Count-Free Single-Photon 3D Imaging with Race Logic

Single-photon cameras (SPCs) have emerged as a promising technology for high-resolution 3D imaging. A single-photon 3D camera determines the round-trip time of a laser pulse by capturing the arrival of individual photons at each camera pixel. Constructing photon-timestamp histograms is a fundamental operation for a single-photon 3D camera. However, in-pixel histogram processing is computationally expensive and requires large amount of memory per pixel. Digitizing and transferring photon timestamps to an off-sensor histogramming module is bandwidth and power hungry. Here we present an online approach for distance estimation without explicitly storing photon counts. The two key ingredients of our approach are (a) processing photon streams using race logic, which maintains photon data in the time-delay domain, and (b) constructing count-free equi-depth histograms. Equi-depth histograms are a succinct representation for ``peaky'' distributions, such as those obtained by an SPC pixel from a laser pulse reflected by a surface. Our approach uses a binner element that converges on the median (or, more generally, to another quantile) of a distribution. We cascade multiple binners to form an equi-depth histogrammer that produces multi-bin histograms. Our evaluation shows that this method can provide an order of magnitude reduction in bandwidth and power consumption while maintaining similar distance reconstruction accuracy as conventional processing methods.Comment: Accepted for presentation at the 2023 International Conference on Computational Photograph

Case study successful use of stent graft in post-catherization massive pseudoaneurysm of femoral artery with wide neck

Pseudoaneurysms are not rare and can occur due to varied reasons including percutaneous vascular access. If left untreated, pseudoaneurysms can be fatal. Here, we have presented a classic case study where a large pseudoaneurysm of left femoral artery with very wide neck was closed using stent graft.  A 55 years old male was presented with severe painful large mass in left groin.  The mass was soft tissue swelling with severe tenderness and pulsatile in nature. The doppler suggested it to be filled with blood and communicating with femoral artery hence diagnosed as pseudoaneurysm. Attempt was made to compress the neck which was large not clearly defined, hence failed. Multiple interventional and surgical options of closure of pseudoaneurysm was discussed.  Patient was taken for stent graft deployment in cath lab. Check angiogram showed nicely flowing femoral artery with no signs of pseudoaneurysm. The patient immediately improved with decrease in pain and swelling

Prediction of Late Disease Recurrence and Extended Adjuvant Letrozole Benefit by the HOXB13/IL17BR Biomarker

BackgroundBiomarkers to optimize extended adjuvant endocrine therapy for women with estrogen receptor (ER)–positive breast cancer are limited. The HOXB13/IL17BR (H/I) biomarker predicts recurrence risk in ER-positive, lymph node–negative breast cancer patients. H/I was evaluated in MA.17 trial for prognostic performance for late recurrence and treatment benefit from extended adjuvant letrozole.MethodsA prospective–retrospective, nested case-control design of 83 recurrences matched to 166 nonrecurrences from letrozole- and placebo-treated patients within MA.17 was conducted. Expression of H/I within primary tumors was determined by reverse-transcription polymerase chain reaction with a prespecified cutpoint. The predictive ability of H/I for ascertaining benefit from letrozole was determined using multivariable conditional logistic regression including standard clinicopathological factors as covariates. All statistical tests were two-sided.ResultsHigh H/I was statistically significantly associated with a decrease in late recurrence in patients receiving extended letrozole therapy (odds ratio [OR] = 0.35; 95% confidence interval [CI] = 0.16 to 0.75; P = .007). In an adjusted model with standard clinicopathological factors, high H/I remained statistically significantly associated with patient benefit from letrozole (OR = 0.33; 95% CI = 0.15 to 0.73; P = .006). Reduction in the absolute risk of recurrence at 5 years was 16.5% for patients with high H/I (P = .007). The interaction between H/I and letrozole treatment was statistically significant (P = .03).ConclusionsIn the absence of extended letrozole therapy, high H/I identifies a subgroup of ER-positive patients disease-free after 5 years of tamoxifen who are at risk for late recurrence. When extended endocrine therapy with letrozole is prescribed, high H/I predicts benefit from therapy and a decreased probability of late disease recurrence

THEMODIFIED CONSTANT Q SPECTROGRAM(MCQS) AND ITS APPLICATION TO PHASE VOCODING

This thesis discusses the development of amodified constant Q spectrogram representation which is invertible in a least-squares sense. A good quality inverse is possible because this modified transform method, unlike the usual sliding window constant Q spectrogram, does not discard any data samples when performing the variable length discrete Fourier transforms on the original signal. The development of a phase vocoder application using this modified technique is also discussed. It is shown that MCQS phase vocoding is not a trivial extension of the regular FFT-based phase vocoder algorithms and some of the mathematical subtleties related to phase reconstruction are addressed

The Future of Camera Technology with Atul Ingle

Single-photon camera sensors have the potential to revolutionize digital camera technology. These sensors can capture individual photons at high speeds, circumventing some of the limitations of current digital camera technologies. One challenge, however, is the sheer amount of data generated by the sensor, which is a hindrance to their widespread adoption. With the support of the National Science Foundation, Assistant Professor Atul Ingle is developing algorithms to solve this problem--algorithms that could enable the adoption of single-photon sensors in applications ranging from autonomous vehicles to medical imaging and the cameras in cellphones

Count-Free Single-Photon 3D Imaging with Race Logic

Single-photon cameras (SPCs) have emerged as a promising new technology for high-resolution 3D imaging. A single-photon 3D camera determines the round-trip time of a laser pulse by precisely capturing the arrival of individual photons at each camera pixel. Constructing photon-timestamp histograms is a fundamental operation for a single-photon 3D camera. However, in-pixel histogram processing is computationally expensive and requires large amount of memory per pixel. Digitizing and transferring photon timestamps to an off-sensor histogramming module is bandwidth and power hungry. Can we estimate distances without explicitly storing photon counts? Yes-here we present an online approach for distance estimation suitable for resource-constrained settings with limited bandwidth, memory and compute. The two key ingredients of our approach are (a) processing photon streams using race logic, which maintains photon data in the time-delay domain, and (b) constructing count-free equi-depth histograms as opposed to conventional equi-width histograms. Equi-depth histograms are a more succinct representation for “peaky” distributions, such as those obtained by an SPC pixel from a laser pulse reflected by a surface. Our approach uses a binner element that converges on the median (or, more generally, to another k-quantile) of a distribution. We cascade multiple binners to form an equi-depth histogrammer that produces multi-bin histograms. Our evaluation shows that this method can provide at least an order of magnitude reduction in bandwidth and power consumption while maintaining similar distance reconstruction accuracy as conventional histogram-based processing methods