (Superficial)
• Ophthalmic
• Pediatric
• Peripheral vessel
• Small Organ (breast, thyroid, testicles, prostate)
• Transesophageal (cardiac)
• Transrectal
• Transvaginal
• Needle Guidance

Modes of operation include: B Mode (B), M-Mode (M) (including simultaneous M-mode and anatomical M-M-Mode), PW Doppler (PWD) (including High Pulse Repetition Frequency (HPRF) and simultaneous PWD for certain exam types), Tissue Doppler Imaging (TDI), Continuous Wave Doppler (CWD), Color Power Doppler, Velocity Color Doppler, Color Variance, Tissue Harmonic Imaging (THI), Multi-beam imaging, Steep Needle Profiling, Trapezoid, and combined modes, including duplex and triplex imaging: B+M, B+PWD, B+CWD, B+C, (B+C)+PWD, (B+C)+CWD.

This device is indicated for Prescription Use Only.

The Sonosite LX and Sonosite PX ultrasound systems are intended to be used in medical practices, clinical environments, including Healthcare facilities, Hospitals, Clinics, and clinical point-of-care for diagnosis of patients.

The systems are used with a transducers attached and they are powered either by battery or by AC electrical power. The clinician is positioned next to the patient and places the transducer onto the patient's body where needed to obtain the desired ultrasound image.

Device Description

The Sonosite LX and Sonosite PX Ultrasound Systems are full featured, general purpose, software controlled diagnostic ultrasound systems used to acquire and display high-resolution, real-time ultrasound data in 2D, M-Mode, Pulsed Wave (PW) Doppler, Continuous Wave (CW) Doppler, Color Power Doppler (CPD), and Color Doppler (Color) or in a combination of these modes.

The systems include a variety of accessories including needle guide starter kits. The systems include USB host support for peripherals such as input devices, storage devices and Ethernet port. Input devices include wired and wireless devices. The systems also include an ECG-specific port to support the ECG feature. The non-diagnostic ECG module provides ECG tracing of the cardiac signal synchronized with the ultrasound image.

AI/ML Overview

The provided document details the 510(k) clearance for the Sonosite LX and Sonosite PX Ultrasound Systems, specifically focusing on the addition of the PIV Assist AI feature. Here's a breakdown of the acceptance criteria and the study proving the device meets them:

Acceptance Criteria and Reported Device Performance

The document presents performance metrics for the PIV Assist AI algorithm, which serve as the acceptance criteria for its functionality. Specifically, the metrics cover "Vessel Precision," "Vessel Recall," "Vein Classification Accuracy," and "Artery Classification Accuracy" for two different transducers (L19-5 and L12-3). Additionally, average depth and diameter errors are reported.

Here's a table summarizing the reported device performance against implicitly defined acceptance criteria (as these are the results presented to demonstrate performance). No explicit "desired" or "threshold" values are given for acceptance criteria; rather, the reported performance is the demonstration of meeting the criteria.

Metric	Transducer	Reported Performance (95% CI)
Vessel Precision	L19-5	97.32% (97%-98%)
	L12-3	95.58% (95%-96%)
Vessel Recall	L19-5	97.07% (96%-98%)
	L12-3	94.49% (93%-95%)
Vessel Classification for Veins	L19-5	96.01% (95%-97%)
	L12-3	94.54% (93%-96%)
Vessel Classification for Arteries	L19-5	89.71% (87%-92%)
	L12-3	86.06% (83%-89%)
Average Depth Error	L19-5	0.065mm (0.062-0.068mm)
	L12-3	0.105mm (0.103-0.108mm)
Average Diameter Error	L19-5	6.2% (5.5-7.1%), 0.203mm (0.186-0.219mm)
	L12-3	5.6% (5.0-6.2%), 0.19mm (0.18-0.21mm)

Note: While specific acceptance thresholds are not explicitly stated, the reported high percentages and low error margins demonstrate the device's acceptable performance for its intended use.

Study Details for PIV Assist AI Algorithm Performance Testing

Here's a breakdown of the study details as provided in the document:

1. Sample Size used for the test set and the data provenance:

   • Sample Size: 584 ultrasound clips from 292 subjects.
   • Data Provenance: The data was collected prospectively from 3 hospitals within the United States. The document explicitly states that the validation dataset was collected at a "much later timeframe" and at "different sites from the training and tuning data" to ensure independence.

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

   • The document states that "certified Clinical Sonographers" independently labeled the data.
   • For adjudication, an "Interventional Radiologist" evaluated the labeled data.
   • Specific numbers of sonographers or the interventional radiologist are not provided. Their general qualifications (certified Clinical Sonographers, Interventional Radiologist) are mentioned, but specific experience (e.g., "10 years of experience") is not detailed.

3. Adjudication method for the test set:

   • An adjudication process took place "in cases where there was disagreement between the images."
   • The adjudication was performed by an "Interventional Radiologist" who evaluated the labeled data to establish the final ground truth. This suggests a form of expert consensus with a tie-breaker, though specific methods like "2+1" or "3+1" are not explicitly stated. It implies a process where disagreements among sonographers were resolved by a higher-level expert.

4. If a multi-reader multi-case (MRMC) comparative effectiveness study was done:

   • No, an MRMC comparative effectiveness study was not done. The document focuses solely on the "AI algorithm performance testing" in a standalone manner, evaluating its accuracy against ground truth. There is no mention of comparing human reader performance with and without AI assistance, nor any effect size.

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

   • Yes, a standalone study was done. The "Summary of PIV Assist AI Algorithm Performance Testing" section details metrics like precision, recall, and classification accuracy, which are inherent to the algorithm's performance when processing and interpreting ultrasound data. There's no indication of human interaction during the measurement of these performance metrics.

6. The type of ground truth used:

   • The ground truth was established through expert consensus and adjudication of ultrasound clips and frames. "Certified Clinical Sonographers" independently labeled the data, and an "Interventional Radiologist" adjudicated disagreements to establish the "final ground truth."

7. The sample size for the training set:

   • The document states that the validation dataset was collected independently from the "training and tuning data," but it does not provide the sample size of the training set.

8. How the ground truth for the training set was established:

   • The document mentions "training and tuning data" but does not explicitly detail how the ground truth for the training set was established. It can be inferred that a similar process of expert labeling, potentially with adjudication, was used given the rigorous approach for the validation set, but this is not explicitly stated.

Regulation Number and Section

§ 892.1550 Ultrasonic pulsed doppler imaging system.

(a)
Identification. An ultrasonic pulsed doppler imaging system is a device that combines the features of continuous wave doppler-effect technology with pulsed-echo effect technology and is intended to determine stationary body tissue characteristics, such as depth or location of tissue interfaces or dynamic tissue characteristics such as velocity of blood or tissue motion. This generic type of device may include signal analysis and display equipment, patient and equipment supports, component parts, and accessories.(b)
Classification. Class II.