(87 days)
Not Found
No
The description details a traditional laser Doppler imaging system using established techniques and signal processing. There is no mention of AI, ML, or any learning algorithms for image processing or analysis. The processing described is based on detecting Doppler shifts and calculating flux and concentration parameters directly from the signal.
No.
The device is intended for studies of blood flow in the microcirculation for clinical research applications and does not mention any therapeutic use.
No
The moorLDI Laser Doppler Imager is intended for "studies of blood flow in the microcirculation" and for "clinical research applications." While it measures physiological parameters, its stated purpose is for research and monitoring, not for diagnosing specific diseases or conditions.
No
The device description clearly outlines hardware components including a control box, scanner head, laser, mirrors, photodiodes, and electronic circuits, indicating it is not a software-only device.
Based on the provided information, the moorLDI Laser Doppler Imager is not an In Vitro Diagnostic (IVD) device.
Here's why:
- Intended Use: The intended use clearly states "studies of blood flow in the microcirculation... suitable for a wide range of clinical research applications". This indicates the device is used for in vivo measurements on living tissue, not for testing samples in vitro (outside the body).
- Device Description: The description details how the device scans a laser beam over the skin surface and detects light scattered by blood cells beneath the skin surface. This is a direct measurement on the body.
- Anatomical Site: The anatomical sites listed are all parts of the body (skin, forearm, finger tip, etc.).
- Performance Studies: The performance studies involve in vivo measurements on humans and rabbits, comparing the device's performance to other in vivo measurement techniques (microsphere technique, other laser Doppler imagers).
IVD devices are specifically designed to examine specimens derived from the human body (like blood, urine, tissue samples) in vitro to provide information for diagnosis, monitoring, or screening. The moorLDI operates directly on the living body to measure blood flow.
N/A
Intended Use / Indications for Use
The moorLDI Laser Doppler Imager is intended for blood flow studies in a wide range of clinical research applications including plastic surgery, diabetes, dermatology, vascular surgery, wound healing, neurology, physiology, neurosurgery and anaesthetics.
The moorLDI Laser Doppler Imager is intended for studies of blood flow in the microcirculation, e.g. blood flow in the small blood vessels of the skin. It is suitable for a wide range of clinical research applications including plastic surgery, diabetes, dermatology, vascular surgery, wound healing, neurology, physiology, neurosurgery and anaesthetics.
Product codes (comma separated list FDA assigned to the subject device)
GEX
Device Description
The moorLDI laser Doppler imager is a device for imaging blood flow in the microcirculation of surface tissue e.g. blood flow in skin. It uses the established laser Doppler technique to quantify movement of blood cells beneath the skin surface. Unlike existing laser Doppler monitors, which use optical fibre probes at fixed tissue sites, moorLDI scans a low power laser beam in a raster pattern over the skin surface to build up a colour coded image of blood flow.
A beam of light from a low power HeNe red laser is directed by a moving mirror which is driven by the DC servo motors to execute a raster pattern across the tissue surface. The incident light is scattered by static tissue and by moving blood. The Doppler frequency shifted light from moving blood and non-shifted light from tissue is then directed by the same moving mirror (and focusing lenses) onto two photodiodes. Light 'beats' at the detectors due to constructive and destructive mixing of the light. These intensity fluctuation are then processed in suitable electronic circuits to give parameters of flux (proportional to tissue blood flow) and conc (proportional to the concentration of moving blood cells). The outputs of the Doppler signal processor and a DC signal (the light intensity) are sent to the computer (PC) via an opto isolated RS232 serial port, so an intensity photo image and a colour-coded blood flow image can be displayed and processed by the computer.
The moorLDI consists of a control box, scanner head and optional bench top or a mobile stand. The system interfaces with the PC via an opto isolated RS232 serial port at a baud rate of 19200. The moorLDI control box contains a power supply unit and all main electronic circuit board. The optical and mechanical components are mounted on the base plate of the scanner head. The control signals for the mirror, shutter, laser power attenuator, etc. are provided by the control box via a 37 way cable. The laser Doppler shifted signals detected by the photo detector board, which is mounted on the base plate of the scanner head, are sent to the control box via a 9 way analogue cable.
