(195 days)
For evaluation of colonic transit in adult and pediatic patients (at least 2 years old) with chronic constipation and used to aid in differentiating slow and normal transit constipation.
The device is intended to be used for evaluation of colonic transit time in patients with chronic constipation and used to aid in differentiating slow and normal transit constipation in adults and pediatric patients (at least 2 years old). Ten (10) radiopaque markers per day are swallowed for six consecutive days. On day seven an abdominal radiograph is taken. Based on the number of retained markers and the position in colonic transit time is calculated and compared to reference values. Both total transit and segmental transit dysfunction in the colon can be evaluated with the device. By dividing the particle dose on day six by taking five (5) markers in the morning and five (5) markers in the evening, the whole range of transit times (slow, normal, rapid) transit can be measured from the radiograph.
The device is a convenience package of radiopaque markers (22% Barium Sulphate, 78% Elastosil® R 401/60 Silicone rubber) placed in vegetarian capsules from cellulose (HPMC, Hydroxypropylmethylcellulose), intended for single patient use. The dimension of the markers is 2x4.5mm (ring-formed markers) and 6x2mm (tube-formed markers). The capsules are packed in a blister pack is placed inside a folding box.
Here's an analysis of the acceptance criteria and the study proving the device meets them, based on the provided FDA 510(k) summary for Transit-Pellets:
It's important to note that this document is a 510(k) clearance, which determines substantial equivalence to a predicate device, rather than a full pre-market approval (PMA) that requires extensive clinical trials to establish de novo safety and effectiveness. Therefore, the "studies" mentioned often refer to comparisons with predicate devices, existing literature, or post-market follow-up, rather than new, large-scale randomized controlled trials.
Acceptance Criteria and Reported Device Performance
The document does not explicitly state formal "acceptance criteria" in a quantitative, measurable format with target performance values (e.g., "sensitivity must be >X%", "specificity must be >Y%"). Instead, the performance is demonstrated by showing substantial equivalence to a legally marketed predicate device (Sitzmarks) and by leveraging existing clinical literature and post-market data.
The key performance aspect for Transit-Pellets is its ability to accurately measure colonic transit time (CTT) and thereby aid in differentiating slow and normal transit constipation. The acceptance is implicitly based on the predicate device's established performance and the demonstration that the subject device performs equivalently and safely, especially for the expanded pediatric population.
Table of Performance Comparison (based on equivalence to predicate):
| Performance Characteristic/Acceptance Criteria | Reported Device Performance (Transit-Pellets) - based on equivalence and PMCF |
|---|---|
| Ability to Measure Colonic Transit Time | Equivalent to K181760 (Primary Predicate) and K181750 (Reference Predicate, Sitzmarks). Capable of calculating CTT/OATT numerical values in days. |
| Aid in Differentiating Constipation Types | Equivalent to K181760 and K181750. Used to differentiate slow and normal transit constipation. |
| Safety in Adult Population | Established by K181760 clearance. |
| Safety in Pediatric Population (≥ 2 years) | Supported by PMCF study literature review (1054 children/young adults across 18 studies). No device-related adverse events reported. Confirmed by user survey. |
| Biocompatibility | Confirmed non-cytotoxic, non-irritant, non-sensitizing per ISO 10993-5, -10. No systemic toxicity or pyrogenic response per ISO 10993-11. |
| Radiopacity | Confirmed visible for intended use duration/environment per ASTM F640-12. |
| Mechanical Strength (Bite Force) | Can withstand similar forces as the reference predicate Sitzmarks, for accidental biting of markers without capsules in pediatric use. |
Study Details:
The document primarily refers to a Post-Market Clinical Follow-Up (PMCF) study as the clinical evidence for the expanded pediatric population. This PMCF study appears to be a literature review combined with a user survey.
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Sample Size Used for the Test Set and Data Provenance:
- Literature Review: The PMCF study identified 18 clinical investigations involving similar devices. These studies collectively involved 1054 children and young adults.
