RespiratoryVolumes & Capacities 2/1/00

Measurement of Respiration Respiratory flow, volumes & capacities are measured using a spirometer Amount of water displaced gives you estimate of the air required to displaces it Air Chamber Water Recording Drum

Spirometry The measurement of air volumes and capacities –Volume: subdivision of the total amount of air that can be contained in the lungs –Capacity: Sum of two or more volumes

Spirometer

Respiratory Volumes Total Capacity Vital Capacity Residual Volume Inspiratory Volume Reserve Tidal Volume Expiratory Volume Reserve Residual Volume Percent Vital Capacity

Residual volume (RV)= Quantity of air remaining in the lungs after as much air as possible has been expelled from the lungs (25% of TLC) Total Lung Capacity (TLV)= The sum of inspiratory reserve volume, tidal volume, expiratory & inspiratory reserve volume and residual volume (TLC=IC + FRC). Vital Capacity (VC)= The maximum volume of air that can be exchanged during respiration is the difference between TLC and RV. Tidal Volume (TV)= Volume of air exchanged in one cycle of respiration (one breath). Inspiratory & Expiratory Reserve Volume (IRV) & (ERV): Part of VC still available at the end of a given inhalation or exhalation respectively. Functional Residual Capacity (FRC): The volume of air in the body at the end of passive exhalation, including expiratory reserve & residual volumes (FRC=ERV+RV)

Total Lung Capacity Tidal Volume Inspiratory Capacity Vital Capacity Expiratory Reserve Volume Inspiratory Reserve Volume Tidal Volume (Increasing Activity) Residual Volume Resting Expiratory Level Functional Residual Capacity Spirometer for measuring respiratory volume

Measurement of Respiration cm H 2 O Manometer -Measures Pressure; more force used the higher the water rises

Respiration for Life Quiet respiration –Economy of effort –Minimum departure from the resting volume –Relaxed balance exists between tendencies of thorax expansion & lung collapse –Balance is typically at 35-40% of vital capacity (amount available for use) –Quiet inspiration= the volume of air that can be inhaled from a resting level with muscle contraction –Quiet expiration= Passive process by elastic recoil of lungs & abdomen

Quiet Respiration 40% Insp. 60% Exp. Resting Tidal Volume Resting Volume 0 40 Percent of Vital Capacity *Volume of air move called resting tidal volume

Vital Capacity based on Age & Gender Male Female VC (ml) Age (Years)

Typical Respiratory Volumes & Capacities in Adults Volume/ Capacity Males (cc) Females (cc) Average (in cc) VC 4800 cc 3200 cc 4000 cc TLC 6000 cc 4800 cc 5100 cc Resting TV 600 cc 450cc 525cc Males: VC in ml= (0.112 x age in years) x ht.in cm Females: VC in ml= (0.101 x age in years) x ht.in cm

Breathing for Speech Same respiratory equipment and measures of air volume &lung capacity apply for speech breathing Difference? How & Why they are used! –Life- Objective to move O 2 & CO 2 in & out of lungs resistance interferes –Speech- Objective to have air under pressure; force vocal folds to vibrate Achieve pressure by resisting airflow

Passive & Active Forces Active Forces = Muscles (Rib Cage, Abdomen, diaphragm) Passive Forces = Generated by elastic properties of respiratory tissue (lungs, muscles, tendons) when returning to rest

Lung Chest Wall High Low FRC Lung Volume Vital Capacity (%) Alveolar pressure (cm H 2 0) Recoil Properties of Chest wall & Lung Relaxation Pressure Curve

Recoil: Chest Wall & Lung High LV = Both chest wall & lung collapse due to extension beyond rest 50% VC = Chest wall is neutral, but lungs tend to collapse FRC = Tendency of expansion of chest wall is equal to opposite tendency of lungs to collapse Low LV = Chest wall tends to expand & lungs tend to collapse

Relaxation-Pressure Curve Passive conditions- absence of muscular effort Passive alveolar pressures generated at a particular lung volume –High LV = combined recoil forces contribute to high alveolar pressure –38% LV = Equilibrium; alveolar pressure is 0 –38% & below = relaxation pressure is negative (alveolar pressure less than atmospheric); inspiratory forces are passive

Vital Capacity (%) Alveolar Pressure (cm H 2 0) IPIP RPRP EPEP Pressure- Volume Diagram

Flow Volume Loop Relation between rate of airflow & LV for inspiration & expiration. Expiration phase indicates peak exp. flow rate achieved at low LV (30%) Peak rate of airflow is greater for expiration

Respiratory Kinematics

Introduction Dynamic aspects of the chest wall function during speech via motion of the chest wall Measuring changes in the anteroposterior diameters (RC & AB) Motions of RC, AB & Diaphragm sum to match movements of the lung (LV can be determined) Individual volume displacements of RC & AB Contributions to LV from RC & AB

Magnetometer Position

Method Equipment: –Rib cage & abdominal magnetometers Two generator-sensor coil pairs –Catheter-balloon techniques esophageal & gastric pressures Measurements: –made in supine and upright positions –VC –Isovolume maneuvers at specified LV’s (20% VC) Created relaxation curve

Method Utterances: –Sustained production of / a / At 130 Hz 3 loudness levels- soft, comfortable, loud –Repeated syllable task /p a / 4 per/second 3 loudness levels- soft, comfortable, loud –Spontaneous conversation –Normal reading “The Rainbow Passage”

Results Motion Diagrams: –Left of relaxation = pressures operating to make RC larger &AB smaller –Right of relaxation = pressures operating to make RC smaller & AB larger compared to relaxation

Motion Diagram: Relaxation

Sustained Vowel & Syllable Repetition High lung volumes for initiation Chest wall configuration different than relaxation RC expanded more than AB during speech (left of relaxation) RC larger than AB for loud productions

Relative Motion Charts: Supine Both RC & AB decrease in LV Majority of volume change above FRC Gravity acts on RC & AB in expiratory position

Discussion Regulation of alveolar pressure in accordance with the demands of the utterance –Accomplished by adding muscular pressure Chest wall exerted increasingly more positive effort as lung volume decreased –Decreased passive recoil from relaxation pressure means more active muscular forces are necessary Louder speech –Higher lung volumes (relaxation pressure high)