Mentions image processing
Yes
Mentions AI, DNN, or ML
Not Found
Input Imaging Modality
Laser Doppler
Anatomical Site
Microcirculation of surface tissue e.g. blood flow in skin, forearm, finger tip, dorsum of the hand, rabbit knee joint capsule, knee ligaments of adult rabbits (medial collateral ligament)
Indicated Patient Age Range
Not Found
Intended User / Care Setting
Not Found
Description of the training set, sample size, data source, and annotation protocol
Not Found
Description of the test set, sample size, data source, and annotation protocol
A flow simulator was constructed to evaluate the predicted linear relationship between measured perfusion values from the moorLDI and flow rates. The flow model consisted of five rows of the silicone rubber tubing, with inner diameter of 0.76mm, laid side by side over an aluminium reflective background. A translucent plastic cover was placed over the top of the lengths of tube to simulate the diffusing effect of skin tissue on incident laser light. The motility standard was diluted down to 0.1% solution with purified water and pumped through the tube by an infusion pump to simulate the blood flow. For each rate of flow, two types of measurements were performed, i.e. 1) non-scan mode at a fixed beam position with lower cut-off frequencies of 20Hz, 100Hz and 250Hz, 2) imaging the whole flow model at two scan speeds, 4ms/pixel and 50ms/pixel.
The measurements were taken forearm using a stationary beam and scan speed of 50ms/pixel, 10ms/pixel and 4ms/pixel.
Both the MBF3D and moorLDI were used to monitor Flux and Conc signals at the finger tip. A pressure cuff was used to partially occlude and then release the blood flow to see the changes in the laser Doppler signals monitored by the MBF3D and moorLDI.
Images of blood flow in the dorsum of the hand were recorded using the moorLDI at two resolutions (64 x 64 pixels and 256 x 256 pixels) and the PIM 1.0 at its maximum resolution of 64 x 64 pixels.
Experiments were performed in 12 adult male New Zealand rabbits to evaluate the moorLDI for measuring blood flow in the rabbit knee joint capsule. The femoral artery of one hindlimb was cannulated both proximally and distally, and the circulation to the hindlimb controlled via a pump (Gilson minipuls). During the experiment, two pump speeds were selected: a low speed (2.8 ml/min) and a high speed (11.0 ml/mim). The microsphere labels and the pump speeds were randomly varied between experiments, and for each pump speed, image scans at three different scan rates (4ms/pixel, 10ms/pixel and 50ms/pixel) were performed. Therefore, a total of 72 images have been obtained.
The purpose of this study is to compare two different laser Doppler imaging technologies for measuring blood flow in hypoaemic (low flow) tissues, one is the PIM 1.0 using step scanning method and the other is the moorLDI using continuous scanning method. Experiments were performed on 9 female, one year old, New Zealand White rabbits. Normal and knee-injured rabbits were used. Knee injuries consisted of transection of the intra-articular anterior cruciate ligament (ACL) of the right knee according to a standardised protocol. LDI measurements were made in the exposed medial collateral ligament (MCL) at several intervals after ACL transection. All LDI measurements for both imagers were obtained sequentially from exposed MCLs.
Summary of Performance Studies (study type, sample size, AUC, MRMC, standalone performance, key results)
Flow Model Study:
Study type: Experimental model study.
Sample size: Not explicitly stated, but multiple measurements were taken at different flow rates and scan settings.
Key results: A linear relationship between the flux outputs and the flow rates has been established for different lower cut-off frequencies and different scan speeds. The use of the higher cut-off frequency (250Hz) for the high pass filter effectively reduces the movement artefact introduced by the fast image scanning with small loss of low flow information.
Assessment of Movement Artefact Study:
Study type: In vivo measurement comparison.
Sample size: Not explicitly stated, measurements taken on a forearm.
Key results: Comparable flux values can be obtained even at a 4ms/pixel scan speed with 250Hz lower cut-off frequency, similar to stationary measurements. Continuous beam movement is not considered to compromise the effectiveness of the moorLDI for blood flow measurement.
