**1. Introduction**

The technological development achieved in recent decades has made possible to access previously unimaginable information. Sensors with greater sensitivity, more detailed imaging tools and accurate sound analyzers have brought to light pathophysiological parameters previously inaccessible. The new technologies also disclose a new trend to the medical area, the possibility of accessing patient information with noninvasive devices, minimizing risks, costs and opening new possibilities for better management.

This chapter addresses how the new tools can enlarge the therapeutic window, thereby bringing more patient safety and assertiveness to physicians. The following technologies will be presented in this chapter:


The objective of this chapter is to present these technologies and stimulate the search for more information to the application of these technologies in daily practice of health professionals.

### **2. ICP pulse waveform monitoring**

Intracranial pressure (ICP) is an important clinical parameter, it is related to the volumes of the intracranial contents and the skull bone cavity. The ICP monitoring provides three distinct information:


The ICP mean value directly and punctually portrays the pressure value in the environment in which the sensor is inserted. Clinical experience has shown that as important as knowing ICP values, was to have information about the period of time in which the subject was submitted to hypertensive conditions, that is, the possibility of ICP trend following over time [1]. Studies initiated from the second half of the last century correlated the ICPwf with intracranial compliance, a new parameter introduced in medicine used to assist in the diagnosis and prognosis of patients [2].

The invasibility of methods that allowed obtaining ICP pulse morphology caused this parameter to be indicated only in high risk of herniation cases. Most ICP monitoring techniques do not present information on ICP pulse morphology. The absence of accurate ICP pulse morphological displaying and information on the waveform components relations in invasive methods make this analysis operator dependent.

The noninvasive detection of the morphology of ICP pulses became a reality in 2007, when Brazilian researchers began studies to monitor cranial elasticity over time. Cranial elasticity was initially analyzed by gluing strain-gauges to the cranial bone. This study was important to show that it is possible to capture pulses over the skull, and that these pulses are related to changes in intracranial volumes and pressure [3].

These results allowed the development of a noninvasive sensor (brain4care corp.), which touches the surface of the patient's scalp. This sensor mechanically captures the variations in the trend and morphology of the intracranial pressure pulse, without radiation, light or sound emissions for patients and operators [4].

ICP pulses are the result of blood pressure, breathing and cerebrospinal fluid (CSF) interaction. The cardiac-derived ICP pulse is formed by three components, P1 formed by the systolic wave, P2 originated by the scattering of fluids in this environment and p3, resulting from aortic valve closure [5] (**Figures 1** and **2**).

Subjects with ICP pulse morphology considered normal have the first component (P1), higher than the second (P2). When there is alteration of this order, ICPwf is considered abnormal [6].

This noninvasive sensor acquires beat by beat ICPwf spectrum and translates its peak relations to numbers. The algorithm calculates the amplitudes of pulses P1 and P2 and the ratio of these parameters (P2/P1 ratio = AmpP2/AmpP1). When the value of this ratio is greater than 1, morphology is considered abnormal as it indicates that peak P2 is greater than peak P1.

**101**

**Figure 3.**

*Management of Patients with Brain Injury Using Noninvasive Methods*

This method can be used to aid diagnosing and assisting patients with risk of intracranial hypertension (ICH), and consequently reduction of intracranial compliance (ICC) [4]. The latter is called with reference to the homeostasis among intracranial structures, such as the brain itself, vascular volume and CSF

**Figure 3** shows a monitoring sample with this technique, in a patient with neurological drawdown before and after the procedure to control ICH. The first waveform shows an altered morphology before the procedure, with 1.22 its P2/P1 ratio. Posterior to treatment, is presented his ICPwf pattern with a P2/P1 ratio of 0.87. This technique is already in clinical use and has collaborated with the diagnosis and follow-up of patients who present suspicion, risk or confirmed conditions

*DOI: http://dx.doi.org/10.5772/intechopen.94143*

volume [7].

