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Respiratory sound energy and its distribution patterns following clinical improvement of congestive heart failure: a pilot study.

Wang Z, Baumann BM, Slutsky K, Gruber KN, Jean S - BMC Emerg Med (2010)

Bottom Line: Twenty-three consecutive CHF patients were imaged at the time of presentation to the emergency department and after clinical improvement.Geographical area of the images and respiratory sound patterns were quantitatively analyzed.Data from the CHF patients were also compared to healthy volunteers.

View Article: PubMed Central - HTML - PubMed

Affiliation: Division of Critical Care Medicine, Robert Wood Johnson School of Medicine, Camden, NJ 08103, USA. wangzhen1369@hotmail.com

ABSTRACT

Background: Although congestive heart failure (CHF) patients typically present with abnormal auscultatory findings on lung examination, respiratory sounds are not normally subjected to additional analysis. The aim of this pilot study was to examine respiratory sound patterns of CHF patients using acoustic-based imaging technology. Lung vibration energy was examined during acute exacerbation and after clinical improvement.

Methods: Respiratory sounds throughout the respiratory cycle were captured using an acoustic-based imaging technique. Twenty-three consecutive CHF patients were imaged at the time of presentation to the emergency department and after clinical improvement. Digital images were created (a larger image represents more homogeneously distributed vibration energy of respiratory sound). Geographical area of the images and respiratory sound patterns were quantitatively analyzed. Data from the CHF patients were also compared to healthy volunteers.

Results: The median (interquartile range) geographical areas of the vibration energy image of acute CHF patients without and with radiographically evident pulmonary edema were 66.9 (9.0) and 64.1(9.0) kilo-pixels, respectively (p < 0.05). After clinical improvement, the geographical area of the vibration energy image of CHF patients without and with radiographically evident pulmonary edema were increased by 18 +/- 15% (p < 0.05) and 25 +/- 16% (p < 0.05), respectively.

Conclusions: With clinical improvement of acute CHF exacerbations, there was more homogenous distribution of lung vibration energy, as demonstrated by the increased geographical area of the vibration energy image.

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Vibration energy image. 36 vibration response imaging (VRI) sensors are spaced over the patient's back and detect vibrations during respiration. The size of the dots is a cartoon representation of the amount of vibration energy detected by that sensor. When the detected vibrations are uniform, the resulting VRI image will be large (A). When the detected vibration is less homogeneous, i.e. if the lower sensors have decreased vibrations (B) or if the middle sensors detect increased vibration (C), a smaller VRI image results. The visual geographical area is therefore determined not by intensity of vibration but by the distribution of intensity. VRI: vibration response imaging.
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Figure 1: Vibration energy image. 36 vibration response imaging (VRI) sensors are spaced over the patient's back and detect vibrations during respiration. The size of the dots is a cartoon representation of the amount of vibration energy detected by that sensor. When the detected vibrations are uniform, the resulting VRI image will be large (A). When the detected vibration is less homogeneous, i.e. if the lower sensors have decreased vibrations (B) or if the middle sensors detect increased vibration (C), a smaller VRI image results. The visual geographical area is therefore determined not by intensity of vibration but by the distribution of intensity. VRI: vibration response imaging.

Mentions: Respiratory sounds were captured using a vibration response imaging device (Deep Breeze™, Or-Akiva, Israel). This is a non-invasive computerized acoustic-based imaging technique that displays the geographic distribution of vibration energy of respiratory sounds throughout the respiratory cycle [4,5]. With this technique, 36 sensors (two arrays, one array over each lung) were adhered to the patient's back in a sitting position by a computer-controlled low vacuum and record the respiratory sound patterns. Subjects were instructed to take deep, comfortable breaths during 20 seconds of recording. Data collected by the sensors were processed and a grayscale video depicting the relative geographical distribution of respiratory sound was created. Each frame of the video was created from 0.17 seconds worth of data. The maximal energy frame was the frame in the video sequence that usually provided the most information on the distribution of lung vibration and usually approximated peak inspiration. The image from this frame was used for the area measurements. The image represents the relative distribution of vibration energy, not the absolute energy. A larger image indicates a more homogeneous distribution of vibration intensity throughout the lung and a smaller image a more focal distribution (Figure 1).