Single Point Measurements Study:
Study type: Comparison with predicate device (MBF3D).
Sample size: Not explicitly stated, measurements taken at finger tip.
Key results: The signals recorded by the MBF3D monitor and the moorLDI running in single point mode illustrates their equivalence in terms of blood flow measurement.
Image Scanning Study:
Study type: Comparison of image resolution and scan time with predicate device (PIM 1.0).
Sample size: Not explicitly stated, images of blood flow in the dorsum of the hand.
Key results: The moorLDI provided more detailed information (256 x 256 pixels) in approximately the same overall scan time (5 minutes) as the PIM 1.0 (64 x 64 pixels). The moorLDI 64 x 64 pixels image is similar to the PIM 1.0 image but can be scanned in approximately 40 seconds.
Compared with Microsphere Technique Study:
Study type: In vivo correlation study.
Sample size: 12 adult male New Zealand rabbits.
Key results: Highly significant correlations (correlation coefficient r = 0.9) were obtained between moorLDI and microsphere measurement techniques. This was higher than the r = 0.76 obtained using the PIM 1.0 in similar experiments. Acceptable agreement without significant bias between measurements was demonstrated across three scan speeds, validating the use of LDI for assessing joint capsule perfusion.
Compared with PIM 1.0: Measurement in Knee Ligaments of Adult Rabbits Study:
Study type: In vivo comparison study.
Sample size: 9 female, one year old, New Zealand White rabbits.
Key results: The mean LDI outputs from the PIM 1.0 and the moorLDI were significantly correlated (r = 0.999). The results suggest that the effects of a continuous moving laser beam on the perfusion measurement are not statistically significant for the flows present in these MCLs. Nor were the flows significantly affected by the band pass and faster scanning technique of the moorLDI.
Key Metrics (Sensitivity, Specificity, PPV, NPV, etc.)
Correlation coefficient r = 0.9 (moorLDI vs microsphere)
Correlation coefficient r = 0.76 (PIM 1.0 vs microsphere)
Correlation coefficient r = 0.999 (PIM 1.0 vs moorLDI for MCL measurements)
Predicate Device(s): If the device was cleared using the 510(k) pathway, identify the Predicate Device(s) K/DEN number used to claim substantial equivalence and list them here in a comma separated list exactly as they appear in the text. List the primary predicate first in the list.
PIM 1.0 Laser Doppler Perfusion Imager 510(k) Number - K920844, Moor Laser Blood Flow Monitor MBF3D 510(k) Number - K905232
Reference Device(s): Identify the Reference Device(s) K/DEN number and list them here in a comma separated list exactly as they appear in the text.
Not Found
Predetermined Change Control Plan (PCCP) - All Relevant Information for the subject device only (e.g. presence / absence, what scope was granted / cleared under the PCCP, any restrictions, etc).
Not Found
§ 870.2120 Extravascular blood flow probe.
(a)
Identification. An extravascular blood flow probe is an extravascular ultrasonic or electromagnetic probe used in conjunction with a blood flowmeter to measure blood flow in a chamber or vessel.(b)
Classification. Class II (performance standards).
0
APR 30 1998
Delail Banks (1 mart 1 . F . . . .
...
Premarket Notification 510(k) Summary
Company Name:
Address:
Telephone No:
Fax No:
Contact Name:
Contact Title:
Date:
MOOR INSTRUMENTS LIMITED
MILLWEY AXMINSTER, DEVON U.K. EX13 5HU
+44 (0)1297 35715
+44 (0)1297 35716
DAVE BOGGETT
Managing Director
15/01/1998
1
| Classification Name: | Not Known |
|---|---|
| Common/Usual Name: | Laser Doppler Perfusion Imager |
| Trade/Proprietary Name: | moorLDI Laser Doppler Imager |
| Establishment Registration No: | 8043564 |
| Classification: | Regulatory Class II |
| Performance Standard: | The equipment conforms to the provisions of |
| US 21 CFR 1040.10 and 1040.11 as a Class | |
| IIIa Medical Laser Product. | |
| Reason for Submission: | New Device |
| Predicate Devices: | PIM 1.0 Laser Doppler Perfusion Imager |
| 510(k) Number - K920844 | |
| Moor Laser Blood Flow Monitor MBF3D | |
| 510(k) Number - K905232 |
Description of the Device
The moorLDI laser Doppler imager is a device for imaging blood flow in the microcirculation of surface tissue e.g. blood flow in skin. It uses the established laser Doppler technique to quantify movement of blood cells beneath the skin surface. Unlike existing laser Doppler monitors, which use optical fibre probes at fixed tissue sites, moorLDI scans a low power laser beam in a raster pattern over the skin surface to build up a colour coded image of blood flow.