**Figure 1.**

**Figure 2.**

*Normal intracranial pressure pulse waveform.*

*Abnormal intracranial pressure pulse waveform.*

*Effect of a procedure to decrease the intracranial pressure monitored with the brain4care sensor.*

*Management of Patients with Brain Injury Using Noninvasive Methods DOI: http://dx.doi.org/10.5772/intechopen.94143*

This method can be used to aid diagnosing and assisting patients with risk of intracranial hypertension (ICH), and consequently reduction of intracranial compliance (ICC) [4]. The latter is called with reference to the homeostasis among intracranial structures, such as the brain itself, vascular volume and CSF volume [7].

**Figure 3** shows a monitoring sample with this technique, in a patient with neurological drawdown before and after the procedure to control ICH. The first waveform shows an altered morphology before the procedure, with 1.22 its P2/P1 ratio. Posterior to treatment, is presented his ICPwf pattern with a P2/P1 ratio of 0.87.

This technique is already in clinical use and has collaborated with the diagnosis and follow-up of patients who present suspicion, risk or confirmed conditions

**Figure 1.** *Normal intracranial pressure pulse waveform.*

**Figure 2.**

*Advancement and New Understanding in Brain Injury*

• Near-infrared spectroscopy - NIRS

The objective of this chapter is to present these technologies and stimulate the search for more information to the application of these technologies in daily

Intracranial pressure (ICP) is an important clinical parameter, it is related to the volumes of the intracranial contents and the skull bone cavity. The ICP monitoring

The ICP mean value directly and punctually portrays the pressure value in the environment in which the sensor is inserted. Clinical experience has shown that as important as knowing ICP values, was to have information about the period of time in which the subject was submitted to hypertensive conditions, that is, the possibility of ICP trend following over time [1]. Studies initiated from the second half of the last century correlated the ICPwf with intracranial compliance, a new parameter introduced in medicine used to assist in the diagnosis and prognosis of patients [2]. The invasibility of methods that allowed obtaining ICP pulse morphology caused this parameter to be indicated only in high risk of herniation cases. Most ICP monitoring techniques do not present information on ICP pulse morphology. The absence of accurate ICP pulse morphological displaying and information on the waveform components relations in invasive methods make this analysis operator dependent. The noninvasive detection of the morphology of ICP pulses became a reality in 2007, when Brazilian researchers began studies to monitor cranial elasticity over time. Cranial elasticity was initially analyzed by gluing strain-gauges to the cranial bone. This study was important to show that it is possible to capture pulses over the skull, and that these pulses are related to changes in intracranial volumes and pressure [3]. These results allowed the development of a noninvasive sensor (brain4care corp.), which touches the surface of the patient's scalp. This sensor mechanically captures the variations in the trend and morphology of the intracranial pressure pulse, without radiation, light or sound emissions for patients and operators [4]. ICP pulses are the result of blood pressure, breathing and cerebrospinal fluid (CSF) interaction. The cardiac-derived ICP pulse is formed by three components, P1 formed by the systolic wave, P2 originated by the scattering of fluids in this environment and p3, resulting from aortic valve closure [5] (**Figures 1** and **2**). Subjects with ICP pulse morphology considered normal have the first component (P1), higher than the second (P2). When there is alteration of this order,

This noninvasive sensor acquires beat by beat ICPwf spectrum and translates its peak relations to numbers. The algorithm calculates the amplitudes of pulses P1 and P2 and the ratio of these parameters (P2/P1 ratio = AmpP2/AmpP1). When the value of this ratio is greater than 1, morphology is considered abnormal

• Transcranial Doppler - TCD

practice of health professionals.

**2. ICP pulse waveform monitoring**

provides three distinct information:

• The average value of ICP

• The trend of ICP over time

• ICP pulse waveform (ICPwf)

ICPwf is considered abnormal [6].

as it indicates that peak P2 is greater than peak P1.

**100**

*Abnormal intracranial pressure pulse waveform.*

**Figure 3.** *Effect of a procedure to decrease the intracranial pressure monitored with the brain4care sensor.*

of reduction of ICC, in situations as traumatic brain injury, stroke, intracranial tumors, hydrocephalus, central nervous system infections, reduction in cerebral flow, post cardiorespiratory arrest, liver diseases, kidney diseases and other conditions that may lead to ICH.
