(240 days)
The Mercy TAPE device (2D and 3D models) is intended to estimate the body weight of pediatric patients between the ages of 2 months and 16 years, using linear measurements from specific anatomical landmarks made with the Mercy TAPE device for humeral length (HL, for the 2D model) or half-humeral length (HHL, for the 3D model) and the mid-upper arm circumference (MUAC).
The Mercy TAPE device may be less reliable for use in children with known or apparent limb deformities, or abnormal body proportions caused by conditions such as edema or severe malnutrition.
The Mercy TAPE Device (2D and 3D Models) consists of semi-durable or disposable flexible strips of coated paper, fabric or plastic tape printed with numbered bins proportional to fractional body weight of pediatric patients. The markings correspond to the validated Mercy Method (calculation algorithm) for determining pediatric body weight using humeral length and mid-upper arm circumference.
The Mercy TAPE Device 2D Model consists of a single strip of tape that is used in two (2) stages to measure humeral length and mid-upper arm circumference. For the Mercy TAPE Device 3D Model, two (2) perpendicular strips of tape are designed to be joined into a sliding "T" shape so that humeral length and mid-upper arm circumference can be measured.
The provided text describes the Mercy TAPE device, which estimates pediatric patient body weight using linear measurements. While the document mentions clinical studies and a human factors/usability study, it does not explicitly define acceptance criteria in a quantifiable manner (e.g., "The device must achieve an accuracy of X% within Y kg"). Instead, it broadly states that "the device shows acceptably small variability from true weight with minimal bias" and that "the estimated weights generated by the Mercy TAPE Device (2D and 3D Models) are more accurate than the weights returned with existing weight estimation strategies."
It also states that the device was "validated against a mechanical scale to demonstrate equivalent performance," but the specific metrics and thresholds for this equivalence are not provided.
Therefore, I will extrapolate the "acceptance criteria" based on the general statements of acceptable performance and the study's conclusions, and then provide the reported performance based on the descriptions of the clinical studies.
Here's the information structured as requested, with details extracted from the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
Note: As explicit quantitative acceptance criteria were not stated, these are inferred from the study's conclusions regarding acceptable performance and equivalence.
| Aspect | Inferred Acceptance Criteria (not explicitly stated) | Reported Device Performance |
|---|---|---|
| Accuracy / Variability | Acceptably small variability from true weight with minimal bias. | "The device shows acceptably small variability from true weight with minimal bias." |
| Comparative Accuracy | More accurate than existing weight estimation strategies. | "The estimated weights generated by the Mercy TAPE Device (2D and 3D Models) are more accurate than the weights returned with existing weight estimation strategies." |
| Ease of Use (Usability) | No significant differences in subjective determinations for ease of use compared to existing strategies. | "Our human factors/usability analyses reveal no significant differences in subjective determinations for ease of use between the Mercy TAPE Device (2D and 3D Models) and existing weight estimation strategies." |
| Critical Task Errors (Usability) | Frequency of critical task errors similar to or lower than standard medical equipment. | "The critical task errors observed with the Mercy TAPE Device (2D and 3D Models) occur with a frequency similar to or lower than the error rates observed with standard medical equipment (e.g., scales, stadiometers, and tape measures)." |
| Equivalence to Mechanical Scale | Equivalent performance to a mechanical scale for weight estimation (no specific metrics provided). | "The Mercy TAPE Device (2D and 3D Models) ... has been validated against scales that use mechanical strain or balance methods to obtain an estimate of body weight." and "was validated against a mechanical scale to demonstrate equivalent performance." |
2. Sample Size Used for the Test Set and Data Provenance
The document describes several clinical studies. It seems the "clinical studies" mentioned in Section H encompass both the algorithm development/validation and a separate human factors study.
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Algorithm Validation (Test Set):
- Sample size: 1,938 datasets
- Data Provenance: Not explicitly stated for the validation set, but the underlying algorithm was developed using data from the National Health and Nutrition Examination Survey (NHANES) database. NHANES data is collected in the United States, so the provenance is likely United States.