A beam of light from a low power HeNe red laser is directed by a moving mirror which is driven by the DC servo motors to execute a raster pattern across the tissue surface. The incident light is scattered by static tissue and by moving blood. The Doppler frequency shifted light from moving blood and non-shifted light from tissue is then directed by the same moving mirror (and focusing lenses) onto two photodiodes. Light 'beats' at the detectors due to constructive and destructive mixing of the light. These intensity fluctuation are then processed in suitable electronic circuits to give parameters of flux (proportional to tissue blood flow) and conc (proportional to the concentration of moving blood cells). The outputs of the Doppler signal processor and a DC signal (the light intensity) are sent to the computer (PC) via an opto isolated RS232 serial port, so an intensity photo image and a colour-coded blood flow image can be displayed and processed by the computer.
2
The moorLDI consists of a control box, scanner head and optional bench top or a mobile stand. The system interfaces with the PC via an opto isolated RS232 serial port at a baud rate of 19200. The moorLDI control box contains a power supply unit and all main electronic circuit board. The optical and mechanical components are mounted on the base plate of the scanner head. The control signals for the mirror, shutter, laser power attenuator, etc. are provided by the control box via a 37 way cable. The laser Doppler shifted signals detected by the photo detector board, which is mounted on the base plate of the scanner head, are sent to the control box via a 9 way analogue cable.
Intended Use
The moorLDI Laser Doppler Imager is intended for blood flow studies in a wide range of clinical research applications including plastic surgery, diabetes, dermatology, vascular surgery, wound healing, neurology, physiology, neurosurgery and anaesthetics.
Technological Characteristics
moorLDI Compared with PIM 1.0 Laser Doppler Imager .
The moorLDI and PIM 1.0 have the same intended use. Both devices rely on the same physical principle, i.e. the laser Doppler principle, to measure the tissue blood perfusion. Both instruments scan a low power laser beam over the tissue surface in a raster pattern to produce a two dimensional colour coded blood perfusion image. The main difference is the beam scanning method. The PIM 1.0 scans a laser beam in a step mode, i.e. the laser beam is halted for about 50ms at each measurement site to allow the stepper motors time to settle and then the measurement is taken. The moorLDI uses a continuous mode of scanning. For each line scan the laser beam is scanned at a constant speed across the tissue surface with measurements made at regular intervals along the scan line. This mode of scanning, in comparison to stopping the beam for each measurement, eliminates the need for a settling time and enables relatively short imaging times to be achieved. For a 256 × 256 pixel image, the moorLDI takes under 5 minutes when the 4ms/pixel scan speed is selected. This is approximately the same time for a 64 x 64 pixel image recorded with the PIM 1.0 imager. The moorLDI provides optional scan speeds of 4ms/pixel, 10ms/pixel or 50ms/pixel and implements a high pass filter with different high pass cutoff frequencies for different speeds to reduce movement artefact introduced by continuous image scanning. Measurements with a moorLDI have demonstrated that: 1) the high pass filter with higher cut-off frequency (e.g. 250Hz for 4ms/pixle scan speed) effectively removes the movement artefact with small loss of low flow information. 2) A slow scan speed (e.g. 50ms/pixel) can be used to improve the signal quality when looking at a low flow region. At this scan speed a high pass filter with a cut-off frequency of 20Hz is used. The PIM 1.0 imager has a high pass filter of 20Hz and a low pass filter of 10khz. The moorLDI has low pass frequency options of 3KHz, 15KHz and 22KHz.
