(448 days)
The B4C System is intended for the monitoring of variation in intracranial pressure in patients with suspected alteration of intracranial pressure (ICP) or change in intracranial compliance, by providing surrogate ICP waveforms and associated parameters (estimated P2/P1 ratio, normalized Time-to-Peak, derived useful ICP pulses and cardiac pulses) for interpretation.
The B4C System is a non-invasive device intended for the monitoring of variation in intracranial pressure, including patients with suspected alteration of intracranial pressure (ICP) or change in intracranial compliance. It consists of a sensor with Bluetooth wireless module, headband, mobile device software application, receiver, external battery pack and charger, as well as processing and analytical software. The sensor contains four strain gauges situated on a metal bar that detects variations in skull deformation through tension and compression of the metal bar in response to changes in intracranial pressure. These resistance measures are converted to a digital signal using a high-resolution ADC (Analog to Digital Converter) in the sensor that is transmitted to software components for viewing, processing and analysis. The proposed device does not measure absolute intracranial pressure values, but produces surrogate waveform morphology, its trend, and associated parameters reflecting changes in ICP. The B4C System and surrogate waveform and associated outputs do not substitute ICP monitoring methods when measurement of the absolute value of ICP is required to make a clinical decision.
Here's a breakdown of the acceptance criteria and the study that proves the B4C System meets them, based on the provided FDA 510(k) summary:
Acceptance Criteria and Reported Device Performance
The acceptance criteria for the B4C System's clinical performance are implicitly derived from the study objectives and the statistical analyses performed. The primary objective was to demonstrate a "consistent correlation" and "reliability and accuracy of the correlation" between the B4C System's surrogate ICP waveform and parameters and those from invasive ICP monitoring.
| Acceptance Criteria (Implicit) | Reported Device Performance |
|---|---|
| P2/P1 Ratio Correlation: Statistically significant correlation with invasive ICP monitoring. | Spearman correlation: 0.495 [0.471, 0.517], p0.7. |
| Normalized Time-to-Peak (TTP) Correlation: Statistically significant correlation with invasive ICP monitoring. | Spearman correlation: 0.318 [0.291, 0.345], p0.2. |
| Safety: No serious adverse events related to the device. | No adverse events were reported. |
| Substantial Equivalence: Demonstrate comparable performance to predicate device with respect to ICP waveform morphology monitoring. | The study concluded that results demonstrated a statistically significant correlation in the ICP signal and waveform parameters between the B4C System and the gold standard invasive ICP monitoring device. The outcomes demonstrate comparable effectiveness between the Braincare device and commonly used invasive ICP devices for monitoring and assessing variations in ICP waveform associated parameters over time. Based on performance testing and comparison, it was deemed substantially equivalent to the predicate device. |
Detailed Study Information:
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Sample sizes used for the test set and data provenance:
- Total enrolled subjects: 123
- Subjects after device label check: 107
- Subjects after data quality check: 85 (78 adults, 7 pediatric)
- Analyzed participants (test set): 78 adults (due to reduced quantity of pediatric subjects, enabling statistically relevant performance only for adults).
- Total acquisition time analyzed: 4695 minutes (98% adult, 2% pediatric across the broader dataset).
- Data Provenance: Not explicitly stated, but the mention of "4 centers" suggests a multi-center study. The sponsor is Braincare Desenvolvimento e Inovacao Tecnologica S.A. based in Brazil, suggesting the origin of the data is likely within Brazil or other international sites. The study was described as "combined prospective, multi-center, observational study."
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Number of experts used to establish the ground truth for the test set and qualifications of those experts:
- The document implies that the ground truth was established using "gold standard invasive ICP monitoring methods such as the external ventricular drain or intraparenchymal micro transducers."
- It does not explicitly state the number of experts or their qualifications for establishing the ground truth from these invasive methods. It relies on the inherent validity of the invasive measurements as the "gold standard."
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Adjudication method for the test set:
- No adjudication method (e.g., 2+1, 3+1) is mentioned for the test set ground truth. The ground truth was established directly from invasive ICP devices. This type of data does not typically involve multiple human readers or adjudication in the same way as, for example, image interpretation.
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If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance:
- No, a multi-reader multi-case (MRMC) comparative effectiveness study was not explicitly performed or described. This study focused on the technical correlation and agreement between the device's output and invasive ICP measurements. It did not directly assess the impact of the B4C System on human reader performance or diagnostic accuracy.
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If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- The study primarily focused on the standalone performance of the B4C System's ability to produce surrogate ICP waveforms and associated parameters that correlate with invasive ICP measurements. The analysis (Spearman correlation, normalized mutual information, Bland-Altman, Deming regression) evaluates this algorithm-only performance.
- The device is intended to provide "surrogate ICP waveforms and associated parameters... for interpretation," implying a human-in-the-loop for interpretation, but the study itself is about the accuracy of the device's output compared to ground truth.
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The type of ground truth used:
- Objective/Physiological Data: The ground truth was established using "gold standard invasive ICP monitoring methods such as the external ventricular drain or intraparenchymal micro transducers." This represents direct physiological measurement rather than expert consensus on subjective interpretation.
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The sample size for the training set:
- The document does not specify a separate training set size. The clinical study described appears to be a validation study (test set) for the pre-existing B4C System, which includes processing and analytical software. Given the description, the models and algorithms within the B4C System would have been developed and trained using other data, but that training data and its size are not disclosed in this 510(k) summary.
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How the ground truth for the training set was established:
- As the training set details are not provided, the method for establishing its ground truth is also not described in this document.
§ 882.1620 Intracranial pressure monitoring device.
(a)
Identification. An intracranial pressure monitoring device is a device used for short-term monitoring and recording of intracranial pressures and pressure trends. The device includes the transducer, monitor, and interconnecting hardware.(b)
Classification. Class II (performance standards).