KEYWORDS: Wound healing, Arteries, Data acquisition, Diseases and disorders, Vascular diseases, Lab on a chip, Blood, Optical spectroscopy, Animal model studies, Optical sensing
SignificanceDue to the persistence of chronic wounds, a second surgical intervention is often necessary for patients with peripheral arterial disease (PAD) within a year of the first intervention. The dynamic vascular optical spectroscopy system (DVOS) may assist physicians in determining patient prognosis only a month after the first surgical intervention.AimWe aim to assess the DVOS utility in characterizing wound healing in PAD patients after endovascular intervention.ApproachThe DVOS used near-infrared light (670 < λ < 850 nm) to record hemodynamic response to a cuff inflation in 14 PAD patients with lower limb ulcers immediately before, immediately after, and at a first follow-up 3 to 4 weeks after intervention. Ankle-brachial index (ABI) and arterial duplex ultrasound (A-DUS) measurements were obtained when possible.ResultsThe total hemoglobin plateau time differed significantly between patients with ulcers that reduced in size (N = 9) and patients with ulcers that did not (N = 5) 3 to 4 weeks after intervention (p value < 0.001). Data correlated strongly (89% sensitivity, 100% specificity, and AUC = 0.96) with long-term wound healing. ABI and A-DUS measurements were not statistically associated with wound healing.ConclusionsThis pilot study demonstrates the potential of the DVOS to aid physicians in giving accurate long-term wound healing prognoses 1 month after intervention.
In this retrospective study, we evaluated imaging data from 65 breast cancer patients that were obtained one to three days before the initiation of neoadjuvant chemotherapy (NAC). Imaging was performed with a dynamic optical tomography breast imaging system (DOTBIS) over the course of a breath hold. From this imaging data, we extracted time-dependent signal traces of the total hemoglobin in the whole volume of the tumor-bearing breast. The inflection point and the slope at the steepest part of the curve were calculated for both the ascending (patient holds her breath) and descending slopes (patient releases her breath and starts breathing normally again). Our results show statistically significant differences in vascular changes between patients with a pathologic complete response (pCR) and non-pCR patients. This suggests that differences in the tumor-bearing breasts of these two patient groups exist even before treatment is started.
This work evaluates changes in features of 3D breast images generated by a so-called dynamic optical tomographic imaging system (DOTBIS) during neoadjuvant chemotherapy (NAC). Images from 23 breast cancer patients were analyzes and correlated with respect to treatment outcome and status of hormone receptors and human epidermal growth factor receptors. Our data shows that the ratio of the mean value of deoxy-hemoglobin (ctHHbN) at two weeks after the first treatment compared to baseline was statistically significantly lower in patients that achieve a pathologic complete response (pCR) (0.77 ± 0.22) as compared to patients with a non-pCR (1.14 ± 0.24, P < .005). These observations indicate that early changes in DOTBIS images can potentially be used to predict breast cancer response to NAC and may allow a better way to customize therapy to HR+/HER2- patients in order to optimize treatment.
Ulcers are a common occurrence in diabetic patients with peripheral arterial disease (PAD). Early prognosis of ulcer healing can help patients avoid prolonged pain and future amputation by alerting physicians to intervention efficacy. However, monitoring of ulcers and predicting intervention success remains a challenge. We have developed a so-called vascular optical tomography imaging system (VOTIS) to address this problem. The system consists of patches with infrared sources and silicon photodiodes. The patches are placed on areas of interest in the lower extremities and light attenuation data is obtained at multiple frames per second. During data acquisition, a thigh cuff is inflated and deflated to affect blood flow to the lower extremities, resulting in dynamic changes of the recorded signals. Features such as maximum change in total absorption, response time to cuff inflation, and plateau time (PT) between cuff inflation and deflation can be extracted. Here we report on a pilot study of 10 PAD patients (70% diabetic) with ulcers, who had a surgical intervention to improve blood flow. VOTIS measurements were obtained immediately after the intervention, and again three weeks later. Prognosis was determined from EHR and classified as improvement (N=7) - when an ulcer reduces in size - or no improvement (N=3). In an ROC analysis, the VOTIS-derived biomarker PT demonstrated high classification potential (Sn=86%, Sp=100%, AUC=0.95).
Optical imaging techniques have emerged as a possible alternative to predict pathological complete response (pCR) in breast cancer patients undergoing neoadjuvant chemotherapy (NAC). Our team developed a so-called diffuse optical tomographic breast imaging system (DOTBIS) which does not require the use of contrast agents or compression and enables imaging of the whole breast volume using low intensity near infrared light capable to measure tissue concentration of total hemoglobin (ctTHb). In this retrospective study, we evaluated 55 stage II-III BC patients in the neoadjuvant setting who received weekly paclitaxel x 12, followed by dose-dense adriamycin/cyclophosphamide every 2 weeks x 4. DOTBIS images were acquired from the patient whole breast volume at 6 different time points: at baseline (TP0); two weeks after the first taxane infusion (TP1); after four infusions of taxane (TP2); at the end of the taxane regimen and before starting AC cycle (TP3); after two AC infusions (TP4); and at the end of NAC and before surgery (TP5). In order to evaluate whether pCR status influences the change of ctTHb over time, we designed a multilevel mixed-effect model. pCR was defined as no invasive tumor cells from the breast and axillary tissue at surgery (ypT0 ypN0). Changes in ctTHb levels compared to baseline (TP0) values were statistically significant different between pCR (n = 20) and non-pCR (n=35) at all time points except at TP1 and at the end of the taxane cycle (TP3).
The aim of this study was to investigate the optical chemotherapy changes induced by neoadjuvant chemotherapy (NAC) in PgR-positive and PgR-negative breast cancer subtypes using a diffuse optical tomographic breast imaging system (DOTBIS). ctTHb reduction in the tumor volume was greater for patients with PgR-negative, a statistically significant difference of 48.91μM, p = .022, which suggest that PgR-negative tumors are generally less resistant to NAC. These observations indicate that PgR negativity may be combined to optically derived biomarkers for predicting pCR during neoadjuvant chemotherapy.
In this retrospective cohort study, we examine the hypothesis that baseline oxygen saturation (SO2%) in contralateral normal tissue can be a quantitative measurement for predicting tumor response to neoadjuvant chemotherapy (NAC). Using our dynamic custom-built dual breast dynamic diffuse optical tomography (DOT) imager, we reconstructed SO2% measurement concentration for 12 stage II or III breast cancer patients. Six patients achieved pCR (RCB-0) and the other half had extensive residual disease (RCB-III). Baseline SO2% in contralateral normal tissue was statistically significantly higher in RCB-III subjects than in pCR (p = 0.025). From ROC analyses, baseline SO2% in contralateral normal breast tissue was able to discriminate pCR from RCB-III patients (AUC 0.889) with sensitivity and specificity of 83%.
Endoscope cameras play an important and growing role as a diagnostic and surgical tool. The endoscope camera is
usually used to provide a view of the scene straight ahead of the instrument to the operator. As is common in many
remotely operated systems, the limited field of view and the inability to pan the camera make it challenging to gain a
situational awareness comparable to an operator with direct access to the scene. We present a spectral multiplexing
technique for endoscopes that allows for overlay of the existing forward view with additional views at different angles to
increase the effective field of view of the device. Our goal is to provide peripheral vision while minimally affecting the
design and forward image quality of existing systems.
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