Respiratory sound energy and its distribution patterns following clinical improvement of congestive heart failure: a pilot study.

Wang Z, Baumann BM, Slutsky K, Gruber KN, Jean S - BMC Emerg Med (2010)

Vibration energy image. 36 vibration response imaging (VRI) sensors are spaced over the patient's back and detect vibrations during respiration. The size of the dots is a cartoon representation of the amount of vibration energy detected by that sensor. When the detected vibrations are uniform, the resulting VRI image will be large (A). When the detected vibration is less homogeneous, i.e. if the lower sensors have decreased vibrations (B) or if the middle sensors detect increased vibration (C), a smaller VRI image results. The visual geographical area is therefore determined not by intensity of vibration but by the distribution of intensity. VRI: vibration response imaging.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2821310&req=5

Figure 1: Vibration energy image. 36 vibration response imaging (VRI) sensors are spaced over the patient's back and detect vibrations during respiration. The size of the dots is a cartoon representation of the amount of vibration energy detected by that sensor. When the detected vibrations are uniform, the resulting VRI image will be large (A). When the detected vibration is less homogeneous, i.e. if the lower sensors have decreased vibrations (B) or if the middle sensors detect increased vibration (C), a smaller VRI image results. The visual geographical area is therefore determined not by intensity of vibration but by the distribution of intensity. VRI: vibration response imaging.
Mentions: Respiratory sounds were captured using a vibration response imaging device (Deep Breeze™, Or-Akiva, Israel). This is a non-invasive computerized acoustic-based imaging technique that displays the geographic distribution of vibration energy of respiratory sounds throughout the respiratory cycle [4,5]. With this technique, 36 sensors (two arrays, one array over each lung) were adhered to the patient's back in a sitting position by a computer-controlled low vacuum and record the respiratory sound patterns. Subjects were instructed to take deep, comfortable breaths during 20 seconds of recording. Data collected by the sensors were processed and a grayscale video depicting the relative geographical distribution of respiratory sound was created. Each frame of the video was created from 0.17 seconds worth of data. The maximal energy frame was the frame in the video sequence that usually provided the most information on the distribution of lung vibration and usually approximated peak inspiration. The image from this frame was used for the area measurements. The image represents the relative distribution of vibration energy, not the absolute energy. A larger image indicates a more homogeneous distribution of vibration intensity throughout the lung and a smaller image a more focal distribution (Figure 1).

Bottom Line: Twenty-three consecutive CHF patients were imaged at the time of presentation to the emergency department and after clinical improvement.Geographical area of the images and respiratory sound patterns were quantitatively analyzed.Data from the CHF patients were also compared to healthy volunteers.

View Article: PubMed Central - HTML - PubMed

Affiliation: Division of Critical Care Medicine, Robert Wood Johnson School of Medicine, Camden, NJ 08103, USA. wangzhen1369@hotmail.com

ABSTRACT

Background: Although congestive heart failure (CHF) patients typically present with abnormal auscultatory findings on lung examination, respiratory sounds are not normally subjected to additional analysis. The aim of this pilot study was to examine respiratory sound patterns of CHF patients using acoustic-based imaging technology. Lung vibration energy was examined during acute exacerbation and after clinical improvement.

Methods: Respiratory sounds throughout the respiratory cycle were captured using an acoustic-based imaging technique. Twenty-three consecutive CHF patients were imaged at the time of presentation to the emergency department and after clinical improvement. Digital images were created (a larger image represents more homogeneously distributed vibration energy of respiratory sound). Geographical area of the images and respiratory sound patterns were quantitatively analyzed. Data from the CHF patients were also compared to healthy volunteers.

Results: The median (interquartile range) geographical areas of the vibration energy image of acute CHF patients without and with radiographically evident pulmonary edema were 66.9 (9.0) and 64.1(9.0) kilo-pixels, respectively (p < 0.05). After clinical improvement, the geographical area of the vibration energy image of CHF patients without and with radiographically evident pulmonary edema were increased by 18 +/- 15% (p < 0.05) and 25 +/- 16% (p < 0.05), respectively.

Conclusions: With clinical improvement of acute CHF exacerbations, there was more homogenous distribution of lung vibration energy, as demonstrated by the increased geographical area of the vibration energy image.

Show MeSH
Related in: MedlinePlus