Ultrasensitive deafness gene DNA hybridization detection employing a fiber optic Mach-Zehnder interferometer: Enabled by a black phosphorus nanointerface.

The rapid and efficient detection of deafness gene DNA plays an important role in the clinical diagnosis of deafness diseases. This study demonstrates the ultrasensitive detection of complementary DNA (cDNA) by employing a nanointerface-sensitized fiber optic biosensor. The sensor consists of SMF-TNCF-MMF-SMF (abbreviated as STMS) structure with lateral offset. Besides, it is functionalized with a nanointerface of black phosphorus (BP) to enhance the light-matter interaction and eventually improve the sensing performances. Relying on this nanointerface-sensitized sensor, we successfully realize the in-situ detection of cDNA at concentrations ranging from 1 pM to 1 µM, with a sensitivity of 0.719 nm/lgM. The limit of detection (LOD) is as low as 0.24 pM, which is at least two orders of magnitude lower than those of existing methods. The sensor exhibits the advantages of simple operation, fast response, label-free measurement, excellent repeatability, and high selectivity. Our contribution suggests a convenient approach for deafness gene DNA detection and can be extended for general ultra-low concentration DNA detection applications.

Shikani Optical Stylet for Awake Nasal Intubation in Patients Undergoing Head and Neck Surgery.

OBJECTIVES: To evaluate the efficacy and safety of the Shikani optical stylet (SOS) versus fiberoptic bronchoscope (FOB) for awake nasal intubation in head and neck surgery patients with an anticipated difficult airway. STUDY DESIGN: Prospective randomized clinical trial. METHODS: This study involved 50 adult patients scheduled for elective head and neck surgery and presented with an anticipated difficult airway. Patients planned for awake nasotracheal intubation were randomly divided into two groups: FOB (n = 25) and SOS (n = 25). Patients were intubated under local anesthesia and sedation using the randomly assigned intubation device by anesthetists proficient in both airway devices. The time to successful intubation was regarded as the primary endpoint. RESULTS: The median time (interquartile range) to tracheal intubation in the FOB group was 74 seconds (57-108) and 38 seconds (27-60) in the SOS group (P < .001). Intubation success rates on the first attempt in the FOB and SOS groups were 96% and 92%, respectively (P > .999). Airway assisted maneuvers were required in six (24%) SOS intubations compared to 21 (84%) FOB intubations (P < .001). There were no significant differences between the groups in the incidences of oxygen desaturation and postoperative complications related to intubation. CONCLUSION: Compared to the FOB group, awake nasal intubation in the SOS group required significantly less time and fewer airway-assisted maneuvers on adult head and neck surgery patients with anticipated difficult airway. LEVEL OF EVIDENCE: 2 Laryngoscope, 131:319-325, 2021.

Airway Blocks Vs LA Nebulization- An interventional trial for Awake Fiberoptic Bronchoscope assisted Nasotracheal Intubation in Oral Malignancies.

BACKGROUND: Patients with intra-oral malignancies warrants use of awake Fiberoptic assisted naso-thracheal intubation to secure an airway due to multiple risk factors leading to anticipated difficult airway. Different techniques such as airway blocks, local anesthesia (LA) gargles, spray, nebulization and  mild  sedation are in practice to improve  the success rate of fiberoptic assisted intubation. METHODS: Sixty patients  of  ASA I and II with Mallampatti score 3 and above, posted for Commando operations were enrolled in this study and were divided into 2 groups. Group AB (Airway Block, n=30) were given Superior laryngeal nerve block bilaterally and recurrent laryngeal nerve block  transtracheally  with Inj  2% Lignocaine. Second Group AN (Airway Nebulization, n=30)  patients airway was nebulized with 4% Lignocaine  with ultrasonic nebulizer. After confirmation of satisfactory anesthesia clinically Fiber-optic assisted naso-tracheal intubation was attempted. Hemodynamic monitoring, total time taken for intubation, patients comfort and any complications occurred were noted. Statistical Analysis- All the observed values were tabulated and analyzed using software SPSS version 17.0. RESULTS: Demography and Hemodynamic observations were comparable in the groups.  The time taken for intubation, patient comfort score, intubation conditions were excellent in AB group than in group AN. Airway complications like laryngospasm and cough were noted in AN Group. CONCLUSIONS: Judicial use of combined Airway blocks such as Bilateral Superior and trans-tracheal recurrent laryngeal nerve blocks could facilitate a successful fiber-optic assisted awake naso-tracheal intubation in anticipated difficult intubation with negligible complications.
.