3
The other main difference between the two imagers is the light collection method. The PIM 1.0 uses a single photodetector for collecting the scattered light from the tissue surface so a relatively small amount of light collected. This is the main reason that the PIM 1.0 can only work at a distance range of 15cm to 20cm from the system to patient tissue surface and requires low light conditions. In contrast to the PIM 1.0, the moorLDI uses a 100mm diameter mirror to direct the beam to the tissue surface and reflect laser light scattered from this surface to two large area convex lenses which focus the collected light to two photodetectors; therefore a relatively large amount of scattered light can be collected with a consequent improvement in the signal to noise ratio. Use of two photodetectors also enables the moorLDI to implement a differential amplifier circuit to reduce common mode noise such as laser noise, ambient light and mains interference. As a result, the moorLDI achieves a working distance range of 20cm to 100cm and a tissue surface scan area upto 50cm. In addition, a pair of narrow pass band optical filters are fitted in the front of the photodetectors so the moorLDI can work under ambient light conditions, which makes its operation convenient for the user. The PIM 1.0 which does not have optic filters has to be operated in a darkened room.
moor LDI Compared with the Moor Instruments MBF3D Laser Doppler Monitor .
The basic principle of measurement and the technical features of the moorLDI and MBF3D monitor are the same in that they both utilise the Doppler broadening of a low power laser beam to record tissue perfusion, and they both use the same analogue circuit design for laser Doppler signal processing. The MBF3D uses optical fibres to transmit laser light to a tissue site and collect light scattered from the tissue. An optical probe is placed in contact with the skin to provide a real-time continuous blood flow measurement at a fixed site. The moorLDI provides a two dimensional colour coded image of blood flow from a scanned tissue area, and with a fixed beam position provides a real-time continuous blood flow measurement at a fixed point. Since the laser beam is directed to the tissue surface remotely, there is no contact between the tissue surface and the moorLDI during measurements.
Performance Data
In order to evaluate the performance of the moorLDI and determine its substantial equivalence to the PIM 1.0 laser Doppler perfusion imager and the MBF3D laser Doppler monitor, a set of tests has been carried out. A brief discussion of these testes are given below.
. Flow Model
A flow simulator was constructed to evaluate the predicted linear relationship between measured perfusion values from the moorLDI and flow rates. The flow model consisted of five rows of the silicone rubber tubing, with inner diameter of 0.76mm, laid side by
4
Image /page/4/Figure/0 description: The image contains three figures, each consisting of two plots, illustrating the moorLDI Flux Output versus Flow Rate under different measurement conditions. The first figure, labeled "Figure 4-1," shows data from a single-point measurement with a bandwidth of 20Hz to 15KHz. The second figure, "Figure 4-2," presents data from a single-point measurement with a bandwidth of 250Hz to 15KHz. The third figure, "Figure 4-3," displays data from an image scan with a scan speed of 50ms/pixel and a bandwidth of 20Hz to 15KHz.
Figure 4-4. moorLDI Flux Output vs Flow Rate (Measurement: image scan, Scan Speed: 4ms/pixel, Bandwidth: 250Hz to 15KHz)
5
side over an aluminium reflective background. A translucent plastic cover was placed over the top of the lengths of tube to simulate the diffusing effect of skin tissue on incident laser light. The motility standard was diluted down to 0.1% solution with purified water and pumped through the tube by an infusion pump to simulate the blood flow.
For each rate of flow, two types of measurements were performed, i.e. 1) non-scan mode at a fixed beam position with lower cut-off frequencies of 20Hz, 100Hz and 250Hz, 2) imaging the whole flow model at two scan speeds, 4ms/pixel and 50ms/pixel.
The results (Figures 4-1 to 4-4) show that a linear relationship between the flux outputs and the flow rates has been established for different lower cut-off frequencies and different scan speeds. The use of the higher cut-off frequency (250Hz) for the high pass filter effectively reduces the movement artefact introduced by the fast image scanning with small loss of low flow information.
Assessment of Movement Artefact .
This test was designed to assess the effect of continuous beam movement on flux measurement which is one of the technical differences between the moorLDI and PIM 1.0.
