# US 2018/0020962 A1 · Compact low-cost fiberless diffuse speckle contrast flow-oximeter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0020962 A1 - Document ID: US20180020962A1 - Status: Published application - Kind: A1 - Application number: 15/655,988 - Filed: 2017-07-21 - Published: 2018-01-25 - Earliest claimed: 2016-07-21 - Assignees: University of Kentucky Research Foundation - Applicants: University of Kentucky Research Foundation - Inventors: Guoqiang Yu; Chong Huang; Jeffrey Todd Hastings - Web page: https://patentgrep.com/patent/US20180020962A1 ## CPC - A61B 5/14552: {Details of sensors specially adapted therefor} - A61B 5/0059: {using light, e.g. diagnosis by transillumination, diascopy, fluorescence (photoacoustic A61B5/0093; optical measurement of heart rate A61B5/02416; optical measurement of blood flow A61B5/0261; optical measurement of analytes A61B5/1455)} - A61B 5/0205: Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition - A61B 5/0261: {using optical means, e.g. infrared light} - A61B 5/6814: {Head} - A61B 5/6824: {Arm or wrist} - G01N 2021/479: {Speckle} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract A low-cost compact fiberless diffuse speckle contrast flowmeter includes a small laser diode and a 2-dimensional imaging device such as a charge coupled device (CCD) or complementary metal oxide semiconductor (CMOS) for directly contacting the tissue and measuring a parameter such as blood flow in a deep/thick volume of tissue (up to 10 mm depth). The small laser diode is fixed at a certain distance (0 to 20 mm) from the imaging device and directly contacts the tissue. Light emitted from the laser diode penetrates through the tissue and reflects back to the imaging device without passing through any lenses or fibers. One or more additional laser diodes may be added for producing light at different wavelengths, and the combination of measurements taken by the imaging device at the different wavelengths allows for measuring additional parameters, such as both blood flow and blood oxygenation. ## Claims ### Claim 1 A probe for use in measuring a hemodynamic parameter within a tissue of a subject, said probe comprising: a laser diode for emitting light into the tissue of the subject; and a bare imaging device adapted to contact the tissue of the subject and receive light reflected from the tissue to detect diffuse speckle contrast variations in the tissue for measurement of the hemodynamic parameter; wherein said probe includes no optical cable. ### Claim 2 (depends on 1) The probe of claim 1, further including a retainer for retaining the laser diode and the bare imaging device at fixed positions relative to each other. ### Claim 3 (depends on 2) The probe of claim 2, wherein the retainer comprises a foam pad. ### Claim 4 (depends on 1) The probe of claim 1, wherein the laser diode produces a coherence length in human tissue of between 10 cm and 1 m. ### Claim 5 (depends on 1) The probe of claim 1, wherein the bare imaging device is adapted to receive the light reflected from the tissue without passing through any lenses prior to receiving the light. ### Claim 6 (depends on 1) The probe of claim 1, wherein the laser diode and the bare imaging device are fixed relative to one another at a distance of between 13 mm-18 mm. ### Claim 7 (depends on 1) The probe of claim 1, further including a controller for controlling the function of the bare imaging device. ### Claim 8 (depends on 7) The probe of claim 7, wherein the controller is remote from the bare imaging device. ### Claim 9 (depends on 8) The probe of claim 8, wherein the controller is connected to the bare imaging device via electrical wires. ### Claim 10 (depends on 8) The probe of claim 8, wherein the controller is wirelessly connected to the bare imaging device. ### Claim 11 (depends on 1) The probe of claim 1, wherein the bare imaging device comprises a bare charge coupled device. ### Claim 12 (depends on 1) The probe of claim 1, wherein the bare imaging device comprises a bare complementary metal oxide semiconductor. ### Claim 13 A probe for use in measuring at least one hemodynamic parameter within a tissue of a subject, said probe comprising: a first laser diode adapted for emitting light into the tissue of the subject at a first wavelength; a second laser diode adapted for emitting light into the tissue of the subject at a second wavelength different from the first wavelength; a bare imaging device adapted to contact the tissue of the subject and receive light reflected from the tissue to detect diffuse speckle contrast variations in the tissue for measurement of the at least one hemodynamic parameter; and a retainer adapted to receive and maintain a constant distance from each of the first laser diode and the second laser diode to the bare imaging device, said retainer including a contact surface adapted to contact the tissue of the subject; wherein the retainer is adapted to maintain the bare imaging device in contact with the tissue with no lens therebetween. ### Claim 14 (depends on 13) The probe of claim 13, wherein the probe includes no optical cable. ### Claim 15 (depends on 13) The probe of claim 13, wherein the bare imaging device comprises a charge coupled device. ### Claim 16 (depends on 13) The probe of claim 13, wherein the bare imaging device comprises a bare complementary metal oxide semiconductor. ### Claim 17 A method of measuring at least one hemodynamic parameter within a tissue of a subject, said method comprising: emitting light at a first wavelength from a first laser diode into the tissue, said light not received through an optical cable; placing a bare imaging device in contact with the tissue with no lens therebetween; and measuring reflected light from the tissue to detect diffuse speckle contrast variations in the tissue in order to measure the at least one hemodynamic parameter. ### Claim 18 (depends on 17) The method of claim 17, further including the step of emitting light at a second wavelength from a second laser diode into the tissue, and wherein the measuring step comprises measuring reflected light from the tissue from the first laser diode and the second laser diode. ### Claim 19 (depends on 17) The method of claim 17, further including the step of attaching each of the first laser diode and the bare imaging device to a retainer in order to maintain a fixed distance between the first laser diode and the bare imaging device. ### Claim 20 (depends on 19) The method of claim 19, wherein the fixed distance is between 13 mm and 18 mm.