A History of Flexible Gastrointestinal Endoscopy.

Surgeons have been involved, since the beginning, in the development and evolution of endoscopy. They have been instrumental in developing new methods and have been actively involved in most of the therapeutic applications. The continued evolution of endoscopic technique is inevitable and will involve the integration of new technology with innovative thinking.

Awake fiberoptic intubation in patients with stenosis of the upper airways: Utility of the laryngeal nerve block.

Awake fiberoptic intubation (AFOI) is mandatory to manage difficult airways. Superior laryngeal nerve block (SLNB) could reduce risks and improve patient comfort. The aim of this study is to assess the procedural comfort of SLNB during AFOI in a population of patients undergoing upper airway oncological surgery. Forty patients were randomized into two groups and were treated with continuous infusion of remifentanil, topic anesthesia and intercricoid block. In the study group (=20), SLNB was performed with lidocaine (L-SLNB); in the control group (n=20) SLNB was performed using saline (S-SLNB). AFOI was more comfortable in the L-SLNB group compared to S-SLNB patients [FOICS ≤ 1 in 18 patients (90%) L-SLNB; 2 (10%) S-SLNB (P <0.001)]. Intubation was faster in L-SLNB (47.45 ±15.38 sec) than S-SLNB (80.15 ±37.91 sec) (p <0.001). The SLNB procedure during AFOI is a safe and comfortable procedure in a population of patients undergoing upper airways surgery. Time to intubation was shorter in L-SLNB than in S-SLNB.

Ytterbium-doped fibre femtosecond laser offers robust operation with deep and precise microsurgery of C. elegans neurons.

Laser microsurgery is a powerful tool for neurobiology, used to ablate cells and sever neurites in-vivo. We compare a relatively new laser source to two well-established designs. Rare-earth-doped mode-locked fibre lasers that produce high power pulses recently gained popularity for industrial uses. Such systems are manufactured to high standards of robustness and low maintenance requirements typical of solid-state lasers. We demonstrate that an Ytterbium-doped fibre femtosecond laser is comparable in precision to a Ti:Sapphire femtosecond laser (1-2 micrometres), but with added operational reliability. Due to the lower pulse energy required to ablate, it is more precise than a solid-state nanosecond laser. Due to reduced scattering of near infrared light, it can lesion deeper (more than 100 micrometres) in tissue. These advantages are not specific to the model system ablated for our demonstration, namely neurites in the nematode C. elegans, but are applicable to other systems and transparent tissue where a precise micron-resolution dissection is required.

Clinical application of near infrared fiber optic spectroscopy for noninvasive bone assessment.

Approaches for noninvasive bone quality assessment are of great clinical need, particularly in individuals that require close monitoring of disease progression. X-ray measurements are standard approaches to assess bone quality; however, they have several disadvantages. Here, a nonionizing approach for noninvasive assessment of the second metacarpal bone based on near infrared (NIR) spectroscopy was investigated. Transcutaneous bone signal detection was experimentally confirmed with cadaveric hand data, and Monte Carlo modeling further indicated that 50% of the measured signals arise from bone. Spectral data were collected via a NIR fiber optic from the bone of individuals with osteogenesis imperfecta, a disease marked by frequent bone fractures and fragility. Multiple significant correlations were found between spectral parameters related to water, protein and fat, and standard bone quality parameters obtained by X-ray measurements. The results from this preliminary study highlight the potential application of NIR spectroscopy for the noninvasive assessment of bone quality.

New high intensity fibreoptic phototherapy devices in healthy newborns: a single pad wrapped around the neonate body in comparison with a double pad device.