- Data Provenance: The document does not specify the country of origin for these 18 studies. The nature of these studies (retrospective/prospective) is also not explicitly stated, but common for such literature reviews, they could include both types.
- User Survey (part of PMCF): No specific sample size for the user survey is provided, only that it involved "professional users." Data provenance is implied to be from current users of Transit-Pellets or similar devices, likely international given the company's location (Sweden).
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Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications:
- Ground Truth for Literature Review: The "ground truth" in the 18 studies would have been established by the methods and clinicians within those individual studies, which are not detailed here. For colonic transit time, the ground truth is typically the radiological assessment of marker distribution and retention by medical professionals (e.g., radiologists, gastroenterologists).
- Experts for PMCF Literature Review: The document does not explicitly state how many experts reviewed the identified 18 clinical investigations or their specific qualifications for the PMCF literature review itself. It implies a "literature review carried out during the PMCF study," suggesting a regulatory or scientific team conducted the review.
- Experts for User Survey: "Professional users" were surveyed, but their number and specific qualifications (e.g., pediatric gastroenterologists, radiologists) are not provided.
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Adjudication Method:
- Not explicitly described. For the PMCF literature review, it's unlikely a formal adjudication method (like 2+1 or 3+1 for individual case review) was applied since it was a review of aggregate published data, not individual case interpretations.
- For the original 18 studies, the adjudication methods would vary per study; this document does not provide such detail.
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Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
- No, an MRMC study was not done in the context of this 510(k) submission. This is not typically required for a Class II diagnostic device seeking substantial equivalence, especially when expanding an indication based on existing technology and literature. The focus is on the device's inherent ability to measure CTT, not on reader performance improvement with AI assistance.
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Standalone Performance (Algorithm Only without Human-in-the-Loop Performance):
- Yes, in essence, the "device" is standalone. Transit-Pellets are passive markers. The "performance" being evaluated is their physical and chemical properties (biocompatibility, radiopacity, mechanical strength) and their ability to be visualized and used by a clinician to manually calculate colonic transit time from an X-ray image. There is no AI component or algorithm-only performance to assess in the typical sense of software as a medical device. The physician interprets the X-ray/fluoroscopy image and calculates CTT based on the marker count and position.
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Type of Ground Truth Used:
- The ground truth for measuring colonic transit time is based on radiological imaging (abdominal radiograph or fluoroscopy) and the subsequent manual counting and positional analysis of the radiopaque markers by a clinician. This is a well-established method in gastroenterology.
- For the safety and effectiveness in the pediatric population, the PMCF study relied on published clinical investigation results (which would have used radiological ground truth) and user feedback.
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Sample Size for the Training Set:
- Not applicable in the typical sense of AI/ML training. There is no "training set" for an algorithm, as this device consists of physical markers interpreted by human readers.
- If viewed in a broad sense, the "training" for the device's design (marker size, material, dosing regimen) comes from decades of clinical practice and research using radiopaque markers for colonic transit studies, which predates this specific device.
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How the Ground Truth for the Training Set Was Established:
- Not applicable as there is no specific training set for an algorithm. The principle of "ground truth" in this context refers to the accuracy of colonic transit time measurements derived from the markers. This has been established through clinical consensus and research over time, validating the correlation between marker distribution on X-rays and actual colonic transit physiology.
§ 876.1725 Gastrointestinal motility monitoring system.
(a)
Identification. A gastrointestinal motility monitoring system is a device used to measure peristalic activity or pressure in the stomach or esophagus by means of a probe with transducers that is introduced through the mouth into the gastrointestinal tract. The device may include signal conditioning, amplifying, and recording equipment. This generic type of device includes the esophageal motility monitor and tube, the gastrointestinal motility (electrical) system, and certain accessories, such as a pressure transducer, amplifier, and external recorder.(b)
Classification. Class II (performance standards).