Comparison of Tissue Oxygenation Measurement Using Multimodal Devices
Condition: Oxygen Saturation
Study type: Interventional

Summary: 
      Pulse oximeters are common medical devices used to measure blood oxygen saturation (SpO2).
      These devices are either stand-alone or integrated into physiologic monitoring systems, using
      2 wavelengths of light to determine SpO2. With recent advances in technology, Spatial
      Frequency Domain Imaging (SFDI) uses a range of light wavelengths from red to near-infrared
      (NIR), and smartphones such as Apple Watch, and transcutaneous oximetry TCOM now have pulse
      oximetry capabilities. Since it is possible that most patients could utilize this technology,
      we sought to assess the accuracy, reliability, and usability of these oximeters and compare
      outcomes. In this study, a cohort of 20 healthy volunteers above the age of 18 including
      males and females of different skin colors will be assessed at the same site and data will be
      compared. We aim to provide a set of data that will support the clinical and scientific
      community and identify more than one reliable skin oxygen measurement modality.
    

Detailed description: 
      The subjects will go through a questionnaire session about their medical history by a
      designated study team member. The questionnaire data will be placed in RedCap using a subject
      ID that cannot be linked back to the subject. Then the subject will consent and be enrolled.
      Then the non-invasive data-collecting procedure will start on the following equipment.

      Spatial Frequency Domain Imaging (SFDI): During the consenting period, the Modulim equipment
      will be calibrated and set up ready for scanning. The subject's volar aspect of the thumb
      along with the palm surface will be ready to target the optical camera head. Actual scanning
      takes less than 60 seconds. The images will be processed offline. During processing 3-5
      different regions of interest (ROI) will be taken to measure the oxygen parameters such as
      tissue oxygen saturation (StO2), oxy-hemoglobin (HbO2), deoxy-hemoglobin (HbR), superficial
      hemoglobin (HbT1, sub-surface hemoglobin (HbT2). The model used is a Clarifi Modulim
      Transcutaneous oxygen monitoring (TCOM): Transcutaneous oxygen monitoring (TCOM or TcpO2) is
      a noninvasive, clinically-approved method to obtain skin oxygen levels. The method is
      quantitative and measures oxygen delivery to the skin from underlying tissue. Before
      positioning the electrode, an adhesive fixation ring will be placed on the dry skin on the
      volar aspect of the thumb and an electrolyte as a contact liquid will be filled in half and
      the probe is aligned into it by rotating clockwise to fasten it. The recording will be
      started and waited for the oxygen level to stabilize and a fixed value will be recorded. The
      model used is a Perimed PeriFlux 5000. The probe will be heated to about 45 degrees C.
      Although this device has other options, only the measurement of O2 will be performed using
      this device.

      Apple Watch Oxygen Sensor: Smartwatch blood oxygen sensors also measure blood oxygen levels
      in the tissue. Apple Watch Series 6 introduced this new feature for monitoring blood oxygen
      levels using light-emitting diodes (LEDs) at the back of apple watches. A low blood oxygen
      level can be indicative of a serious health issue that needs immediate attention. The apple
      watch is equipped with green, red, and infrared LEDs that shine light onto the blood vessels
      in the wrist, with photodiodes measuring the amount of light reflected back. Apple's
      algorithms use this information to calculate the color of the blood, which is an indication
      of how much oxygen is in the blood. Bright red blood is well-oxygenated, while darker blood
      has less oxygen. This can measure blood oxygen levels between 70 and 100 percent. Most
      healthy people have blood oxygen levels that range from 95 to 100 percent. The apple watch
      sensor will be positioned on the user's preferred wrist.

      Pulse Oximeter for Oxygen Monitoring: The pulse oximeter enables transcutaneous monitoring of
      the oxygen saturation of hemoglobin in arterial blood (StO2). Pulse oximetry is so widely
      prevalent in medical care that it is often regarded as a fifth vital sign[3]. It is important
      to understand how the technology functions as well as its limitations. To recognize the
      settings in which pulse oximeter readings of oxygen saturation (SpO2), an understanding of
      two basic principles of pulse oximetry is required: (i) how oxyhemoglobin (HbO2) is
      distinguished from deoxyhemoglobin (HbR) and (ii) how the SpO2 is calculated only from the
      arterial compartment of blood. Pulse oximetry is based on the principle that HbO2 and HbR
      differentially absorb red and near-infrared (IR) light. It is fortuitous that HbO2 and HbR
      have significant differences in absorption at red and near-IR light because these two
      wavelengths penetrate tissues well whereas blue, green, yellow, and far-IR light are
      significantly absorbed by non-vascular tissues and water [3]. HbO2 absorbs greater amounts of
      IR light and lower amounts of red light than does HbR; this is consistent with experience -
      well-oxygenated blood with its higher concentrations of HbO2 appears bright red to the eye
      because it scatters more red light than does HbR. On the other hand, HHR absorbs more red
      light and appears less red. Exploiting this difference in light absorption properties between
      HbO2 and HbR, pulse oximeters emit two wavelengths of light, red at 660 nm and near-IR at 940
      nm from a pair of small light-emitting diodes located in one arm of the finger probe. The
      light that is transmitted through the finger is then detected by a photodiode on the opposite
      arm of the probe. In this study, the volar aspect of the thumb and index finger of the
      subject will be used to measure SpO2.
    

Intervention name(s): Clarifi Modulum; Perimed PeriFlux 5000; Apple Watch Oxygen Sensor; Innovo iP 900AP
Intervention type(s): Device; Device; Device; Device
Intervention description(s): During consenting period, the Modulim equipment will be calibrated and setup ready for scanning. Subject's volar aspect of the thumb along with the palm surface will be ready to target the optical camera head. Actual scanning takes less than 60 seconds. The images will be processed offline. During processing 3-5 different regions of interest will be taken to measure the oxygen parameters such as tissue oxygen saturation, oxy-hemoglobin, deoxy-hemoglobin, superficial hemoglobin, and sub-surface hemoglobin.; Transcutaneous oxygen monitoring (TCOM or TcpO2) is a noninvasive, clinically-approved method to obtain skin oxygen levels. The method is quantitative, and measures oxygen delivery to the skin from underlying tissue. Before positioning the electrode, an adhesive fixation ring will be placed on the dry skin on the volar aspect of the thumb and an electrolyte as a contact liquid will be filled half and the probe is aligned into it by rotating clock-wise to fasten it. Recording will be started and waited for the oxygen level to stabilize and a fixed value will be recorded. The probe will be heated to about 45oC. Although this device has other options, only the measurement of O2 will be performed using this device.; The apple watch is equipped with green, red, and infrared LEDs that shine light onto the blood vessels in the wrist, with photodiodes measuring the amount of light reflected back. Apple's algorithms use this information to calculate the color of the blood, which is an indication of how much oxygen is in the blood. Bright red blood is well oxygenated, while darker blood has less oxygen. This can measure blood oxygen levels between 70 and 100 percent. Most healthy people have blood oxygen levels that range from 95 to 100 percent. The apple watch sensor will be positioned on the user's preferred wrist.; The pulse oximeter enables transcutaneous monitoring of the oxygen saturation of hemoglobin in arterial blood. In this study, volar aspect of thumb and index finder of the subject will be used to measure blood oxygen saturation.
Other intervention name(s): Spatial Frequency Domain Imaging (SFDI); Transcutaneous oxygen monitoring (TCOM); Pulse Oximeter
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Other
Keywords: SFDI, oxygenation, healthy volunteers