BACKGROUND: Fibreoptic Phototherapy (FPT) allows to lower total serum bilirubin (TSB) levels in healthy neonates maintained in rooming-in with their mothers. The 2004 Cochrane review showed that, differently from preterm neonates, FPT was not as effective as traditional phototherapy in term neonates (TN), unless the simultaneous utilization of two FPT devices. Aim of this study was to compare the efficacy of two FPT devices, both equipped with a single light-emitting diode (LED): the first one has a single large pad wrapped around the infant body (Bilisoft, GE Health Care) (device A), the second one is a double-pad phototherapy device (BiliCocoon, CremascolieIris) (device B). METHODS: We studied 172 healthy neonates with non-hemolytic hyperbilirubinaemia: 57 TN and 57 late preterm neonates (LPN) treated with device A (Group 1); 47 TN and 11 LPN treated with device B (Group 2). We evaluated the differences between groups by the Student's t-test for continuous variables and by chi square test for categorical data. A two tailed p < 0.05 was considered significant. RESULTS: There were no differences in term of duration of FPT, TSB hourly reduction, percentage of TSB reduction after FPT, TSB maximum rebound, percentage of TSB increase after FPT discontinuation and number of after-discharge checks. Two neonates treated with device B showed no decrease in TSB values during FPT. Seven infants treated with device B experienced hyperpyrexia. CONCLUSIONS: The two LED FPT devices were both effective in lowering TSB either in TN or LPN. Device A was effective in all treated neonates without negative side effects during treatment; device B was effective in all but 2 infants and 12% of the neonates in the same group experienced hyperpyrexia. According to our results, the single big pad wrapped around the infant body has the same efficacy as a double FPT device in TN and LPN.

Light Emitting Diode (LED) Phototherapy versus Conventional Phototherapy in Neonatal Hyperbilirubinemia: A Single Blinded Randomized Control Trial from Coastal India.

Neonatal hyperbilirubinemia is a common problem with potentiality to cause irreversible brain damage. Reduction of serum bilirubin level is essential to minimize such damage. Compact fluorescent tubes, halogen bulbs, fiber optic blankets, and LEDs are commonly used light sources for phototherapy with varying efficacies. This study aimed at evaluating the effect of LED versus conventional phototherapy on (a) rate of reduction in total serum bilirubin levels, (b) effect on urinary lumirubin excretion, and (c) comparing side effects of phototherapies among neonates with hyperbilirubinemia. In this randomized control trial, 166 neonates ≥ 35 weeks of age requiring phototherapy were recruited and further divided into 2 groups [LED (83) and conventional (83)] by using computer generated random numbers. Serial total serum bilirubin levels and random urinary lumirubin levels were collected and side effects of phototherapy were noted. Rate of fall in total serum bilirubin levels (TSB, µmol/L/hour) and random urinary lumirubin levels were computed. Data were collected using a pretested proforma. Analysis was done with Statistical Package for Social Sciences (SPSS) version 11.5. Independent sample "t" test and Chi-square tests were used with p value of <0.05 being significant. Significant difference was documented in mean rate of decrease of TSB (µmol/L/hour) in LED group (5.3 ± 2.91) when compared to conventional group (3.76 ± 2.39) (p <0.001). A significant increase in mean random urinary lumirubin levels (arbitrary units) was observed in LED group (129.01 ± 33.18) when compared to conventional group (114.44 ± 44.84) (p = 0.021). Side effects were minimal and comparable in both groups. This study concludes the rates of decrease in total serum bilirubin levels and increase in urinary lumirubin levels were significant with LED when compared with conventional phototherapy, implying LED to be more efficacious.

Black phosphorus based fiber optic biosensor for ultrasensitive cancer diagnosis.

We propose the first black phosphorus (BP) - fiber optic biosensor for ultrasensitive diagnosis of human neuron-specific enolase (NSE) cancer biomarkers. A novel optical-nano configuration has been exploited by integrating BP nanosheets with a largely tilted fiber grating (BP-TFG), where the BP is bio-functionalized by the poly-L-lysine acting as a critical cross-linker to facilitate bio-nano-photonic interface with extremely enhanced light-matter interaction. BP nanosheets are synthesized by a liquid ultrasonication-based exfoliation and deposited on fiber device by an in-situ layer-by-layer method. The BP-induced optical modulation effects in terms of thickness-tunable feature, polarization-dependence and enhanced light-matter interaction are experimentally investigated. The anti-NSE immobilized BP-TFG biosensor has been implemented to detect NSE biomarkers demonstrating ultrahigh sensitivity with limit of detection down to 1.0 pg/mL, which is 4 orders magnitude lower than NSE cut-off value of small cell lung cancer. The enhanced sensitivity of BP-TFG is 100-fold higher than graphene oxide or AuNPs based biosensors. We believe that BP-fiber optic configuration opens a new bio-nano-photonic platform for the applications in healthcare, biomedical, food safety and environmental monitoring.

The Application of a Nanomaterial Optical Fiber Biosensor Assay for Identification of Brucella Nomenspecies.

