• INNOVATIVE-DEVICE INNOVATIVE DEVICE
  • NEW-METHOD NEW METHOD
  • NON-INVASIVE-TEST NON-INVASIVE TEST
  • IMMEDIATE-RESULTS IMMEDIATE RESULTS
angioexpert_logo2

INNOVATIVE MEDICAL DEVICE FOR NON-INVASIVE EVALUATION
OF MICROCIRCULATION AND METABOLIC REGULATION USING
FMSF (FLOW MEDIATED SKIN FLUORESCENCE)

PRODUCT

AngioExpert is a medical device which uses the FMSF-PORH method to evaluate microvascular circulation.

AngioExpert is intended for non-invasive monitoring of microcirculation, metabolic regulation and vascular complications in diabetes.

machine

The optical head of the AngioExpert is now based on photodiode technology. Two diodes are used, the first as a source of exciting light (LED) and the second as a fluorescence detector. A set of filters incorporated into the optical head ensures proper selection of excitation light for NADH (340 nm) and detection of fluorescence (460 nm). This solution allows for enhanced miniaturization and reduced signal noise.

Block scheme for AngioExpert device utilizing FMSF.

Front (a) and back (b) views of the commercial AngioExpert medical device.

BACKGROUND

Lifestyle-related diseases (so-called diseases of civilization), including cardiovascular disease, cancer and neurodegenerative diseases (such as Alzheimer’s disease), continue to affect growing numbers around the world. Many national health programs define diseases of civilization as the most serious threat to their populations’ quality of life. According to global statistics, ischemic heart disease is the most common cause of death and the main reason for hospitalization, followed by cancer (malignant tumors). The prevention and treatment of such diseases is one of the most important challenges for the future, and has become part of strategic research plans. There is therefore a need for extensive cooperation between science and industry to develop the most effective (especially non-invasive) solutions for early diagnosis and monitoring of patient health.

What is measured?

  • Flow Mediated Skin Fluorescence (FMSF) is a technique based on the measurement of NADH fluorescence from skin tissue cells.
  • Nicotinamide adenine dinucleotide (NADH) and its oxidized form (NAD+) play a crucial role in biological systems as redox coenzymes.
  • The NADH/NAD + pair is the carrier of electrons in the respiratory chain of each living cell.

Chemical structures of NADH and NAD+.

 

  • Although NADH emits significant fluorescence, this is not the case with NAD+.

Absorption and emission properties of NADH/NAD+ couple.
(a) Electronic absorption spectra of NADH and NAD+.
(b) Normalized absorption and fluorescence spectra of NADH.

 

  • The fluorescence from NADH is the strongest component of the overall fluorescence emitted from human skin.
  • The penetration depth of excitation light for NADH (340 nm) in skin tissue is low (about 0.5 mm), therefore a substantial fraction is absorbed by the epidermis and papillary dermis.
  • In these skin regions, the density of blood microvessels is low and the changes in NADH fluorescence depend on the supply of oxygen diffused from deeper layers.

How is it measured?

  • The FMSF technique measures changes in the intensity of NADH fluorescence from the skin on the forearm as a function of time, in response to blocking and releasing blood flow in the forearm.
  • Blood flow in the forearm is blocked using a typical occlusion cuff, as used to measure blood pressure.

Advantages of FMSF method:

  • useful for assessing circulatory status by comparing the vascular response to reactive hyperemia (PORH) to the resting state (before occlusion),
  • suitable for assessing the degree of ischemia and reperfusion in skin cells depending on blood flow in the vessels,
  • useful for assessing the progress and remission of microcirculation disorders, metabolic regulation and vascular complications,
  • optimal for the observation of microcirculation oscillations, the amplitude and frequency of which may signal irregularities in the microcirculation,
  • helpful for monitoring vascular circulation disorders and selecting individualized forms of therapy.

 

The FMSF method enables disorders to be detected at an early stage of development and monitoring of the treatment process. It helps to identify patients in possible need of preventive or therapeutic interventions, who may be referred for further diagnosis.

The FMSF method has intellectual property protection, including in the following countries: EU, USA, Canada, China, Japan, Australia, Russia.

The first test implemented by Angionica is the FMSF–PORH test (Flow Mediated Skin Fluorescence–Post-Occlusive Reactive Hyperemia), which is used to assess microvascular circulation (vascular endothelial function) based on circulatory stimulation in response to induced reactive hyperemia (PORH). The test makes it possible to assess levels of both contraction and vasodilation and to follow the kinetics of changes in response to reactive hyperemia. In general, the FMSF-PORH test enables identification of patients requiring prophylactic or therapeutic interventions, and more accurate and complex diagnostic tests. It also facilitates monitoring of the treatment process, the influence of drugs on the condition of vessels and the effects of training and physical exertion on overall health.