The measurements were taken forearm using a stationary beam and scan speed of 50ms/pixel, 10ms/pixel and 4ms/pixel.
| Scan Speed | Bandwidth | Forearm |
|---|---|---|
| Stationary | 20Hz-15KHz | 25 ± 4.1 |
| 50ms/pixel | 20Hz-15KHz | 24 ± 4.5 |
| 10ms/pixel | 100Hz-15KHz | 24 ± 6.4 |
| 4ms/pixel | 250Hz-15KHz | 25 ± 7.7 |
The results indicate that compared with the stationary measurement, comparable flux values can be obtained even at a 4ms/pixel scan speed with 250Hz lower cut-off frequency. The continuous beam movement is not considered to compromise the effectiveness of the moorLDI used as a tool for blood flow measurement. In fact for clinical research reduced scan times are a significant advantage.
. Single Point Measurements
In addition to laser Doppler image scanning, the moorLDI provides a single point measurement function, enabling monitoring of the blood flow signal with time at a fixed position. This is comparable to the blood flow measurement made with a laser Doppler monitor such as the Moor Instrument MBF3D. For comparison, both the MBF3D and moorLDI were used to monitor Flux and Conc signals at the finger tip. A pressure cuff
6
was used to partially occlude and then release the blood flow to see the changes in the laser Doppler signals monitored by the MBF3D and moorLDI. The signals recorded by the MBF3D monitor and the moort.DI running in single point mode illustrates their equivalence in terms of blood flow measurement. The advantage of the moorLDI for this type of measurement is that there is no direct contact with the tissue surface other than the laser beam, the beam can be directed remotely to any position within the image area, and as there are no optic fibres noise associated with fibre movement is eliminated.
- Image Scanning �
To compare the performances of the moorl.DI with that of the PIM 1.0 and to illustrate the high resolution image capability of the moorLDI, a series of image scans were performed.
Images of blood flow in the dorsum of the hand were recorded using the moorLDI at two resolutions (64 x 64 pixels and 256 x 256 pixels) and the PIM 1.0 at its maximum resolution of 64 x 64 pixels. All three laser Doppler images show similar blood flow distributions (Figures 4-9, 4-10 and 4-11). The 256 x 256 pixels photo and laser Doppler images recorded with the moor! DI has more detailed information compared with the PIM 64 x 64 image recorded in a similar overall scan time of approximately 5 minutes. 1.0 The moorLDI 64 x 64 pixels image is similar to the PIM 1.0 image yet can be scanned in approximately 40 seconds.
Image /page/6/Figure/4 description: The image contains two heatmaps, one labeled "PHOTO" and the other labeled "FLUX". The "PHOTO" heatmap ranges from 0 to 800, while the "FLUX" heatmap ranges from 0 to 1500. The "PHOTO" heatmap shows a series of horizontal bands, with the intensity increasing from dark to light. The "FLUX" heatmap shows a more complex pattern, with several distinct areas of high intensity.
Figure 4-9. Photo and Laser Doppler Images Obtained by the moorLDI Scan Mode: continuous at scan speed of 4ms/pixels Resolutions: 64 x 64 pixels Time Taken: approx. 45 seconds
7
Image /page/7/Figure/0 description: The image contains two side-by-side images labeled "PHOTO" and "FLUX". The "PHOTO" image shows a grayscale representation with a color scale ranging from 0 to 800, with intermediate values at 200, 480, and 600. The "FLUX" image also shows a grayscale representation, but with a color scale ranging from 0 to 1500, with intermediate values at 375, 750, and 1125. The bottom right of the "FLUX" image contains some text that is not easily readable.
Figure 4-10. Photo and Laser Doppler Images Obtained by the moorLDI Scan Mode: continuous at scan speed of 4ms/pixels Resolutions: 256 x 256 pixels Time Taken: approx. 4 minutes and 45 seconds
Image /page/7/Picture/2 description: The image shows a perfusion map with a color-coded legend on the left side. The legend indicates the perfusion values corresponding to different colors, ranging from 0-16 with a value of 0.58-1.13 to >80 with a value of 3.31. The map itself displays perfusion levels across a region, with varying colors indicating different perfusion rates. The image also includes information such as format (64x64), threshold (6.20), resolution (Min: 0.58, Max: 4.93), time (17:06), date (1997-10-29), and file (tech129).