Bacteria in the genus Brucella are the cause of brucellosis in humans and many domestic and wild animals. A rapid and culture-free detection assay to detect Brucella in clinical samples would be highly valuable. Nanomaterial optical fiber biosensors (NOFS) are capable of recognizing DNA hybridization events or other analyte interactions with high specificity and sensitivity. Therefore, a NOFS assay was developed to detect Brucella DNA from cultures and in tissue samples from infected mice. An ionic self-assembled multilayer (ISAM) film was coupled to a long-period grating optical fiber, and a nucleotide probe complementary to the Brucella IS711 region and modified with biotin was bound to the ISAM by covalent conjugation. When the ISAM/probe duplex was exposed to lysate containing ≥100 killed cells of Brucella, or liver or spleen tissue extracts from Brucella-infected mice, substantial attenuation of light transmission occurred, whereas exposure of the complexed fiber to non-Brucella gram-negative bacteria or control tissue samples resulted in negligible attenuation of light transmission. Oligonucleotide probes specific for B. abortus, B. melitensis, and B. suis could also be used to detect and differentiate these three nomenspecies. In summary, the NOFS biosensor assay detected three nomenspecies of Brucella without the use of polymerase chain reaction within 30 min and could specifically detect low numbers of this bacterium in clinical samples.

Awake Fiberoptic Intubation Protocols in the Operating Room for Anticipated Difficult Airway: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

Awake fiberoptic intubation is one of the recommended strategies for surgical patients with anticipated difficult airway, especially when concurrent difficult ventilation is expected. We performed the first systematic review of randomized controlled trials assessing different protocols for awake fiberoptic intubation in anticipated difficult airway, including studies investigating elective awake fiberoptic intubation for scheduled surgery; randomized controlled trials comparing different methods for performing awake fiberoptic intubation; and adult patients with anticipated difficult airway. We excluded studies in the nonoperating theater settings, randomized controlled trials comparing awake fiberoptic intubation with other techniques, and studies based on simulation. Primary outcomes were success rate and death; secondary outcomes were major adverse events. Thirty-seven randomized controlled trials evaluating 2045 patients and 4 areas were identified: premedication, local anesthesia, sedation, and ancillary techniques to facilitate awake fiberoptic intubation. Quality of evidence was moderate-low and based on small-sampled randomized controlled trials. Overall, 12 of 2045 intubation failures (0.59%) and 7 of 2045 severe adverse events (0.34%) occurred, with no permanent consequences or death. All evaluated methods to achieve local anesthesia performed similarly well. No differences were observed in success rate with different sedatives. Dexmedetomidine resulted in fewer desaturation episodes compared to propofol and opioids with or without midazolam (relative risk, 0.51 [95% CI, 0.28-0.95]; P = .03); occurrence of desaturation was similar with remifentanil versus propofol, while incidence of apnoea was lower with sevoflurane versus propofol (relative risk, 0.43 [95% CI, 0.22-0.81]; P = .01). A high degree of efficacy and safety was observed with minimal differences among different protocols; dexmedetomidine might offer a better safety profile compared to other sedatives.

Toward 19F magnetic resonance thermometry: spin-lattice and spin-spin-relaxation times and temperature dependence of fluorinated drugs at 9.4 T.

OBJECTIVE: This study examines the influence of the environmental factor temperature on the 19F NMR characteristics of fluorinated compounds in phantom studies and in tissue. MATERIALS AND METHODS: 19F MR mapping and MR spectroscopy techniques were used to characterize the 19F NMR characteristics of perfluoro-crown ether (PFCE), isoflurane, teriflunomide, and flupentixol. T1 and T2 mapping were performed, while temperature in the samples was changed (T = 20-60 °C) and monitored using fiber optic measurements. In tissue, T1 of PFCE nanoparticles was determined at physiological temperatures and compared with the T1-measured at room temperature. RESULTS: Studies on PFCE, isoflurane, teriflunomide, and flupentixol showed a relationship between temperature and their physicochemical characteristics, namely, chemical shift, T1 and T2. T1 of PFCE nanoparticles was higher at physiological body temperatures compared to room temperature. DISCUSSION: The impact of temperature on the 19F NMR parameters of fluorinated compounds demonstrated in this study not only opens a trajectory toward 19F MR-based thermometry, but also indicates the need for adapting MR sequence parameters according to environmental changes such as temperature. This will be an absolute requirement for detecting fluorinated compounds by 19F MR techniques in vivo.

Near infrared photoimmunotherapy using a fiber optic diffuser for treating peritoneal gastric cancer dissemination.