Main parts of a typical trace recorded for an individual patient using AngioExpert

  • Baseline – collected for 3 min (or 4 min if unstable).
  • Ischemic response (IR) – 3 min occlusion with cuff inflated to 60 mmHg above systolic blood pressure, resulting in an increase of NADH fluorescence.
  • Hyperemic response (HR) caused by releasing pressure in the occlusion cuff – NADH fluorescence decreases below the baseline, reaching a minimum followed by a return to the baseline.
  • Hyperemic response (HR) with two distinct phases:
    1) hyperemia – related to a sharp drop in NADH fluorescence for 20–30 s;
    2) reperfusion – a much slower return to the baseline.

Definition of measured parameters

Hyperemic response parameters HRmax and HRindex express changes in NADH fluorescence (mainly from the keratinocytes in the epidermis) and determine the metabolic reaction of the skin cells to hyperemia and reperfusion.
Ischemic response parameters IRmax and IRindex express changes in NADH fluorescence (mainly from keratinocytes in the epidermis) and determine the sensitivity of skin cells to hypoxia caused by blocking blood flow in the forearm. This sensitivity is determined primarily by the efficiency of oxygen transport to the epidermal cells just before occlusion.

Definition of the measured parameters, (a) IRmax and HRmax (b) IRindex and HRindex.

 

Interpretation of the measured parameters

  • HRmax refers to the efficacy of oxygen supply to the epidermis during hyperemia via skin microcirculation and can be treated as an indirect measure of NO bioavailability in the microcirculation.
  • HRindex refers to the recovery of metabolic status in the epidermis following hyperemia caused by the release of pressure in the occlusion cuff.
  • HRmax and HRindex are key parameters demonstrating the diagnostic power of the FMSF technique.
  • Parameters IRmax and IRindex are sensitive to deviations from the measurement procedure and carry auxiliary diagnostic significance.
  • Microvascular oscillations on the baseline and the hyperemic response line express the efficacy of vascular-metabolic regulation related to microvascular dermal flow. A weakening of their amplitude and changes in frequency may indicate the presence of microvascular dysfunction.

Threshold values of the key parameters for diabetes

Based on the results of tests and experiments, threshold values have been established indicating serious disorders in microvascular and metabolic regulation and signaling the risk of vascular complications in diabetes patients.
The HRindex parameter has particularly high diagnostic sensitivity and specificity for assessing the risk of developing vascular complications:

The FMSF technique enables early diagnosis of dysfunction and disturbances in vascular circulation and metabolic regulation. It is therefore suitable for monitoring diabetes at intervals adjusted to the individual patient’s needs and on the basis of medical consultations. The FMSF method is applicable to both type 1 and type 2 diabetes. The manufacturer recommends repeating the test annually or more frequently when significant changes in the HRindex parameter are observed, subject to medical advice.

Advantages of the FMSF technique:

  • enables early diagnosis of dysfunctional vascular circulation,
  • identifies diabetic patients at risk of vascular complications at an early stage,
  • assesses the risk of metabolic disorders in patients with type 1 diabetes,
  • assesses the risk of serious cardiovascular complications in patients with type 2 diabetes,
  • is recommended for monitoring patients with diabetes over time to enable early identification of dysfunction and disturbances in vascular circulation and metabolic regulation.

Publications:

  • Majewski S., Szewczyk K., Białas A. J., Miłkowska-Dymanowska J., Kurmanowska Z., Górski P. Assessment of microvascular function in vivo using flow mediated skin fluorescence (FMSF) in patients with obstructive lung diseases: A preliminary study. Microvasc. Res. 2020; 127: 103914; doi.org/10.1016/j.mvr.2019.103914
  • Katarzynska J., Lipinski Z., Cholewinski T., Piotrowski L., Dworzynski W., Urbaniak M., Borkowska A., Cypryk K., Purgal R., Marcinek M., Gebicki J. Non-invasive evaluation and metabolic regulation using flow mediated skin fluorescence (FMSF): Technical aspects and methodology. Rev. Sci. Instrum. 2019; 90: 104104
  • Bugaj O., Zielinski J. , Kusy K., Kantanista A., Wielinski D. Guzik P. The effect of exercise on the skin content of the reduced form of NAD and its response to transient ischemia and reperfusion in highly trained athletes. Front. Physiol. 2019; 10: 600: doi: 10.3389/fphys.2019.00600
  • Katarzynska J., Borkowska A., Czajkowski P., Los A., Szczerbinski L., Milewska-Kranc A., Marcinek A., Kretowski, A., Cypryk K., Gebicki J., Flow Mediated Skin Fluorescence technique reveals remarkable effect of age on microcirculation and metabolic regulation in type 1 diabetes Microvasc. Res. 2019; 124: 19-24 doi.org/10.1016/j.mvr.2019.02.005
  • Tarnawska M., Dorniak K., Kaszubowski M., Dudziak M., Hellmann M. A pilot study with flow mediated skin fluorescence: A novel device to assess microvascular endothelial function in coronary artery disease. Cardiol. J. 2018; 25: 120-127; doi.org/10.5603/CJ.a2017.0096
  • Sibrecht G., Bugaj O., Filberek P., Jan Nizinski J., Kusy K., Zielinski J., Guzik P. Flow-mediated skin fluorescence method for non-invasive measurement of the NADH at 460 nm – a possibility to assess the mitochondrial function. Post. Biol. Komórki 2017; 44: 333-352
  • Woźniacka A., Tokarska K., Bogaczewicz J. Zmienność fluorescencji zredukowanej formy koenzymu NADH w toczniu rumieniowatym i twardzinie układowej. Prz. Dermatol. 2017; 104: 206
  • Hellmann M., Tarnawska M., Dudziak M., Dorniak K. Roustil, J.-L. Cracowski. Validation of flow mediated skin fluorescence: a new technique to assess microvascular function in coronary artery disease. J. Vasc. Res. 2017; 54 (S1): 34
  • Hellmann M., Tarnawska M., Dudziak M., Dorniak K., Roustit M., Cracowski J.-L. Reproducibility of flow mediated skin fluorescence to assess microvascular function. Microvasc. Res. 2017; 113: 60-64; doi.org/10.1016/j.mvr.2017.05.004
  • Tarnawska M., Dudziak M., Hellmann M. Zastosowanie pookluzyjnej reakcji przekrwiennej w ocenie funkcji śródbłonka mikrokrążenia. Chor. Serca Naczyń 2016; 13(6): 429-433
  • Piotrowski L., Urbaniak M., Jedrzejczak B., Marcinek A., Gebicki J. Flow mediated skin fluorescence – A novel technique for evaluation of cutaneous microcirculation. Rev. Sci. Instrum. 2016; 87: 036111; aip.scitation.org/doi/10.1063/1.4945044

Provides a simple and non-invasive procedure
for identifying patients at increased risk of vascular complications.
Helps detect vascular circulation dysfunction
at an early stage.
Suitable for use by diabetologists,
cardiologists and general practitioners.
Supports treatment selection
and monitoring of treatment response.

ABOUT US

Angionica Ltd. is a spin-off company whose main goal is the implementation of the innovative Flow Mediated Skin Fluorescence (FMSF) method developed by Lodz University of Technology (TUL) and the Jagiellonian University (UJ).

FMSF is a new diagnostic method based on photodiode technology, protected by international patents in the world’s major markets.

The FMSF technique is intended for use in everyday clinical practice to assess microvascular circulation and disorders caused by lifestyle-related diseases.

ISO 13485:2016

Angionica Ltd. has implemented and maintains Quality management system in accordance with PN-EN ISO 13485:2016-04 – Medical devices – Quality management systems – Requirements for regulatory purposes.

 

MDD 93/42/EEC

Angionica Ltd. has established a quality system for design, production and final testing of AngioExpert according to the requirements of the Medical Device Directive 93/42/EEC.

 

 

 

 

 

 

 

 

 

FUNDING

This work was supported by the European Union under the European Regional Development Fund as part of the Smart Growth Operational Program, Grant No. POIR. 01.01.01-00-0540/15-00.

CONTACT

Zeromskiego street 116, bldg. A24/1, 90-924 Lodz
phone: +48 42 631 30 81 (83)
e-mail: biuro[at]angionica.com.pl
REGON: 361456370
NIP: 7262656550
KRS: 0000557122

We inform you that your personal data provided in the contact form will be processed by the Personal Data Controller, which is ANGIONICA Ltd. with its registered office in Łódź at ul. Żeromskiego street 116, Building A-24, entered into the Register of Entrepreneurs of the National Court Register under KRS number 0000557122 by the District Court for Łódź-Śródmieście in Łódź, 20th Division of the National Court Register (contact data: biuro@angionica.com.pl, phone number: 42 631-30-81), solely for the purpose of sending a reply to the message received.
The legal basis for the processing of your personal data is the justified interest of the Controller, i.e. sending a reply to the message received. Providing your personal data is voluntary, but necessary for receiving this reply. If the data is not provided, it will not be possible to give the reply.
You have the right to access your personal data and to demand that this data is corrected or deleted or the processing of this data is limited. You also have the right to raise an objection to the processing of the data and to transfer the data to the Personal Data Controller indicated by you, as well as the right to lodge a complaint with the President of the Personal Data Protection Office.
Your personal data will not be transferred to any other entities or any third party country.
Your personal data will be processed for the period necessary to provide the reply, not longer than for 1 year from the moment of sending the reply to the inquiry by the Controller.