| Popis: |
Monitoring intracranial pressure (ICP) is a standard diagnostic tool for various neurological conditions such as head injury, ruptured aneurysms, intracerebral and intracranial hemorrhage, and hydrocephalus. Currently, ICP monitoring relies on invasive pressure measurements. These include intraventricular catheter, subdural screw, epidural sensor, and lumbar puncture. Invasive methods pose the risk of infection and hemorrhage, are expensive, and require special clinical skills. A noninvasive method that is reliable, simple to use, low-cost, and provides easily interpretable results can help avoid the complications associated with the invasive methods. This study proposes a novel method for noninvasive ICP monitoring using tympanic membrane pulsation (TMp). ICP signals propagate through the cochlear aqueduct, cochlea, and middle ear bones to reach the tympanic membrane where it can be observed as a TMp signal. Therefore, TMp may provide useful information about ICP and possibly intracranial compliance. To investigate the utility of the proposed approach, TMp signals were acquired from 15 healthy subjects. Subjects performed specific maneuvers that are known to induce ICP changes. Maneuvers included head-down-tilt, head-up-tilt, and hyperventilation. A custom-made system utilizing a stethoscope headset and a pressure transducer was used to measure TMp signals. Morphological changes in the TMp waveform were observed when subjects underwent ICP changes. Waveform changes included rise-decay patterns and high-frequency components. The study results suggest that TMp waveform measurement and analysis may offer an inexpensive, non-invasive, accurate tool for the detection and monitoring of ICP. More studies are needed in larger sample sizes and patients with elevated ICP to further investigate the utility of the proposed method. |