BACKGROUND: Peritoneal dissemination (PD) of abdominal malignancies is a common form of metastasis and its presence signals a poor prognosis. New treatment is required for patients with PD. Near infrared photoimmunotherapy (NIR-PIT) is a highly selective tumor treatment that employs an antibody-photo-absorber conjugate (APC). In this study, we investigate in vitro and in vivo efficacy of trastuzumab (tra)-IR700DX NIR-PIT on a human epidermal growth factor receptor type 2 (HER2)-positive gastric cancer cell line. METHODS: NIR-PIT effects were investigated in vitro and in vivo. Disseminated peritoneal implants mice were separated into 5 groups: (1) no treatment; (2) tra-IR700 i.v. only; (3) NIR light only; (4) NIR-PIT; (5) repeated NIR-PIT. The peritoneal cavity was irradiated with NIR light using a fiber optic diffuser delivered through the catheter. RESULTS: Specific binding and cell-specific killing was observed after NIR-PIT in vitro. In the in vivo study, fluorescence endoscopy showed high tumor accumulation of tra-IR700 within tumors. Significantly prolonged survival was achieved in the three treatment groups (tra-IR700 i.v. only, NIR-PIT, and repeated NIR-PIT groups) compared with control and NIR light only group (p < 0.05 for tra-IR700 i.v. only, p < 0.01 for NIR-PIT, and p < 0.0001 for repeated NIR-PIT). Moreover, most prolonged survival was shown for the repeated NIR-PIT group (p < 0.0001 vs tra-IR700 i.v. only, p < 0.01 vs NIR-PIT). CONCLUSION: NIR-PIT using a fiber optic diffuser to deliver light is a promising candidate for the treatment of disseminated peritoneal metastases and could be readily translated to humans.

Validation of Noninvasive Ultrasound Temperature Measurement System Through Experiments Using Resonant Cavity Applicator.

We developed a resonant cavity applicator for noninvasive deep hyperthermia treatment of osteoarthritis. In previous studies, we confirmed its viability by heating agar phantoms and conducting computer simulations. To evaluate the heating performance of this system on human subjects, it is necessary to develop a new noninvasive temperature measurement system. In this study, we developed a new temperature measurement system utilizing ultrasound imaging techniques. After heating an agar phantom with our resonant cavity applicator, temperature measurements from both our custom-made noninvasive ultrasonic thermometer and an optical fiber thermometer were collected and compared. Both temperature distributions showed a reliable trend, with heat energy concentrated at the center of the agar phantom. Average error rates were less than 13% for temperatures. The results of this study describe the viability of the temperature measurement system and the resonant cavity applicator for clinical applications.

Endoscopic near infrared photoimmunotherapy using a fiber optic diffuser for peritoneal dissemination of gastric cancer.

Near infrared photoimmunotherapy (NIR-PIT) is a highly selective tumor treatment that employs an antibody-photo-absorber conjugate (APC) which is activated by near infrared light. Here, we describe the efficacy of endoscopic NIR-PIT using the APC trastuzumab-IR700DX (tra-IR700) in the setting of human epidermal growth factor 2 positive (HER2 + ) gastric carcinoma with peritoneal disseminations. In this in vivo study, fluorescence endoscopy showed high tumor accumulation of tra-IR700 within disseminated peritoneal implants. Mice with disseminated peritoneal gastric cancer were separated into 4 groups: (i) control (no treatment); (ii) tra-IR700 i.v. only; (iii) NIR light only; and (iv) endoscopic NIR-PIT. NIR light irradiation was carried out through a fiber optic diffuser under endoscopic guidance. In vivo bioluminescence images showed significantly greater therapeutic effect in the endoscopic NIR-PIT group than that in the control groups (P < .01 vs other control groups). Histological analysis showed diffuse cancer cell death in NIR-PIT-treated tumors. In conclusion, NIR-PIT with NIR light delivered via an endoscopic fiber optic diffuser is a promising method for the treatment of peritoneal dissemination of gastric cancer. Moreover, this technique could be readily used in other types of cancers with peritoneal dissemination provided that suitable antibodies could be found.

Awake Fiberoptic Intubation in Cervical Spine Injury: A Comparison between Atomized Local Anesthesia versus Airway Nerve Blocks.