Figure 4-11. Laser Doppler Images Obtained by the PIM 1.0 Scan Mode: step, 50ms for each measurement Resolutions: 64 x 64 pixels Time Taken: approx. 4 minutes
8
The moorLDI has a photodetection system with a large effective light collecting area. Because of this it has a working distance of upto 100cm between the scan head and the tissue surface and can scan over areas as large as 50cm. This compares with the 15cm x 15cm of the PIM 1.0.
Compared with Microsphere Technique .
The radiolabelled microsphere technique is a well-established technique for quantitative measurements of blood flow. Experiments were performed in 12 adult male New Zealand rabbits to evaluate the moorLDI for measuring blood flow in the rabbit knee joint capsule. The femoral artery of one hindlimb was cannulated both proximally and distally, and the circulation to the hindlimb controlled via a pump (Gilson minipuls). During the experiment, two pump speeds were selected: a low speed (2.8 ml/min) and a high speed (11.0 ml/mim). The microsphere labels and the pump speeds were randomly varied between experiments, and for each pump speed, image scans at three different scan rates (4ms/pixel, 10ms/pixel and 50ms/pixel) were performed. Therefore, a total of 72 images have been obtained.
The comparison of the moorLDI and microsphere measurement techniques yielded highly significant correlations (correlation coefficient r = 0.9), which is higher than a significant correlation of r = 0.76 obtained by using the PIM 1.0 in similar experiments. Comparison of the three scan speeds demonstrated acceptable agreement without significant bias between measurements, suggesting that the inevitable narrowing of the bandwidth at the fastest scan speed (4ms/pixel) does not cause significant deterioration of the signal. These results validate the use of LDI for the assessment of joint capsule perfusion.
- Ref: J. Lockhart, W. Ferrell and W. Angerson. Laser Doppler Perfusion Imaging of Synovial Tissues Using Red and Near Infra-Red Lasers. Int. J Microcirc, 1997; 17:130-137. (Appendix B3)
. Compared with PIM 1.0: Measurement in Knee Ligaments of Adult Rabbits
The purpose of this study is to compare two different laser Doppler imaging technologies for measuring blood flow in hypoaemic (low flow) tissues, one is the PIM 1.0 using step scanning method and the other is the moorLDI using continuous scanning method. Experiments were performed on 9 female, one year old, New Zealand White rabbits. Normal and knee-injured rabbits were used. Knee injuries consisted of transection of the intra-articular anterior cruciate ligament (ACL) of the right knee according to a standardised protocol. LDI measurements were made in the exposed medial collateral ligament (MCL) at several intervals after ACL transection. All LDI measurements for both imagers were obtained sequentially from exposed MCLs.
9
The comparison between the mean LDI outputs from the PIM 1.0 and the moorLDI shows that the data points were significantly correlated (r = 0.999). The results suggest that the effects of a continuous moving laser beam on the perfusion measurement is not statistically significant for the flows present in these MCLs. The flows measured in this experiment were not significantly affected by the band pass and faster scanning technique of the moorLDI.