- Retrospective/Prospective: The use of "datasets" from NHANES suggests a retrospective analysis of existing data for algorithm development and validation.
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Human Factors/Usability Study (Test Set):
- Sample size: 1,412 assessments (performed by healthcare providers). This implies that a number of pediatric patients were assessed multiple times. The exact number of unique "patients" in this study is not specified, but the number of "assessments" is 1,412.
- Data Provenance: Not specified, but given the context of Children's Mercy Hospital in Kansas City, MO, it is likely United States.
- Retrospective/Prospective: These were active "assessments" comparing the device to other strategies, so this was likely a prospective study.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications
- The document does not specify the number or qualifications of experts used to establish ground truth for either the algorithm validation or the human factors study.
- The ground truth for weight was established using "scales that use mechanical strain or balance methods" for comparison, which implies a direct measurement, not an expert consensus for the "true weight."
4. Adjudication Method for the Test Set
- The document does not describe any adjudication method for the test set. The ground truth appears to be based on objective measurements (mechanical scales), removing the need for expert adjudication.
5. Multi Reader Multi Case (MRMC) Comparative Effectiveness Study
- Yes, a MRMC-like study was done in the context of the human factors/usability study.
- The human factors study evaluated "front-line" healthcare providers (ED nurses and first responders) comparing the Mercy TAPE device against five other weight estimation strategies. This involves multiple "readers" (healthcare providers) evaluating cases (presumably pediatric patients).
- Effect size of how much human readers improve with AI vs without AI assistance: The document states that the Mercy TAPE device yielded "more accurate" estimated weights than existing strategies, even when factoring in errors and close-calls. However, it does not provide a specific quantitative effect size (e.g., percentage improvement in accuracy, reduction in error margin) for this improvement.
6. Standalone (Algorithm Only) Performance
- Yes, a standalone performance evaluation was done. The "clinical studies" section states: "Clinical studies were conducted to evaluate the predictive performance of the Mercy TAPE Device (2D and 3D Models) and their equivalence to the underlying Mercy Tape method algorithm." This primarily refers to the algorithm's performance in estimating weight.
- This performance was described as showing "acceptably small variability from true weight with minimal bias."
7. Type of Ground Truth Used
- The ground truth used for weight estimation was direct measurement from mechanical scales (e.g., "scales that use mechanical strain or balance methods"). This is an objective measurement, not expert consensus, pathology, or outcomes data.
8. Sample Size for the Training Set
- The Mercy Tape method algorithm was developed using "demographic and anthropometric data on 17,328 individual children." This represents the training/development set.
9. How the Ground Truth for the Training Set Was Established
- The ground truth for the training set (17,328 children) was established using data from the National Health and Nutrition Examination Survey (NHANES) database. NHANES collects comprehensive health and nutrition data, which includes anthropometric measurements and likely objective weight measurements, establishing the ground truth for algorithm development.
§ 878.4800 Manual surgical instrument for general use.
(a)
Identification. A manual surgical instrument for general use is a nonpowered, hand-held, or hand manipulated device, either reusable or disposable, intended to be used in various general surgical procedures. The device includes the applicator, clip applier, biopsy brush, manual dermabrasion brush, scrub brush, cannula, ligature carrier, chisel, clamp, contractor, curette, cutter, dissector, elevator, skin graft expander, file, forceps, gouge, instrument guide, needle guide, hammer, hemostat, amputation hook, ligature passing and knot-tying instrument, knife, mallet, disposable or reusable aspiration and injection needle, disposable or reusable suturing needle, osteotome, pliers, rasp, retainer, retractor, saw, scalpel blade, scalpel handle, one-piece scalpel, snare, spatula, stapler, disposable or reusable stripper, stylet, suturing apparatus for the stomach and intestine, measuring tape, and calipers. A surgical instrument that has specialized uses in a specific medical specialty is classified in separate regulations in parts 868 through 892 of this chapter.(b)
Classification. Class I (general controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter, subject to the limitations in § 878.9.