Background In cooperative patients with cervical spine injury, awake fiberoptic intubation is an excellent option for elective and semi urgent situations. It allows documentation of neurologic examination before and after intubation and surgical positioning. We have compared anesthesia of airway by nerve block and the local anesthesia atomizer undergoing awake fiberoptic intubation in cervical spine injury patients, in terms of the intubation time and discomfort. Objective To compare the intubation time and discomfort in patient with cervical spine injury with anticipated difficult airway potential to aggravate pre-existing injury undergoing awake fiberoptic intubation, based on cough and gag scores, between anesthesia of airway by (transtracheal and bilateral superior laryngeal) nerve block with local anesthetic agent and the local anesthesia atomizer. Method After institutional ethical approval and having informed written consent, 30 patients scheduled for elective surgery who require awake fiberoptic intubation, were included in the study. Patients were allotted by computer-generated random series into two groups; Group N received nerve block (transtracheal and bilateral recurrent laryngeal nerve block) and Group A received atomized lignocaine. Result The time taken for awake fiberoptic intubation was significantly lower in nerve blocks group as compared with the atomizer group [Group N: 90.2±11.7secs and Group A: 210.4±10.6 secs (p=0.041)]. Atomizer group had an increased coughing and gagging episodes than nerve block group [Group N: one patient, Group A: 11 patients (p=0.006)]. Ease of intubation and patient comfort were significantly better in nerve block group. Demographic and hemodynamic parameters were comparable in the two groups. Conclusion The nerve blocks (bilateral superior laryngeal and transtracheal recurrent laryngeal) provides adequate airway anesthesia, lesser patient discomfort, and faster intubation to aid in awake fiberoptic intubation in patients with anticipated difficult airway as compared to topical anesthesia using atomizer.

Novel carbon fiber probe for temperature monitoring during thermal therapies.

Thermal treatments are a valid clinical option in the management of several solid tumors. The difficulties to perform an accurate prediction improve the selectivity of the treatment effects represent the main hurdles in the spread of these techniques. Among other solutions, thermometric techniques are gaining acceptance in monitoring the effects of thermal treatments because they provide a clear end-point to obtain the complete removal of cancer without damaging the surrounding healthy tissue. This paper proposes a custom needle-like probe made of carbon fibers to embed seven fiber Bragg grating (FBG) sensors. This tool aims at a multiple points monitoring the tissue temperature during the thermal procedures, streamlining the FBG sensors insertion within the organ. After the description of the probe manufacturing, we reported the calibration of the seven sensors embedded within the probe, their step response, and the feasibility assessment of the probe for temperature monitoring during laser ablation on animal model (both in vivo and ex vivo). Results show that the proposed probe is easily maneuverable by the clinician, the sensors have a linear response with the temperature and a short step response; moreover, the probe allows measuring the temperature in seven points of the tissue; finally, it can be used during CTand MR-guided procedures without causing any artifact to the images. Thanks to these features the probe may be an useful solution to improve the safety and the outcomes of minimally invasive thermal ablation procedures, so to spread these procedures in the clinical field.

Tapered fiber optic applicator for laser ablation: Theoretical and experimental assessment of thermal effects on ex vivo model.

Laser Ablation (LA) is a minimally invasive technique for tumor removal. The laser light is guided into the target tissue by a fiber optic applicator; thus the physical features of the applicator tip strongly influence size and shape of the tissue lesion. This study aims to verify the geometry of the lesion achieved by a tapered-tip applicator, and to investigate the percentage of thermally damaged cells induced by the tapered-tip fiber optic applicator. A theoretical model was implemented to simulate: i) the distribution of laser light fluence rate in the tissue through Monte Carlo method, ii) the induced temperature distribution, by means of the Bio Heat Equation, iii) the tissue injury, by Arrhenius integral. The results obtained by the implementation of the theoretical model were experimentally assessed. Ex vivo porcine liver underwent LA with tapered-tip applicator, at different laser settings (laser power of 1 W and 1.7 W, deposited energy equal to 330 J and 500 J, respectively). Almost spherical volume lesions were produced. The thermal damage was assessed by measuring the diameter of the circular-shaped lesion. The comparison between experimental results and theoretical prediction shows that the thermal damage discriminated by visual inspection always corresponds to a percentage of damaged cells of 96%. A tapered-tip applicator allows obtaining localized and reproducible damage close to spherical shape, whose diameter is related to the laser settings, and the simple theoretical model described is suitable to predict the effects, in terms of thermal damage, on ex vivo liver. Further trials should be addressed to adapt the model also on in vivo tissue, aiming to develop a tool useful to support the physician in clinical application of LA.