- Ref: K. Forrester, M. Doschak and R. Bray. In Vivo Comparison of Scanning Technique and Wavelength in Laser Doppler Perfusion Imaging: Measurement in Knee Ligaments of Adult Rabbits. Medical & Biological Engineering & Computing 1997, Nov. (Appendix B4)
Safety and Certification Standards
The moorLDI has been fully tested by BSI (British Standard Institute) and has been found to comply with following standards:-
IEC 601-1:1988 including Amendment 1, 1991 and Amendment 2, 1995/ EN 60601-1:1990 including Amendments A1, A11, A12 and A2 excluding IEC 601-1-4 reference in Sub-clause 52.1, IEC 601-2-22:1995/BS EN 60601-2-22:1996, BS EN 60825-1:1994/IEC 825-1:1993 UL 2601-1 Medical Electrical Equipment, Part 1: General Requirements for Safety CSA Standards C22.2 No 0 - General Requirements, Canadian Electrical Code, Part II No 601.1-M90: Medical Electrical Equipment, Part 1: General Requirements for Safety No 601.1-1S1-94: Supplement No 1-94 to C22.2 No 601.1-M94 No 601.2.22-94: Medical Electrical Equipment, Part 2.22: Specification for Diagnostic and Therapeutic Laser Equipment The classification of the moorLDI is as follows: Type of protection against electric shock: Class I Degree of protection against electric shock: Type B Portable Degree of mobility: Laser class: 3B Wavelength: 633mm Maximum accessible power: He-Ne laser 2.0mW
BSI test report is attached in Appendix D1 CSA test report is attached in Appendix D2
10
Conclusions
From the above performance data, it can be seen that the moorLDI provides a non-invasive and non-contact technique for blood flow imaging and monitoring. The main conclusion which can be drawn from the above tests is that the moorLDI is substantial equivalence to the MBF3D and PIM 1.0 in terms of effectiveness and safety.
Compared with the MBF3D laser Doppler monitor, the features of non-contact measurement and blood flow imaging suggest that the moorLDI is a more effective device for tissue blood flow measurement and safer because it is non-contact .
Compared with the PIM 1.0 laser Doppler perfusion imager, the features of wide working distance range, large image size, image resolution up to 256 x 256 pixels and fast image scan speed up to 4ms/pixel significantly enhance the effectiveness of the moorLDI used for blood flow measurements and extend the application of the laser Doppler imaging technique in the blood flow studies.
11
Image /page/11/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo features the department's seal, which includes an abstract symbol of a human figure. The text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" is arranged around the seal in a circular fashion.
Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850
APR 3 0 1998
Dr. David Boggett Managing Director Moor Instruments Limited Medical and Opto-Electronic Instrumentation Millwey Axminster Devon EX13 5HU, England
Re: K980383 Trade Name: moorLDI Laser Doppler Imager Regulatory Class: II Product Code: GEX Dated: January 19, 1998 Received: February 2, 1998
Dear Dr. Boggett:
We have reviewed your Section 510(k) notification of intent to market the device referenced above and we have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act). You may, therefore, market the device, subject to the general controls provisions of the Act. The qeneral controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. If your device is classified (see above) into either class II (Special Controls) or class III (Premarket Approval), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Requlations, Title 21, Farts 800 to 895. A substantially equivalent determination assumes compliance with the current Good Manufacturing Fractice requirement, as set forth in the Quality System Requlation (QS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic (QS) inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP requlation may result in requlatory action. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal laws or requlations.
12
Page 2 - Dr. Boggett
This letter will allow you to begin marketing your device as described in your 510 k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.
If you desire specific advice for your device on our labeling regulation (21 CFR Part 801 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4595. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its internet address "http://www.fda.gov/cdrh/dsmamain.html".
Sincerely yours,
fu Celia M. Witten, Ph.D., M.D.
Director
Division of General and
Restorative Devices
Office of Device Evaluation
Center for Devices and
Raciological Health
Enclosure
13
Page of
510(k) NUMBER (IF KNOWN) : _ K980383 DEVICE NAME: __ MOOrLOI_Laser Doppler_Imagen INDICATIONS FOR USE:
The moorLDI Laser Doppler Imager is intended for studies of blood flow in the microcirculation, e.g. blood flow in the small blood vessels of the skin. It is suitable for a wide range of clinical research applications including plastic surgery, diabetes, dermatology, vascular surgery, wound healing, neurology, physiology, neurosurgery and anaesthetics.
(PLEASE DO MOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE IF NEEDED.)
| Concurrence of CDRH, Office of Device Evaluation (ODE) | |
|---|---|
| (Division Sign-Off) | |
| Division of General Restorative Devices | |
| 510(k) Number | K980383 |
| Prescription Use (Per 21 CFR 801.109) | ✓ |
|---|---|
| --------------------------------------- | --- |
OR
| Over-The-Counter-Use (Optional Format 1-2-96) | |
|---|---|
| ----------------------------------------------- | -- |